I am not a cardiologist, can only speak to my personal experiences and those I know who deal with AF. I am 37, and was diagnosed 2 years ago, after racing road/MTB at a high level for over 10 years. I have spent the last few years doing my best to learn about the diagnosis, and determine the best way for me to live the happiest, healthiest, longest life possible. This has entailed seeing many electrocardiologists, who specialize in AF, trying many medications, and venturing into the more opaque side of treatments (more below).
As noted, there are 3 types of AF, and it is important to differentiate. AF impacts all people/athletes differently, some do better with HIIT style training (multiple studies saying this helps reduce the occurrence…not for those in chronic AF, however). Food, supplements (Magnesium has been studied and shown to be nearly as effective as Propafanone/Flecanide, for some people, Taurine can help too, as well as fish oil…and many more), and exercise are all so dose dependent, and very much depend on the individual. Many people are triggered by heart rate increases, others stress, others alcohol, etc.
In my experience, there are few cardiologists here in the US who understand AF through an athletes lens, and are able to disentangle ‘you’ from the meta analysis consisting of 70 year old men, with other co-morbidities. Read Dr. Mandrola’s blog as a starting point for info, and to learn the pros/cons of ablation. If ablation is the decision, there are a few docs in the US (Dr. Hao, Dr. Natali) who should be considered. Ablation is not a long term fix for most, with a 2-10 year time horizon being the norm for most, despite with the EC will tell you.
Beta blockers are always going to keep the engine from being able to rev. There is also the question of what other meds he is on, and has he had a stress test performed while on the BB.
Yoga, sleep, stress, diet, hydration and electrolytes can also be very important and effective ways to ‘self medicate’. I have found meditation to be transformative- not just for AF, but other aspects of my life too. There is also some interesting work being done with message of the heart. Yes, this sounds crazy. Similar to massage of muscle- call it the hamstring, the idea is to address any areas of dysfunction (fascia release and better movement of the nerves around the heart). This takes a very trained hand, and someone who has the training and has worked with cadavers to know what they are doing.
Finding a coach who knows about AF, and is able to work with this athlete, holistically, not just with training might be best.
There is a book- ‘Haywire Heart’ which offers an overview (co-authored by Dr. Mandrola), although it might come across as too fear inducing for some.
Dr. Aaron Baggish at MGH in Boston has been studying athletes with AF for a long time, and has authored, or co-authored many studies on it. They also have one of the few cardiac sports labs in the US. It might be worth finding a facility/Doctor with this type experience and facility for counsel.
I work with a handful of athletes with AF, and/or eating disorders. These are 2 areas I have personally struggled (and competed), and feel I can provide the greatest benefit.