Volume loading in patients with ischemic right ventricular dysfunction.

Abstract

Volume loading tests with dextran 40 were performed on 36 patients undergoing hemodynamic monitoring and diagnosed as acute myocardial infarction with ischemic right ventricular dysfunction. This diagnosis was made when right atrial pressure was higher than JO mm Hg and greater than, equal to or not more than 5 mm Hg less than pulmonary capillary pressure in basal conditions (24 patients), or after dextran administration (12 patients). The patients were divided into two groups according to basal cardiac index: group A: 16 patients with cardiac index 2.2 l/min/m2 and group B: 20 patients with cardiac index <2.2l/min/m2. In group B, the right atrial and pulmonary capillary pressures associated with the higher cardiac index were 15.6 ± 4.2 and 16.8 ± 3.3 mm Hg respectively. Ventricular function curves were plotted comparing variations in right atrial and pulmonary capillary pressures with cardiac index and right and left ventricular net work index. The response to volume loading was variable in both groups. Patient mortality in group B was related to basal left ventricular net work index (P<0.05), to a cardiac .index lower than 2.2l/min/m2 after dextran administration (V < 0.02) and to the following ventricular function curves slopes δA cardiac index/δ, right atrial pressure (P <0.05), A cardiac index/δ, pulmonary capillary pressure (P<0.05) and A left ventricular net work index/δ pulmonary capillary pressure (P<0.05). This indicates that mortality is dependent on global cardiac function and more precisely on left ventricular function. Volume loading is useful to demonstrate the presence of ischemic right ventricular dysfunction, to assess right ventricular function, to find the optimal values of ventricular filling pressure in patients with low output, and to determine the prognosis.