Comparison of Single versus Multidose Blood Cardioplegia in Arterial Switch Procedures

Fifty-three patients with transposition of the great arteries and Taussig-Bing anomaly undergoing an arterial switch procedure were divided into two groups. Group 1 (N = 32) received multidose cardioplegia injected initially into the aortic root and subsequently into the coronary artery orifices and Group 2 (N = 21), single-dose cardioplegia injected into the aortic root. The mean aortic cross-clamp and bypass times were generally longer in Group 1 compared with Group 2. Group 1 patients with simple transposition undergoing primary repair (N = 15) had an aortic cross-clamp time of 80 ± 8 minutes and a bypass time of 203 ± 27 minutes versus 64 ± 6 minutes (p < 0.001) and 170 ± 15 minutes (p < 0.01), respectively, for similar patients in Group 2 (N = 10). Group 1 patients with simple transposition undergoing staged repair (N = 7) had an aortic cross-clamp time of 71 ± 6 minutes and a bypass time of 201 ± 24 minutes versus 66 ± 4 minutes (p = not significant [NS]) and 226 ± 25 minutes (p = NS), respectively, for Group 2 (N = 6). In Group 1 patients with complex transposition (N = 10), the aortic bypass time was 79 ± 12 minutes and the bypass time was 261 ± 40 minutes versus 64 ± 11 minutes (p < 0.05) and 225 ± 16 minutes (p < 0.1), respectively, for Group 2 (N = 5). Early mortality was 16% (5/32) in Group 1; there were no early deaths in Group 2. One patient died of an occluded left coronary artery attributed to catheter trauma. Late mortality was 11% (3/27) in Group 1 and 5% (1/21) in Group 2. In Group 1, postoperative ST-T wave changes developed in 37% (10/27) compared with 5% (1/21) in Group 2. The postoperative myocardial performance determined echocardiographically by systolic increase in septal and posterior wall thickness, fractional shortening, and left ventricular end-diastolic dimensions was comparable in the two groups. We conclude that the administration of a single dose of cold blood cardioplegia into the aortic root, along with topical and systemic hypothermia, is a simple and effective method of myocardial protection in infants and young children undergoing the arterial switch procedure.