#orthodromic

[mfx1nkvmz]

Beautiful girl feels corpulent penis entering mouth and pussy fucking myself on snap :) School Girl Sissy rides sissy dildo with tight pussy Sexy Plumper Nurse Oksana Rose Examines John Strange Lesbians Tits Sucking Foot Fetish Domination Pee in condom Thieving teen cums in interracial threeway Gay bdsm group enjoy some hardcore fisting Gay twinks with small cocks wanking vids He did it for a while, until Long Boobs

[map-projection-showdown]

A Glossary of Map Projection Properties

There are a couple of different properties that map projections can have and they can dictate where a map might be useful or how it might be viewed, so I thought it might be useful if I made this before I started the tournament. I'd say there are 3 main categories a map could fall into, plus a couple of smaller less interesting ones.

Conformal Projections

Conformal projections, also known as orthomorphic projections, are those that preserve shapes locally, or more accurately, they preserve angles at a point. So if there are streets meeting at right angles on the globe, then they'll also meet at right angles on the map. They don't necessarily preserve the entire shape of large regions due to uneven area/size distortions, but they get pretty close, I think this image gets the point across well (The left ones are conformal, while the right ones aren't) [Sourced from this article on the topic]

Examples of this type of projection in the tournament include the Stereographic, the Peirce Quincuncial, and the Mercator projections.

Equal-Area Projections

Also known as equivalent or authalic projections, equal-area projections are sort of self explanatory: If regions have the same area on the globe, they will have the same area on the map. However, they usually have bad shape distortions, for example the Gall-Peters projection looks fine around 45° North and South, but is vertically stretched / horizontally compressed closer to the equator, and vice-versa closer to the poles. Examples of this type of projection in the tournament include the Mollweide, the Eckert IV, and the Boggs Eumorphic projections.

Compromise Projections

Conformality and equivalence are mutually exclusive, a map cannot both be conformal and equal-area, so often for general-purpose world maps, map designers will try to find a balance somewhere in the middle. Compromise, or aphylactic, projections are the result, they have both size and shape distortion, but lower size distortion than conformal projections, and lower shape distortion than equal area projections. Examples of this type of projection in the tournament include the Winkel Tripel, the Kavrayskiy VII, and the Dymaxion projections.

Equidistant Projections

Unlike with the conformal or equal-area properties, a projection cannot show the correct distance between every point on the map, and instead only to and from one or two points, or along certain lines (However it can be both equidistant and one of the first two properties). For example, on the Equirectangular projection, distances measured along meridians (vertical lines) are correct, while others are distorted. And with the Azimuthal Equidistant projection, distances measured from the central point are correct, while others are distorted.

The Gnomonic Projection

The gnomonic projection is constructed by projecting from the centre of the earth onto a plane tangent to the surface, and as such can only display less than a hemisphere, but it has the unique property of displaying lines along great circles as straight lines

Great circles, aka orthodromes, are like circles round the surface of the earth that pass through the centre of the earth, like the equator or any meridian. They're the shortest path between any two points.

Note how the parallels are curved in all three because they aren't great circles, while the meridians are all straight.

[samantha-fund]

#straightline on a #mercatorprojection vs #orthodromic or #greatcircle #distance. What appears to be the #shortestroute takes actually far longer #geography #science #cartography #navigation @worldwide_engineering via @piloteyes737 https://www.instagram.com/p/CE5vq7SCgwv/?igshid=169sklzpxnlvp

[drnikolatesla]

“The Future of the Wireless Art.”

“A mass in movement resists change of direction. So does the world oppose a new idea. It takes time to make up the minds to its value and importance. Ignorance, prejudice and inertia of the old retard its early progress. It is discredited by insincere exponents and selfish exploiters. It is attacked and condemned by its enemies. Eventually, though, all barriers are thrown down, and it spreads like fire. This will also prove true of the wireless art.

"The practical applications of this revolutionary principle have only begun. So far they have been confined to the use of oscillations which are quickly damped out in their passage through the medium. Still, even this has commanded universal attention. What will be achieved by waves which do not diminish with distance, baffles comprehension.

"It is difficult for a layman to grasp how an electric current can be propagated to distances of thousands of miles without diminution of intention. But it is simple after all. Distance is only a relative conception, a reflection in the mind of physical limitation. A view of electrical phenomena must be free of this delusive impression. However surprising, it is a fact that a sphere of the size of a little marble offers a greater impediment to the passage of a current than the whole earth. Every experiment, then, which can be performed with such a small sphere can likewise be carried out, and much more perfectly, with the immense globe on which we live. This is not merely a theory, but a truth established in numerous and carefully conducted experiments. When the earth is struck mechanically, as is the case in some powerful terrestrial upheaval, it vibrates like a bell, its period being measured in hours. When it is struck electrically, the charge oscillates, approximately, twelve times a second. By impressing upon it current waves of certain lengths, definitely related to its diameter, the globe is thrown into resonant vibration like a wire, stationary waves forming, the nodal and ventral regions of which can be located with mathematical precision. Owing to this fact and the spheroidal shape of the earth, numerous geodetical and other data, very accurate and of the greatest scientific and practical value, can be readily secured. Through the observation of these astonishing phenomena we shall soon be able to determine the exact diameter of the planet, its configuration and volume, the extent of its elevations and depressions, and to measure, with great precision and with nothing more than an electrical device, all terrestrial distances. In the densest fog or darkness of night, without a compass or other instruments of orientation, or a timepiece, it will be possible to guide a vessel along the shortest or orthodromic path, to instantly read the latitude and longitude, the hour, the distance from any point, and the true speed and direction of movement. By proper use of such disturbances a wave may be made to travel over the earth’s surface with any velocity desired, and an electrical effect produced at any spot which can be selected at will and the geographical position of which can be closely ascertained from simple rules of trigonometry.

"This mode of conveying electrical energy to a distance is not ‘wireless’ in the popular sense, but a transmission through a conductor, and one which is incomparably more perfect than any artificial one. All impediments of conduction arise from confinement of the electric and magnetic fluxes to narrow channels. The globe is free of such cramping and hinderment. It is an ideal conductor because of its immensity, isolation in space, and geometrical form. Its singleness is only an apparent limitation, for by impressing upon it numerous non-interfering vibrations, the flow of energy may be directed through any number of paths which, though bodily connected, are yet perfectly distinct and separate like ever so many cables. Any apparatus, then, which can be operated through one or more wires, at distances obviously limited, can likewise be worked without artificial conductors, and with the same facility and precision, at distances without limit other than that imposed by the physical dimensions of the globe.

"It is intended to give practical demonstrations of these principles with the plant illustrated. As soon as completed, it will be possible for a business man in New York to dictate instructions, and have them instantly appear in type at his office in London or elsewhere. He will be able to call up, from his desk, and talk to any telephone subscriber on the globe, without any change whatever in the existing equipment. An inexpensive instrument, not bigger than a watch, will enable its bearer to hear anywhere, on sea or land, music or song, the speech of a political leader, the address of an eminent man of science, or the sermon of an eloquent clergyman, delivered in some other place, however distant. In the same manner any picture, character, drawing, or print can be transferred from one to another place. Millions of such instruments can be operated from but one plant of this kind. More important than all of this, however, will be the transmission of power, without wires, which will be shown on a scale large enough to carry conviction. These few indications will be sufficient to show that the wireless art offers greater possibilities than any invention or discovery heretofore made, and if the conditions are favorable, we can expect with certitude that in the next few years wonders will be wrought by its application.”

–Nikola Tesla

Wireless Telegraphy & Telephony, 1908.

[adraveins]

3, 21, 36 for the writing asks?

3. How would you describe your writing style?

I like to lean on melancholy and finding between spaces, I suppose? I keep trying to find a balance between stating things plainly (because sometimes you do just need to say it and be done with it) and saying things without saying them, and I'm most comfortable in the space between happiness and tragedy.

I also have a habit of over-describing things, I think, which came about because I felt like I didn’t describe enough setting and such. So I’ve pulled back on that, except now I think I’m on the pendulum swing back to not describing enough. So, like I said.... always trying to strike a balance.

21. Can you accurately predict how long your fics are going to be? If you can, what’s your secret?

I can’t! It always ends up longer than I think.

36. How do you come up with fic titles? What’s the one you’re most proud of?

They’re usually either a quote from the source material, a quote from another piece of literature, a common or scientific phrase, or a song lyric if all of the above fails. I think I like “orthodrome” the best because there are a lot of layers there; all of my Kit/Eothas fics pull from terms related to space or geometry, which is the kind of title I like the most.

