The Annals of Thoracic Surgery, Vol 47, 729-734, Copyright © 1989 by The Society of Thoracic Surgeons
Right ventricular free wall ischemia: correlation of ischemic duration with extent of infarction in dogs
WE Johnston, J Vinten-Johansen, A Patel and WP Santamore
Department of Anesthesia, Wake Forest University Medical Center, Winston-Salem, North Carolina 27103.
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.
