Dog myocardial protection by retrograde coronary sinus perfusion in beating heart

Objective To evaluate the myocardial protective effects of retrograde perfusion via coronary sinus in beating heart in dog.Methods Sixteen dogs were randomly divided into 2 groups: group A (beating heart with continuous (33±1) ℃ warm blood perfusion, n =8) and group B (cold blood cardioplegia group with intervallic heart perfusion, n =8).Retrograde perfusion vis coronary sinus was performed for 120 min and cardiopulmonary bypass (CPB) was performed for 150 min.Calcitonin gene-related peptide (CGRP),atrial natriuretic peptide (ANP),endothelin-1 (ET-1),cardiac troponin T (cTn-T) were measured.Results All of the biochemical values were increased after CPB ( P 0.05).But,ET-1 and cTn-T in group B were higher than in group A ( P 0.05),and CGRP,ANP were lower than group A ( P 0.05) at 60,90 and 120 min by retrograde perfusion through coronary sinus,opening of superior and inferior vena cava for 30,and immediate after operation.Recovery of cadical function in group A was smooth when stopping CPB and immediate after operation.The dose of dopamine used in group B was larger than in group A ( P 0.01).Arrhythmias occurred in 3 dogs of the group B.Conclusion The method of retrograde coronary sinus perfusion in beating heart was a favourable secretion of CGRP and ANP against ET-1.Myocardial protective effects in group A was superier to that of group B.