Myocardial protection in the immature heart.

In an era when essentially no congenital heart defect is considered inoperable, it is reasonable to carefully consider the essentials of neonatal myocardial physiology and biochemistry, especially comparisons between immature and adult myocardial responses to ischemia. Because many special clinical interactions dramatically affect myocardial protection, great care must be taken to analyze each case carefully with protection strategies in mind. Finally, cardioplegia composition and delivery are now quite similar to those used in adults, with new equipment facilitating delivery. Research is underway to supplement protection in immature hearts severely injured by adverse preoperative conditions.