Arrhythmias in Endurance Athletes

May 4, 2017

Peter H Backx, PhD is a senior scientist at Toronto General Hospital Research Institute and also at York University. Dr Backx is a recognised expert in cardiac mechanics, heart failure and arrhythmias. His research focuses on the role of ion transport, ion channels and myocardial signalling in the initiation and progression of heart disease with a particular interest in atrial fibrillation. He holds a patent on tissue-specific drug delivery and has published over 190 peer-reviewed articles, many in the top tier journals like Cell, Nature, Nature Medicine, Journal of Clinical Investigation and Circulation Research. His work has been cited over 12,900 times, with over 5600 in the last 5 years. Dr Backx has delivered over 150 distinguished invited lectures at the national and international level.

You could listen to this podcast to learn more about the causes of arrhythmias in endurance athletes.

Special thanks to Mark Featherman for the introduction to Dr Backx and also some excellent questions.

One piece of simple, actionable advice to improve your health and performance, including the reference(s) to back it up.
One item we read or saw in the health and fitness world recently that we would like to give a different perspective on, and why.
One remarkable thing that we think you’ll enjoy!

Here’s the outline with Peter H Backx, PhD:

[00:00:06] Book: The Haywire Heart: How too much exercise can kill you, and what you can do to protect your heart.

[00:00:21] PHAT FIBRE MCT oil powder.

[00:01:27] Toronto General Hospital Research Institute (TGHRI).

[00:01:50] Atrial arrhythmias.

[00:03:23] The electrical system of the heart.

[00:04:04] SA node.

[00:07:30] Main symptoms: fatigue, dizziness.

[00:09:02] Peter is trained as a cardiac electrophysiologist.

[00:09:18] Sudden cardiac death.

[00:09:43] Ventricular tachycardia.

[00:10:23] The dangers of afib.

[00:11:03] Paroxysmal (acute) afib.

[00:12:07] Tommy and Mark Cucuzzella podcast: greatest risk endurance athletes doing more than an hour per day for 20 years.

[00:13:01] Biggest risk factor is ageing.

[00:13:36] CVD risk factors are also predictive of afib.

[00:14:39] Is there a threshold?

[00:15:25] Athletes may be at great risk for vfib.

[00:17:30] Genetic predisposition.

[00:18:33] Exosome (genetic) testing.

[00:19:15] Ion channels.

[00:20:17] Ablation.

[00:22:24] Mark Featherman, you rock!

[00:22:55] If you continue doing the same thing, will you develop another arrhythmia?

[00:24:44] Finding the sweet spot of exercise.

[00:25:36] Exercise intensity.

[00:26:20] Polarised training. See Hydren, Jay R., and Bruce S. Cohen. "Current scientific evidence for a polarized cardiovascular endurance training model." The Journal of Strength & Conditioning Research 29.12 (2015): 3523-3530.

[00:27:00] Rodent studies.

[00:28:18] Only the mice running on weighted wheels developed pathological changes.

[00:32:13] Chronic inflammation.

[00:32:41] Rheumatoid arthritis.

[00:34:05] TNF-a is a mechanosensor.

[00:34:58] TNF-a inhibitors.

[00:35:51] Etanercept.

[00:36:09] XPro®1595.

[00:37:02] Blood testing for TNF-a.

[00:37:41] Kroetsch, Jeffrey T., et al. "Constitutive smooth muscle tumour necrosis factor regulates microvascular myogenic responsiveness and systemic blood pressure." Nature Communications 8 (2017).

[00:39:01] Sebastian Bolz, PhD. See Hui, Sonya, et al. "Sphingosine-1-phosphate signaling regulates myogenic responsiveness in human resistance arteries." PloS one 10.9 (2015): e0138142.

[00:41:11] The atria as an endocrine organ, see atrial natriuretic factor.

[00:42:36] Stretching the atria.

[00:42:46] Alcohol.

[00:43:54] Increased parasympathetic activity.

[00:45:43] Low-dose alcohol is a stimulant, at higher doses, it's a depressant.

[00:47:31] Caffeine.

[00:50:12] Acid reflux.

[00:50:37] Vagus nerve.

[00:51:54] A hiatal hernia.

[00:52:37] Proton pump inhibitors and dementia.

[00:53:21] The 2016 Nobel Prize in Physiology or Medicine to Yoshinori Ohsumi for his discoveries of mechanisms for autophagy.

[00:53:54] Lysosomes.

[00:55:03] The vulnerability period increases the chances of a “false start”.

[00:58:18] Vagus nerve releases acetylcholine.

[01:00:34] Are ablation procedures overperformed?

[01:01:14] Stroke.

[01:03:16] Increased back pressure “volume overload” models.

[01:05:03] Heart & Stroke/Richard Lewar Centre of Excellence.

[01:05:39] York University, Canada.

[01:05:56] MRI on cyclists.

[01:06:39] PubMed author search for Peter H. Backx.

[01:07:34] Developing methods for producing atrial cardiomyocytes from stem cells.