Had my 3 month ablation follow-up with my EP a few weeks back. I tend to ask a lot of questions as I like to know details (how/why) and I did get some interesting feedback on a few topics. Like many on here I have read extensively about AF and ablations but these details were new to me, perhaps then of interest to some others.
1. What causes the stroke risk deriving from the ablation itself and how is post-ablation anti-coagulation regime determined? The ablation-related stroke risk is highest during a 4 day window post procedure. This is because the anti-clotting lining inside the heart is destroyed at the ablation site and it takes around 4 days for this to grow back. During this time clots could easily form without A-C. I was put on Pradaxa 2 weeks prior to the procedure and asked to continue for 3 months post. This 3 month period commonly applied for post ablation A-C is not based on any particular study findings. When ablations first became a common line of treatment for AF, A-C meds were typically taken for a month post op and this has grown to 3 months over time but there is no hard & fast rule. I had stopped after 2 months, with EP agreement, as I didn't tolerate the Pradaxa very well.
2. Is longer term stroke risk affected by an ablation procedure? I imagined ablation causing an irregular surface due to scar tissue which provided more opportunity for clots to form. Was told this is not the case and there is no increased long term stroke risk deriving from the ablation procedure. In the event that my AF doesn't return (fingers crossed...), my stroke risk is the same as the general population. Of course there is a chance the AF will return.
Again, the above comments on stroke risk relate to the ablation procedure itself, not underlying / ongoing risk & management of each individual.
3. Why is there a change in resting heart rate after ablation? As most others have reported, resting heart rate tends to increase quite significantly post ablation, in my case from below 60bpm to around 90bpm initially, falling to around 84bpm over the first month and currently around 78bpm. The reason this happens is the heat from RF ablation destroys part of the vagus nerve complex at the back of the heart. These nerves regulate parasympathetic control of heart function (which I believe applies when we are at rest), leaving the sympathetic nervous system to control the heart constantly. The sympathetic system generally produces a faster rate. The nerves do grow back, at which time the parasympathetic control can recommence. This nerve re-growth can take up to a year. In my case he expected my resting rate will eventually settle at around 70bpm.