Bradycardia in athletes: clinical evaluation and management
Sinus bradycardia is very common in athletes. Recent evidence has shown that vagal hypertonia is not so much the mechanism behind this physiological adaptation, but rather intrinsic structural and ionic channel remodelling of the sinus node. Some athletes may present with extreme forms of bradycardia, such as a resting sinus rhythm of less than 30 beats per minute or sinus pauses of longer than 3 s. Even if asymptomatic, one may wonder how far this can still be considered ‘physiological’, since it is known that former athletes have a higher likelihood for the development of symptomatic bradycardia and the need for pacemaker implantation. Whereas asymptomatic athletes can participate in all sports, temporary cessation in those with symptoms is warranted to gauge resolution of bradycardia. If persistently symptomatic, pacemaker implantation needs to be considered. In those with extreme bradycardia but who are asymptomatic, a more intensified follow-up is recommended after exclusion of underlying causes (e.g. infiltrative cardiomyopathy, Lyme disease, or sarcoidosis).