The Annals of Thoracic Surgery, Vol 43, 409-415, Copyright © 1987 by The Society of Thoracic Surgeons
Is high potassium solution necessary for reinfusions in "multidose" cold cardioplegia? A randomized prospective study using computerized Holter system
M Dewar, MD Rosengarten, R Samson, C Wittnich, PE Blundell and RC Chiu
Multidose potassium cardioplegia is a common method of myocardial
preservation. Although initial potassium arrest conserves high-energy
phosphates, there is conflicting evidence that repeat high potassium
boluses augment this protection. Fifty-six patients were prospectively
randomized to receive multidose cold high potassium cardioplegia (27 mEq of
KCl/L) both in the initial and subsequent infusions (Group 1) or an initial
cold high potassium (27 mEq/L) cardioplegia followed by boluses of cold low
potassium (7 mEq, of KCl/L) solution (Group 2). The two groups were
compared in terms of postoperative myocardial electrical stability and
hemodynamic performance. Electrocardiograms were recorded by continuous
Holter monitor, and the data were analyzed by computer. The duration of
aortic cross-clamping and cardiopulmonary bypass did not differ between
groups. Group 1, who received more total KCl than Group 2 (p less than
.005), experienced more high-grade ventricular ectopia during both
reperfusion (p less than .001) and the immediate postoperative period (p
less than .001), and required more lidocaine hydrochloride (p less than
.001) for arrhythmias. There was no significant difference in hemodynamic
performance between the two groups. This study fails to show an advantage
to multidose "high potassium" cardioplegia and found a significant increase
in ventricular ectopia associated with its use. We advocate using low
potassium solutions after initial cold high potassium arrest.
