Disturbance of pulmonary gas exchange in patients with right ventricular infarction

To evaluate the difference in pulmonary gas exchange in patients with and without right ventricular infarction, 147 consecutive patients with their first inferior wall Q-wave acute myocardial infarction were studied. Thirty-nine patients (group 1) had electrocardiographic evidence of right ventricular infarction and it was absent in 108 patients (group 2). A significantly wider alveolar arterial oxygen difference and higher roentgenographic scores were observed in group 1 compared with group 2. Although there were no significant differences in pulmonary artery wedge pressure and colloid osmotic pressure between groups 1 and 2, mean right atrial pressure was significantly higher, while cardiac output and mixed venous oxygen saturation were lower in group 1 compared with group 2. Patients in group 1 had significantly more left ventricular segments with advanced asynergy and higher incidence of proximal right coronary artery lesions than those in group 2. Thus, our data suggest that disorder of pulmonary gas exchange in patients with right ventricular infarction may be explained by increased permeability of the alveolar capillary membrane secondary to larger extent of ischemic myocardium and by hemodynamic abnormalities associated with right ventricular infarction.