Effects of training on the distribution of cardiac output in patients with coronary artery disease.

In nine patients with coronary artery disease, cardiac output distribution was evaluated at rest and during exercise by measurement of cardiac output and regional blood flow parameters (hepatic and muscle blood flow). In seven patients repeated values were obtained after a physical training program of 4 to 10 weeks' duration. After training, cardiac output was reduced at moderate work loads (13.1%) causing a change of the relation between oxygen uptake and cardiac output from hyperkinetic to normal. During heavy exercise the cardiac output was increased (5.5%) after training. Similar changes were observed in muscle blood flow, which was reduced at submaximal loads (14.9%) and increased at maximal (8.6%). Hepatic blood flow showed in contrast a less pronounced reduction at both work loads after training (difference, 7.2%). These effects of training could be explained as peripheral regulatory alterations without implying primary improvement in myocardial performance. They are consistent with the view that local changes in the trained muscles are important for the reduction in myocardial pressure-work caused by physical conditioning.