A comparative study of the effect of two different delivery techniques (conventional versus microplegia) of del Nido cardioplegia on myocardium in paeditric congenital heart disease.

Introduction: del Nido cardioplegia was developed for immature myocardium to prevent myocardial damage by Ca⁺² in traditional blood cardioplegia. But due to increased hemodilution and decreased colloid oncotic pressure it may cause myocardial edema and increased cardiac morbidity. Microplegia may have better cardioprotection in comparison to del Nido as there is less hemodilution.

Material and methods: 60 patients from the age group of 1 to 14 years were divided into two groups i.e. del Nido based microplegia group and conventional del Nido group for studying two different cardioplegia technique. Data were collected and compared for intraoperative Hb, CPK-MB and Trop-I levels changes and requirement for defibrillation in intraoperative period. Demographic data, CPB time and ACC time were also collected.

Results: Marked elevation in CPK-MB and Trop-I levels were seen in both groups. Statistically significant difference was seen in CPK-MB levels after 6 h of surgery where del Nido group has higher value in comparison to microplegia group. No statistical difference was seen in Trop-I levels in both groups. Strength of correlation (r) was also stronger for CPK-MB rise in association with CPB time and ACC time, in del Nido group but not for Trop-I. Significantly higher hemodilution was also seen in del Nido group after delivering cardioplegia. None of the patients required defibrillation in any group.

Conclusion: Lesser hemodilution was seen in microplegia group. Significant cardioprotection is associated with use of microplegia solution in pediatric age group.