Right ventricular free wall ischemia: correlation of ischemic duration with extent of infarction in dogs.

The time dependence of myocardial necrosis has not been established for the right ventricle. In 16 dogs, we studied the temporal extension of ischemia-induced right ventricular free wall infarction for one hour (n = 8) and two hours (n = 8) followed by two hours of reperfusion, and quantitated segmental shortening, area at risk from ischemia, and area of necrosis. Stroke volume decreased 7.3 +/- 0.5 mL/beat (+/- standard error of the mean) in one hour (p less than 0.05) and 7.4 +/- 1.3 mL/beat in two hours (p less than 0.05). Segmental shortening was replaced by paradoxical motion in both groups during ischemia, and remained depressed throughout reperfusion. Right ventricular end-diastolic pressure increased with ischemia and then returned to normal during reperfusion. The extent of infarction appeared proportionate to the duration of ischemia, 13.2% +/- 4.1% at one hour and 66.9% +/- 4.5% at two hours (p less than 0.01). We conclude that the wave front of necrosis in the right ventricle progresses with duration of ischemia and that clinical techniques capable of limiting the duration of ischemia might salvage substantial amounts of right ventricular myocardium.