From:
Pam Sessoms
Date: 2003-04-17 16:42:36 UTC
Subject: 3rd degree heart block - another case
To: ferrethealth@smartgroups.com
Message-ID: <Pine.A41.4.44+UNC.0304171237480.37040-100000@login7.isis.unc.edu>
I wanted to get another interesting case involving 3rd degree av heart
block into the archives. I apologize in advance for the long post. As
background, this problem is not a physical blockage in the heart but
rather is the a problem with electrical conductivity. It is graded on a
scale of 1 to 3, with 3 being the worst, and conventional wisdom says that
3rd degree heart block requires a pacemaker. We already have a few cases
in our archives; a good query to use at http://fhl.sonic-weasel.org/ is:
heart and block and (3rd or third)
ANYWAY. Last Wednesday morning, I found one of my girls, Cricket, in
shock. She didn't report for morning gravy, and I went looking for her.
She was cold with a temperature in the low 90's, was breathing fast and
shallow, and most alarmingly, her heart was beating very slowly - around
40-50 beats per minute. I called my vet, treated her for shock as best as
I could at home, and hit the road. Her "known" problems are stable
insulinoma and a mass on her liver (biliary cystadenocarcinoma - this
particular one is inoperable). I could not get a blood sugar; the blood
in her feet was black and thick. She did take some nutrical and a good
bit of gravy, though.
Once at the vet, an ECG was done, revealing 3rd degree av block with an
escape rhythm and occasional bigemini. Thanks to the earlier messages
here about ferrets with this problem, and how sometimes they mysteriously
reverse and in other cases do well for a good while with drug therapy,
Cricket was started on theophylline, lasix, and Clavamox. Pred was
started for possibly worsening insulinoma (she has had surgery and hadn't
needed it yet). My vet called Dr. Jonathan Goodwin from the Veterinary
Heart Institute, who confirmed that many of these ferrets will respond to
theophylline. Besides in cases of underlying heart disease, he has also
seen 3rd degree av block with insulinoma as well as with the presence of
an abdominal mass. The theory with the abdominal mass is that the mass
triggers a vagal nerve response. Cricket has both insulinoma and an
abdominal mass.
I did a search in Pubmed and found that back in the mid-late 1990's,
doctors were using theophylline in humans with 3rd degree heart block
following heart attacks, often with good results.
Cricket really did not improve much that first day, aside from getting
some fluid off of her lungs with lasix, and I took her home for supportive
care, just to see how she would do. Over the next couple of days, her
heart sped up to 75 and then 100 beats per minute, and she gradually came
around and lost the need to stay on a heating pad. On Sunday (4 days
after the initial crisis), she really started improving and displaying
some interest in regular ferret things. Her heart was beating faster but
was very arrhythmic; I was trying to describe it to my vet, and she said,
"sounds like a sneaker in a clothes drier?" YES! That was it. But it
was apparently moving blood around her body pretty well.
Monday morning, Cricket's heart had evened out actually sounded normal to
me, and she was acting pretty much like her old self. However, since I'm
an untrained layperson, I figured I was just hearing what I wanted to
hear, and although it was beating faster, there would still be major
problems. This was the day for the scheduled repeat ECG and cardiac
ultrasound. Everything looked NORMAL! The ECG showed a rate of about 212
bpm and a normal sinus rhythm. The ultrasound failed to show underlying
heart disease; normal measurements, normal contratility and ejection.
Possibly a slightly thickened area on one valve, but nothing that should
be clinical. Amazing. She's still behaving normally, and her rate has
stayed up, although I can hear the occasional "funky" beat.
We'll just follow her closely and hope she keeps doing well. If anyone
who has one of these 3rd degree av block kids has any updates, I'd be
interested to hear how things are going.
Best wishes,
-Pam S.