Svitlyk Y. The impact of epidural anesthesia on the functional parameters of the myocardium in patients with coronary artery disease

The thesis revealed the peculiarities of epidural anesthesia (EA) in patients with coronary artery disease (CAD) who underwent surgery on inguinal hernia. It was found that surgery with the application of ЕА significantly influences the character of autonomic processes, shifting the vegetative balance towards sympathicotonia that is accompanied by an increased risk of life-threatening arrhythmias. Significantly pronounced autonomic changes observed in patients with CAD. According to the dynamics of the heart rate variability the optimal anesthetic to these patients was ropivacaine. EA leads to a decreasing of heart rate. Risk of bradycardia and heart rate fluctuations was significantly lower in the patients to whom ropivacaine was administered. It was revealed that local anesthetics had proarrhythmogenic effects: ropivacaine and bupivacaine increased ectopic activity of the heart, and lidocaine and bupivacaine had negative influences on processes of conduction. In perioperative period significantly increased values of corrected interval QT and its dispersion, which are markers of ventricular arrhythmogenesis. Statistically mean values of QTc and QTd in patients with CAD exceed significantly those in patients without CAD. EA impairs functional properties of the myocardium at a subclinical level (prolongation of duration of isovolumetric contraction and relaxation time, reducing of right ventricular longitudinal contractility). The more pronounced changes were in patients with CAD, especially under anesthesia with bupivacaine. Positive effect on the above mentioned changes during epidural anesthesia has demonstrated administering of methabolic therapy.