[doctorfoxtor]

goddammit I forgot to post yesterday's as well lol

100 days of productivity

day 17

CVS/RS

shock index = HR/SBP (normal 0.5-0.7); >0.85 implies frank shock

nicorandil can cause extensive skin, mucosal and GIT ulcerations

J-point depression is physiological and may confound ST-interval measurements, and hence ST should be measured 80 ms after the J-point

specifically, J-point depression may produce upward-sloping ST-depression, which is physiological, so only horizontal- and downward-sloping ST-depression should be considered

spontaneous complete remission occurs in 2/3rds of patients with acute pulmonary sarcoidosis

volume resus for burns = 1 ml/kg * %BSA for the first 8 hours followed by 1 ml/kg * %BSA for the next 16 hours; target urine output is 0.5 ml/kg/hr

WPW: orthodromic tachy = electric impulse going through AV node then reentering atria via accessory bundle (usually narrow complex SVT); antidromic tachy = electric impulse going directly through accessory bundle (usually broad-complex VT)

biventricular pacing (RA+RV+LV) → BBB causing heart failure

dual chamber pacing (RA+RV) → sick sinus syndrome, AV block

dual site atrial pacing → AF (especially pAF), symptomatic bradycardia

normal anatomical dead space = 150 ml

CNS/Ophthal/ENT

asymmetric diabetic retinopathy → ocular ischaemia syndrome

the most common cause of lateral medullary syndrome is actually vertebral artery disease; PICA disease is the second MCC

Endocrine

rise in TSH is a common finding in adrenal insufficiency

T1DM has a 50% concordance rate in monozygotic twins

Rheum/Derm

pityriasis lichenoides et varioliformis acuta (PLEVA) = scattered papules and nodules with fine scaling and haemorrhagic crust; spontaneously resolves within a few months to few years

erythrasma = asymptomatic, well-circumscribed patches of hyperpigmentation usu. affecting folds and flexures; under Wood's lamp, shows bright pink fluorescence

both excision and radiotherapy are first line tx for labial squamous cell ca

GIT

TPN may precipitate acute mineral deficiencies, especially zinc, by encouraging anabolic processes

bilirubin is NOT raised in 90% of preggos with obstetric cholestasis

rituximab is specifically associated with reactivation of hep B; in Hbs or anti-Hbc positive individuals, lamivudine chemoprophylaxis should be started before rituximab is initiated

Onc/Haem

factor 8 inhibitor develops in 20% of haemophilia A sufferers who receive multiple transfusions of factor 8 concentrate

karyotype is a prognostic marker for AML: t(8;21) is a good prognostic marker whereas chromosome 5/7 involvement is a poor prognostic marker

mild thrombocytopaenia is seen in APLA

Renal

UTI in diabetics can proceed to renal papillary necrosis, the slough from which may cause ureteric obstruction

Stats

Mann-Whitney U test is a nonparametric test that compares two unpaired samples of ordinal data (eg, received intervention vs received placebo, each graded on a scale of 0-5); use t-test for normally distributed continuous data

Wilcoxon signed-rank test can be used under the same circumstances as the U test, but for paired data

chi-square test compares percentages within two populations; it is a simplification of Fisher's exact test

[cofferi]

Sunday evening feeling

Long-Distance Relationship, Established Relationship, Heartache

Being in a long-distance relationship means that whenever Victor does anything cute, Yuuri will experience ten times the number of appropriate heart attacks.

--> ao3

-

Sometimes, Yuuri thinks it’s not the physical distance that separates them.

The cities of Hasetsu and Saint Petersburg are over 7,000 kilometres apart, which seems like a great, great distance, certainly too far to trek on any old day trip whenever Yuuri feels like. And that’s one of the things he really wishes he could do. Just do day trips. Whenever he feels like.

But it isn’t even so bad once Yuuri tells himself to put it into perspective. The cities that are most furthest-apart, on complete opposite sides of the globe, are nearly 20,000 kilometres apart. That’s the farthest you can be. That’s like flying to Saint Petersburg and back and then some.

Wow, don’t go breaking your own heart, Yuuri tells himself.

Have you ever thought about living in Vladivostok? Yuuri types out into a text on his phone because he can’t find the tab for his online conversation with Victor on his computer, squished somewhere in between sixteen Google Maps searches and distancecalculator.net and the Wikipedia page for great-circle distance or orthodromic distance (i.e. the shortest distance between two points measured along the surface of a sphere).

He hopes Victor forgives him for hypothetically asking to uproot his life for him.

Hhhuhhhh why? comes Victor’s understandably puzzled response. Isn’t it in the Far East? I don’t know much about way out there.

Me neither, Yuuri admits.

Yuuri’s the one who brought this up, but the only real takeaway from searching about Vladivostok online is that it’s a port city so it might be similar to Hasetsu in that regard. Though, its population is still five times that of Hasetsu’s.

You’ve never been there? Yuuri wonders.

Nope, he receives from Victor, and then he starts wondering if Vladivostok has any fun winter events that could keep Victor entertained.

Yuuri lives pretty south of his country but he’s been to just about every part of Japan himself—all the way as far as Aomori where the snow packs as high as two metres above his head during wintertime, and on occasion to Hokkaido for the annual Sapporo Snow Festival. He’d drop by there if he gets booted from competition early. Instead of going home, he’ll make himself feel better by getting some hot sake and wandering around to view the sparkling lights and amazingly cut ice sculptures.

He’ll stand around pretending he’s waiting for someone amongst the couples interlocking arms. He’ll tell himself he’s a bigger deal than he is and that he came up north so no one would recognize him.

The sake will warm him right up, get him a bit drunk at the same time so these things are easier to believe, and then magically the season doesn’t feel like as much of a total loss.

Victor continues musing on in text about how he hasn’t had much interest in the rest of Russia anyway and really only been to Saint Petersburg and Moscow. Never had an excuse to visit anywhere else.

Not even to visit some distant uncle? Yuuri teases.

Unfortunately, don’t have any uncles, Victor says.

Not even for vacation then?

Haven’t had a vacation in over two years :)

You’re kidding!!!! Yuuri screeches through text. Because of course Victor’s winter months are jam-packed, training or travelling all over Europe and around the rest of the world that when he has any downtime at all he probably just wants to stay home.

No vacations at all, though… That’s just absurd.

Even if I was allowed some time off, I don’t think I’d be let very far. Vladivostok is certainly too far. Russia’s toooo big a place.

Victor’s being hyperbolic. He has to be. He better be.

The last comment especially stings. Just a bit. Vladivostok is way, way, way too far. Victor won’t even consider going there. How many times a year are they supposed to dedicate over twelve hours each way and thousands of dollars just on airfare to see each other? How long are things supposed to last like this?

Ki ni shi nai de ne? Don’t worry about it, right?

His mind is still swimming when Victor sends that, though it at least pulls a smile out of Yuuri.

Ehhhh, you know that?

Despite the image that Victor is a princess locked away in a tower surrounded by a felt hat-wearing fire-breathing dragon, maybe the only thing he has enough downtime for is learning random Japanese phrases to impress Yuuri with.

Of course! And others too. Victor begins typing out: Daijoubu Tanjoubi Omedetou Aishiteru! Suki!

Oh, god. Yuuri covers half his face so he has to type with one hand. Suki~

Suki~~~~~~!

Yuuri nearly cries at his desk. Victor really must be practicing on his own, which, ah, does so many things to Yuuri’s heart, thinking about how dedicated Victor is to learning Japanese for him. He pictures Victor with stacks of Japanese textbooks sitting all around him, glasses on his face, pencil to his lip, studying hard.

This is killing him. Who decided Yuuri has to sit here, abusing his wandering imagination, until he’s completely and utterly dissolved in his seat?

Shouldn’t you be getting to sleep? Victor reminds him after their back and forth has exhausted Victor’s current vocabulary, which hadn’t been very large to begin with.

But Yuuri wants to keep doing this all night long. He’ll destroy his sleeping pattern if it means Victor can learn Japanese phrases to his heart’s content, getting to say all sorts of things that Yuuri will keep to himself for the long lonely winter days.

Don’t stay up too late, okay? Isn’t it past midnight there? Are you sleeping already? Am I sending too many texts?

Yes, you are, Victor.

It’s like his hands are on autopilot. Yuuri picks up his phone, hits the call icon next to Victor’s name and then waits for the ringing to stop. It only takes one.

He doesn’t know what Victor’s doing right now but Yuuri can still see his cheshired grin. “Hello? Yuuri? Have you decided to use your voice to wish me goodnight?”

Yuuri breathes out, closes his eyes, feels his heart swirl. Hearing Victor’s voice is so relieving that Yuuri quickly closes out of two leftover tabs for Google Images of Vladivostok architecture and four for real estate websites comparing apartment rental prices—done only out of sheer curiosity. He was getting ahead of himself, and the websites were all in Russian anyway so it wasn’t as if he could understand anything enough to actually follow through.

“Did you know… Vladivostok is only a thousand kilometres from Hasetsu?” Yuuri says despite trying (and failing) to rein himself back in. He doesn’t mean to sound like this, wishes he had more of the mental strength to close the one tab that’s been doing the most damage to him all this time: a visual representation of the flight path from Saint Petersburg to Hasetsu—hardly a stone’s throw away.

“Oh,” Victor says, tone somewhat taken aback, probably wondering why they’re back on that now. And then after a long tangent of silence when Yuuri doesn’t elaborate anything more, Victor lights up the phone with the sparkle of his laughter, then says, “How far is a thousand kilometres?”

“It’s…” A lot closer than 7,000.

Yuuri licks his lips, shakes the thought from his mind. It really doesn’t matter if they’re 7,000 or 1,000 kilometres away after all. After some point, it’s all the same. If Victor’s not here, he might as well be as far as outer space, sending messages from another galaxy. He’s here, but he’s never quite here.

“It’s a pretty big city?” Yuuri says, not knowing where to go from here. “The population is six hundred thousand. Okay, I know you’re used to a lot bigger so maybe it’s actually a downgrade. But it’s not remote by any means. I dunno, I guess I just thought that was pretty interesting.”

