PISA--a noninvasive method in the evaluation of protective effect of methylprednisolone on the ischemic myocardium

This study deals with the assessment of the PISA--a new noninvasive method, in relation to conventional ECG, MBCPK and LDH1, in the detection and quantification of coronary ligation-induced myocardial damage. Also this study includes the applicability of the PISA method in the evaluation of the effectiveness of methylprednisolone in the protection of myocardial damage, induced by coronary ligation. The studies were conducted in 15 mongrel dogs: (untreated dogs: 9; methylprednisolone (30 mg/kg I.V.) treated dogs: 6). The PISA signature pattern was normal and the PISA index was small in all the dogs before coronary ligation. The PISA signature was phase-variant in all dogs in the untreated group following coronary ligation. The PISA index increased with time following coronary ligation but the changes at 60 minutes were less than at 30 and 120 minutes. There were no significant changes in the conventional ECG, serum MBCPK and LDH1 for the 120 minute duration of coronary ligation. These results indicate the superiority of the PISA method in the detection and quantification of coronary artery ligation-induced myocardial damage. Coronary ligation in methylprednisolone treated dogs produced significant increases in the PISA index with the time but the increases were significantly lower than those in untreated groups. These lower increases at 60 minutes as compared to 30 and 120 minutes observed in the untreated group were absent in the treated group. Methylprednisolone showed some protective effect against coronary ligation-induced myocardial damage. These results indicate that the PISA method may be a valuable tool in the detection and the measurement of the extent of cardiac injury and in constant monitoring of the changes in the size of myocardial damage.