Ultrasonic Integrated Backscatter Analysis in Patients with Dilated Cardiomyopathy: Comparison with Normal Subjects

Objective: Ultrasonic tissue characterization, based on the measurements of integrated backscatter (IBS) analysis, has the potential to provide quantitative information which could characterize the functional and structural state of cardiac muscle. In this study we aimed to determine whether the integrated backscatter is measurable and quantifiable in left ventricular walls in patients with dilated cardiomyopathy (DCMP) and can be used to identify changes in myocardial structure and contractility. Methods: We studied 32 subjects: 16 patients with idiopathic dilated cardiomyopathy who were free of atrial fibrillation, bundle branch block and valvular heart disease (12 male, 4 female, mean age 48±18) and 16 healthy volunteers (10 male, 6 female, mean age 46±8). Left ventricular diastolic and systolic diameters, septum and posterior wall (PW) systolic and diastolic thickness were measured in the parasternal long axis view with M-mode echocardiography. Ejection fraction (EF), fractional shortening (FS), septum and posterior percent wall thickening (WT%) were calculated in the parasternal long axis view with M-mode echocardiography. Real time IBS was measured from the parasternal long axis view of the left ventricle at the level of basal posterior and septal walls. Mean IBS was expressed as averaged IBS values and cyclic variation of IBS (CVIBS) was expressed as the difference between end-diastolic (peak) and end-systolic (nadir) IBS values averaged over all cardiac cycles. Results: CVIBS values obtained from septum and PW in idiopathic DCMP group were statistically different from control group (p=0,003, p<0,001, respectively). Septal and PW mean IBS values in idiopathic DCMP group were greater and statistically different from control group (p<0,05). Septum and PW CVIBS values correlated with WT%, EF and FS positively. But, septum and PW mean IBS values did not correlate with WT%, EF and FS. Conclusion: CVIBS and mean IBS values which were obtained with IBS method may be useful to determine myocardial contractile performance and myocardial structural properties, respectively.