[Sequential changes in the left ventricular function during ramp exercise in patients with ischemic heart disease: continuous assessment of the left ventricular radioactivity with wireless telemetric cardiac monitoring system].

The left ventricular function during ramp exercise was assessed using 99mTc-labeled red blood cells and a Wireless Telemetric Cardiac Monitoring System (WTCMS) in 34 patients who received coronary angiography. Sequential changes in the left ventricular ejection fraction (EF) during exercise, were classified into the two types, normal response (up slope pattern) and abnormal response (horizontal, down slope and up-down slope pattern) when defined the response as 5 percent or more increment of EF as normal. Six patients without significant stenosis by coronary angiography showed normal response. Seventeen of 28 patients with coronary disease showed abnormal response (sensitivity 61%). Eight of 11 patients (73%) with coronary disease and normal response showed no redistribution on the stress thallium myocardial scintigraphy. Twelve of 17 patients (71%) with coronary disease and abnormal response showed redistribution by the stress thallium scintigraphy. Horizontal and down slope patterns of EF during exercise were more often noted in the groups with redistribution and multivessel coronary disease. After the exercise, the times to the over shoot was significantly longer in groups with redistribution (p < 0.01) in comparison with groups without redistribution. From these results, we conclude that the monitoring the changes in left ventricular activity during ramp exercise with the WTCMS is a very useful method for the evaluation of the sequential changes in left ventricular function in patients with ischemic heart disease.