Exercise testing for assessing the effectiveness of digitalis therapy in compensated heart diseases.

Exercise pulse rate (EPR) during a 6-minute exercise testing and recovery pulse rate (RPR) 5 minutes following the test were determined in three groups of subjects before and after rapid digitalization. Ten normal subjects showed no significant changes in heart rate after rapid digitalization. EPR and RPR decreased and FPR/RPR ratio increased significantly after administration of the cardiac glycoside in 7 patients with congestive heart failure. A similar response was found in 25 out of 36 patients with compensated heart disease (69.4%). Such a response suggests a beneficial effect of chronic digitalis therapy in cardiac patients without heart failure.