Is high potassium solution necessary for reinfusions in "multidose" cold cardioplegia? A randomized prospective study...

Area of Science:

• Cardiology
• Cardiac Surgery
• Cardiovascular Physiology

Background:

• Multidose potassium cardioplegia is standard for myocardial preservation during cardiac surgery.
• Evidence is conflicting regarding whether repeated high potassium infusions enhance protection.

Purpose of the Study:

• To compare the effects of multidose high potassium versus initial high potassium followed by low potassium cardioplegia on postoperative myocardial electrical stability and hemodynamics.

Main Methods:

• Prospective randomized trial of 56 patients.
• Group 1: Multidose cold high potassium (27 mEq/L KCl).
• Group 2: Initial high potassium (27 mEq/L KCl) followed by cold low potassium (7 mEq/L KCl).
• Continuous Holter monitoring for electrocardiograms.
• Comparison of arrhythmias and hemodynamic performance.

Main Results:

• No difference in aortic cross-clamping or cardiopulmonary bypass times.
• Group 1 (more total KCl) had significantly higher rates of high-grade ventricular ectopia during reperfusion and postoperatively (p < .001).
• Group 1 required more lidocaine hydrochloride for arrhythmias (p < .001).
• No significant difference in hemodynamic performance between groups.

Conclusions:

• Multidose high potassium cardioplegia offers no advantage for myocardial preservation.
• Increased ventricular ectopia is associated with the use of multidose high potassium cardioplegia.
• Low potassium solutions are recommended after initial cold high potassium arrest.