Evaluation Of Myocardial Fibrosis And Contractile Function With Integrated Ultrasonic Backscatter

Objective Integrated backscatter is an ultrasonic technique that can detect rayocardial fibrosis, amyloidosis, dropsy and hypertrophy. This study was designed to evaluate the extent of rayocardial fibrosis and myocardial contractibility in patients with old myocardial infarction, ischemic cardiomyopathy and dilated cardiomyopathy by measuring integrated backscatter parameters. The value of this technique in ultrasonic diagnosis was discussed.Methods The study population consisted of 100 patients who were diagnosed by clinical history, chemical examination, chest X-ray, electrocardiogram and ultrasonic echocardiogram. Coronary angiography was done when the diagnosis was not clear. The patients were divided into five groups: 20 with anterior old myocardial infartion; 20 with nontransmural old myocardial infarction; 20 with ischemic cardiomyopathy; 20 with dilated cardiomyopathy and 20 served as controls subjects. Inner diameters of all compartments, ejection fraction, IBS, CVIB and TGIB were measured by ultrasonic echocardiogram and integrated backscatter.Results Using ultrasonic echocardiogram, inner diameters of all compartments were significantly larger in DCM and ischemic cardiomyopathy than in old myocardial infarction and controls. The LVEF of dilated cardiomyopathy and ischemic cardiomyopathy was significantly lower than the one of the old myocardial infarction and controls; The LVEF of old myocardial infarction was obviously lower than the LVEF of controls.AII% was significantly higher and CVIB was significantly smaller in the septum in patients with anterior old myocardial infarction, nontransmural old myocardial infarction, ischemic cardiomyopathy anddilated cardiomyopathy than those in controls. AII% was significantly higher and CVIB was significantly smaller in the posterior wall in patients with cardiomyopathy than those in patients with old myocardial infarction and controls. There was no significant difference in these parameters in the posterior wall between the patients with old myocardial infarction and controls.Neither AII% nor CVIB differed between the right and left ventricular halves of the septum or between the endocardial and epicardial halves of posterior wall in patients with ischemic cardiomyopathy and dilated cardiomyopathy. Also there was no significant difference in these parameters between left and right ventricular halves of the septum in patients with anterior old myocardial infarction. In contrast, AII% was significantly greater and CVIB was significantly smaller in the left ventricular than in the right ventricular half of septum in patients with nontransmural old myocardial infarction.TGIB was significantly greater in the septum in patients with nontransmural old myocardial infarction than in patients with anterior old myocardial infarction, ischemic cardiomyopathy, dilated cardiomyopathy and controls. TGIB was significantly greater in the posterior wall in patients with ischemic cardiomyopathy and dilated cardiomyopathy than in patients with old myocardial infarction and controls.Conclusions The myocardial fibrosis in cardiomyopathy and after myocardial infarction can be reflected by IB parameters. Myocardial contractibility degraded not only after myocardial infarction but also after myocardial fibrosis. CVIB is sensitive to this change of myocardial contractibility. The correlation between CVIB and AT%...