Effect of exercise on left-ventricular systolic time intervals in patients with coronary heart disease

Left-ventricular systolic time intervals measured at rest and after submaximal exercise were analysed in 156 patients with positive exercise test results and in 219 healthy volunteers with negative exercise test results. The patients were suffering with high probability, from coronary heart disease. The healthy subjects as well as the patients were divided into five groups on the basis of the submaximal exercise loads tolerated by them. Load of 30 W was taken as starting point. At rest, the patients had shorter ejection times (LVET) and total electromechanical systolic times (QS2), and longer preejection periods (PEP) and isovolumetric contraction times (ICT), than the healthy subjects. The PEP/LVET ratio for the patients was higher than that for the healthy subjects. In groups of the same tolerance to work, exercise induced less pronounced decreases in PEP and PEP/LVET values and more pronounced decreases in QS2 and LVET values in the patients than in the healthy subjects.