Optimization of cardioprotection using intermittent isothermic blood-cardioplegia

Abstract

Objective. The aim of this research was to optimize cardioprotection by means of isothermal intermittent blood cardioplegia in patients with left ventricle myocardial hypertrophy (LVMH). Materials and methods. We analyzed 700 pair samples of transmyocardial blood, taken from 100 patients divided into two groups: research group with LVMH (n = 50, left ventricle posterior wall ≥ 11 mm), and control group without LVMH (n = 50, LVPW < 11 mm). The comparison of average levels of transmyocardial lactate, venous saturation, pH, oxygen consumption, venous carbon dioxide tension (pvCO2) initially and at the end of each cardioplegia depending on its time and volume parameters was carried out in each group with the use of Student and Wilkokson criteria. Results. Average cross clump time and the number of cardioplegia sessions in research and control groups had no significant differences (37,7 ± 12,8 and 38,9 ± 24,8 minutes; 3,1 ± 2,2 and 3,5 ± 3,1 sessions accordingly; p > 0,05). If the intervals between cardioplegia sessions were 12-15 minutes the average transmyocardial lactate level was significantly higher in research group (2,2 ± 1,7 and 1,6 ± 1,1 mmol/l; p < 0,05), if the intervals were more than 15 minutes the changes were even more expressed (2,5 ± 1,9 and 1,7 ± 0,9 mmol/l; p < 0,05). When the maintenance coronary sinus lactate level was less than 2,2 mmol/l in both groups, average time between cardioplegia sessions was 11,3 ± 5,9 minutes and was significantly lower, than in group with compromised myocardium metabolism. Conclusion. Our data show that the quality of cardioprotection depends on LVMH presence and cardioplegia volume-time characteristics.