Journal of cardiac surgery
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It has been suggested that cardioplegic arrest during cardiopulmonary bypass (CPB) produces global myocardial ischemia with a risk of myocardial stunning. It has also been postulated that anesthetic technique may affect the course of post-CPB myocardial stunning via exaggerated myocardial depression. However, we have previously found that global ventricular and regional myocardial responses to halothane do not differ in post-CPB and pre-CPB dogs. ⋯ Since other data show normal inotropic stimulation of stunned myocardium, decreases in dobutamine responsiveness cannot be explained by beta-receptor desensitization. Overall, these data indicate that CPB does not result in myocardial stunning. The differences between these data and others showing myocardial stunning following CPB may be due to several factors, such as anesthetic regimen, lack of coronary blood flow abnormalities, and a reduction in sarcoplasmic reticular damage due to the hypothermic conditions used.
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Randomized Controlled Trial Clinical Trial
The effect of prophylactic nitroglycerin infusion on the incidence of regional wall-motion abnormalities and ST segment changes in patients undergoing coronary artery bypass surgery.
The effects of nitroglycerin (NTG) on regional wall-motion abnormalities, ST segment changes, and the incidence of myocardial infarction (MI), cardiac failure, and mortality were studied in 30 patients undergoing coronary artery bypass. Patients received continuous infusions of either normal saline or NTG (1 microgram/kg per min [low dose] or 2 micrograms/kg per min [high dose]) beginning at anesthesia and continuing for 4 hours postoperatively. ⋯ There were no significant differences between the control and NTG groups with regard to the incidence of Holter ST segment events or the incidence of MI, cardiac failure, or cardiac death. NTG reduced the incidence of echocardiographic wall-motion abnormalities in a dose dependent manner while having no significant effect on other parameters examined.