Assessing cardiac function in duchenne muscular dystrophy using myocardial work analysis

Abstract

Abstract Background Cardiac complications represent the principal cause of mortality in Duchenne muscular dystrophy (DMD). Conventional measures including left ventricular ejection fraction (LVEF) demonstrate limited sensitivity for early myocardial dysfunction. While global longitudinal strain (GLS) improves detection, myocardial work indices (MWIs) provide unique haemodynamic insights through pressure-strain loop analysis. Methods This prospective case-control study compared 50 genetically confirmed DMD patients (mean age 10.1±3.4 years) with 50 age-matched controls. Comprehensive echocardiographic assessment was performed using speckle-tracking echocardiography (GE Vivid E95) to evaluate LVEF, GLS, and MWIs (global constructive work [GCW], global wasted work [GWW], global work efficiency [GWE]). Motor function was classified using the Ambulation Functional Classification System for DMD (AFCSD). Diagnostic performance was analysed through receiver operating characteristic (ROC) curves. Results DMD patients exhibited preserved LVEF (62.8±4.4% versus 63.4±5.7% in controls, p=0.554) but significantly impaired GLS (-18.4±2.7% versus -20.5±1.9%, p<0.001) with superior diagnostic accuracy (AUC=0.736, 95% CI:0.64-0.83). GCW showed moderate discriminative capacity (1822±276 versus 1963±270 mmHg%, p=0.011; AUC=0.626, 95% CI:0.52-0.73). Regional analysis revealed basal inferior (26%) and lateral (30%) segments as earliest sites of impairment. Progressive motor dysfunction (AFCSD Level 5) correlated with both reduced GCW (p=0.028) and basal segment involvement. Conclusion GLS demonstrates excellent performance for early DMD cardiomyopathy detection, while GCW identifies basal segments as initial sites of dysfunction. Combined assessment enhances surveillance strategies, with MWIs providing complementary haemodynamic profiling to conventional measures.AFCSD Myocardial work analysis (DMD patient)