Circulatory effects of mental stress during exercise in coronary artery disease patients

We examined the effects of mental stress during steady‐state exercise on heart rate, blood pressure, pressure‐rate product, and oxygen uptake in 10 coronary artery disease patients. Subjects walked at three mph with grade increases of 4% every two minutes until the target heart rate (60% peak heart rate from a previous symptom‐limited exercise test) was reached. A computerized Stroop‐Color‐Word Test (mental stress) was added one minute after the subject reached steady‐state exercise and lasted 11±4 minutes. When mental stress was added to steady‐state exercise it significantly (p<0.01) increased the heart rate (101 ±15 to 108± 19 beats per min), systolic (154±26 to 170 ±26 mmHg) and diastolic (86 ±10 to 92 ±13 mmHg) blood pressure, and pressure‐rate product (158 ±42 to 179±48 × 10 ‐ ‐ 2 ). This increase in the mean response during exercise and mental stress was not observed for oxygen uptake (17±6 to 18±5 ml/kg/min). The circulatory changes probably reflect increased sympathetic activity with both centrally mediated cardio‐acceleratory (and probably cardiac output) and vasoconstrictor effects during the combination of mental stress and steady‐state exercise. The altered hemodynamics without concomitant changes in oxygen uptake has major implications concerning the safety of competitive exercise for people with coronary artery disease.