Depression of heart function after angiotensin II infusion in patients on chronic hemodialysis.

The response of heart function to angiotensin II (AT II) was studied in 18 patients on regular hemodialysis. The mean age was 33 years and they had been dialyzed for 55 months in the average. AT II was infused from a large vein and systolic blood pressure was raised by 40 mmHg. Before and after the change in blood pressure, M-mode echocardiogram of left ventricle was recorded. Left ventricular enddiastolic dimension, stroke index and cardiac index were found to be normal except for 9 patients who showed cardiac index above 4.0L/min/m2. No significant change was found in these parameters after the rise of blood pressure by AT II. Control ejection fraction (EF) was slightly but nonsignificantly lower in the patients than the healthy subjects; 0.73 +/- 0.13 vs. 0.80 +/- 0.05. Though significant falls in EF were found in the patient and in the healthy group, the former showed a profound depression of EF to 0.64 +/- 0.10. This value was significantly lower than the value of the latter group; 0.76 +/- 0.04 (p less than 0.01). Since none had overt heart failure, a depression of EF after AT II can be regarded as subclinical abnormality of heart function. AT II will be useful to detect this limited reserve of heart function in patients on regular hemodialysis who may show normal function at rest.