Systolic time intervals in coronary heart disease at rest and during exercise: effect of physical training with and without beta blockade

Systolic time intervals (STIs) were measured in recumbency at rest and in the sitting position at rest and during exercise, before and after a physical training program, in 28 patients with coronary heart disease. Fifteen patients were treated with a beta-blocking drug and 13 were not. After training, oxygen uptake at peak exercise increased similarly in both groups, by 41% and 37%, respectively, whereas heart rate at rest and during submaximal exercise decreased in both groups. Left ventricular (LV) ejection time (ET) adjusted for heart rate was not significantly affected by training. The rate-corrected preejection period (PEP) and the PEP/LVET ratio decreased after training. The changes in the STI after training were not related to the level of physical activity during testing and were similar in the patients treated with beta-blocking drugs and in those not so treated. The changes after training in STI at rest and at exercise in both treatment groups suggest that LV function improves during the training period and that beta-blockade does not alter this outcome.