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Updated: Aug 4, 2026
In vitro Assessment of Myocardial Protection following Hypothermia-Preconditioning in a Human Cardiac Myocytes Model
Published on: October 27, 2020
Pressurized rapid cardioplegia versus administration of exogenous substrate and topical hypothermia
Insights
Rapid, high-flow hypothermic cardioplegia with intermittent reperfusion offers superior myocardial protection during aortocoronary operations compared to slower infusion methods. This technique significantly reduces cardiac enzyme release and improves patient outcomes.
Area of Science:
- Cardiovascular Surgery
- Cardiac Anesthesia
- Cardiomyocyte Protection
Background:
- Myocardial protection during cardiac surgery is critical for patient outcomes.
- Various methods of cardioplegia and hypothermia are employed to minimize ischemia-reperfusion injury.
- Optimizing myocardial protection strategies remains an area of active research in cardiac surgery.
Purpose of the Study:
- To compare the efficacy of two distinct myocardial protection strategies during aortocoronary operations.
- To evaluate the impact of rapid, high-flow hypothermic cardioplegia versus slow-infusion cardioplegia with topical hypothermia on myocardial injury markers.
- To assess the association between different myocardial protection methods and postoperative cardiac function and complications.
Main Methods:
- Retrospective analysis of 559 patients undergoing aortocoronary operations.
- Group 1: Rapid method of hypothermic cardioplegia alone.
- Group 2: Slower infusion of cardioplegia with topical hypothermia.
- Postoperative measurement of cardiac isoenzymes (CPK-MB, LDH1, LDH2, SGOT) and myocardial infarct index (MII) for 48 hours.
Main Results:
- Group 1 demonstrated significantly lower CPK-MB and MII levels immediately post-operation compared to Group 2 (p < 0.01).
- Higher levels of LDH1, LDH2, total LDH, and SGOT were observed in Group 2.
- Group 1 experienced no intraoperative infarctions, compared to ten in Group 2; 45% of Group 2 patients required inotropic agents postoperatively, versus none in Group 1.
- Spontaneous cardiac rhythm post-ischemia was achieved in 89.7% of Group 1 patients versus 29% in Group 2.
Conclusions:
- Pressurized, high-flow rapid cardioplegia with intermittent reperfusion provides superior myocardial protection during aortocoronary operations.
- This method is more effective than slower, low-flow infusion combined with topical hypothermia in preventing myocardial injury and improving postoperative recovery.
- The findings support the adoption of rapid, high-flow cardioplegia as a preferred strategy for myocardial preservation in cardiac surgery.
Abstract:
Five hundred fifty-nine patients undergoing aortocoronary operation were analyzed retrospectively according to the type of myocardial protection implemented during the period of ischemia. In Group 1 (253 patients), a rapid method of hypothermic cardioplegia alone was utilized. In Group 2 (306 patients), slower infusion of the same solution with topical hypothermia was implemented. Cardiac isoenzymes (CPK-MB, LDH1, LDH2, serum glutamic oxaloacetic transaminase [SGOT]) and myocardial infarct index (MII) were measured postoperatively for 48 hours. Immediately after operation, a significant difference was found between Groups 1 and 2 in the CPK-MB isoenzyme mean value levels--12.1 versus 18.6 IU, p less than 0.01--and MII mean values--5.2 versus 8.1, p less than 0.01. CPK-MB variances between subgroups receiving two, three, and four grafts were significantly different in favor of Group 1. Differences were also found in LDH1, LDH2, total lactic dehydrogenase (LDH), and SGOT: Group 2 levels were significantly higher than in Group 1. There were ten intraoperative infarctions in Group 2 and none in Group 1. In 45% of the patients in Group 2, inotropic agents were necessary in the postoperative period versus none in Group 1. Spontaneous cardiac rhythm following ischemia occurred in 89.7% of the patients in group 1 versus 29% in Group 2. A method of pressurized high-flow rapid cardioplegia with intermittent reperfusions alone, seems to provide adequate protection of the myocardium during ischemia over a slower low-flow method of infusion combined with topical hypothermia.
