Evaluation of thoracoabdominal asynchrony in Duchenne Muscular Dystrophy: a pilot study

<fig><object-id>erj;64/suppl_68/PA1443/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> Duchenne Muscular Dystrophy (DMD) is a progressive neuromuscular disorder marked by dystrophin deficiency, precipitating musculoskeletal atrophy and respiratory dysfunction. The aim was to investigate the presence and respiratory implications of thoracoabdominal asynchrony (TAA) in DMD. Eleven ambulatory children with DMD (7.77±2.14 years) were included. Spirometric evaluation (MicroQuark, Cosmed) was employed to assess respiratory function. Thoracoabdominal movements were quantified via Structured Light Plethysmography (Thora 3Di, PneumoCare) over five minutes of tidal breathing. TAA was detected as a result of differences in timing between movement signals in the rib cage (RC) and abdominal (ABD) regions. TAA was detected in 10 participants, predominantly from the ABD region (Fig. 1). A significant negative correlation between FEV1 and respiratory rate (RR; r=-0.667, p=0.05) was identified, while a significant positive correlation was noted between the principal angle of RC and ABD movements and FEV1 (r=0.700, p=0.036). Inspiratory-to-expiratory ratio (I:E) and FEV1/FVC were negatively correlated (r=-0.667, p=0.05). The study demonstrates that TAA in DMD, primarily in the ABD, impacts respiratory mechanics. Increasing asynchrony reduces respiratory efficiency. Conversely, improved synchrony relates to better pulmonary function, emphasizing the need to assess and address TAA in DMD patients for improved respiratory function.