Experiments were carried out according to National Institutes of Health Guidelines on the Use of Laboratory Animals and all procedures were approved by the Thomas Jefferson University Committee on Animal Care. A total of 497 (384 mice for MI and 113 for I/R) male 8-10 week old C57/B6 mice were used for this study. For the MI model, mice were subjected to permanent coronary artery ligation using either the new (N) method or the classical (C) method. Mice were randomly assigned to four groups: new method of MI (MI-N) or sham (S-N); classical method of MI (MI-C) or sham (S-C). There were 119 mice used for survival study. Some of the mice survived at the end of 28 days were also used for echocardiographic, hemodynamic and infarct size studies as indicated in each study. The rest of 232 mice survived from all kinds of 265 procedures (33 mice died) were used for 24h infarct size measurement (32 mice), Masson's trichrome stain (18 mice), arrhythmia analysis (28 mice), myeloperoxidase (MPO, 81) and TNFα (73) assays. In I/R model, mice were subjected to 30 min of myocardial ischemia followed by 24 hrs of reperfusion. Mice were divided into four groups also: new method of I/R (I/R-N, n=41) or sham (SI/R-N, n=16), classical method of I/R or sham I/R (I/R-C, n=40, SI/R-C, n=16, respectively). All animals were monitored after the surgery and received one dose (0.3mg/kg) of buprenophine within 6 hours post surgery and another dose was administered the following morning. No further analgesia was given thereafter.