“Pretty interesting,” Victor echoes, contemplative. “Not as bustling as Saint Petersburg but not as cozy as Hasetsu.”

“So, it’s just right?”

“Hm.”

That’s not a yes or a no or even a maybe. That’s Victor-speak for “you stumble and fall when you’ve got something on your mind, and you’re terrible at trying to hide it.”

“A plane ride would only take an hour,” Yuuri mentions.

“Yeah, it would.”

“We could do day trips to visit each other.”

“I doubt it. Aeroflot has about a thirty percent chance of arriving on time.”

Yuuri laughs, leaning his head down against the desk, presses the phone close into his ear.

Even if Victor’s about to chastise him for saying ridiculous things that’ll never come to fruition anyway, he keeps his hand on it, afraid to let it go in case the phone slips from his grasp or he misses something very important. Phones and signal and cell reception between continents can be pretty unpredictable, and Yuuri wants to hear it all, everything, anything Victor might say to him. No matter what it is.

“Wouldn’t it be nice…” Victor says, “...if we could spend those waiting times together? I wouldn’t detest flying as much.”

And normally they would FaceTime but Yuuri doesn’t want to do that right now. He wants to focus all his attention on listening to Victor’s voice, however crackly or lagged it is. If he were to see or even think about Victor’s face right now, all smiley because Victor smiles when he doesn’t know what else to do—Yuuri feels so sure he’s going to completely come apart.

“I miss you, Victor,” he says, loud enough so the phone is able to pick up his voice, but quick enough that if Victor can’t quite catch it then he’ll ask for Yuuri to repeat himself, and Yuuri gladly will.

But he doesn’t have to. Victor hears him perfectly.

“I miss you, too.” Victor’s voice finally dips towards sounding so uncharacteristically sad, but he’s trying so hard to make the best of it. “I miss you so much, Yuuri.”

There’s a buzz that runs through Yuuri, up his arms, up his spine. He basks in it, bathes in it, wishes it wouldn’t stop. “You do?”

“Of course I do!”

“You mean it?”

“Yes!”

His heart stops beating so fast. In one simple second, he can calm down now. “...Okay, then. Okay, um. That’s all, then. Good night, Victor.”

“Yuuri, wait! You… you can always come live with me in Saint Petersburg, you know? I know I keep bringing it up, but it’s really not so bad. It gets cold sometimes but we can bundle you up in, like, a lot of scarves. Seventeen scarves. I’ll hug you in my arms a lot.”

Oh.

“You don’t have to do that.”

“It won’t be so bad—I want to do it!”

“Don’t push yourself.”

“Please say yes?”

“I know…” Yuuri reassures him, at least hopes it comes across as reassurance for his lack of an answer to Victor’s proposal of this every time, more often completely fizzling out whenever Victor mentions living with him. Whenever he thinks about being able to snuggle up close to Victor every night. It’s too much for him. “Seventeen scarves is… just... a lot of scarves,” Yuuri murmurs.

After a beat, Victor seems to agree, “You’re right. Instead of seventeen crap scarves, I’ll buy you… nine… nine really high quality scarves instead.”

Yuuri lets out a laugh. “Better.” Though, he doubts Victor will actually remember to buy even one when the time comes, but it’s the thought that counts.

“You’ll still visit me for the holidays, right?”

The lilt in his voice turns hopeful, as if this wasn’t already discussed before. Yes, of course Yuuri will. Why does Victor even need to ask that?

Yuuri can hear the phasing in and out of noise in the background on Victor’s side—the clinking of cutlery and vague streams of Russian.

But Victor doesn’t seem to be paying much attention to whatever’s physically happening around him, keen on listening instead for Yuuri’s answer. Yuuri doesn’t know how or why this is always the one thing he’s sure of, among all of the infinite other things he’s not sure of, only going off of how attentive and caring and patiently listening Victor sounds in response to him and only him.

“Yuurriii, please hurry and come. I’m so cold and lonely without you.”

“I thought the cold wasn’t so bad there?”

“It isn’t.”

“Victor… actually, I don’t care all that much about the cold… I actually just…”

“It won’t be cold when you’re here with me.”

“I wish we could just—”

He cuts himself off, squinting into the darkness, mouth unable to form words, not even able to utter an apology when for the first time during conversation Yuuri lets the phone slip from his ear to hold at arm’s length.

The tinny, distant sound of “Yuuri?” sounds very far away. But he’s going to leave Victor hanging for only a few moments.

Because he just can’t stand it sometimes, letting the easiest things affect him like this. Born a charmer, always a charmer—Victor doesn’t even have to touch him or take his time caressing his fingers against Yuuri’s palm to make it so unbearably hard to stay away.

So often there’s a time lag where they end up talking over each other until it gets so ridiculous they both have to stop, meet each other with “You go ahead” in unison and then “No, go ahead!” in exasperated unison again. Because the sound has to travel quite far, over the mountainous Russian expanse and the Sea of Japan, just to get to each other.

But Yuuri is plagued with almost always being able to catch what Victor says when it’s never the other way around. The awareness that this is very much a horrible romantic drama they’re currently living in isn’t enough not to make his heart go crazy every time Victor throws out some off-hand cheesy thing that’s  still audible all the way from the corner of Yuuri’s bedroom, with Victor feigning ignorance while Yuuri suffers alone under the covers of his blanket.

Speechless until it’s far too late to say anything, nothing ever works out well enough to feel totally, honestly satisfied with how often they seem to miss each other.

And Victor keeps pretending he’s about to sleep soon so he insists Yuuri should too, even though it’s nearing only 7 PM for him and there’s no way Yuuri can sleep after the night culminates to this.

His threats are all talk, and it’s the only thing Yuuri can rightfully call him out on from several time zones away.

In the end, Victor presses to stay on the line with him, eating his dinner silently, while Yuuri tucks a pillow under his chin and goes through the process of booking a ticket online to Saint Petersburg—the earliest direct flight on the Eve of Russian Christmas.

-

Victor greets him at Pulkovo International Airport by nearly running headfirst into a solid glass pane, but managing to finally get a kiss successfully in front of a dozen flashing cameras. Victor, this is so embarrassing, Yuuri had planned to say in advance because he knew very well this would happen. But it turns out the long forgotten touch of Victor’s lips on him, reminiscent of a time where they’d almost cracked both their heads on ice during a competition, feels too good to interrupt.

-

“Hello everyone! Thanks for waiting. I’ve brought the one and only: Japan’s Ace, Yuuri Katsuki!” Victor declares this to a restaurant full of Russian skaters and a tableful of Christmas dinner.

“H-Hi,” Yuuri says with a one-handed wave and a sheepish smile.

“Oh, finally. I’m starving.” Yuri P. is the first to shovel his face full of turkey before receiving an elbow to the side from Georgi. “What? I just saw him at GPF. They haven’t seen each other for, what, a couple weeks and you’re acting like he just returned home from war. Holy shit. You all are something else.”

“He did come back from war.”

“He’s a guest.”

“Shush, Yurio.��

“Tyi idiot.”

After they sit down and commotion in Russian begins again, Yuuri leans over to whisper in Victor’s ear, “I thought it was just going to be the two of us?” He’d just come from the airport not an hour ago after all, not that he’s not disappointed. Just surprised. It feels like Victor’s entire ice club is here.

“I might have let slip to Mila what restaurant we were going to.” Victor gives him a small smile, placing a hand on Yuuri’s leg and squeezing. It has Yuuri nearly convulsing. “It’s fine, right? Are you hungry? You’re not too exhausted to eat?”

“Oh—yeah! I mean, no, of course it’s fine. I haven’t washed my face in twenty-two hours but hopefully no one minds.”

“No one minds. Let them have their fun. The kids haven’t seen you in awhile.”

The kids, meaning the up-and-coming soon-to-be Russian Junior Champions at the ice club that latch onto Yuuri’s legs every time he visits. Yuuri doesn’t know why they do when Victor’s right there in front of them everyday, but maybe it’s because Yuuri isn’t as tall so they can actually see his face. And it might have something to do with the fact that Victor is always picking them up and swinging them around, intimidating them out of pair skating forever.

Under the table, Yuuri slides a hand underneath Victor’s, lacing through his fingers, taking hold—if only to prevent Victor’s hand on his thigh from arousing more sweet feelings in him than it should.

When the vodka starts coming around, Yuuri is already shaking his head before anyone can say anything to him.

“Come on!” Mila says. “Just one!” But she has a twinkle in her eye like she knows it won’t end up being just one.

Which is exactly why Yuuri is against it. “No no, I’m so tired. I guarantee you I’ll fall asleep if I do,” Yuuri tells her.

“You won’t,” all the older skaters assure him in unison. But even as Yuuri tries to explain that he literally just came off an exhausting flight, he’s only followed by choruses of “Yuuri Katsuki is not a sleepy drunk” down the table.

It has Yuuri melting into the seat of his chair, with Victor laughing, wrapping a protective arm around Yuuri’s shoulders, and planting kiss after kiss to the side of his forehead. “You’re too cute,” he mutters with a smile into the shell of Yuuri’s ear. And then loudly to everyone else: “I won’t let them make fun of you.”

“You’re the only one here who fell head over heels in love with him because he was like that!”

That’s totally unfair, Yuuri thinks, and so so so totally untrue. If only they could all understand. They have it all wrong. If only Victor especially could understand that it’s not Yuuri who’s the cute one in this relationship.

