Electrocardiographic and hemodynamic changes in experimental right ventricular infarction.

To investigate the electrocardiographic and hemodynamic changes in isolated right ventricular infarction, 0.25 ml or 0.5 ml of metallic mercury was injected into the right coronary artery of 14 closed-chest dogs. At autopsy, at least 60% of the right ventricle was necrotic in every dog. Hemodynamic observations were made in 11 and electrocardiographic mapping was performed in all 14 dogs. Right atrial pressure rose in 10 and left atrial pressure in nine of the 11 dogs; early right atrial pressure did not exceed left atrial pressure, but late right atrial pressure was greater in four dogs. Although cardiac output and blood pressure fell significantly, circulation was maintained. Twelve of 14 dogs had transient ST-segment elevation in the right precordial leads, and 12 developed right bundle branch block. Abnormal Q waves or R waves of 1 mm or less appeared in the right precordial leads in 13 of the 14 dogs. Since right bundle branch block and abnormal Q waves in the right precordial leads have not been recognized as useful signs in human right ventricular infarction, further investigations are warranted to determine their value in clinical applications.