Comparison of retrograde vs simultaneous ante/retrograde cold blood cardioplegia.

BACKGROUND: To evaluate the homeostasis of myocardium during simultaneous continuous retrograde and antegrade cardioplegia vs retrograde continuous cardioplegia. METHODS: 40 patients who underwent elective operation of coronary arteries bypass grafting were randomly assigned to 2 groups: group one consisted of 24 patients who received retrograde continuous blood cardioplegia; group two consisted of 16 patients who received simultaneous continuous ante/retrograde cardioplegia. The following measurements were taken: acidosis, oxygen content, oxygen extraction and oxygen consumption; they were taken before and after cross-clamp releasing from coronary sinus effluent and from arterial line. Incidence of low cardiac output, ventricular fibrillation, raised cardiac enzymes and ischemic changes on ECG was noted. RESULTS: In simultaneous group such parameters as acidosis, oxygen content, oxygen extraction and myocardial oxygen consumption recovered after cross-clamping and changes of their values were respectively: 0.0005, 0.87 ml/100 ml, 0.098 and 1.4 ml/min. The same parameters didn't recovered in retrograde group and changes were respectively: 0.05 - p=0.2; 3.7 ml/100 ml - p=0.006, 0.29 p=0.006 and 7.4 ml/min - p=0.03. These changes were significant between groups. CONCLUSIONS: Metabolic viability of myocardium measured with oxygen utilisation is better preserved with simultaneous antegrade and retrograde cardioplegia.

Does simultaneous antegrade and retrograde cardioplegia improve functional recovery and myocardial homeostasis?

BACKGROUND: The purpose of our research was to evaluate the functional recovery and homeostasis of myocardium during simultaneous continuous retrograde and antegrade cardioplegia versus continuous retrograde cardioplegia. METHODS: Forty patients who underwent elective coronary artery bypass grafting (CABG) were prospectively assigned to two clinically matched groups and analyzed in respect to cardioplegia protocol. Group I consisted of 24 patients who received continuous retrograde blood cardioplegia; Group II consisted of 16 patients who received simultaneous continuous ante- and retrograde cardioplegia. Hydrogen ion release, carbon dioxide, lactate concentration oxygen content, and oxygen extraction were measured from coronary sinus effluent and from the arterial line before and after cross-clamping of the aorta. Median changes of these parameters were reported. Cardiac output was measured and left and right ventricle stroke works were calculated. Incidence of low cardiac output, ventricular fibrillation, raised cardiac enzymes, and ischemic changes on electrocardiogram (ECG) were noted. RESULTS: In the simultaneous group, oxygen content and oxygen extraction recovered well after cross-clamping. The same parameters did not recover to the same extent in the retrograde group. These changes were notable between groups. Hydrogen ion, carbon dioxide, and lactate releases were comparable between groups. Trend toward better recovery of left ventricle stroke work index was encountered in the simultaneous group. CONCLUSIONS: Viability of myocardium measured with oxygen utilization and functional recovery is better preserved with simultaneous antegrade and retrograde cardioplegia. However, there is no difference in anaerobic metabolism markers. Thus simultaneous ante- and retrograde cardioplegia is probably advantageous over retrograde alone.

Comparison of retrograde versus antegrade cold blood cardioplegia: randomized trial in elective coronary artery bypass patients.

OBJECTIVE: Myocardial areas distal to complete coronary artery occlusion are poorly protected by antegrade cardioplegia. Hence, retrograde cardioplegia becomes an important adjunct in myocardial protection. An aim of the study was to compare both methods prospectively. METHODS: 158 coronary artery bypass grafting (CABG) patients were randomly assigned to two groups according to myocardial protection technique: 89 patients to group 1--retrograde cold blood cardioplegia (RCBC); and 69 patients to group 2--antegrade cold blood cardioplegia (ACBC). Preoperative parameters were similar but cross-clamp time and volume of cardioplegia needed were higher in the retrograde group. The results were assessed on the basis of: (1) clinical outcome; (2) ECG and enzymatic parameters of ischemia; (3) assessment of early systolic function by means of cardiac output (CO), stroke work index (SWI), left ventricular stroke work index (LVSWI) and right ventricular stroke work index (RVSWI) taken before, and 1 and 5 h after coming off bypass; (4) late systolic and diastolic function by echo assessment of segmental contractility of 17 segments and indexes of peak transmitral flow (TMI) taken 7 days and 6 months after operation. RESULTS: Ischemic events, inotropes and ventricular fibrillation on reperfusion were significantly more frequent in the antegrade group. Sinus rhythm at an early stage postoperatively was found more frequently in the retrograde group. All these parameters became comparable 24 h after operation. Early myocardial recovery was better in the retrograde group where intraoperative improvement in CO and SWI was significant. At the same time, SWI decreased significantly in the antegrade group. RVSWI changes were similar in both groups. There were no differences in mortality and perioperative MI. Late myocardial performance by segmental contractility and diastolic transmitral flow were similar in both groups. CONCLUSIONS: Retrograde continuous blood cardioplegia reduces ischemic injury and permits better early recovery of myocardial function. There is no difference, however, regarding long-term assessment of myocardial recovery.

Results of mechanical prosthetic valve replacement in active valvular endocarditis.

UNLABELLED: To evaluate the results of mechanical prosthetic valve replacement for active endocarditis 71 patients were reviewed. They were treated surgically between 1988 and 1993 in our institution. Mechanical valves were used in 54 patients (group 1) and bioprosthetic valves were used in 17 patients (group 2). In terms of demographic, clinical and surgical variables prior to operation groups were statistically the same. Follow up ranged from 2-63 months averaged 21 months. This study was carried out to: asses cardiac status postoperatively and assess the rate of mortality, recurrency and reoperations. METHODS: Evaluation of cardiac status was assessed on the basis of symptoms and findings by examination, ECG, X-ray, echocardiography, and laboratory tests. Data analysis was done by means of statistical tests like: Student's "t"-test, Fisher exact test, one sided test of difference between two percentages, Kaplan Meyer survival analysis and Cox test. RESULTS: 4-year mortality was 20% in group 1 comparing to 28,6% in group 2, when early mortality were 13% in group 1 comparing to 17% in group 2. These differences were not significant. The recurrency rate was 8,5% in group 1 comparing to 28,6% in group 2 which was statistically significant (p=0.028). Especially early recurrency rates differed significantly between groups and were 4,2% in group 1 comparing to 21% in group 2 (p=0.022). The reoperations rate was 4,2% in group 1 comparing to 21% in group 2 which was statistically significant (p=0.022). Clinical status showed satisfactory values and significant improvement in both groups, slightly better after mechanical valve replacement. CONCLUSION: It is concluded that mechanical valve is recommended for valve replacement in active valvular endocarditis first of all due to low recurrency and reoperation rate.