Early detection of myocardial dysfunction by echocardiographic markers in patients with neuromuscular dystrophies

Abstract

Duchenne neuromuscular dystrophies (DMD) and Becker (DMB) affect the heart and sometimes with great clinical relevance. The aim of the study was to detect by echocardiographic markers that there is early myocardial dysfunction in patients with neuromuscular dystrophies (DNM). Methods: Case-control study, performed at the Nicolás Avellaneda Clinical Hospital in the city of San Miguel de Tucumán, Argentina, in the period between December 2012 and September 2013; with patients of the neurological rehabilitation service with diagnosis of Duchenne and Becker DNM. Echocardiographic markers values obtained were expressed as Average (P) and Standard deviation (Ds), with 95% confidence intervals (CI 95). For the statistical analysis, Chi square test and Fischer exact test were used. Results: Eighty-two patients were evaluated, 41 in the control group (GC) and 41 in the pathological group (GP) with DNM. 83% of the patients had DMD, 12% DMB and 5% DMD / DMB. There were statistically significant differences in the TEI index by TDI in the lateral wall, septal, tricuspid and in the ejection period (p = 0.0001). There were also statistically significant differences in the TEI index of the mitral and tricuspid annulus with pulsed Doppler (p = 0.0001), TAPSE and in the greater thickness of the RV free wall (p = 0.0001). The ejection fraction (FEY) in the GP had values in normal limits but lower than in the GC (63.9 ± 5% in GP vs 67.8 ± 2.6% in GC) (p = 0.0001). Conclusions: Markers of early myocardial dysfunction can be detected by two-dimensional echocardiography and Doppler (pulsed and TDI) in patients with neuromuscular dystrophies. Its routine use for diagnosis, monitoring, treatment, prognosis and evolutionary control is extremely useful. The screening method should include: FEY, index of TEI, pulsed and tissue Doppler, TAPSE and free thickness of the RV wall, in the cardiovascular evaluation.