Tachyarrhythmia Case

[waterski232002]

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76 yo F with Hx of HTN comes in c/o palpitation and feeling like she's going to pass out. She experienced intermitent palpitations for the past 3 wks usually associated with her smoking cigarettes. They only lasted a few minutes to a maximum of an hour until this morning. She denied any CP, SOB, N/V. Her initial ER vitals were 36.8 91/45 178 20 98% RA.

Her initial EKG was interpreted as SVT (regular rate/rhythm, narrow complex). Vagal maneuvers failed. She was given adenosine 6 mg with no response. Adenosine 12 mg was given and she broke with p-waves running through. Her ventricular rate for the first 3 minutes after the bolus was 20-30 and then it rose to a HR of 115.

Repeat EKG was interpreted as Sinus Tach. 20 minutes later, the nurse called over and said she was back in SVT again at 178. Adenosine 12 mg was given again and my attending interpreted the breakthrough p-waves as flutter waves (but they were definitely p-waves, and not the saw-tooth flutter waves I generally associate with A-flutter). Her HR remained 178, so we gave amiodarone 150 and started a gtt which slowed her to about 100. Medicine interpreted the EKG's as possible SA nodal re-entry with an atrial rate of 180 vs an ectopic atrial escape rhythm.

So... my questions:

1) Would you have done anything differently?

2) In a patient with SVT (ie AVNRT or orthodromic AVRT) do you generally see p-waves during the pause after giving adenosine IVP?

3) What do you usually see during the pause if the patient is in A-fib or Flutter? I assume it's just fibrillation in A-fib, and flutter waves in A-flutter.

 

[basementbeast]

i often see flutter waves running for a few seconds (which often makes the diagnosis if i couldn't tell beforehand)....

 

[Halaljello]

why amio? why not dilt or lopressor first since you're thinking aflutter?

 

[waterski232002]

Because the patient was boarderline hypotensive... her repeat systolic pressures were consistently between 80 - 100.

 

[kungfufishing]

nm

 

[basementbeast]

i think amio was ok...it can cause hypotension too....i think IVFs, calcium, and gentle dilt would have been ok too....

 

[NinerNiner999]

1) Even if they look like P-waves, with a rate of 178, I would think the flutter would be more likely. Agree with above concern for hypotension. Were you running IVF? I would have given a round of Diltiazem (20mg) first and watched BP. Ibutilide is another reasonable drug. Hypotensive fib/flutter is very fluid dependent, and if there isnt a response to what you did, plus the above, I would actually entertain the possibility of a PE vs. MI.

2) If you are dealing with a re-entrant tachycardia (AVNRT, etc) you should see p waves after giving adenosine (which can convert to sinus by itself). If you don't see these clearly, you are likely dealing with flutter/fib.

3)If you are dealing with flutter, the flutter waves can be obvious. If you are seeing fibrillation with QRS complexes, then you are likely dealing with atrial fib. If you are seeing V-fib, you should have probably given procainamide for WPW and you should be ready to shock...

 

[gutonc]

1) Even if they look like P-waves, with a rate of 178, I would think the flutter would be more likely. Agree with above concern for hypotension. Were you running IVF? I would have given a round of Diltiazem (20mg) first and watched BP. Ibutilide is another reasonable drug. Hypotensive fib/flutter is very fluid dependent, and if there isnt a response to what you did, plus the above, I would actually entertain the possibility of a PE vs. MI.

2) If you are dealing with a re-entrant tachycardia (AVNRT, etc) you should see p waves after giving adenosine (which can convert to sinus by itself). If you don't see these clearly, you are likely dealing with flutter/fib.

I ran into a similar situation 2 wks ago. 45yo CP/MR w/ a family who was @ bedside but not much more helpful than the non-verbal patient (they mostly wanted to tell us about the bearded man who molested her 30y ago but had no idea what the meds they gave her were or what they were for..."she takes a pink pill, two blue pills and 3 white pills at night").

PSVT in the ED, broke w/ adenosine and controlled w/ IV and PO metop until she hit the floor. An hour after coming to the floor she's back in SVT. Gave adenosine again (6 then 12mg) and broke both times (w/ clear P waves) but right back in to SVT in less than 10 min, even w/ more BB on board. Gave dilt 20mg IVP then verapamil IVP (don't remember the dose since at this point CCU fellow was on board and I was just following along) x2 w/o conversion. Finally got a CCU bed (still in SVT, now for >5h, VS stable) and sent her over. Turns out she had a huge saddle embolus. Finally converted in the CCU w/ a dilt drip (which was headed to the floor when I sent her to the unit) and got rx'd w/ heparin.

Good times.

 

[Painter1]

1) Even if they look like P-waves, with a rate of 178, I would think the flutter would be more likely. Agree with above concern for hypotension. Were you running IVF? I would have given a round of Diltiazem (20mg) first and watched BP. Ibutilide is another reasonable drug. Hypotensive fib/flutter is very fluid dependent, and if there isnt a response to what you did, plus the above, I would actually entertain the possibility of a PE vs. MI.

2) If you are dealing with a re-entrant tachycardia (AVNRT, etc) you should see p waves after giving adenosine (which can convert to sinus by itself). If you don't see these clearly, you are likely dealing with flutter/fib.

about seeing p waves after adenosine, i'm confused, i thougth that with adenosine if it wasn't svt but for example a sinus tachy, adenosine could transiently slow the rythm to see p before every QRS.

