ABSTRACT
Objective To compare the efficacy of retrograde cardioplegia for myocardial perfusion with that of antegrade cardioplegia at the same flow rate using magnetic resonance techniques. Methods Myocardial perfusion was evaluated with magnetic resonance imaging in isolated pig hearts during antegrade and retrograde cardioplegia. Phosphorus 31 magnetic resonance spectroscopy was used to determine the efficacies of both cardioplegic techniques in sustaining myocardial energy metabolism. Results Magnetic resonance images showed that contrast-enhanced signal-time courses obtained from different regions of the myocardium during retrograde cardioplegia varied significantly, whereas signal-time courses acquired during antegrade cardioplegia appeared more uniform. Localized phosphorus 31 spectra showed that retrograde cardioplegia resulted in myocardial ischemia at the flow rate of 10 ml/min. However, no significant changes were observed in myocardial energy metabolites until the flow rate was decreased to 3 ml/min during antegrade cardioplegia. Conclusion Microvascular perfusion provided by retrograde cardioplegia varies more significantly among various small areas of the myocardium than that did by antegrade cardioplegia. Moreover, the efficacy of retrograde cardioplegia in sustaining normal myocardial energy metabolism is lower than that of antegrade cardioplegia.
ABSTRACT
Two recipients of orthotopic heart transplantation have all recovered from their serious heart disease and returned to their previous work with good condition for 3 and 1 year respectively.This article discusses with emphasis some steps happened before,during and after the operation of heart transplantation,especially the donor heart protection,immunosuppressant administration,diagnosis and treatment of rejection.