Atrial Fibrillation in a GSD

Re: Atrial Fibrillation in a GSD

Fiona French — Fri, 15 Apr 2011 19:39:54 GMT

I saw him again today. The heart rate is 180 and his pulses are quite strong now, and his owner thinks that the heart rate is slower when at home and is going to try to count it by feeling the apex beat. He has stopped coughing and is keen to go on walks and seems like he always used to, so owner is really pleased.

I have added in vetmedin, but not prilactone yet as the owner is already confused with all the pills and would like to add one at a time! The owner will check his insurance limit and decide if referral is an option, as he does not want to spend most of the money on referral fees and leave nothing for the medication, understandably.

Many thanks fof the advice from everyone, especially Mike. You have given me the confidence to be able to manage this case if the owner chooses against referral. This forum is great!

Re: Atrial Fibrillation in a GSD

Mike Martin — Fri, 15 Apr 2011 14:31:58 GMT

[quote user="Fiona Dale"]or just add in the vetmedin and prilactone and see how he responds to that[/quote] That's what I would do first.

[quote user="Fiona Dale"]If the heart rate is still at 200 should I add in something else to try to reduce the rate [/quote] There's mixed opinion on this subject, some cardiologists are keen to get rate control and commonly add diltiazem. A few are less so - which is the view I have.

I'm concerned that an in-clinic HR does not represent the heart rate at home. So whilst the 'conventional wisdom' is to control AF to a HR <150-160/min - how do we establish this?

An elevated HR in-clinic?
The mean HR from a 24 hr Holter at home?
An owner taking resting HR at home?
A pet HR monitor which the owner can use?

So for HR control of AF I tend to follow the philosophy "treat the dog, not the test". So if he is on all cardiac meds and HF is controlled and the dog is well & happy - then ignore the HR! If it does seem too high, try to measure it at rest at home, by some means.

Finally, there is a nice paper in humans to show strict HR control had no benefits over lenient HR control in AF. http://www.nejm.org/doi/full/10.1056/NEJMoa1001337 [quote user="NEJM"]In patients with permanent atrial fibrillation, lenient rate control is as effective as strict rate control and is easier to achieve.[/quote]

Re: Atrial Fibrillation in a GSD

David Mills — Fri, 15 Apr 2011 01:11:02 GMT

Chasing heart rates in my experience can be costly and frustrating, and sometimes a false end-point - ask yourself what rate are you aiming for/would be happy with? Having the owners measure it at home (right owners required) through chest palpation can be really useful, or even a holter recording if insured (can hire for around £200 including interpretation, really easy to use in big dogs) - see www.holtermonitoring.co.uk over 24 hours.

As covered expertly above, large LA = likely MVD. Vetmedin a fantastic beast. Generally control primary disease (CHF) and worry above rate afterwards. Remember ACEi can take 7-10 days to reach peak efficacy.

Sounds like a great work up so far.

Re: Atrial Fibrillation in a GSD

Fiona French — Thu, 14 Apr 2011 17:23:56 GMT

Many thanks for that Mike, much appreciated.

I am seeing the dog again tomorrow, so will post an update after that. If the heart rate is still at 200 should I add in something else to try to reduce the rate further, or just add in the vetmedin and prilactone and see how he responds to that?

Re: Atrial Fibrillation in a GSD

Mike Martin — Thu, 14 Apr 2011 14:42:55 GMT

[quote user="Fiona Dale"]weak pulses and a heart rate too fast to count prompted me to run an ECG, which revealed a heart rate of 240 and atrial fibrillation.[/quote] [quote user="Fiona Dale"]Chest radiographs showed an enlarged heart shadow and some pulmonary oedema. [/quote] Good, you've got the diagnosis of CHF + AF

[quote user="Fiona Dale"]The left atrium was certainly very large, but the left ventricle seemed to have fairly normal contractility. There was no pericardial effusion, but a small volume pleural effusion.[/quote] Excellent, ruled out pericaridal effusion (some CHF cases can have a 'small' pericardial effusion, ie. less than 2-3mm), ruled in a BIG left atrium. If LV contracts normal - then likely MVD. So again, well done.

[quote user="Fiona Dale"]I have started the dog on frusemide, fortekor and digoxin.[/quote] Excellent, I would do the same and also add Vetmedin, even if he is a MVD case. And would also add Prilactone.

[quote user="Fiona Dale"]So far his heart rate has decreased to approx 200 and he is brighter and coughing less. [/quote] Good result.

I would agree, referral to Mark Patteson is a good option and he goes to a clinic near you. And if the owners can't afford the cost of referral, a cheaper option would be send him the ECG, x-rays and some echo-movies for interpretation.

To summarise.... I think you've done a great job, I've only suggested small tweaking. How's the dog responding now?

Re: Atrial Fibrillation in a GSD

Arlo Guthrie — Wed, 13 Apr 2011 16:55:57 GMT

[quote user="Fabian Kaelin"]Hi Fiona,

Mark Patterson is a very good cardiac referral option in the Plymouth area. He works certain days at South Devon Referrals in Newton Abbot and at A30 Referrals near Newquay. He's also on vetsurgeon.org so you can check his profile.[/quote]

Just what I was thinking. Here's his profile: http://www.vetsurgeon.org/members/heartvetconsultants/default.aspx

Incidentally, referral practitioners from all different disciplines can be found on the 'Find Colleagues' page (under 'Community' at the top). Just select the discipline from the drop-down list adjacent to 'find members by type'.

Re: Atrial Fibrillation in a GSD

Fabian Kaelin — Wed, 13 Apr 2011 16:34:51 GMT

Hi Fiona,

Re: Atrial Fibrillation in a GSD

Martin Atkinson — Wed, 13 Apr 2011 12:36:37 GMT

Apart from the above suggestions, do a NTproBNP to help rule in/rule out cardiac disease as a cause of the cough. If it is cardiac disease then I would use Vetmedin regardless of whether you can make a diagnosis of DCM and once the CHF is controlled if there is still AF after digitalisation a beta blocker may be useful, finally quinidine or Verapamil I've used successfully in the past.

Re: Atrial Fibrillation in a GSD

Emma Middleton — Wed, 13 Apr 2011 10:08:28 GMT

Have you ruled out lungworm? Apparently increasingly common in UK and I think many cases shed larvae in faeces. However cannot rule it out on a faecal sample, and may need BAL to look for larvae there. May be worth doing faecal analysis before referral if dog is stable?

Re: Atrial Fibrillation in a GSD

Glen McIntosh — Tue, 12 Apr 2011 22:59:08 GMT

You could use diltiazem to decrease heart rate - it slows conduction via the av node and seems to be recommended in many texts as the first line method of reducing tachycardia in atrial fibrilation. You can use it in combination with digoxin. The aim would be to get the heart rate below 160.

I can't see a problem with using vetmedin. Is there a murmur in this dog?

But if the dog is insured and if you (like me) do not have lots of experience and training in echo and therefore cannot reliably and repeatably measure fractional shortening etc, then I would definitely refer ASAP - because you have done as much as you can do and a cardiologist/diagnostic imager might well be able to obtain a diagnosis, or at least narrow down the differential list.