LEFT-VENTRICULAR EJECTION FRACTION RESPONSE DURING EXERCISE IN ASYMPTOMATIC SYSTEMIC HYPERTENSION

To study the effect of mild-to-moderate elevations in diastolic blood pressure (BP) on systolic left ventricular (LV) function, 28 hypertensive patients and 20 normal subjects underwent upright exercise first-pass radionuclide angiography. All were asymptomatic, had normal rest and exercise electrocardiographic findings and no evidence of LV hypertrophy or coronary artery disease. LV function at rest was similar in the 2 groups, but with exercise hypertensive patients had a greater end-systolic volume (69 .+-. 19 vs 51 .+-. 19 ml, p < 0.002) and lower ejection fraction (EF) (0.59 .+-. 0.09 vs. 0.72 .+-. 0.07, p < 0.0001), stroke volume (101 .+-. 28 vs 130 .+-. 36 ml, p < 0.005) and peak oxygen uptake (23 .+-. 7 vs 33 .+-. 9 ml/kl/min, p < 0.05). Hypertensive patients were separated into 3 groups: group 1-12 patients with an increase in EF with exercise .gtoreq. 0.05; group 2-7 patients with a change in EF with exercise < 0.05; and group 3-9 patients with a decrease in EF with exercise .gtoreq. 0.05. Group 3 hypertensive patients were older, had a higher heart rate at rest and lower peak oxygen uptake. Rest LV function was similar in the 3 hypertensive subgroups, but exercise end-systolic volumes were higher in groups 2 and 3. Exercise thallium-201 images was normal in all but 1 of 14 hypertensive group 2 or 3 patients. Thus, most (57%) patients with asymptomatic hypertension have abnormal LV systolic function that is not related to electrocardiographic LV hypertrophy or ischemic heart disease. Abnormalities of LV systolic performance are most marked in older patients. Inferences about the presence of coronary artery disease should not be based on abnormal exercise LV function response in hypertensive patients.