-

Yuuri wakes up the next morning with Victor’s head smushed underneath his chin, arms around his middle, straggly silver hair tickling his nose, and the familiar scent of Victor’s apartment in Saint Petersburg that he hadn’t quite gotten to enjoy taking in the night before.

He remembers promising Victor to never ever leave his side ever again the night before. No, that doesn’t mean one of them is moving to Vladivostok. And no, that doesn’t mean one of them is retiring from competitive skating for good.

But if Yuuri could wake up every day like this, falling asleep to Victor’s “Oyasuminasai” and then waking up to an even huskier “Dobroye utro, Yuuri” every morning, then he’ll need a little more time to think about it. He'll need to stay in Victor's arms just a litle longer to make things easier to take on. It’s a good thing Yuuri had hesitated on buying that return trip ticket.

[arabellaflynn]

Monday Mystery: L'Oiseau Blanc

On the 8th of May, 1927, François Coli and Charles Nungesser -- two French aviators, both aces in the dogfights of WWI -- took off from Paris en route to New York City. They flew a Levasseur PL.8 they called L'Oiseau Blanc, a biplane purpose-built for the task, in the hopes of winning the $25,000 prize for the first non-stop transatlantic flight between the two cities. They were escorted to the coast by French fighter planes, logged by a British submarine off the Isle of Wight, and spotted over the Irish towns of Dungarvan and Carrigaholt. The biplane took off heavy, with a full load of fuel that should have given it 42 hours of flight time, enough to reach the Atlantic coast of North America. As the estimated time of arrival came near, thousands of people crowded onto the waterfront and into places like Battery Park, where they would be able to see the planned water landing in front of the Statue of Liberty. Rumors had been swirling of L'Oiseau Blanc being sighted over Nova Scotia, over Maine, or even over Long Island. Curiously, I can find no reports of rumors that placed the plane over Boston, which was right in their path, and over which they planned to pass before heading for New York City. The scheduled moment came and went. L'Oiseau Blanc was never heard from again. Coli and Nungesser planned to take a "great circle" route across the ocean, so-called because when you plot it on a 2D map of the 3D Earth, it appears to swing way out of the way in a giant arc. (Great circles, also known as orthodromes, are the path of intersection between a sphere and a plane that passes through the sphere's center. An arc of a great circle is the shortest distance between two points on a sphere in the same way a straight line is the shortest distance between two points on a plane.) It would have been roughly this, although the NYC end is approximate; the field they took off from, Le Bourget, still exists, but JFK appears to be the nearest airport, as the crow flies. To give you some perspective, Coli and Nungesser's route swung north of where the Titanic sank, over a section of the Atlantic beset by storms and clogged with ice. The most reasonable hypothesis, pursued by a collection of search parties run by the US Navy, the Canadian Navy, and the French authorities, was that they had run afoul of weather and gone down in a squall. No traces were found, but the ocean is big, and the PL.8 was tiny and fragile. The search continues into the present day, headed by organizations like TIGHAR, which is overenthusiastic and somewhat questionable, and NUMA, which is weirdly less questionable despite having been founded by Clive Cussler and named for the fictitious agency in his books. There have been reports over the years of various people in Newfoundland and/or Maine having spotted a small white plane, and salvaged pieces of it when it crashed. Both locations would have been reasonable places for L'Oiseau Blanc to have flown over on its way to NYC. Rumors have swirled since about 1930 of someone in Maine having hauled away a small aircraft engine, but never anything about finding the actual plane, or the remains of the pilot and navigator. As of 2011, an unofficial French team has focused on the prospect that they encountered headwinds on the way out and ran out of fuel, going down in Eastern Canada somewhere. Links: http://ift.tt/1FSXphr http://ift.tt/2kKE5yW http://ift.tt/2lfSmQY from Blogger http://ift.tt/2lfW1ym via IFTTT -------------------- Enjoy my writing? Consider becoming a Patron, subscribing via Kindle, or just toss a little something in my tip jar. Thanks!

[khamgiodau]

NHỊP NHANH KỊCH PHÁT TRÊN THẤT

NHỊP NHANH KỊCH PHÁT TRÊN THẤT

I. Định nghĩa

Nhịp nhanh kịch phát trên thất (SVT) là rối loạn nhịp nhanh có phức bộ QRS hẹp ( giây) phản ánh kích hoạt nhanh chóng của các tâm

thất thông qua hệ thống His- Purkinje bình thường, do đó cho thấy rối loạn nhịp bắt nguồn ở trên hoặc trong bó His. Các vị trí xuất phát có thể ở nút xoang, tâm nhĩ, nút nhĩ thất (AV), bó His hoặc các vị trí kết hợp.

Một số SVT có phức bộ QRS rộng do có kích thích sớm qua đường phụ hoặc bị dẫn truyền lệch hướng, blốc nhánh bó từ trước hoặc xuất hiện khi có nhịp nhanh.

Trong phần này tập trung vào nhịp nhanh vào lại nút nhĩ thất và nhịp nhanh vào lại nhĩ thất.

II. Nguyên nhân và cơ chế

Nguyên nhân phức tạp nhưng đều do một trong các cơ chế có thể gây ra gồm:

- Cơ chế vào lại.

- Tính tự động và các hoạt động khởi kích, gồm:

• Tính tự động bình thường gia tăng.

• Tính tự động bất thường.

• Hoạt động khởi kích.

III. Yếu tố nguy cơ

Bất kỳ điều kiện ảnh hưởng hoặc gây tổn thương cơ tim đều làm tăng nguy cơ nhịp nhanh. Các yếu tố nguy cơ có thể là:

- Bệnh tim thực thể.

- Bệnh hô hấp ảnh hưởng đến tim.

- Tăng huyết áp.

- Hút thuốc.

- Sử dụng nhiều rượu.

- Sử dụng nhiều caffeine.

- Sử dụng các loại thuốc kích thích.

- Tâm lý căng thẳng hoặc lo âu.

- Yếu tố nguy cơ khác:

• Lớn tuổi

• Yếu tố gia đình...

IV. Chẩn đoán

4.1. Dịch tễ

Các cơn nhịp nhanh trên thất chiếm tỷ lệ 35/100.000 người/năm.

4.2. Lâm sàng

Khi bệnh nhân có tần số > 100 ck/phút cần dựa vào các yếu tố sau để chẩn đoán.

4.2.1. Bệnh sử

- Thời gian khởi phát cơn nhịp nhanh,

- Yếu tố khởi phát.

- Triệu chứng trong cơn nhịp nhanh.

- Tần suất các cơn nhịp nhanh trước đây và điều trị trước đây.

- Tiền sử bệnh tim mạch và bệnh lý nội khoa khác.

- Tất cả các thuốc đã và đang điều trị.

4.2.2. Triệu chứng lâm sàng

Lâm sàng phụ thuộc vào tần số nhịp nhanh, huyết áp và kết quả tưới máu tổ chức, các bệnh đi kèm và sự nhạy cảm của bệnh nhân. Có thể có triệu chứng sau:

- Đánh trống ngực.

- Ngất hoặc gần ngất.

- Đầu óc quay cuồng hay chóng mặt.

- Toát mồ hôi.

- Đau ngực.

- Khó thở.

- Bệnh nhân thường trong trạng thái hoảng sợ, lo lắng.

- Nhịp nhanh đôi khi là dấu hiệu duy nhất ở bênh nhân khỏe mạnh và dự trữ huyết động tốt.

- Bệnh nhân có dự trữ huyết động kém có thể có khó thở nhanh và tụt huyết áp, ran ở phổi, tiếng tim T3 và tĩnh mạch cổ nổi.

4.3. Cận lâm sàng

4.3.1. Điện tâm đồ

Cần thực hiện ngay khi có thể. Phân tích ECG cho phép xác định nhịp nhanh và phân loại các loại nhịp nhanh trên thất gồm:

Nhịp nhanh nguồn gốc tổ chức nhĩ

Nhịp nhanh xoang

Nhịp nhanh xoang không phù hợp

Nhịp nhanh vào lại tại nút xoang (SANRT)

Nhịp nhanh vào lại trong nhĩ (IART)

Nhịp nhanh nhĩ Nhịp nhanh nhĩ đa ổ

Nguồn gốc bộ nối AV

Nhịp nhanh vào lại tại nút nhĩ thất (AVNRT)

Nhịp nhanh vào lại nhĩ thất (AVRT)

Nhịp nhanh bộ nối

Nhip nhanh lạc chỗ bộ nối ở trẻ em (Junctional ectopic tachycardia in children)

Nhịp nhanh bộ nối không thành cơn ở người lớn (Nonparoxysmal junctional tachycardia in adults)

4.3.1.1. Các nhận định chung dấu hiệu ECG của nhịp nhanh trên thất

a. Cơn tim nhanh thường khởi phát và kết thúc đột ngột, cơn có thể từ vài giây, vài phút đến nhiều giờ, nhiều ngày.

b. Cơn thường được khởi phát do một ngoại tâm thu nhĩ hoặc ngoại tâm thu thất.

c. Tần số tim thường từ 140 - 250 nhịp/phút, rất đều.

d. Sóng P:

- Hình dạng: thường khác với P cơ sở. Trừ nhịp nhanh vào lại tại nút xoang.

