Oxygen transport to muscle during exercise in chronic congestive heart failure secondary to idiopathic dilated cardiomyopathy

In chronic heart failure, oxygen delivery during exercise is impaired mainly because of failure of cardiac output to increase normally. Compensatory mechanisms are hemoglobin concentration increase, right-ward shift in the oxyhemoglobin dissociation curve, and blood flow redistribution from the nonexercising organs to the exercising muscles.