HELP identifying arrhythmia on ECG

RE: HELP identifying arrhythmia on ECG

Anthony Todd — Thu, 31 Oct 2019 12:56:08 GMT

I always found it helpful when ECGing horses to move the front or rear legs [or the horse did!] if I wanted to get a better trace [or bigger amplitude] for the standard limb leads, especially when looking for PR interval re first degree heart block.

I suppose everyone does this in dogs when trying to find small amplitude P waves, particularly in AF?

RE: HELP identifying arrhythmia on ECG

Roger Wilkinson — Sun, 27 Oct 2019 21:44:53 GMT

Always more stuff to know isn't there! I hadn't ever come across an AF that fast but, having spent a few minutes trawling t'internet, fastest I can find (anecdotal) is 320bpm.

This is also potentially relevant:

https://www.ncbi.nlm.nih.gov/m/pubmed/30797441/

Let us know outcome if poss

RE: HELP identifying arrhythmia on ECG

Tassadar — Sun, 27 Oct 2019 08:13:37 GMT

Thank you for your insight and reply Dave, and everyone else who responded. It certainly makes things more clear on how to approach these complicated cases.

RE: HELP identifying arrhythmia on ECG

Dave Dickson — Sat, 26 Oct 2019 22:25:46 GMT

One more for SVT, though I'm going to throw it out there that this could be very rapid AF. It's hard to be sure at this rate and paper speed, but I think the RR intervals are irregular and I don't see consistent P-waves. The QRS looks wide which could be just some cardiomegaly or delayed conduction. There are a couple of wide-complexes which could be ventricular or Ashmans. So - treatment. A nightmare choice. I agree with Roger, we need to get info about the case to decide on if there is CHF present. If there is, treat that first. If the rate stays this fast then I'd try either IV lidocaine or oral diltiazem (2mg/kg). You could also do a vagal manoeuvre to see if you can break this. If you can break back into sinus then that (pretty much) excludes AF. Long-term meds depend on what is actually going on but most SVTs respond to diltiazem. Some need other meds too. Sotalol is not a bad choice but if the LV systolic function is poor then it could worsen the CHF and dramatic reductions in HR aren't always ideal. The bottom line is - this is a tricky ECG. Ideally, get some more ECG recorded at a faster rate to see if we can see more of the rhythm. Or treat the primary problem and hope the arrhythmia starts to settle. Dave

RE: HELP identifying arrhythmia on ECG

Roger Wilkinson — Sat, 26 Oct 2019 21:58:48 GMT

I'd agree likely SVT. p waves presumably buried somewhere in the QRST.

Potential causes many and various: both cardiac and non-cardiac.

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1476-4431.2008.00346.x

it would be useful to establish if the dog has L CHF and, for that, lung ultrasound would be useful and simple to carry out.

beyond that an echocardiogram and abdo ultrasound plus abdo fluid analysis would obviously be useful.

lidocaine infusion would probably be my choice to try control the arrhythmia in the short term.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1939-1676.2006.tb02856.x

good luck

Roger

RE: HELP identifying arrhythmia on ECG

Beats — Sat, 26 Oct 2019 20:41:20 GMT

This primarily looks like SVT to me, with some ventricular complexes mixed in (e.g. on top picture the beat under the "254", or in the bottom picture, the last beat that can be seen on all lines on right).

In a german shepherd, maybe don't rule out extracardiac causes of ahhythmia (eg be sure that ascites is cardiac ascites and not hemoabdomen from bleeding spleen or something.

Otherwise, I guess at 300/minute [and assuming this is sustained arather than transient] that will be a significant enough arryhtmia to treat alongside any primary cardiac disease as can't imagiine ventricles filling well. If it's chronic, then you probably have time to seek some further assistance/advice, otherwise I would wonder re pimobendan/furosemide [assuming fairly convinced that ascites is due to right-sided CHF rather than abdominal cause...] and sotalol or low-dose bisoprolol/atenolol/propranolol [NB: with any of the latter I believe that beta=blockers can technically decrease cardiac output - in practice I'm not sure I think this is important with hemodynamically significant tachyarrhythmia] or lidocaine (somewhat short-term benefit to infusion, so I woudln't bother unless thought life-threatening for some reason; in old days I would give this dog mexilitine but that will not be of much help to you tonight!]

If you can wait, then there are posters with much better cardiac knowledge who might be along.