- P âm ở D2 D3 aVF (nhịp nhanh vào lại nút nhĩ thất)

- Vị trí: sóng P có thể không nhìn thấy vì chồng lên phức bộ QRS và bị che khuất trong phức bộ QRS. Sóng P trong một số trường hợp nhô ra ở phần cuối của phức bộ QRS tạo ra hình ảnh “giả sóng r’” ở V1 và “giả sóng s’” ở D2, D3, aVF, làm trông giống hình ảnh blốc nhánh phải không hoàn toàn (trong AVNRT).

- Sóng P có thể tách khỏi QRS và đi sau QRS, rơi vào đoạn ST với RP < PR (AVRT do dường phụ nhĩ - thất và vòng vào lại chiều xuôi).

e. Phức bộ QRS: Trong cơn nhịp nhanh thường hẹp < 0.12giây, có hình dạng giống QRS cơ sở lúc nhịp xoang. Tuy nhiên những trường hợp sau QRS giãn rộng:

- Có blốc nhánh từ trước.

- Nhịp nhanh trên thất có dẫn truyền lệch hướng.

4.3.1.2. Nhịp nhanh vào lại tại nút nhĩ thất (AVNRT):

- Tần số 150-200/phút.

- Sóng P lẫn vào trong QRS hay ngay sau QRS.

- Khoảng RP ngắn trong nhịp nhanh vào lại tại nút nhĩ thất điển hình và RP dài trong nhịp nhanh vào lại tại nút nhĩ thất không điển hình.

Hình 1. Nhịp nhanh vào lại nút nhĩ thất (AVNRT)

4.3.1.3.Nhịp nhanh vào lại nhĩ thất (AVRT):

- Đặc trưng bằng đường phụ ngoài nút nối với nhĩ và thất.

- Có sóng delta trong quá trình nhịp xoang nếu có dẫn truyền xuôi qua đường phụ, đưa đến chẩn đoán hội chứng Wolff-Parkinson-White

(wpW).

- Sóng delta không có trong orthodromic AVRT, loại này thường gặp nhất ở các bệnh nhân WPW (chiếm 90% loạn nhịp này) tần số 150-250/phút, QRS hẹp trong dạng nhịp nhanh thể orthodromic.

- Có sóng delta làm QRS rộng trong dạng nhịp nhanh thể antidromic (10%).

- Sau khi kết thúc cơn nhịp nhanh cần đo ECG trong nhịp xoang để sàng lọc hội chứng WPW.

Hình 2. Nhịp nhanh vào lại nhĩ thất thể orthodromic.

4.3.I.4. Nhịp nhanh nhĩ đa ổ (MAT)

- Nhịp nhanh > 100 ck/ph.

- Có ≥ 3 sóng P có hình dạng và PR khác nhau.

- Thường hay gặp ở các bệnh nhân có bệnh phế quản tắc nghẽn mãn tính.

- Có thể sử dụng theophyllin là yếu tố thúc đẩy.

Hình 3. Nhịp nhanh nhĩ đa ổ (MAT)

4.3.I.5. Chẩn đoán phân biệt nhịp nhanh trên thất QRS rộng với nhịp nhanh thất

Đôi khi rất khó khăn. Dựa vào tiêu chuẩn Brngada (xem thêm phác đồ nhịp nhanh thất). Bảng dưới đây so sánh hình dạng sóng trên các chuyển đạo trước tim.

4.3.I.5. Dựa vào kết quả điều trị để chẩn đoán phân biệt các loại nhịp nhanh trên thất. (xem lưu đồ)

4.3.2. Xét nghiệm khác:

- CK-MB, TnI, có thể Pro- BNP.

- Ion đồ máu

- Công thức máu

- TSH, T3, T4, T4 tự do

- Nồng độ digoxin máu.

- Chụp X- quang ngực thẳng

- Siêu âm tim Doppler màu

- Holter ECG trong trường hợp chưa phân định được cơn nhịp nhanh hoặc cần thêm các bằng chứng về rối loạn nhịp khác.

- Test Adenosine và các thủ thuật kích thích phó giao cảm có thể hỗ trợ cho chẩn đoán và điều trị.

- Thăm dò điện sinh lý tim: giúp chẩn đoán cơ chế nhịp nhanh trên thất, vị trí con đường phụ và vòng vào lại. Thường làm kết hợp với quá trình can thiệp điện sinh lý như loại trừ các đường phụ và các ổ loạn nhịp bằng năng lượng tần số radio (RFA).

✓. Điều trị

5.1. Điều trị cấp cứu cắt cơn nhịp nhanh

5.1.1. Trường hợp nhịp nhanh trên thất có huyết động không ổn định:

Bệnh nhân có tụt huyết áp: huyết áp tâm thu <90mmHg. Trường hợp bệnh nhân có tăng huyết áp, huyết áp tâm thu giảm > 40 mmHg so với huyết áp trước cơn được coi như rối loạn huyết động.

- Rối loạn tri giác, co giật.

- Chân tay lạnh.

- Đau thắt ngực.

- Phù phổi cấp.

→ Chuyển nhịp bằng sốc điện đồng bộ ngay: năng lượng khởi đầu 50 J đến 100 J.

5.1.2. Trường hợp huyết động ổn định

Việc điều trị cấp cứu được thực hiện theo các bước, gồm :

Các thủ thuật cường phế vị:

- Xoa xoang cảnh :

• Không thực hiện nếu bệnh nhân: có ngất xoang cảnh, có tiền sử tai biến mạch máu não thoáng qua, bệnh lý động mạch cảnh, người vừa có nhồi máu cơ tim trước đó 6 tháng và > 65 tuổi.

• Bệnh nhân nằm ngửa, quay mặt về đối bên, xoa nhẹ nhàng từng bên từ 10-20s, sau đó chuyển sang bên kia.

• Không nên tiến hành xoa đồng thời hai bên.

- Nghiệm pháp Valsalva:

• Hít thở thật sâu, rồi thở ra thật mạnh, trong khi không cho khí ra ngoài bằng đóng nắp thanh môn. Thủ thuật này có thể làm bằng cách cho bệnh nhân thổi thật nhanh và mạnh vào đầu ống cao su của máy đo huyết áp đồng hồ sau khi bỏ quả bơm ra và buộc chặt băng quấn của máy đo. Thổi khi kim chỉ áp lực lên trên 40 mmHg là đạt yêu cầu.

• Tác dụng của xoa xoang cảnh và Valsava sẽ tăng nếu bệnh nhân đã được dùng digitalis và các thuốc chống loạn nhịp khác trước đó.

• Các thủ thuật như ấn nhãn cầu: nuốt một miếng bánh to, chúng tôi khuyên không nên làm.

• Trong quá trình trên cần theo dõi trên monitoring điện tâm đồ, ghi lại hoặc nghe tim để xử lý các trường hợp nhịp quá chậm hoặc vô tâm thu sau cơn nhịp nhanh, khi cần đấm vào trước tim để kích thích tim đập trở lại tránh cơn ngừng kéo dài và cho các thông tin để xác định chẩn đoán.

Các thuốc cắt cơn

Adenosin : là một thuốc có tác dụng gây cường phế vị mạnh, làm chậm dẫn truyền, gây blốc ở nút nhĩ thất phá vỡ được vòng vào lại cắt được cơn nhanh trên thất.

- Thuốc có nửa đời sống rất ngắn < 10s và thải trừ hoàn toàn khỏi huyết

tương trong 30s nên phải tiêm tĩnh mạch thật nhanh (1-2s).

- Thuốc có thể gây ngừng tim ngắn vài giây hoặc nhịp chậm sau khi cắt cơn.

- Tác dụng phụ : gây cảm giác bồn chồn khó chịu.

- Liều lượng :

• Tiêm tĩnh mạch 1 ống - 6mg.

• Nếu không kết quả sau 2-3 phút tiêm liều thứ 2 hoặc thứ 3 là 12mg. Nếu sau 3 liều không kết quả thì chuyển thuốc khác.

- Nên chuẩn bị atropin để đề phòng nhịp quá chậm (0,5-1mg tiêm TM).

- Chống chỉ định :

• Những trường hợp có hội chứng nút xoang bệnh lý.

• Những trường hợp đã dùng các thuốc ức chế nút xoang hoặc nút Tawara.

• Chống chỉ định tuyệt đối ở bệnh nhân hen phế quản.

• Nếu sau khi tiêm bệnh nhân có vô tâm thu trên monitor hoặc ngất cần đấm mạnh vào vùng trước xương ức cho tim đập trở lại.

Verapamil (Isoptin - ống 5mg) : tiêm tĩnh mạch chậm trong 2-3phút, liều lượng: 2,5mg/lần, nếu cần thiết có thể tiêm thêm các liều 2,5mg/lần sau 15 -30phút, khi tình trạng huyết động ổn định.

- Verapamil làm giảm sức co bóp cơ tim rất mạnh nên chỉ dùng cho

những trường hợp chức năng tim tốt và huyết động ổn định.

- Chống chỉ định:

• Suy tim.

• Huyết áp thấp.

• Tiền sử có hội chứng nhịp nhanh chậm.

• Nhịp nhanh vào lại nhĩ thất chiều ngược (hội chứng WPW điển hình).

Diltiazem: liều 0,25mg/kg, tĩnh mạch chậm. Thuốc này ức chế sự co bóp cơ tim ít hơn Verapamil. Nếu liều trên không cắt được cơn có thể cho liều 0,35mg/kg sau 15-30 phút nếu cần thiết và sau đó truyền 5-15mg/giờ.

