Acute right ventricular failure is caused by inadequate right ventricular hypothermia
Gonzalez, A.C.; Brandon, T.A.; Fortune, R.L.; Casano, S.F.; Martin, M.; Benneson, D.L.; Guilbeau, E.J.; Fisk, R.L.
Journal of Thoracic and Cardiovascular Surgery 89(3): 386-399
1985
ISSN/ISBN: 0022-5223 PMID: 3974274 Document Number: 251276
Inadequate right ventricular hypothermia may contribute to the right ventricular dysfunction occasionally observed after cardiac operations. Dogs were placed on cardiopulmonary bypass and 60 min periods of hypothermic myocardial ischemia were imposed. Left ventricular temperature was always maintained at 15.degree. C and right ventricular temperatures were maintained at 15.degree. C (Group I, n = 8), 25.degree. C (Group II, n = 8) and 35.degree. C (Group III, n = 8). These temperatures were produced by infusion of hypothermic crystalloid cardioplegic solution and appropriate topical cooling and heating of the left and right ventricles, respectively. Multiple indices of ventricular function were obtained 15, 30, 45 and 60 min after bypass and compared to prebypass control values. In all Group I animals (left ventricular temperature = 15.degree. C, right ventricular temperature = 15.degree. C), postischemic indices of right ventricular function were not different from control values (non-significant). In Group II (left ventricular temperature = 15.degree. C, right ventricular temperature - 25.degree. C) 2 animals died 30 and 45 min after bypass, respectively, of right ventricular failure. In the other 6 animals in Group II, all indices of right ventricular function were significantly reduced (P < 0.05) except for right ventricular systolic pressure. In Group III (left ventricular temperature = 15.degree. C, right ventricular temperature - 35.degree. C) 2 animals could not be weaned from cardiopulmonary bypass because of right ventricular akinesia. Six animals were from bypass, but 2 died 15 min, 1 died 30 min, and one 45 min after bypass. Two animals lived 60 min but all indices of right ventricular function were decreased. Failure to maintain right ventricular temperatures < 25.degree. C during 1 h of cardiac ischemia in the dog can result in fatal right ventricular failure.