Assesement of new myocardial protection strategies during CPB may be made at the functional, biochemical, or pathologyc level.

While evidence of arrhythmias or poor returnof contractility after reperfusion is often indicative of poor cardioprotevtion, accelerated myocyte ATP depletion, presence of markers of myocardial cell injury (CPK, troponin T), or pathologic evidence of ischemic contractures are also indicators of inrffective cardiac protection.

Specific circumstances may increase risk for poor myocardial protection;the andocardium, perticulary in the hypertrophied heart, is at risk, as are regions of myocardium supplied by critically stenosed vessels. Ideal myocardial protection strategies must be safe and amenable to delivery to all myocardial locations, while also being flexble to the unique considerations of a surgery for which theyb are being selected.