- Chống chỉ định: Tương tự như Verapamil Chẹn beta giao cảm:

Esmolol: Là một chẹn bêta giao cảm có tác dụng ngắn, liều lượng TM : 250-500pg/kg trong 1-2 phút. Sau đó truyền duy trì 50-200pg/kg/phút. Thuốc có thời gian bán huỷ ngắn: 8 phút Metoprolol: Liều lượng 5mg trong thời gian 2 phút; có thể cho liều thứ 2 sau 15 phút

Propranolol: liều lượng:0.15mg/kg, trong thời gian 2 phút

- Tác dụng bất lợi chính của các thuốc chẹn beta giao cảm:

• Hạ huyết áp.

• Blốc nhĩ thất.

• Giảm sức bóp cơ tim gây suy tim.

Chống chỉ định của các thuốc chẹn beta giao cảm:

• Hen phế quản và các bệnh phổi tắc nghẽn mãn tính.

• Suy tim, huyết áp thấp.

Amiodanone (biệt dược: Cordarone, Sedacorone... ống 150mg).

- Tiêm tĩnh mạch chậm: trong trường hợp cần cắt cơn nhanh, nhưng chỉ dùng khi chức năng tim còn tốt, huyết động ổn định.

- Thông thường và an toàn: pha 1 ống (150mg) + 20ml (bơm tiêm điện) đến 50 ml (không có bơm tiêm điện) huyết thanh đẳng trương truyền tĩnh mạch chậm trong 10 phút đến 15 phút.

- Truyền tĩnh mạch: 2 ống liều 5mg/kg. ở người lớn thường dùng 2 ống (300mg) pha trong 100-150ml huyết thanh đẳng trương truyền TM nhanh trong khoảng 60 phút. Không nên pha nồng độ thấp và truyền chậm vì hiệu quả cắt cơn thấp.

- Tuy ít làm giảm sức co bóp cơ tim nhưng do dùng tiêm tĩnh mạch chậm hoặc truyền nhanh có thể một số trường hợp hạ huyết áp nên cần theo dõi huyết động khi sử dụng Cordarone đường tĩnh mạch.

Dronedarone: tương tự như amiodarone nhưng không gây độc với gan, thận.

- Chống chỉ định: suy tim nặng.

- Liều dùng 400mg/12giờ.

Digitalis: là thuốc có hiệu quả và an toàn nhưng cần mất vài giờ để có tác dụng.

- Liều lượng: Digoxin 0,5mg; Isolanide, Cedilanide 0,4mg tiêm tĩnh mạch, sau 4-6 giờ có thể cho lại nếu cần hoặc sau đó 0,25 - 0,125mg cứ 2-4h/lần. Tổng liều 1- 1,25mg/ngày.

- Với trẻ nhỏ nên dùng digitalis trước tiên nếu như các thủ thuật cường phế vị thất bại.

- Nên dùng digitalis trong trường hợp cơn tim nhanh có kèm suy tim Amiodarone, Ibutinide, Procainamide (TM) , Flecainide (TM) là những

thuốc được lựa chọn trong nhịp nhanh trên thất tiền kích thích.

Các biện pháp cắt cơn nhịp nhanh trên thất khác

Tạo nhịp: Thường được chỉ định khi các biện pháp trên không hiệu quả.

Máy tạo nhịp phát ra một loạt các xung động với mục đích một trong các xung động đó xâm nhập được vào vòng vào lại và như vậy sẽ phá vỡ vòng vào lại làm cắt được cơn tim nhanh. Tạo nhịp cắt cơn tim nhanh trên thất có thể :

- Tạo nhịp vượt tần số.

- Tạo nhịp dưới tần số.

- Tạo nhịp qua thực quản hoặc trong buồng tim.

Sốc điện chuyển nhịp: được chỉ định khi:

- Các cơn tim nhanh trên thất có huyết động không ổn định cần phải cắt cơn ngay.

- Các thuốc adenosin, verapamil có chống chỉ định hoặc không có hiệu quả.

- Các biện pháp và thuốc khác không hiệu quả.

• Liều điện : bắt đầu 50 - 100J, khi cần sẽ tăng liều điện.

• Sốc đồng bộ.

• Không sốc điện nếu có nhiễm độc digitalis hoặc nhịp nhanh nhĩ bị blốc nghi do ngộ độc digitalis.

5.1.3. Điều trị lâu dài và dự phòng cơn nhịp nhanh trên thất

Việc lựa chọn thuốc để điều trị dự phòng hoặc điều trị triệt để cơn nhịp nhanh kịch phát trên thất tuỳ thuộc vào biểu hiên lâm sàng của từng loại nhịp nhanh trên thất.

5.1.4. Nhịp nhanh vào lại nút nhĩ thất

Khuyến cáo điều trị lâu dài nhịp nhanh vào lại nút nhĩ thất tái phát

Nhịp nhanh vào lại nút nhĩ thất dung nạp kém, huyết động không ổn định

+ Triệt bỏ đường dẫn truyền chậm qua catheter ( Chỉ định loại I).

+ Verapamil, diltiazem, chẹn beta giao cảm, sotalol, amiodarone (Chỉ định loại Ilb).

- Verapamil: uống; liều lượng: 80 - 240mg/ ngày.

- Metoprolol: uống; liều lượng: 50-200mg/ngày.

- Bisoprolol: uống; liều lượng: 2.5-10mg/ngày.

- Atenolol: uống 50-100mg/ngày.

- Propranolol: uống; 40-240mg/ngày.

- Digoxin: uống; liều lượng: 0.125-0.375mg/ngày.

- Sotalol: uống ; 80-320mg/ngày.

- Amiodarone: uống; 200mg/ngày.

Flecainide, propafenone ( Chỉ định loại IIb)

- Flecainide: uống; liều lượng: 100-300mg/ngày.

- Propafenone: uống; liều lượng: 300-600mg/ngày.

Nhịp nhanh vào lại nút nhĩ thất tái phát có triệu chứng

- Triệt bỏ đường dẫn truyền chậm qua catheter ( Chỉ định loại I).

- Verapamil (Chỉ định loại I) ( liều lượng như trên).

- Diltiazem, chẹn bêta giao cảm ( Chỉ định loại I ).

- Digoxin (Chỉ định loại IIb).

Nhịp nhanh vào lại nút nhĩ thất tái phát, không đáp ứng với chẹn beta giao cảm hoặc chẹn kênh canxi và bệnh nhân không muốn điều trị bằng RF.

+ Flecainide, Propafenone, Sotalol: uống. ( Chỉ định loại IIa).

- Amiodarone : uống; (Chỉ định loại IIb).

Nhịp nhanh vào lại nút nhĩ thất có cơn thưa hoặc cơn đầu tiên nhưng bệnh nhân mong muốn điều trị triệt để:

- Triệt bỏ đường dẫn truyền chậm qua catheter ( Chỉ định loại I)

Nhịp nhanh trên thất, nhưng thăm dò điện sinh lý tim chỉ thấy đương dẫn truyền kép tại nút nhĩ thất hoặc một nhát echo nhưng không gây được cơn nhịp nhanh:

+ Verapamil, diltiazem, chẹn beta giao cảm, Flecainide, Propafenone (Chỉ định loại I).

+ Triệt bỏ đường dẫn truyền chậm qua catheter ( Chỉ định loại I).

Nhịp nhanh vào lại nút nhĩ thất, cơn thưa và dung nạp tốt:

+ Không điều trị gì ( Chỉ định loại I).

+ Nghiệm pháp cường phế vị ( Chỉ định loại I).

+ Luôn mang thuốc trong túi ( Chỉ định loại I).

+ Verapamil, diltiazem, chẹn beta giao cảm ( Chỉ định loại I).

+ Triệt bỏ đường dẫn truyền chậm qua catheter ( Chỉ định loại I).

5.1.5. Nhịp nhanh vào lại nhĩ thất do đường phụ nhĩ - thất

Khuyến cáo điều trị lâu dài các rối loạn nhịp tim ở bệnh nhân có hội chứng WPW.

a. Các rối loạn nhịp tiền kích thích, có triệu chứng, dung nạp tốt ở bệnh nhân WPW:

- Triệt bỏ đường dẫn truyền phụ qua Catheter (Chỉ định loại I).

- Dùng Flecainide, Propafenone (Chỉ định loại IIa).

- Sotalol, amiodarone, chẹn beta giao cảm (Chỉ định loại IIa).

- Không dùng: Digoxin, diltiazem, verapamil (Chỉ định loại III).

b. Hội chứng WPW có rung nhĩ với tần số thất nhanh hoặc cơn nhịp nhanh vào lại nhĩ thất dung nạp kém:

- Triệt bỏ đường dẫn truyền phụ qua Catheter (Chỉ định loại I).

c. Nhịp nhanh vào lại nhĩ thất có dung nạp kém (không có tiền kích thích):

- Triệt bỏ đường dẫn truyền phụ qua Catheter (Chỉ định loại I).

- Flecainide, Propafenone (Chỉ định loại IIa).

- Sotalol, amiodarone (Chỉ định loại IIa).

- Chẹn beta giao cảm (Chỉ định loại IIb).

