Comparison of ambulatory left ventricular ejection fraction and blood pressure in systemic hypertension in patients with and without increased left ventricular mass. To evaluate the effects of long-standing systemic hypertension on left ventricular (LV) function during daily activities, ambulatory radionuclide monitoring of LV ejection fraction (EF) and blood pressure was performed during exercise and other structured activities in 31 hypertensive patients. Patients were divided into 3 groups based on the absence of LV hypertrophy (group 1 [n = 16], LV mass 107 +/- 12 g/m2), presence of LV hypertrophy without electrocardiographic changes (group 2 [n = 10], LV mass 141 +/- 8 g/m2) and LV hypertrophy with associated electrocardiographic changes (group 3 [n = 5], LV mass 158 +/- 9 g/m2). The groups were similar with respect to age, baseline medication, treated and untreated blood pressure, resting EF and treadmill exercise time. Patients in group 3 had the longest history of hypertension. Peak filling rate was normal in group 1 (2.9 +/- 0.4 end-diastolic volume/s), but reduced at rest in groups 2 (2.4 +/- 0.4) and 3 (2.1 +/- 0.3). Patients in group 1 had normal EF responses to exercise and mental stress testing, as well as during routine ambulatory activities. Patients in group 2 had a blunted EF response to exercise, and those in group 3 had a significantly abnormal response. Both group 2 and 3 patients demonstrated abnormal EF responses to mental stress, as well as cold pressor testing in association with significant increases in mean arterial pressure and marked reduction in diastolic filling rate. Decreases in EF were also observed during routine patient monitoring in 3 group 3 patients and 4 group 2 patients. These events were associated with significantly increased blood pressure. 