Mystery Arrhythmia?

Trying to make a long story short (I posted about the history of this awhile back) My dog's new vet along with the vet tech both clearly heard an arrhythmia during my dogs last visit. She had seen another vet (our holistic one) a few months prior who detected no arrhythmia's and had a listen at a clinic by a cardiologist in March with no problems detected then either. So our new vet referred us to a cardiologist who did a full EKG, ECG, etc. When she listed to Polly she detected the arrhythmia right away. But then only minutes later it never showed up during the EKG/ECG which was surprising to everyone (the tests also came back 100% normal. No murmur, no MVD, nothing) So they set her up with a heart holter which would record her rhythm for 24 hours. We got the results yesterday and much to the cardio vet's surprise...no arrhythmia's were detected. Cardiologist said she's actually rather baffled..as both she and the vet the day before heard it clearly. I did ask her about the possibility of it just being something that may happen when she is nervous (which she said can happen sometimes)..but then it doesn't make a lot of sense because you would think when they were holding her down and doing the EKG she would have been terrified. And she seemed rather calm during her vet visits when they clearly heard it. Any ideas?

Erin2854 said:

Any ideas?

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I hate to answer that question with a "No", but, in fact, no, I don't. Except to take her to see a cardiologist annually, like at a heath clinic at a nearby dog show, and see if it shows up again.

I'm not sure why the cardiologist would be so baffled - it's not uncommon for a transient arrhythmia not to be caught on a 24 hour Holter. (Frustrating, but not uncommon.) Arrhythmias can be very intermittent. Have you been told what kind of arrhythmia was heard - for example, atrial premature complexes, ventricular tachycardia, atrial fibrillation (unlikely), etc. Did the GP vet, vet tech and cardiologist all hear the same type of arrhythmia? That might be one clue.

There are two types of ambulatory ECGs - 24 or 48 hour (there are now some digital recorders that can record continuously up to seven days) continuous recording Holter and event recorders. Event recorders continually record and then erase at five minute intervals. When a button is activated, the minute before and four minutes after the button push are stored. An event recorder is used for evaluation of infrequent syncope in which an intermittent arrhythmia is suspected. (I'm not sure if it was ever determined if Polly's prior "episodes" were sycopal events.). An event recorder is typically worn for one week to one month. It sounds as if an event recorder may be appropriate in Polly's case if she continues to have the episodes that you described in the past.

Exactly what tests did the cardiologist perform - you said an EKG and an ECG but those are the same thing - an electrocardiogram. Was an echocardiogram also done?

I would guess that the next step will depend on whether or not Polly continues to have the strange episodes. If so, I would opt to try an event recorder for a period of several weeks in an attempt to try to evaluate the episodes. If the events don't happen again, I'd probably follow up with another cardiologist workup in six months to a year just to be proactive. Also I'd be guided by what type of arrhythmia the group of vets thinks they heard as some are more serious than others. What does the cardiologist recommend as the next steps?

Pat

Pat,
Just looking over her paperwork, it says they did an echocardiogram and electrodcardiogram. The results showed that she had normal cardiac dimensions, normal cardiac functions and normal blood flow patterns. None of the reports from any of the vets specify what type of arrhythmia was heard. Just says "arrhythmia was clearly audible during her physical examination". Two diff vets heard it within 24 hours of eachother but nothing on the holter. The cardiologist said Polly is a bit of a mystery at this point. It really hasn't been confirmed if the 2 epsidoes she had even had anything to do with a heart issue. We are kind of exploring different options. Her symptoms match such a wide variety of things- from low blood sugar to a neurology problem. But other than those 2 brief episodes (has only happened twice since I've had her and were two months apart. Last episode she slept for a few hours and was back to her normal self) she has been 100% fine. No problems at all. She said if it happens again, then our next step would either be to talk to a neuro doctor to see if he thinks it could be anything neurological and/or get a a small device (like a microchip) implanted under the skin that she can keep in for up to a year and will start to record when and after anything odd is detected (sounds like something you were talking about). I did not see in her records or hear any menton of syncope (although I'm not totally sure what this means..?) but will possibly mention it in the future. The cardiology unit I'm working with is supposed to be the best in the state so I sure hope we get this figured out! Thanks for your info by the way!!