- Không dùng: Digoxin, diltiazem, verapamil (Chỉ định loại III).

d. Cơn nhịp nhanh vào lại nhĩ thất lần đầu hoặc thưa

- Không cần điều trị (Chỉ định loại I).

- Thủ thuật cường phế vị (Chỉ định loại I).

- Luôn mang thuốc trong túi: verapamil, diltiazem, chẹn beta giao cảm (Chỉ định loại I)

- Triệt bỏ bằng RF (Chỉ định loại IIa).

- Sotalol, amiodarone (Chỉ định loại IIb).

- Flecainide, propafenone (Chỉ định loại IIb).

- Không dùng Digoxin.

e. Tiền kích thích không có triệu chứng

- Không điều trị (Chỉ định loại I).

- Triệt bỏ bằng RF (Chỉ định loại IIa).

5.2. Biến chứng

- Biến chứng cấp tính: rối loạn huyết động dẫn đến sốc. Điều trị sốc.

- Biến chứng mạn: có thể gây bệnh cơ tim do nhịp nhanh, giãn lớn tim và suy tim. Điều trị vẫn là điều trị loạn nhịp kết hợp với điều trị triệu chứng suy tim.

VI. Lưu đồ xử trí

Lưu đồ 1. Chẩn đoán nhịp nhanh trên thất

Lưu đồ 2. Chẩn đoán dựa vào kết quả điều trị

Lưu đồ 3. Điều trị nhịp nhanh trên thất.

I. Tiên lượng và phòng ngừa

- Tiên lượng của SVT ngày nay đã thay đổi nhờ tiến bộ của thuốc và điều trị điện sinh lý can thiệp.

- Kỹ thuật chẩn đoán và loại bỏ các đường bất thường, cũng như các ổ gây ra loạn nhịp bằng năng lượng tần số radio qua catheter đã giải quyết khỏi với tỷ lệ khá cao từ 70 đến trên 90%, đặt biệt là AVNRT và AVRT.

- Phường ngừa trên hai phương diện:

+ Loại trừ các yếu tố nguy cơ + Uống thuốc chống tái phát (như trình trên)

Tài liệu tham khảo

1. Leonard I Ganz, MD, FHRS, FACC. Clinical manifestations, diagnosis, and evaluation of narrow QRS complex tachycardias. This topic last updated: thg 11 1, 2013.

2. Philip J Podrid, MD. Leonard I Ganz, MD, FHRS, FACC. Clinical features and treatment of ventricular arrhythmias during acute myocardial infarction. This topic last updated: thg 11 1, 2013.

3. Luigi Di Biase, MD, PhD, FHRS. Edward P Walsh, MD. Treatment of symptomatic arrhythmias associated with the Wolff-Parkinson-White syndrome. This topic last updated: thg 11 1, 2013.

4. Link MS. Clinical practice. Evaluation and initial treatment of supraventricular tachycardia. N Engl J Med 2012; 367:1438.

5. Smith GD, Dyson K, Taylor D, et al. Effectiveness of the Valsalva Manoeuvre for reversion of supraventricular tachycardia. Cochrane Database Syst Rev 2013; 3:CD009502.

6. Blomstrốm-Lundqvist C, Scheinman MM, Aliot EM, et al. ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias--executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Supraventricular Arrhythmias). Circulation 2003; 108:1871.

.Bài viếtNHỊP NHANH KỊCH PHÁT TRÊN THẤT xuất hiện lần đầu tại website http://khamgiodau.com

[drrajeshbadani-blog]

Interventional Cardiologist in Pune | Best Cardiologist in Pune | Dr. Rajesh Badani

Interventional Cardiologist in Pune

Interventional Cardiology is dealing with disorders of the heartbeat it human or animal. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology.

The Visible Heart is an educational tool for observing how a real heart works from within. You can see a beating heart, all the valve actions, the contractions of atria and ventricles, and the architecture of the heart as it beats; great live video of the beating Best heart surgery center in Pune.

Electrophysiology:

An Electrophysiology is a test to measure the electrical activity of the heart and to diagnose an arrhythmia or abnormal heart rhythms. Catheter ablation is a procedure performed to treat some types of arrhythmia.

Dr. Rajesh Surendra Badani Consultant,

Interventional Cardiology and Electrophysiology

Interventional cardiology (Coronary angiography and angioplasty)

Interventional electrophysiology (Electrophysiology study and Radiofrequency ablation)

Device implantation (Pacemaker, ICD and CRT)

Complex arrhythmia ablation (3D mapping for Atrial fibrillation and Ventricular Tachycardia)

 Education

MBBS from Mumbai University Seth G.S. Medical College, KEM Hospital, Mumbai

MD from Mumbai University Grant Medical College, J. J. Group of Hospitals, Mumbai

DNB Mumbai University, Grant Medical College, J. J. Group of Hospitals, Mumbai.

FCPS from Mumbai University, Grant Medical College, J. J. Group of Hospitals, Mumbai.

DNB (cardiology) from National Board of Examinations, Delhi.

Fellowship in Electrophysiology: SEPT 2006, CARE Hospitals, Hyderabad

 Experience / Achievements

More than nine years experience in Interventional cardiology and electrophysiology.

More than five international and ten national publications.

P. Basu award recipient CSI Dec 2008 for the best original research paper all over India.

Role of catheter ablation in VT storm.

Academics-Faculty for DNB cardiology students.

Conducted various national level conferences in cardiology.

PublicationsInternational  Fascicular Tachycardia, Is it really All That Benign?

Sharada Kalavakolanu Rajesh Badani, Hygriv B Rao,  Narasimhan Calambur. CARE Hospital and CARE Foundation, Hyderabad, India.

Does Regional Wall Motion Abnormality influence assessment of Dyssynchrony in Heart Failure?

Hygriv B Rao, Raghu Krishnaswamy, Rajesh Badani, Sharada Kalavakolanu, Narasimhan Calambur. CARE Hospital and CARE Foundation, Hyderabad, India

Ablation of incessant orthodromic reciprocating tachycardia in a child with congenitally corrected transposition of great arteries and ebsteinoid malformation of the left atrioventricular

valve.Chavan C, Rao HB, Badani RS, Raju PR, Narasimhan C. J Interv Card Electrophysiol. 2008 Nov;23(2):149-52. Epub 2008 Aug 8. PubMed PMID: 18688702.

Evaluation of Bachmann Bundle Pacing Versus Right Atrial Pacing in Prevention of Atrial Fibrillation After Coronary Artery Bypass Surgery

Chandrakant Chavan, Mukund Karmalkar, Rajesh Badani, K Sharada, Usha Rani, Prasad Rao, Ram Subramanyam, Narasimhan C Indian Pacing and Electrophysiology Journal; 2010; 10(12):529-535

NationalRole of Substrate Mapping in Hemodynamically Unstable Ventricular Tachycardia

Rajesh Badani, Chandrakant B Chavan, Sharada K, Hygriv B Rao, Narasimhan C, CARE Hospital, (The Institute of Medical Sciences), Hyderabad

D.P.Basu award recipient  CSI   Dec 2008—Best original research paper all over India

For more information, Visit: http://interventionalcardiologistpune.com

[drnikolatesla]

 "The Future of the Wireless Art."

"A mass in movement resists change of direction. So does the world oppose a new idea. It takes time to make up the minds to its value and importance. Ignorance, prejudice and inertia of the old retard its early progress. It is discredited by insincere exponents and selfish exploiters. It is attacked and condemned by its enemies. Eventually, though, all barriers are thrown down, and it spreads like fire. This will also prove true of the wireless art.

"The practical applications of this revolutionary principle have only begun. So far they have been confined to the use of oscillations which are quickly damped out in their passage through the medium. Still, even this has commanded universal attention. What will be achieved by waves which do not diminish with distance, baffles comprehension.

"It is difficult for a layman to grasp how an electric current can be propagated to distances of thousands of miles without diminution of intention. But it is simple after all. Distance is only a relative conception, a reflection in the mind of physical limitation. A view of electrical phenomena must be free of this delusive impression. However surprising, it is a fact that a sphere of the size of a little marble offers a greater impediment to the passage of a current than the whole earth. Every experiment, then, which can be performed with such a small sphere can likewise be carried out, and much more perfectly, with the immense globe on which we live. This is not merely a theory, but a truth established in numerous and carefully conducted experiments. When the earth is struck mechanically, as is the case in some powerful terrestrial upheaval, it vibrates like a bell, its period being measured in hours. When it is struck electrically, the charge oscillates, approximately, twelve times a second. By impressing upon it current waves of certain lengths, definitely related to its diameter, the globe is thrown into resonant vibration like a wire, stationary waves forming, the nodal and ventral regions of which can be located with mathematical precision. Owing to this fact and the spheroidal shape of the earth, numerous geodetical and other data, very accurate and of the greatest scientific and practical value, can be readily secured. Through the observation of these astonishing phenomena we shall soon be able to determine the exact diameter of the planet, its configuration and volume, the extent of its elevations and depressions, and to measure, with great precision and with nothing more than an electrical device, all terrestrial distances. In the densest fog or darkness of night, without a compass or other instruments of orientation, or a timepiece, it will be possible to guide a vessel along the shortest or orthodromic path, to instantly read the latitude and longitude, the hour, the distance from any point, and the true speed and direction of movement. By proper use of such disturbances a wave may be made to travel over the earth's surface with any velocity desired, and an electrical effect produced at any spot which can be selected at will and the geographical position of which can be closely ascertained from simple rules of trigonometry.

