The application of image analysis in the measurement of the myocardial infarct area in an experimental model.

Background: Thrombolytic therapy improves left ventricular ejection fraction and survival. Using the image analysis method, the study was undertaken to evaluate the effects of intraaortic balloon pump used in conjunction with reperfusion in reducing infarct size by measuring the infarct area. Also, the usefulness of image analysis as an objective method for the measurement of myocardial infarct area is evaluated.

Methods: 22 dogs were subjected to proximal left anterior descending coronary artery occlusion. The dogs were classified into 3 groups. In group I (n = 7), occlusion lasted for 6 hours. In group II (n = 6), 2 hours of occlusion were followed by reperfusion. In group III, (n = 9) after 2 hours of occlusion, the dogs were assisted with the intraaortic balloon pump throughout the 4 hours of reperfusion. The measurement of the infarcted area components (fragmentation, edema, hemorrhage and polymorphonuclear infiltrations) was followed by a semiautomatic method including in connection a microscope photographic camera, a scanner and a computer with the appropriate software. The results were analyzed statistically using the t-test.

Result: In group I, the mean value of fragmentation was 28.2%, in group II, 10.1% (p < 0.01 versus group I) and in group III, 3.9% (p < 0.01 versus I and p < 0.05 versus group II).

Conclusion: Reperfusion and intraaortic balloon pump increased the salvage of the ischemic myocardium over that achieved by reperfusion alone in a canine occlusion - reperfusion model. Image analysis could be considered as an accurate and objective method for the measurement of the myocardial infarct area in the experimental model of our study and it could be used in any other experimental study in which the accurate measurement of myocardial infarct area is needed.