Despite meticulous adherence to presently known principles of surgical myocardial protection using advanced cardioplegic technologies, some patients require inotropic support and/or mechanical assist devices postoperatively, when none were required preoperatively.There is good clinical evidence to support the concept that all patients undergoing cardiac surgery utilizing induced ischemic cardiac arrest associated with aortic cross-clamping have varying degrees of myocardial stunning, occasionally requiring inotropic support, which after abatement over hours or days after surgery have no objective evidence of myocardial infarction.