Clinical Evaluation of Hypothermic Ventricular Fibrillation, Multi-Dose Blood Cardioplegia, and Single-Dose Bretschneider Cardioplegia in Coronary Surgery

Abstract

37 patients undergoing coronary revascularization were randomly assigned to three protocols for intraoperative myocardial protection: hypothermic ventricular fibrillation (HF) (n = 13), multi-dose blood cardioplegia (BCP) (n = 12) and single-dose Bretschneider's crystalloid cardioplegia (CCP) (n = 12). As intraoperative markers of ischemic damage myocardial ultrastructure, ATP, and CP contents were determined in left ventricular biopsy specimens taken before and after cardiac arrest. Release of serum enzymes (CK, CK-MB, LDH, SGOT) was determined pre- and postoperatively. Hemodynamic data were assessed before, during, and after operation. The incidence of low cardiac output, positive inotropic support, intraaortic balloon counterpulsation, peri-operative myocardial infarction, rhythm disturbances, and the rate of spontaneous defibrillation was compared between groups. The results show a better preservation of high energy phosphates in the BCP group as compared to the HF and CCP groups. Myocardial ultrastructure showed moderate ischemic damage in the hypothermic fibrillation group; in contrast, only slightly deteriorated cells were seen after cardiac arrest, when cardioplegia was used. The incidence of rhythm disturbances was 25% for HF and 42% for CCP. In contrast, only 17% of new rhythm disturbances were seen in the BCP group. Functional recovery (i.e. CI and SWI) of hearts protected with BCP was generally greater as compared to HF and CCP. Release of MB-creatine-kinase isoenzyme was higher in the HF group as compared to cardioplegia. Clinical outcome in terms of incidence of peri-operative infarction, positive inotropic support and low cardiac output was superior in the BCP group but not significantly different between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Fascicular Conduction Disturbances After Coronary Artery Bypass Surgery: A Review With a Meta-Analysis of Their Long-term Significance

“…Given the increased vulnerability of the conduction system to ischemia, myocardial enzyme elevation could be representative of ischemic damage and myocardial necrosis in the conduction system, without simultaneous infarction of the nearby myocardium 22 . However, its utility probably lies more in ruling out a perioperative myocardial infarction than in the diagnosis of conduction disturbances 13,14,16,23,30 . Hake and coworkers studied the utility of 2‐dimensional transesophageal echocardiography (TEE) in the diagnosis of conduction disturbances 16 .…”

“…Baerman and Gundry found that blood cardioplegia is associated with a higher incidence, 10,15 while Rousou and Beyersdorf found a protective effect of blood cardioplegia on postoperative conduction disturbances. 8,13 This discrepancy could be explained by the difference in temperatures of the cardioplegia solutions employed in these studies, with the first two studies using cold blood cardioplegia, and the latter two using warm blood cardioplegia. Cold cardioplegia is shown to be associated with higher rates of conduction disturbances.…”

“…41 Other diagnostic modalities that have been used include myocardial enzyme levels and echocardiography. 11,13,16,20,22,23,26,27,29,30 Given the increased vulnerability of the conduction system to ischemia, myocardial enzyme elevation could be representative of ischemic damage and myocardial necrosis in the conduction system, without simultaneous infarction of the nearby myocardium. 22 However, its utility probably lies more in ruling out a perioperative myocardial infarction than in the diagnosis of conduction disturbances.…”

“…22 However, its utility probably lies more in ruling out a perioperative myocardial infarction than in the diagnosis of conduction disturbances. 13,14,16,23,30 Hake and coworkers studied the utility of 2-dimensional transesophageal echocardiography (TEE) in the diagnosis of conduction disturbances. 16 A proportion of patients with bundle branch blocks demonstrated paradoxical septal movement.…”

Narrow-pore Flow Behavior of Blood Cells in Cardioplegic Suspension

“…Potassium cardioplegia with added magnesium has become the standard approach, which can either be diluted in a cell-free medium (crystalloid cardioplegia) or in oxygenated blood (blood cardioplegia). Blood cardioplegia seems to offer advantages over crystalloid cardioplegia both clinically and experimentally (1,4,8,12,15). However, it is not known whether this unphysiological concentration of potassium has any effects on red blood cell (RBC) or white blood cell (WBC) populations.…”