Scintigraphically detected predominant right ventricular dysfunction in acute myocardial infarction: clinical and hemodynamic correlates and implications for therapy and prognosis.

To determine the clinical and hemodynamic correlates as well as therapeutic and prognostic implications of predominant right ventricular dysfunction complicating acute myocardial infarction, 43 consecutive patients with scintigraphic evidence of right ventricular dyssynergy and a depressed right ventricular ejection fraction (less than 0.39) in association with normal or near normal left ventricular ejection fraction (greater than or equal to 0.45) were prospectively evaluated. All 43 patients had acute inferior infarction, forming 40% of patients with acute inferior infarction, and only eight (24%) had elevated jugular venous pressure on admission. On hemodynamic monitoring, 74% of patients had a depressed cardiac index (less than or equal to 2.5 liters/min per m2), averaging 2.0 +/- 0.05 for the group. Of these, 30% did not demonstrate previously described hemodynamic criteria of predominant right ventricular infarction (right atrial pressure greater than or equal to 10 mm Hg or right atrial to pulmonary capillary wedge pressure ratio greater than or equal to 0.8, or both). The left ventricular end-diastolic volume was reduced to 49 +/- 11 ml/m2 (n = 22) and correlated significantly with the stroke volume index (r = 0.82; p less than 0.0001) and cardiac index (r = 0.57; p = 0.005). The follow-up right ventricular ejection fraction, determined in 33 patients, showed an increase of 10% or greater in 26 (79%), increasing from a mean value of 0.30 +/- 0.06 to 0.40 +/- 0.09 (p less than 0.0001) without a significant overall change in the mean left ventricular ejection fraction (0.56 +/- 0.10 to 0.56 +/- 0.11, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)