"This mode of conveying electrical energy to a distance is not 'wireless' in the popular sense, but a transmission through a conductor, and one which is incomparably more perfect than any artificial one. All impediments of conduction arise from confinement of the electric and magnetic fluxes to narrow channels. The globe is free of such cramping and hinderment. It is an ideal conductor because of its immensity, isolation in space, and geometrical form. Its singleness is only an apparent limitation, for by impressing upon it numerous non-interfering vibrations, the flow of energy may be directed through any number of paths which, though bodily connected, are yet perfectly distinct and separate like ever so many cables. Any apparatus, then, which can be operated through one or more wires, at distances obviously limited, can likewise be worked without artificial conductors, and with the same facility and precision, at distances without limit other than that imposed by the physical dimensions of the globe.

"It is intended to give practical demonstrations of these principles with the plant illustrated. As soon as completed, it will be possible for a business man in New York to dictate instructions, and have them instantly appear in type at his office in London or elsewhere. He will be able to call up, from his desk, and talk to any telephone subscriber on the globe, without any change whatever in the existing equipment. An inexpensive instrument, not bigger than a watch, will enable its bearer to hear anywhere, on sea or land, music or song, the speech of a political leader, the address of an eminent man of science, or the sermon of an eloquent clergyman, delivered in some other place, however distant. In the same manner any picture, character, drawing, or print can be transferred from one to another place. Millions of such instruments can be operated from but one plant of this kind. More important than all of this, however, will be the transmission of power, without wires, which will be shown on a scale large enough to carry conviction. These few indications will be sufficient to show that the wireless art offers greater possibilities than any invention or discovery heretofore made, and if the conditions are favorable, we can expect with certitude that in the next few years wonders will be wrought by its application."

–Nikola Tesla

Wireless Telegraphy & Telephony, 1908.

[adraveins]

For Watcher Wednesday, I’m going to do the Love Yourself Challenge for Pillars fic, because writing is not happening at the moment. But it certainly has been happening, and I’ve really been enjoying myself.

Rules: It’s time to love yourselves! Choose your 5 favourite works you created in the past year (fics, art, edits, etc. ) and link them below to reflect on the amazing things you brought into the world.

1. orthodrome: Deadfire AU concept fic, in which Kit finds Eothas in her basement ahead of time, yells at him, and tries to pretend that the idea of helping him to break the Wheel isn’t thrilling. There are a lot of things I like about this, but most especially the big metaphor I made out of feedback loops.

2. scientific inquiry and 3. threading the needle: Some Kit/Ydwin, wherein I was trying to get a feel for a very rare pair. I just really love how these turned out, especially because neither character is given to overt romantic tendencies, but these fics felt nice and natural.

4. when you see him, look him in the eye: The beginning of Hakona’s relationship with Magran and Rymrgand. I wanted to get at the more indirect nature of the dynamic at that point in her life, by tying gods to environment both internal and external, and I like the result.

5. a violent collision: Not actually Watcher-related, but some Waidwen and Eothas pre-Saint’s War, because I love to care about minor characters and situations glimpsed in passing. And I just really love this fic’s vibes.

[thgphotos]

" as the crow flies" ( orthodromic distance ) My flight Paris-Houston '1985 Map as the gift of the crew Air France #flight#orthodromic

[adraveins]

Fic masterlist:

To stay organized.

a violent collision: Eothas & Waidwen, pre-Saint’s War. ⯈ AO3 ⯈ Tumblr

how like a god: Eothas & Waidwen, Waidwen as a Dawn godlike. ⯈ AO3 ⯈ Tumblr

black-body curve: Eothas & Waidwen, Waidwen’s mother. ⯈ AO3 ⯈ Tumblr

Tumblr prompts: ⯈ AO3: All short prompted fics posted under one title. ⯈ Eothas & Waidwen: For the prompt “too loud.”

⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆ ⯆

Watcher Kit

a day trip: Kit, Edér, & Aloth, early POE 1. ⯈ AO3 ⯈ Tumblr

a group effort: Kit & party, mid-POE 1. ⯈ AO3 ⯈ Tumblr

the hollows of the world: Kit’s relationship with Caed Nua and Eora, pre-, during, and post-POE 1. ⯈ AO3 ⯈ Tumblr

if not you: Kit/Iovara, post-POE 1. ⯈ AO3 ⯈ Tumblr

orthodrome: Kit & Eothas, Deadfire AU. ⯈ AO3 ⯈ Tumblr

antipathetic field: Kit & Aloth, ft. Kit’s mentor, early Deadfire. ⯈ AO3 ⯈ Tumblr

scientific inquiry: Kit/Ydwin, ft. Vela, early Deadfire. ⯈ AO3 ⯈ Tumblr

threading the needle: Kit/Ydwin, mid-Deadfire. ⯈ AO3 ⯈ Tumblr

perpetual motion of the second kind: Kit/Ydwin, post-BOW. ⯈ AO3 ⯈ Tumblr

serendipity: Kit/Edér, late Deadfire. ⯈ AO3 ⯈ Tumblr

strike the sky until the sun bows: Kit & Waidwen, late Deadfire. ⯈ AO3 ⯈ Tumblr

swan song: Kit & Hylea, post-Deadfire. ⯈ AO3 ⯈ Tumblr

lightmonger: Kit, Bekarna, & Onekaza, post-Deadfire. ⯈ AO3  ⯈ Tumblr

tactical meld: Kit & party vs. Kit’s mentor, post-Deadfire. ⯈ AO3

better days: Kit/Edér ficlets spanning both games. Prompts from the Bad Things Happen Bingo. ⯈ AO3 ⯈ Tumblr: Hallucinations, Bedside Vigil, Taking The Bullet, Came Back Wrong, Migraine, Hidden Scar, Insecurity, Mind Control, Outnumbered In A Fight

All fics focused on a Deadfire / post-Deadfire AU in which a piece of Eothas remains with the Watcher: from ruin: Kit & Abydon, ft. Modwyr, early Deadfire. ⯈ AO3 ⯈ Tumblr better days: Kit/Edér, for the Bad Things Happen prompt “Came Back Wrong.” ⯈ AO3 ⯈ Tumblr axis of revolution: Kit/Eothas, across Deadfire. ⯈ AO3 ⯈ Tumblr apsides: Kit/Eothas, post-Deadfire. ⯈ AO3 ⯈ Tumblr syzygy: All other oneshots in this AU. ⯈ AO3 ⯈ Tumblr: Kit/Eothas (poetry prompt), Kit/Eothas (prompt: stars or space), Edér/Eothas, Kit/Eothas

Tumblr prompts: ⯈ Young Kit: For the prompt “green.” ⯈ Kit/Edér: For the prompt “waiting impatiently for something.” ⯈ Kit and cipher powers: For the prompt “each with his own weapon.” ⯈ Kit/Edér: For the prompt “empty.” ⯈ Kit/Edér: For the prompt “petrichor.”

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Watcher Hakona

when you see him, look him in the eye: Hakona’s early life, and relationship with Magran and Rymrgand, pre-POE 1. ⯈ AO3 ⯈ Tumblr

scattered faith: Hakona & Edér, mid-POE 1. ⯈ AO3 ⯈ Tumblr

Tumblr prompts: ⯈ Hakona & Pallegina: For the prompts “subtle kindness” and “a flash of anger.” ⯈ Hakona & her mother: For the prompt “coming home.” ⯈ Hakona, the Steward, Adaryc, and swords: For the prompt “the sword which was a sword once in another grasp.” ⯈ Hakona & Sagani: For the prompt “And what remains when disbelief has gone?” ⯈ Hakona/Xoti: For the prompt “harsh whisper.” ⯈ Hakona & the Bleak Walkers: For the prompt “monachopsis.”

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Watcher Jordan

Tumblr prompts: ⯈ Jordan/Aloth: For the prompt “accursed.”

[adraveins]

orthodrome (3 / 3)

➸ The Watcher, Edér, Eothas ➸ 7k ➸ AU, canon divergence ➸ Chapter 1 // Chapter 2 // Chapter 3

The figure blazes before you, faceless and still. You blink and blink again, afterimages of the sickle and lantern imprinting on your eyelids and vanishing, and there is more sorrow than gladness filtering through the parts of his mind that you can touch. I would rather have you hate me than need me, Edér.

You feel the way the words strike at Edér like a blow, but he doesn't pull back. He stares unflinchingly at the light, his mouth set in an angry line. "Well," he says, his voice low, "you've done a pretty good job of getting folks to hate you. But that's the thing." His steadying breath isn't so steady. "I don't." His voice trembles with the admission. "I don't even know how to. I wish I did, believe me."

You don't think he wants that. You think he just wants to hurt Eothas even a fraction as much as Eothas has hurt him, in the only way he can.

But the full weight of that isn't easily grasped by a god, you think, even a well-meaning one like Eothas. That mortals dare and defy, pray and persist, just to see a reaction, and one on their level, not on a god's. It means more than the grandest gestures, and it's power too, in its own way, that evens the footing by a margin. You know that Edér wants to see it in Eothas, and you know that Eothas won't give it to him, that his patience and understanding is a double-edged sword. And Edér has no cipher's senses that let him feel a sliver of it anyway.

There’s something underneath the keep. The Watcher is sure of it. // AO3