Increased cardiac performance has been documented in patients with early systemic hypertension, but its prevalence and determinants in patients with uncomplicated sustained essential hypertension have not been characterized. Radionuclide cineangiography in 116 patients with uncomplicated essential hypertension showed that 12 of 116 (10%) had supranormal resting left ventricular (LV) ejection fraction (greater than 70%, above the highest value in normal subjects), while 104 patients had a normal resting ejection fraction (45 to 70%). Patients with a high resting ejection fraction had higher systolic and diastolic blood pressure compared with patients with normal resting ejection fraction (182 mm Hg vs 169, p less than 0.01, and 110 vs 103, p less than 0.05, respectively), markedly greater echocardiographic LV mass (136 vs 94 g/m2, p less than 0.01), smaller ventricular dimensions in systole (2.5 vs 3.1, p less than 0.01) and diastole (4.4 vs 4.9, p less than 0.05), and higher relative wall thickness (0.61 +/- 0.20 vs 0.39 +/- 0.98, p less than 0.001). Patients with supranormal resting ventricular performance had lower end-systolic wall stress than normal volunteers or patients with normal resting LV function (48 vs 64 vs 74 X 10(3) dynes/cm2, respectively). Patients with an elevated LV ejection fraction also had significantly more abnormal funduscopic examinations and greater proteinuria. Thus, a subset of essential hypertensive patients with moderately to severely elevated blood pressure developed marked concentric LV hypertrophy associated with subnormal end-systolic stress and supranormal LV performance.(ABSTRACT TRUNCATED AT 250 WORDS)