Evaluation of Left Ventricular Performance in Acutely Ill Patients with Chronic Obstructive Lung Disease

Among 28 patients with chronic obstructive pulmonary disease (COPD) with increasing dyspnea, the resting mean pulmonary arterial wedge pressure was elevated (greater than 12mm Hg) in 4 and became abnormal with exercise in 3 other subjects. Stroke volume index was reduced (less than 36 ml/beat/M2) in 16 of 26 patients (62 percent). The resting pre-ejection period index was prolonged (greater than 144 msec) in 17 patients (65 percent), while the left ventricular (LV) ejection time index was reduced (less than 408 msec) in 23 patients (88 percent). The ratio of the pre-ejection period to the LV ejection time was within the normal range (0.309 to 0.381) in only 3 of 26 patients (12 percent). Echocardiographic measurements of LV function were normal in nine patients, seven of whom had one or more abnormal values for systolic time intervals (STIs). These data suggest that reduced LV filing results in abnormal values for STIs in patients with COPD, and therefore that in such patients STIs are not accurate indices of LV function.