Analytic Review: Right Ventricular Infarction

Abstract

Right ventricular myocardial infarction (RVMI) usually occurs after occlusion of a dominant right coronary artery, and the amount of right ventricular necrosis depends on whether this occlusion occurs proximal or distal along the length of the coronary artery. In patients who have a considerable amount of right ventricular necrosis, the physical examination reveals an elevated jugular venous pressure and Kussmaul's sign. Acute hemodynamic monitoring demonstrates a disproportionate elevation of the right atrial pressure (RAP) when compared with the pulmonary artery wedge pressure (PAWP). Previously validated hemodynamic criteria for identifying hemodynamically important RVMI include an RAP greater than or equal to 10 mm Hg and a RAP: PAWP ratio greater than or equal to 0.8. These hemodynamic findings can be seen in approximately 10% of patients who are seen with acute inferior transmural myocardial infarction; the findings can be produced in another 10% of patients after volume loading. Radionuclide angiography accurately assesses right ventricular systolic function using either the first pass or equilibrium technique. When the right ventricular ejection fraction is less than 40% and there is evidence of right ventricular wall motion abnormalities, the presence of hemodynamically important RVMI is highly likely. When a patient presents with hypotension and low cardiac index, volume therapy should be instituted initially. However, if cardiac index does not improve after RAP and PAWP have increased to greater than 20% above control values, intravenous dobutamine should be instituted without delay to restore circulatory stability. The acute and long-term prognosis of patients with RVMI is excellent as long as extensive left ventricular necrosis does not occur concomitantly. Furthermore, right ventricular systolic function has been shown to improve significantly in the recovery period so that the patient's functional capacity is not imparied.