title: Asystole with syncope following strenuous exercise in a man without organic heart disease.
abstract: A 29-year-old man without organic heart disease who had a history of six episodes of syncope following sudden cessation of strenuous exercise over the last 18 years was reported. Resting electrocardiogram and 24-hour electrocardiographic monitoring did not show any rhythm disturbance or ischemic changes. Sinus node recovery time, sinoatrial conduction time and A-V conduction were normal on electrophysiologic study. Asystole with syncope occurred immediately following sudden cessation of strenuous exercise and following release of intrathoracic pressure during Valsalva's maneuver performed after subcutaneous administration of 0.5 mg of epinephrine. However, Master's single two-step test and Valsalva's maneuver performed without epinephrine could not evoke asystole. It was assumed from these results that transient overactivity of the autonomic nervous system and sympathetic-parasympathetic interactions were the underlying factors responsible for the occurrence of asystole following sudden cessation of strenuous exercise in the present case.
authors.affiliation: Third Department of Internal Medicine, Nagasaki University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hirata
authors.forename: K
authors.initials: K
authors.lastname: Yano
authors.forename: T
authors.initials: T
authors.lastname: Okui
authors.forename: T
authors.initials: T
authors.lastname: Mitsuoka
authors.forename: K
authors.initials: K
authors.lastname: Hashiba
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000150:complications*; D004562:Electrocardiography; D004837:Epinephrine; D006323:Heart Arrest / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D008297:Male; D005082:Physical Exertion; D013575:Syncope / Q000150:complications*; D014636:Valsalva Maneuver
chemical_list: D004837:Epinephrine