Friday, August 19, 2011

EKG Du Jour #22: A Rare Classic

I offer this gem to the EKG enthusiasts out there to ponder. It's not every day we find a 12-lead EKG of this from a post-operative patient with an ischemic cardiomyopathy:

Click image to enlarge
-Wes

14 comments:

godsfshrmn said...

Hopefully this EP rotation has paid off... Is it Ashman phenomenon?

Anonymous said...

Bi-directional VT = dig toxicity?

Anonymous said...

BI-directional VT concerning for dig toxicity

Jonathan said...

Junctional rhythm with bigeminy?

Anonymous said...

Nice catch on all leads!! (of bidirectional VT..)

Anonymous said...

Definitely bigeminal rhythm. width and morphology suggest a RBBB, axis appears normal. Inverted T-waves in inferior and precordial leads suggestive of ischemia.

casey said...

hmm. ugly, for sure! i don't think it's ashman's due to regularity; i'm inclined to go with a bigeminal junctional rhythm of sorts. as for VT, is the rate too slow to be considered VT?

can't wait to find out!

casey said...

hmm. i'm inclined to go with a bigeminal accelerated junctional rhythm. ashman's doesn't seem right due to the regularity of the rhythm...as for VT, isn't the rate too slow? just curious and my 2 cents.

can't wait to find out the answer.

Gilles Delmiglio said...

Bidirectional VT. Too old for Catecholaminergic Polymorphic Ventricular Tachycardia, so prob. digitalis toxicity or reentry?

Anonymous said...

Nice catch in all leads! (of bidirectional VT..)

Anonymous said...

Gonna say sinus rhythm RBBB rate around 100 using large block method with PVC's in bigeminny. I see P waves in lead I and AVF (zoom in)

Steve Smith said...

Looks to me like bidirectional tachycardia. This is a regular rhythm, so cannot be atrial fibrillation. Ashmann's phenomenon happens mostly in atrial fib or with premature atrial contractions. It happens if a beat comes directly after a previous long R-R interval; the refractory period after this long R-R interval is prolonged, and so the next beat, though supraventricular (a fib or PAC), is aberrant. These are all wide and regular beats but with alternating axes.

Steve Smith of Dr. Smith's ECG Blog

Steve Smith said...

By the way, I have posted another example of bidirectional tachycardia here: http://hqmeded-ecg.blogspot.com/search/label/bidirectional%20tachycardia

Steve Smith

DrWes said...

Congrats to all of you who recognized the regular wide complex rhythm with alternating axes which define bidirectional ventricular tachycardia. (Yes, it truely is a regular rhythm - print it out to see).

Of interest, this patient was NOT on digoxin. Note that both QRS morphologies seen in this tachycardia have a RBBB morphology (predominant R wave in V1) suggesting this arrhythmia arose from the left ventricular chamber.

The mechanism of this arrhythmia is controversial. Many <a href="http://content.onlinejacc.org/cgi/content/full/54/13/1189>believe</a> the rhythm is an automatic or triggered arrhythmia from two locations in separate portions of the distal conduction system (e.g., the left anterior and left posterior fascicles). Reentrant mechanisms have been proposed as well but the usual inability to overdrive pace this arrhythmia makes many feel the arrhythmia is more likely a triggered phenomenon.

In this patient's case, these tracings were recorded after the patient was placed on dobutamine for reduced LVEF (estimated EF 24%) following a transmyocardial laser revascularization procedure via a thorocotomy approach. Discontinuation of dobutamine helped decrease the frquency of the arrhythmia, but did not completely control it. Low-dose beta blockers and (later) Amiodarone were eventually successful at maintaining sinus rhythm.