Nitroglycerine-induced volume loading.

Fifty-five patients who underwent elective aortic aneurysmorrhaphy were studied intraoperatively to assess ventricular function responses to volume loading and nitroglycerine/inotrope mini-infusions. Assessments of preoperative cardiac reserve and risk of perioperative myocardial infarction were based on ejection fraction (EF); an algorithm was developed to direct differential preanesthetic loading to maximize ventricular performance in normal (EF, greater than 60%), moderate-risk (EF, 35% to 60%), and high-risk (EF, less than 35%) patients. Sixty percent of the patients in the series were at significant risk of myocardial infarction, including 25 with an EF from 35% to 60% and seven with an EF less than 35%; the perioperative myocardial infarction rate was zero. Nitroglycerine-induced volume loading in this series allowed aortic aneurysmorrhaphy without any decrease in ventricular function at the critical points of anesthetic induction, aortic cross clamping, or declamping; such optimization of myocardial performance appears to prevent perioperative myocardial infarction, even in high-risk patients.