To evaluate the difference in DT and systolic time intervals during one-handed and two-handed weight holding with the same total load, the DT-heart rate relationship was studied in 12 patients and ten normal volunteers. Heart rate, blood pressure, and pressure-rate product were significantly higher in one-handed compared with two-handed weight-holding exercise in patients with MI. Although there were no significant differences in QS2 and DT between the two types of weight-holding exercise in normal volunteers, QS2 was significantly longer and DT was significantly shorter in one-handed compared with two-handed weight-holding exercise in patients with MI. Disproportionate shortening of DT with higher pressure-rate product during one-handed compared with two-handed weight-holding exercise can initiate an imbalance of myocardial oxygen supply and demand in patients with MI.