Cardiac Ablation for Intermittent Arrhythmia

[3mm]

How does an electrophysiologist planning a cardiac ablation approach an arrhythmia that is intermittent?

Some arrhythmias are intermittent, but still serious enough to consider surgery. Many days I have 20%, perhaps even 30%, PVC loading (premature ventricular contractions) for several hours or more. (Note: 20% PVC loading means that 20% of my heartbeats are PVCs) So my electrophysiologist recommends intervention because over time these PVCs are damaging my heart. I accept this is a good idea, since I want to keep my heart healthy.

However, some days I only an occasional PVC, or even have 0 PVCs. Other days I have 0 PVCs in the morning, but after exercising I have PVCs for several hours. So I'm not sure if the surgical team will see the problem while I'm on the table. All my engineering experience tells me it is very hard to fix a problem you cannot recreate.

When an arrhythmia is intermittent, how does the electrophysiologist know what to ablate during surgery? I have seen a reference to using a drug to force the heart into arrhythmia; but how would the surgeon know if the arrhythmia they forced the heart into is the patient's real problem?

I'm not finding much information about this aspect of cardiac ablations. I have emailed questions to my electrophysiologist, but I've not yet heard from their office. I will appreciate any references to medical reports, personal experience, etc. I want to get some background so I can have a useful conversation with my electrophysiologist. Thank you!

 

[Timmay]

Hi 3mm,

Out of my own personal curiosity, how did they quantify your PVC loading? Did you wear a monitor for a week or so? I too have Exercise Induced PVCs (aka EI-PVC). Metoprolol seems to help significantly with mine. Are you on Metoprolol at all?

Thanks.

 

[3mm]

how did they quantify your PVC loading? Did you wear a monitor for a week or so? I too have Exercise Induced PVCs (aka EI-PVC). Metoprolol seems to help significantly with mine. Are you on Metoprolol at all?

I've worn a Holter monitor for 3 tests, twice for 2 week tests, and once for a 1 week test.

I take metoprolol. During 2 tests I was taking metoprolol tartrate, 12.5mg twice daily. During the other test I took metoprolol succinate, 25mg daily. I do not see any relation between PVCs and the time I took my metoprolol when I look at the data from my tests.

 

[Timmay]

Thanks 3mm. Appreciate your experience.

 

[Woodcutter]

How does an electrophysiologist planning a cardiac ablation approach an arrhythmia that is intermittent?

My understanding is they attempt to induce them (I've had a couple of ablations but my issues were not intermittent):

Sympathomimetic agents (isoproterenol or epinephrine), methylated xanthines (aminophylline or caffeine), or awakening the patient on the table may provoke PVCs. Rapid atrial or ventricular pacing causes an increase in triggered PVCs. In some instances, high-frequency electrical stimulation (50 ms train) in the proximal main or left pulmonary artery can induce outflow tract PVCs.41,42 On the other hand, atrial or ventricular extrastimulation may provoke reentrant PVCs.

Alternatively, with a multielectrode catheter, multiple points can be acquired in a single beat when the PVC is very infrequent

The above are a couple sentences from this article. It's got a nice reference list for digging even deeper

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4547666/

 

[dornole]

Interesting, never really thought about that. I have paroxysmal afib and they will probably do a Maze procedure tomorrow during my mitral valve replacement. I got the impression that for afib they kind of know where the chaotic impulses are coming from, near the pulmonary artery I believe. Maybe it is different for PVCs.

For me I estimate the afib burden by telling them how many episodes and how many hours they lasted. It's extremely apparent to me when they are happening and I verify with a Kardia.

I also have an older Apple Watch - it doesn't do the mini EKGs on demand, but it does do a passive heart rate variability measurement (HRV) throughout the day. I've noticed that the HRV spikes strongly on afib days (e.g. 150 ms vs a normal of about 30 ms for me) and the height of the spike roughly correlates to the number of hours in afib. Very strong match in this data to my perceptions of afib as well as what the Kardia says.

I've never had an afib episode when wearing a Holter (naturally). Only official time they documented it was in the ER before cardioversion. Which lasted 4 days before the next episode.

Curious to see what you find out.

 

[pellicle]

12.5mg twice daily. During the other test I took metoprolol

Both very low doses, personally I'd prefer trying a higher dose before starting ablations.