Cardiovascular effects of dobutamine stress testing in healthy women.

Dobutamine echocardiography is frequently used for detection of coronary artery disease. The circulatory response in patients is known to some extent, but studies in normals are lacking. Hypotensive response during the test is a common side effect, the cause of which is unclear. The aim of this study was, therefore, to investigate the hemodynamic response to dobutamine in women without cardiovascular disease and interfering medications. Eleven healthy women, age 53-71 years, were investigated with Doppler echocardiography and venous occlusion plethysmography during intravenous infusion of increasing doses of dobutamine according to a standardized protocol. An average peak dose of 22 +/- 7.5 micrograms kg-1 min-1 was administered. Cardiac output increased by 93%, heart rate by 68%, and stroke volume by 15%, while peripheral vascular resistance decreased by approximately 50%. Systolic blood pressure remained unchanged and diastolic blood pressure decreased by 21%. One subject demonstrated a decreased systolic blood pressure exceeding 10 mmHg. Outflow obstruction from the left ventricle was seen in two subjects, one of whom had a slight decrease of 10 mmHg in systolic blood pressure. Subjects > 65 years demonstrated a less pronounced increase in heart rate, cardiac output, and decrease in peripheral vascular resistance compared with those < 65 years.