Thread by @sargsyanz

There’s a bit of a loophole in the ACLS protocols that allows afib at its worst to get away with murder.

Let’s look at two scenarios and vote about a #cardioversion decision.

#Tachyarrhythmia #tweetorial

1/7

Scenario/poll 1:

70 yo, has severe aortic stenosis, admitted with pneumonia. She was eating dinner -> suddenly complained of palpitations then became unresponsive.

Preceding: BP 98/67, HR 90 in sinus.

Now: BP 48/30, HR 180s in a-fib, pulse very thready but palpable.

Do you:

Scenario/poll 2:

Same patient and history: severe aortic stenosis, admitted w pneumonia, sudden palpitations -> unresponsiveness.

VS earlier: BP 98/67, HR 90 in sinus.

Now: BP cuff not reading, HR 180s in a-fib, no convincing pulse.

Do you:

Let’s think through what happened here. She was preload dependent (AS) and vasoldilated, but hanging in there. Suddenly flips into rapid AF. Loss of atrial kick + very short diastole -> preload & stroke volume tank -> shock. Drastic clinical change from an acute arrhythmia.

4/7

The difference between the scenarios: in 2, hemodynamics were even more compromised by the arrhythmia, and BP was so low as to not register a cuff reading or pulse.

But in both cases, the afib is killing her, and if we get her into sinus, she can finish dinner. Cardiovert!

5/7

But: within ACLS, there’s a big distinction.

Scenario 1 is unstable tachyarrhythmia: cardiovert.

Scenario 2 is PEA: give epi (and do CPR of course, appropriately). But don’t treat the rhythm because it’s not VF/VT.

It really seems like we should...

Can’t wait to hear thoughts from #medtwitter, but two safe take-aways:

- In low-preload or preload-dependent states, flipping into rapid afib can dramatically worsen hemodynamics
- It’s hard for any protocol or guideline to include/be right for every patient

7/7

@goosecoid @MKIttlesonMD @docHJ @EM_RESUS @CPSolvers @criticalecho @ddefariayeh #cardiotwitter