Altered Wave Reflection in Patients with Duchenne Muscular Dystrophy (DMD)

Abstract

Cardiovascular complications are progressive in Duchenne Muscular Dystrophy (DMD) with cardiomyopathy/heart failure characterized as the leading cause of death in these young patients. Increased wave reflection augments pulsatile load on the heart and is known to be predictive of new onset heart failure in adults. Patients with DMD may have higher wave reflection as measured by augmentation index (AIx) but this has yet to be comprehensively studied in these patients. Given the incidence of dilated cardiomyopathy in DMD, a better understanding of the pulsatile load and ventricular‐arterial interactions could provide valuable insight into disease progression and management.PURPOSEThus, the purpose of this study was to characterize wave reflectance and pulsatile load with wave separation and wave intensity analyses in a group of patients with DMD compared to typically‐developing controls.METHODSAssessments were performed on 23 boys (10 DMD and 13 typically‐developing controls (CON)) between the ages of 8 and 18 years. A brachial artery oscillometric‐cuff device was used to record brachial artery pressure waveforms that were calibrated and synthesized to central pressure waves using a generalized transfer function. Pulse wave analysis (PWA) was performed to determine central blood pressures and AIx. Wave separation analysis was also used to determine the relative contributions of forward (Pf) and backward (Pb) pressure waves and reflection magnitude (RM=Pb/Pf).RESULTSPatients with DMD had a significantly higher augmentation index (AI) as measured by PWA (DMD: 21.2 ± 5 vs CON: 0.9 ± 2 %, p<0.05) but no difference in central pulse pressure (DMD: 34 ± 3 vs CON: 30 ± 1 mmHg). There was also no difference in Pf between groups (DMD: 27 ± 2 vs CON: 26 ± 2 mmHg). However, both Pb (DMD: 14.0 ± 1 vs CON: 11.7 ± 1 mmHg, p<0.05) and RM (DMD: 52.0 ± 1 vs CON: 43.5 ± 2 %, p<0.05) were significantly elevated in the children with DMD.CONCLUSIONThese preliminary data suggest that patients with DMD have higher wave reflection, which may indicate increased arterial stiffness and increased pulsatile load on the heart.Support or Funding InformationGrant support: NIH P20GM113125This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.