Short-term physical training improves ventilatory response to exercise after coronary arterial bypass surgery.

The issue of whether exercise training improves exercise hyperpnea in patients after coronary arterial bypass graft (CABG) surgery has not been fully explored. Effects of short-term physical training on ventilatory response and cardiac output during exercise in patients following coronary arterial bypass grafting surgery is studied. Thirty-four patients underwent exercise training for 2 weeks after the second postoperative week (Ex group); 23 stayed sedentary (Sed group). Ventilatory and cardiac output response during the cardiopulmonary exercise test was measured before and after the training period. The minute ventilation - carbon dioxide output (VE-VCO2) slope decreased from 38.9±8.1 to 35.1±6.7 (p<0.05) in the Ex group, but failed to decrease in the Sed group (39.7±11.1 to 41.5 ±11.4). Cardiac output during exercise at 20 W and at peak exercise, and peak oxygen pulse (VO2/HR) increased significantly only in the Ex group after training. There was a correlation between improvement of the VE-VCO2 slope and peak cardiac output during the training interval (r=-0.47) in the Ex group. Short-term physical training after CABG improves ventilatory response to exercise and increases cardiac output during exercise. Improvement of cardiac output is correlated with a decreased value of the VE-VCO2 slope. (Jpn Circ J 2001; 65: 419 - 423)