Epidemiologic features of isolated syncope: the Framingham Study.

To obtain epidemiologic information regarding syncope, 2336 men and 2873 women aged 30 to 62 years at entry to the study were evaluated for syncope. During 26 years of surveillance, evidence of cardiac or neurologic morbidity and mortality was also recorded. At least one syncopal episode was reported by 71 (3.0%) of the men and 101 (3.5%) of the women during the course of the study. Criteria for isolated syncope (i.e., transient loss of consciousness in the absence of prior or concurrent neurologic, coronary, or other cardiovascular disease stigmata) were met by 56 (79%) of the 71 men and by 89 (88%) of the 101 women with syncope. During 26 years of follow-up isolated syncope was not associated with any excess of stroke (including transient ischemic attack) or myocardial infarction. Similarly, isolated syncope was not associated with any excess of all-cause or cardiovascular mortality (including sudden death).