Coronary Sinus Flow and Myocardial Strain Impairment in Behçet's Disease: Microvascular Dysfunction or Mechanical Constraint Related to Thoracic Geometry?

The integration of coronary sinus flow (CSF) and myocardial deformation imaging represents an emerging non-invasive approach for detecting subclinical cardiac involvement in systemic diseases. In their recent study, Güleşir et al. provide evidence of reduced CSF and impaired biventricular strain in patients with Behçet's disease (BD), suggesting a potential link between coronary microvascular dysfunction and myocardial mechanical alterations. While this interpretation is biologically plausible in the context of systemic vasculitis, alternative mechanisms may contribute to the observed findings. In particular, extrinsic mechanical factors related to thoracic shape that affect cardiac geometry and venous drainage may simultaneously influence both CSF and myocardial strain parameters. Insights from conditions such as pectus excavatum, where chest wall deformity induces apparent reductions in myocardial strain despite preserved intrinsic function, highlight the potential role of mechanical constraint as a confounding factor. This commentary discusses the interplay between coronary flow, myocardial deformation, and cardiac mechanics, emphasizing the need for a more nuanced interpretation of echocardiographic findings. A comprehensive approach integrating structural, hemodynamic, and microvascular determinants may be essential to accurately characterize subclinical cardiac involvement in BD and other systemic conditions.