Delay of ST Depression after Maximal Exercise by Walking for 2 Minutes

Maximal exercise testing of 241 healthy, highly selected, middle-aged American men in Taiwan and Hong Kong revealed a lower prevalence of ST-segment depression than among American men in Seattle. This difference was attributed to circumstances restricting availability of American men in Taiwan and Hong Kong with risk factors ordinarily associated with this response. ST depression, when present, was usually manifested after a delay of 4 to 5 min in the American men studied in the Orient, as previously noted, in healthy Chinese men. This delay is attributed to the circulatory effects of walking slowly for 2 min after maximal exercise which prevents venous pooling and a rapid decrease in cardiac output and coronary perfusion. Occurrence of ST depression in these selected American men in the Orient was more frequently associated with higher systolic pressure and minor ST-T abnormalities in the resting electrocardiogram than in American men in Seattle.