Introduction:  In cardiac surgery is essential protect myocardial tissue during cardiac arrest to perform the surgical procedure. The Cardioplegic solution has showed significant efficacy for myocardial protection by providing buffer mediators. The volume needed to achieve cardiac arrest is usually calculated using patient's weight or body surface area as a reference. However, the increase in ventricular mass secondary to cardiac pathology frequently does not coincide with the patient's weight and body surface area, requiring different cardioplegic solution volume to achieve myocardial arrest and protection. In this study we explored the true volume of cardioplegia administered to achieve myocardial arrest and protection adjusted to myocardial mass index.
Method:  We selected patients undergoing open heart surgery with cardiac arrest and administration of cardioplegia solution as myocardial protector and were registered following variables: Age, sex, body weight, body surface, Mass Ventricular Index, cardiovascular factor risk, cardiac pathology and surgical complications.
Results: Were analyzed 112 patients of 60±10 years old, 76% (n = 85) were male and 24% (n = 27) female. The cardioplegic solution calculated at 30, 40 and 50 ml using as reference Body Weight (BW) and Body Surface (BS) showed significant differences with real volume administrated to approach electromechanical cardiac arrest, as well as between BW and BS (p = 0.001), indicated that adjust 14 ml for each gram indexed myocardial mass probably could provide better performance to achieve myocardial arrest and protection.
Conclusion: The real cardioplegic solution volume administrated in open heart surgery is significantly different with volume calculated with BW and BS as reference and calculated with VMI very probably is a better way to calculate the cardioplegia solution volume.