Post-exercise cardiac asystole in persons without underlying heart disease: management and follow-up of three cases

Abstract

We report post-exercise cardiac asystole after treadmill exercise test in three patients without structural heart disease. Post-exercise asystole in healthy individuals is a potentially life-threatening incident with a presumably underestimated prevalence. It may be responsible for some of the sudden deaths in young persons and athletes. Although the underlying mechanism of this event is not clear, it is hypothesised to be due to a vasovagally mediated cardioinhibition. While tilt table testing is a useful tool in evaluating these patients, its use in guiding therapy is far less clear. Owing to the reproducible nature of syncope documented by a positive tilt table test, permanent pacemakers (DDDR) were implanted in two of our patients. Both remained asymptomatic during a follow-up period of 12 and 26 months, respectively. The third patient, who refused further evaluation and management, also remained asymptomatic for 3 years with the advice to avoid strenuous exercise. At present, there is no general agreement on the management of patients with post-exercise cardiac asystole. The prognosis of this syndrome and management modalities are not well defined. Diagnosis of this syndrome and appropriate management may decrease the risk of sudden death and improve the quality of life in many patients.