Importance of Left Ventricular Chamber Size in Determining the Response to Hydralazine in Severe Chronic Heart Failure

Abstract

To examine the importance of left ventricular chamber size in determining the response to vasodilator therapy, we performed echocardiography in 40 patients with chronic refractory heart failure before they were treated with oral hydralazine. The left ventricular end-diastolic dimension (LVEDD) correlated significantly with the per cent change in stroke volume (r = 0.77), left ventricular filling pressure (r = −0.68), and stroke work index (r = 0.87) during short-term drug administration. After 14 to 21 days of maintenance therapy, 15 of 24 patients with an LVEDD ≥60 mm were improved, and one was worse; mean blood urea nitrogen decreased from 45.6 to 30.6 mg per deciliter in the 21 patients in this group who completed the study (16.3 to 10.9 mmol per liter) (P<0.001). In contrast, only two of 16 patients with an LVEDD <60 mm improved, whereas 10 showed clinical deterioration; blood urea nitrogen increased from 49.3 to 64.2 mg per deciliter in the 13 patients in this group who completed the study (17.6 to 22.9 mmol per liter) (P<0.01). These findings indicate that left ventricular chamber size is an important factor in the response to hydralazine in patients with severe chronic heart failure. (N Engl J Med. 1980; 303:250–5.)