Related Experiment Videos
Comparison of cold versus warm cardioplegia. Crystalloid antegrade or retrograde blood?
T Z Lajos1, C C Espersen, P S Lajos
1State University of New York at Buffalo, School of Medicine.
Insights
Cold cardioplegia, whether crystalloid or blood-based and delivered retrograde, offers safe myocardial protection during coronary artery bypass surgery. Warm cardioplegia requires continuous oxygen delivery for effective protection.
Area of Science:
- Cardiovascular Surgery
- Cardioplegia Techniques
- Myocardial Protection
Background:
- Evaluating the efficacy of warm versus cold and antegrade versus retrograde cardioplegia in coronary artery bypass grafting.
- 163 patients were randomized into three groups undergoing isolated coronary artery bypasses.
Purpose of the Study:
- To compare the myocardial protection offered by different cardioplegia strategies.
- To assess the safety and efficacy of warm vs. cold and antegrade vs. retrograde cardioplegia delivery.
Main Methods:
- Three groups received different cardioplegia: Group 1 (cold crystalloid antegrade), Group 2 (warm retrograde), Group 3 (cold retrograde blood cardioplegia).
- Patients were monitored for supraventricular tachycardia, ECG changes, cardiac enzymes (CPK-MB), and hemodynamic parameters.
- Intraoperative measurements included aortic and coronary sinus sampling for pH, A-VO2 differences, and enzyme leak.
Main Results:
- No significant difference in supraventricular tachycardia or CPK-MB levels among groups.
- Warm heart consumed significantly more oxygen (1.3-1.6 mL O2/100 mL flow) compared to cold groups (0.5-0.6 mL O2/100 mL flow).
- Hemodynamics were similar across all groups; two deaths occurred in the warm retrograde group, with three strokes also noted in this group.
Conclusions:
- Continuous warm cardioplegia did not offer superior myocardial protection.
- Intermittent cold crystalloid and cold retrograde cardioplegia provided better operative conditions.
- Cold cardioplegia (crystalloid or blood) is safe under hypothermia for procedures under 90 minutes, while warm cardioplegia necessitates continuous oxygenation.
Background:
To evaluate the efficacy of warm versus cold and antegrade versus retrograde cardioplegia, 163 patients were randomized in sequence in three groups and underwent isolated coronary artery bypasses (mean, 4 grafts/patients) alternating in sequence.
Methods And Results:
The demographic profiles were identical. Cold crystalloid cardioplegia (group 1) was delivered through the aortic root intermittently. The warm retrograde (group 2) was started antegrade with high potassium solution until the heart stopped. It was continued with retrograde coronary sinus perfusion, 100 mL/min of warm blood. Cold retrograde blood cardioplegia (4:1) (group 3) was started antegrade and continued retrograde through the coronary sinus. The heart temperature was kept at 10 degrees to 15 degrees C. Patients were evaluated intraoperatively and postoperatively for (1) supraventricular tachycardia, (2) ECG changes, (3) lactate dehydrogenase and total CPK and isoenzyme (MB) studies, and (4) hemodynamic studies in the intensive care unit. Warm retrograde and cold retrograde patients had sampling of the ascending aorta (antegrade) and the coronary sinus (retrograde) measuring pH, A-VO2 differences, and CK enzyme leak.
Results:
The incidence of supraventricular tachycardia was 29% in group 2, 22% in group 1, 18% in group 3; not significant (NS). CPK isoenzyme MB fraction showed identical levels (NS). The warm heart consumed 1.3 to 1.6 mL O2/100 mL flow, while the cold group 3 showed 0.5 to 0.6 mL O2/100 mL flow (P < .001). Cold crystalloid cardioplegia (group 1) was similar to group 3 (0.3 mL O2/100 mL). All three groups were similar hemodynamically (cardiac output, cardiac index, left ventricular stroke work index). Two of 163 patients died in group 2. Four sustained stroke, three in group 2, one with a fatal outcome.
Conclusions:
Continuous warm cardioplegia (group 2) did not provide better myocardial protection despite that no CK-MB isoenzyme leak was demonstrated intraoperatively. Intermittent cold crystalloid cardioplegia and cold retrograde provided a clearer operative field and motionless heart. As long as O2 was adequately supplied, under 90 minutes' cross-clamp time, cold crystalloid cardioplegia and cold retrograde blood cardioplegia is safe under hypothermic conditions, whereas warm cardioplegia requires continuous uninterrupted technique with oxygen delivery.