 

[WilcoWorld]

Great point that failure of a flutter / fib / svt to respond to conventional measures should raise the suspicion of PE.

As for the case of the 45 yo with a PE who was given metoprolol, diltiazem, and verapamil... I would be VERY careful when mixing all those drugs as it could cause some serious block and or hypotension. The fact that you had a cardiology fellow at the bedside suggests that you were respectful of the seriousness here, but I just wanted to make that point clear.

 

[waterski232002]

Great point that failure of a flutter / fib / svt to respond to conventional measures should raise the suspicion of PE.

As for the case of the 45 yo with a PE who was given metoprolol, diltiazem, and verapamil... I would be VERY careful when mixing all those drugs as it could cause some serious block and or hypotension. The fact that you had a cardiology fellow at the bedside suggests that you were respectful of the seriousness here, but I just wanted to make that point clear.

I agree with that point... I would use adenosine, then either a CCB or BB, but not both (and not 2 types of CCB). You've got a bigger problem if you induce a 2nd or 3rd degree heart block. If a bolus didn't work, then the next step in my mind would be a CCB or BB gtt of whatever you were bolusing. If there were BP issues, then I'd just skip straight to an agent to convert the rhythm... like amio

 

[waterski232002]

1) Even if they look like P-waves, with a rate of 178, I would think the flutter would be more likely. Agree with above concern for hypotension. Were you running IVF? I would have given a round of Diltiazem (20mg) first and watched BP. Ibutilide is another reasonable drug. Hypotensive fib/flutter is very fluid dependent, and if there isnt a response to what you did, plus the above, I would actually entertain the possibility of a PE vs. MI.

2) If you are dealing with a re-entrant tachycardia (AVNRT, etc) you should see p waves after giving adenosine (which can convert to sinus by itself). If you don't see these clearly, you are likely dealing with flutter/fib.

3)If you are dealing with flutter, the flutter waves can be obvious. If you are seeing fibrillation with QRS complexes, then you are likely dealing with atrial fib. If you are seeing V-fib, you should have probably given procainamide for WPW and you should be ready to shock...

Thanks for your input NinerNiner999...
A liter of NS was being infused while we were getting the EKG's and pushing the adenosine. The problem with identifying the underlying rhythm immediately after giving adenosine was that I was watching the monitor (and not the EKG rhythm strip which has a rate calibration). Because I used the monitor, all I could see were p-waves, and I didn't know the rate was 178. A-flutter should have revealed flutter waves at a rate of 300... this is why cardiology finally agreed it was an ectopic atrial escape rhythm (the underlying p-wave rate was too slow for flutter). Plus, on repeat EKG, the p-waves were inverted in the inferior leads, which indicated it was not coming from the sinus node (thus, not a SA Nodal re-entry).

 

[NinerNiner999]

Cool case. What was the outcome? Did they get an EP study?

 

[gutonc]

I agree with that point... I would use adenosine, then either a CCB or BB, but not both (and not 2 types of CCB). You've got a bigger problem if you induce a 2nd or 3rd degree heart block. If a bolus didn't work, then the next step in my mind would be a CCB or BB gtt of whatever you were bolusing. If there were BP issues, then I'd just skip straight to an agent to convert the rhythm... like amio

I should point out that all of this was done on a medicine floor that, while it has tele and can do drips (but not titrate them) it doesn't have much more than dilt and metop IV in the pyxis. The timing of all of this wasn't clear in my post either, this stuff didn't happen in a 30 minute period, more like over 4 hours and the metop and dilt were spaced by at least 2h w/ the verap coming an hour or so after the dilt push. Drips were next on the list and were ordered but take about an hour to come up from the pharmacy and by the time it came, I was back from transferring the pt to the CCU.

By the time I'd done adenosine x2 and metop and dilt x1 each I was at the outer limit of my comfort zone w/ cardioactive meds in an "asymptomatic" pt (remember from the beginning that this pt was non-verbal and the combined IQ of the other family members in the room was just barely pushing 100 so figuring out how symptomatic she was, was tough, particularly given her rock-solid stable O2 sats of 98% on RA and SBP in the 100-110 range even w/ the meds on board) so I'd already touched base w/ cards twice and had the fellow over to review the EKG tracings.

Not really trying to defend myself here. The main thing was that I learned something I had probably read or heard but hadn't actually seen - recalcitrant SVT may be a PE - and for that reason, it will stick w/ me.

 

[waterski232002]

There's no right answer... I think the important thing is to take away the fact that there are multiple ways to skin a cat. We all have our own preferences and as long as you recognize the pro's and con's of what you're doing, then you're a safe doc (for the most part).

Ninerniner999.... The last I caught wind of from the cards team was that they were getting an EP consult for possible radiofrequency ablation. They ended up stopping my amio gtt on the floor and converting her to metoprolol IV, then PO, after she re-entered a sinus rhythm and her pressures stabilized in the 120's.

 

[Jeff698]

The question of what type of atrial activity pops up after adenosine is important. It is also helpful to have the best information available to answer it.

That's why I always have the ECG tech running a continuous 12 lead as I push adenosine or cardiovert. 12 leads are better than 1. 🙂

Take care,
Jeff