Atrial fibrillation in a bleeding dog

Re: Atrial fibrillation in a bleeding dog

Thomas Johnson — Fri, 24 Jun 2011 15:56:00 GMT

I once saw a dog for episodes of collapse, ECG showed runs of VPCs, eventually turned out to have a nasal tumour.

Re: Atrial fibrillation in a bleeding dog

Charlotte Marshall — Fri, 24 Jun 2011 06:53:46 GMT

1 week post op after a day off digoxin heart sounded fine so I will keep my fingers crossed for the future. I shall definately remember this next time I see a dog with an arrythmia!

Re: Atrial fibrillation in a bleeding dog

Evelyn Barbour-Hill — Thu, 16 Jun 2011 02:48:32 GMT

[quote user="Richard Fox"]

I whole heartily agree Alex - a pathologist can never have too much tissue

[/quote]

Second helping of treacle pud for you then

Re: Atrial fibrillation in a bleeding dog

Richard Fox — Wed, 15 Jun 2011 20:11:24 GMT

I whole heartily agree Alex - a pathologist can never have too much tissue

Re: Atrial fibrillation in a bleeding dog

Mike Martin — Wed, 15 Jun 2011 16:38:23 GMT

[quote user="alex gough"]If you can post the ECG[/quote]

Knowing if the ECG shows AF or VPCs would be useful.......

Re: Atrial fibrillation in a bleeding dog

Alex Gough — Wed, 15 Jun 2011 16:29:22 GMT

We do have a bit of a running joke in our practice that histopathologists will always say a sample size is too small unless you submit the whole organ. Only teasing Richard!

Re: Atrial fibrillation in a bleeding dog

Michael Woodhouse — Wed, 15 Jun 2011 16:25:31 GMT

[quote user="Richard Fox"]Did you sent the liver off for histo [/quote]

That would lead to a rather untimely death - no?

[maybe the most accurate prognosis a pathologist would give ]

Re: Atrial fibrillation in a bleeding dog

Alex Gough — Wed, 15 Jun 2011 13:39:57 GMT

If you can post the ECG would be interesting. Very common, as mentioned above to get ventricular arrhythmias with splenic tumours, I always scan the abdomen with any ventricular arrhythmia on ECG. Depending on which lead you are looking at, trace speed, degree of artefact, and left or right ventricular origin of the VPCs, I can see how it would be possible to think a ventricular tachycardia is an AF. AF is almost always associated with a large left atrium, either pathologically or due to large size of animal (wolfhounds, horses), so it would be unusual to go into AF from a splenic tumour if the left atrium was not enlarged.

Mike Martin might pop by and comment at some point if we are lucky too.

As for mechanism, last I read was that the arrhythmias are related to release of myocardial depressant factor from the compromised spleen

Alex

Re: Atrial fibrillation in a bleeding dog

Richard Fox — Wed, 15 Jun 2011 09:19:00 GMT

Did you sent the liver spleen off for histo - in my experience these lesions can have a variable aetiology (myelolipoma, nodular hyperplasia, infarcts, idiopathic as well as HSA etc) thus would be good for the long term? I asked about whether the heart had been imaged? As said above there have been a few posts in vetsurgeon about these arrhythmias with splenic disease but I would also want to exclude a atrial lesion as well?

Re: Atrial fibrillation in a bleeding dog

Charlotte Marshall — Tue, 14 Jun 2011 23:30:14 GMT

[quote user="phipps"]

What were the ECG findings that led to the diagnosis of atrial fibrillation (normal QRS complexes, absence of an identifiable P wave, variable R-R intervals?). Do you have traces of the ECG that you could post?

[/quote]

At home so I do not have the trace which was done by a colleague and I only had a quick squint at it. As I recall it was no recognisble P waves and variable R-R intervals. Auscultation certainly sounded like a typical atrial fib a bit all over the place only slower than usual for atrial fib. What was assumed to be the QRS complexes were narrow and sharp but negative in lead II assumed to be due to right shift.

Unfortunately chest radiographs or ultrasound were not performed at this stage.

After surgery auscultation did not sound like a typical atrial fib more like just getting a few ectopic beats. My colleague examined the dog this morning before discharge and said it was similar but more tachycardic.
However given everyones comments I am going in tomorrow to recommend we take the dog off the digoxin he prescribed, I was inclined to wait but he was worried by the increased tachycardia.

I am surprised that neither of us had come across a splenic mass dog with arrhythmia before if it is a known complication - just lucky I guess!

Re: Atrial fibrillation in a bleeding dog

Richard Fox — Tue, 14 Jun 2011 09:49:25 GMT

Is there any evidence of a concurrent atrial HSA?

Re: Atrial fibrillation in a bleeding dog

Glen McIntosh — Mon, 13 Jun 2011 23:08:20 GMT

Arrhythmia is a relatively common finding with splenic disease and also haemangiosarcoma situated not only at the spleen but also at other sites (though not pathognomonic). The type of arrythmia seen with these diseases tend to be ventricular premature contractions and ventricular tachycardia, rather than a supraventricular tachycardia that is associated with atrial fibrillation. The mechanism causing arrythmia in splenic disease/heamangiosarcoma is not well understood.

You noted pulse deficits prior to surgery (HR 180, PR 130). The presence of pulse deficits is more suggestive of VPCs/ventricular tachycardia than supraventricular tachycardia.

For VPC's and ventricular tachyarrhythmias associated with splenic disease/haemangiosarcoma, specific treatment with antiarrhythmics is usually not necessary, unless the animal is showing signs of forward heart failure/hypoperfusion because of the arrhythmia. These arrhythmias usually resolve spontaneously in 3-4 days post surgical correction of the initial problem.

Fluid overload is an unlikely cause of cardiac arrhythmia. Hypovolaemia would be much more of a concern as an exacerbating factor of cardiac arrhythmia in an animal that has bled into its abdomen.

Re: Atrial fibrillation in a bleeding dog

Martin Jones — Mon, 13 Jun 2011 23:02:57 GMT

I seem to remember a discussion before on this topic, coming from the other direction - more a 'why has this dog got arrhythmia, ooh look - a splenic mass'.

Not to be the voice of doom, but don't discount heart base tumour. By this stage would be likely to have caused clinically significant effusion in any case, and would probably have shown up on the ECG. Any rads?

But to echo other comments, these often do self-correct after a few days. I always worry that I'm missing some weird acid-base-electrolyte-blood gas-haemodynamic-coronary vasculature-proinflammatory effect, but by the time I've thought it all through, dog is ready to go home (or in heaven)

Re: Atrial fibrillation in a bleeding dog

Andrew Kent — Mon, 13 Jun 2011 22:46:31 GMT

It is not unusual to see a variety of arrhythmias after splenectomys and on the whole they resolve within a few days of surgery. It is important to monitor blood pressure and ensure this is not affected by the abnormal periods. I'm sure there are some cardiologists lurking that can give you more details! Andy

Re: Atrial fibrillation in a bleeding dog

Michael Woodhouse — Mon, 13 Jun 2011 22:44:30 GMT

I don't know the mechanism but spleens do cause that sometimes. In my limited experience they have usually resolved by stitches out!