Malignant hypertension is a unique and natural model for the study of abnormalities of left ventricular function due to arterial hypertension, because the development and regression of these abnormalities can be observed in a short period. Studies of ventricular function by radionuclide ventriculography, either before or after therapy, have not been previously reported in malignant hypertensive patients. We used this methodology to study left ventricular function in 17 malignant/accelerated hypertensive patients at the time of admission to the hospital and 3, 6, and 9 months after discharge. Seventy percent of patients (12 of 17) had symptoms of congestive heart failure at admission. We compared these data with those obtained in 12 normotensive subjects and 13 mild-to-moderate untreated hypertensive patients. Blood pressure of malignant hypertensive patients was 213 +/- 26/140 +/- 17 mm Hg at admission and 165 +/- 23/101 +/- 15 after 9 months of therapy. Radionuclide ventriculography at admission showed that peak filling rates of malignant hypertensive patients (2.13 +/- 0.21 end-diastolic volume [counts] [EDV]/sec) were significantly lower than those in normotensive subjects (2.40 +/- 0.41) and in mild-to-moderate hypertensive patients (2.46 +/- 0.21). In contrast, peak ejection rates were significantly higher in malignant hypertensive patients (3.44 +/- 0.38 EDV/sec) than in the two control groups (3.01 +/- 0.32 and 3.10 +/- 0.43, respectively). Ejection fractions were similar in the three groups of patients. After 9 months of therapy, peak filling rates of malignant hypertensive patients increased to 2.38 +/- 0.35 EDV/sec, whereas peak ejection rates decreased to 2.89 +/- 0.43 EDV/sec, both not significantly different from data in controls.(ABSTRACT TRUNCATED AT 250 WORDS)