The value of combining noninvasive techniques in exercise testing

A 3-stage cycle ergometer exercise test which combines the noninvasive measurement of systolic time intervals (STI's), stroke volume (SV), mean systolic ejection rate (MSER) and blood pressure was administered to 2 groups of middle-aged men. Group 1 included 15 healthy men. Group 2 consisted of 20 men with coronary artery disease (CAD), confirmed by a proven myocardial infarction. The groups were matched for age, weight and height. Over the range of heart rates (HR's) encountered (70--173 beats min-1) the STI's described an inversely linear relationship with HT. At all exercise HR's, group 2 displayed higher values for total electromechanical systole (QS2), left ventricular ejection time (LVET) and the pre-ejection period (PEP), and lower values for SV and MSER. Statistical comparison of all variables at a common HR of 100 beats min-1 indicated that QS2 and MSER best discriminated between the groups. It was concluded that this test is sufficiently sensitive to detect differences in cardiac performance in groups of subjects, but not for the diagnosis of CAD in individual patients.