Ratlarda Deneysel Miyokard İnfarktüsünün Yaygınlığını Öngörmede EKG, Kardiyak Troponin T ve Yüksek Duyarlıklı C Reaktif Proteinin Önemi

Abstract

Objective: To analyze the predictive value of ECG variables, cardiac troponin T (cTnT) and high-sensitive C reactive protein (hsCRP) levels in estimating the degree of experimental myocardial infarction in the living rats before euthanasia. Material and Methods: Permanent ligation of the left anterior descending coronary artery was performed to develop acute myocardial infarction in 4-month-old male Wistar rats (n=18). Saline (n=5), low-dose erythropoietin (5 000 U.kg−1, n=6) and high-dose erythropoietin (10 000 U.kg−1, n=7) were administered intraperitoneally after the ligation to obtain varying degree of infarction. ECG records were taken before (phase 1), at the end of (phase 2), and at 6 hours after the ligation (phase 3). cTnT and hsCRP levels were measured in phase 3. The size of infarct area was calculated with planimetry on a single midventricular slice stained with triphenyltetrazolium chloride. Results: The height of ST segment in phase 2, the Q/R and ST/R ratios measured in phase 3, and the Q/R ratio difference between phases 2 and 3 were found to be associated with the large infarct area. The cutoff values estimated for these variables were capable of predicting the presence of an infarct area ≥40%. cTnT and hsCRP levels were unsuccessful in estimating the size of infarction. Conclusion: The variables of a 3-lead ECG may have a predictive value in estimating the presence of large infarction before euthanasia. ST segment elevation may be significantly different as early as the first-half hour of coronary ligation. The levels of cTnT and hsCRP are not associated with the size of infarction, and do not have a predictive value.