Alterations of postural and Valsalva responses in coronary heart disease

Patients in congestive heart failure are known to have altered autonomic responses to circulatory stress. In this study, two different age groups of male coronary heart disease (CHD) patients, not in failure, as well as normal male subjects, underwent standard 20-min 70 degrees head-up tilt and Valsalva tests. Responses were monitored by noninvasive methods and cardiac output was estamated with a transthoracic impedance method. During tilt, the CHD patients and control subjects had similar heart rate and diastolic pressure responses. However, the CHD patients had a greater decline in pulse pressure during tilt, mainly due to a decrease in systolic pressure. CHD patients had lesser declines in stroke volume and cardiac index and lesser increases in total vascular resistance than did control subjects. In the Valsalva, the heart rate phase increments (and decrements) from control and rate increments (and decrements) between successive phases were less in the coronary patients. The results indicate that coronary patients, not in failure, have diminished circulatory responses to the tilt and Valsalva maneuver and suggest that these tests may be useful functional indices of cardiovascular capability in coronary disease.