The effect of cold cardioplegic cardiac arrest and electrically induced ventricular fibrillation on human cardiac beta-adrenoceptors during open-heart surgery.
This study was designed to test the hypothesis that distinct alterations in cardiac beta-adrenoceptors (betaARs) may occur during cardiopulmonary bypass (CPB) alone, during CPB with cold cardioplegic cardiac arrest (CCCA), and during CPB with electrically induced ventricular fibrillation (EIVF). We assessed the density and affinity of right atrial betaARs in 27 patients undergoing open-heart surgery by (-)-[125I]iodocyanopindolol binding before CPB, defined as the "control," immediately after initiation, defined as "before," and immediately before the cessation of CCCA or EIVF, defined as "after." The density of betaARs was equivalent between the "control" and "before" groups; however, during CPB with EIVF, the density of betaARs decreased significantly (P < 0.001), whereas during CPB with CCCA, it increased significantly (P < 0.01). The rate of changes of the betaAR density was not correlated with the "before"-"after" interval, and the affinity of the betaARs did not change throughout these CPBs. These findings demonstrate that: CPB alone does not affect cardiac betaARs, at least until the onset of EIVF or CCCA; CPB with EIVF induces rapid desensitization of cardiac betaARs; and CPB with CCCA induces rapid sensitization of cardiac betaARs.
Second Department of Surgery, Gunma University School of Medicine, Maebashi, Japan.
K
K
Tsuda
Y
Y
Hamada
Y
Y
Morishita
D000293:Adolescent; D000328:Adult; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D002648:Child; D002675:Child, Preschool; D004558:Electric Stimulation; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods*; D006325:Heart Atria / Q000737:chemistry*; D006330:Heart Defects, Congenital / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011943:Receptors, Adrenergic, beta / Q000032:analysis*; D014693:Ventricular Fibrillation
D011943:Receptors, Adrenergic, beta