RESUMO
BACKGROUND: Coronary artery bypass grafting (CABG) surgery is widely accepted as a revascularization method for coronary artery disease (CAD). Despite survival benefit and improvement in quality of life, CABG may impose major morbidities and significant complications. Right ventricle (RV) dysfunction is an important complication that may affect patient's longevity and functional capacity. The aim of this study was to evaluate the relationship between RV dysfunction and some invisible parameters like inferior vena cava (IVC) size with physical capacity. METHODS: In this prospective study, 61 eligible CABG candidates were enrolled and RV function was assessed by echocardiographic parameters before CABG and one week and six months after the procedure, using tricuspid annular plane systolic excursion (TAPSE), Tei Index (TI), peak systolic movement (Sm) (cm/s), and IVC size. Functional capacity was assessed by six-minute walk test (6-MWT) 6 months after CABG. RESULTS: 58 patients who did not have any perioperative RV dysfunction were remained until the end of study; mean age was 58.2 ± 7.9 years with 68.9% being men, and 3 patients died after CABG. Preoperatively, septal motion, RV indices, and IVC size were normal in all patients. The frequency of RV dysfunction according to abnormal TAPSE index, TI, and peak Sm one week after surgery was 81.0%, 79.0%, and 62.0%, respectively, and 6 months after surgery was 49.0%, 49.0%, and 37.0%, respectively. Mean walked distance in 6-MWT was significantly less in patients with RV dysfunction, older age, and higher number of involved vessels (P < 0.001). CONCLUSION: The significant reduction in RV function and impairment of exercise capacity after CABG in this study suggests cardiologists to pay more attention to RV assessment in follow-up visits of patients undergoing GABG.
RESUMO
BACKGROUND: Cardiac surgery is associated with some degree of myocardial injury. Preconditioning first described in 1986 was pharmacologic and non- pharmacologic. Among the long list of anesthetic drugs, isoflurane as an inhaling agent along with midazolam and propofol as injectable substances have been documented to confer some preconditioning effects on myocardium. OBJECTIVES: In this study cardiac Troponin T (cTnT) ,as a reliable marker, was used for evaluating myocardial injury. METHODS: This prospective double blind study was comprised of 60 patients scheduled for CABG and were randomly assigned into three groups who received infusion of propofol or midazolam or isoflorane. Surgical procedures and anesthetics were similar for 3 groups. cTnT measured preoperatively and at 12, 24 and 36hr after arrival in ICU. RESULTS: There were no statistically significant differences in mean cTnT levels between three groups in the preoperative period and 12-24 hours after arrival in ICU. However, mean cTnT in 3 groups at 36 hours after arrival in ICU were different (P< 0.013) and cTnT level was significantly higher in midazolam group (P<0.001) and lowest in isoflurane group (P=0.002). CONCLUSION: There were significant differences on cTnT levels between anesthetic groups of isofluran, midazolam and propofol at 36 hr after surgery. Preconditioning effect of isoflurane was higher than the other two groups.
