Improved Myocardial Protection Using Continuous Coronary Perfusion with Normothermic Blood and Beta-Blockade with Esmolol*

Abstract

Continuous coronary perfusion with warm ß-blocker-enriched blood has been suggested as an alternative to cardioplegic arrest for myocardial protection during coronary artery surgery. The purpose of the present work was 1.) to experimentally inves-tigate this technique using an animal model, and 2.) to clinically apply this alternative myocardial protection technique and com-pare it to Standard crystalloid cardioplegia in a controlled study. We placed 6 dogs on CPB and 6 dogs on a biventricular assist de-vice and created “ ß-blocker-induced cardiac surgical conditions” by suppressing myocardial chronotropy and inotropy with sys-temic infusion of the ultra-short acting ß-blocker esmolol. For the clinical study we randomized 60 coronary artery surgery pa-tients to receive either crystalloid cardioplegia (Bretschneider HTK) or selective continuous coronary perfusion via the aortic root with warm esmolol-enriched CPB blood. In the experimental study we found that continuous coronary perfusion with warm esmolol-enriched blood avoided myocardial ischemia and mi-nimized myocardial edema, thus completely preserving cardiac Performance. Our clinical data showed the alternative technique to be superior to Standard crystalloid cardioplegia in terms of both functional and structural myocardial protection. The con-cept of ß-blocker-induced cardiac surgical conditions is a useful alternative for myocardial protection during coronary artery surgery and may be particularly beneficial for severely com-promised hearts.

Key words

Myocardium - Cardioplegia - Edema - Myocardial protection - Coronary disease