Diastolic time during exercise in normal subjects and in patients with coronary artery disease. A plethysmographic study.

Percent diastole (%D) was evaluated at rest and during effort (submaximal upright exercise) in 13 normal subjects and in 14 age-matched patients with coronary artery disease (CAD). Systolic time intervals were also simultaneously recorded by using the thermistor pulse transducer. At rest, in both groups, a positive linear regression was found between %D and cycle length (RR) (%D = 19.1 + 0.044RR, r = 0.83 in normals; %D = 21.2 + 0.044RR, r = 0.88 in CAD). During effort, while in normals no correlation was found between %D and RR values, in CAD patients %D and RR were linearly related (%D = -12.81 + 0.087RR, r = 0.67). These results prove that diastolic time is differently affected by the exercise in the two examined groups and that in CAD patients an abnormal reduction of %D occurs during stress test.