CARDIAC ASYSTOLE POSTEXERCISE - A REPORT OF 2 CASES

Two patients are described with reproducible cardiac asystole post-exe rcise. No structural heart disease was demonstrable. At autonomic func tion testing no abnormal responses were noted. Also, head-up tilt test s were normal. However, electrophysiologic testing and heart rate vari ability during 24-h Holter monitoring were indicative of a high vagal tone in both patients. The findings suggest that post-exertional asyst ole may not be due solely to a vasovagal mechanism; excessive rebound vagotonia per se may also play a role.