To test the diagnostic value of different hemodynamic indexes for the diagnosis of acute right ventricular (RV) ischemic dysfunction, we studied 2 groups of consecutive patients admitted for an acute left ventricular inferior wall myocardial infarction: 51 patients with (group 1) and 32 patients without (group 2) RV ischemia as determined by coronary angiography. In both groups, we analyzed by right-sided cardiac catheterization right-sided heart pressures, pulmonary capillary wedge pressure, and cardiac index. We also calculated pressure ratios (mean right atrial pressure or RV end-diastolic over pulmonary capillary wedge pressures), pulmonary vascular resistance, and RV stroke work index. We found significant differences (p < 0.01) between the 2 groups when comparing mean right atrial pressure, RV end-diastolic pressure, ratio of these 2 pressures over pulmonary capillary wedge pressure, RV stroke work index, and right atrial and RV pressure waveforms. The best combined sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were found for the right atrial M or W waveform pattern, isolated or combined with a disproportionate elevation of RV end-diastolic over pulmonary capillary wedge pressures (respectively, 92%, 94%, 90%, 87%, and 89%). Volume loading was performed in 27 patients (18 with and 9 without RV ischemia). Right heart pressures and RV stroke work index increased significantly and similarly in both groups. Cardiac index increased significantly only in patients without RV ischemia (p = 0.02). However, volume loading did not significantly modify the diagnostic value of the different hemodynamic criteria studied.(ABSTRACT TRUNCATED AT 250 WORDS)