Progressive Subvalvular Right Ventricular Outflow Tract Obstruction With a Single Coronary Artery in an Adult
Masashi Koga1, Rei Ito2, Syoko Doi2
1Department of Cardiology, Sagamihara Kyodo Hospital, Sagamihara, Japan; Department of Cardiology, St. Marianna University School of Medicine, Kawasaki, Japan.
Case Summary:
A 57-year-old man with a history of ventricular septal defect and prior infective endocarditis presented with progressive exertional dyspnea. Multimodality imaging demonstrated severe subvalvular right ventricular outflow tract (RVOT) obstruction with a marked intraventricular pressure gradient (190 mm Hg proximal right ventricle vs 15 mm Hg pulmonary artery). Coronary angiography revealed a single coronary artery arising from the left coronary sinus (Lipton type L1), with a branch crossing anterior to the RVOT.
Discussion:
Progression of obstruction suggested evolving double-chambered right ventricular physiology and/or superimposed infection-related remodeling. The anomalous coronary course had important procedural implications.
Take-Home Messages:
Progressive subvalvular RVOT obstruction in adults warrants consideration of both congenital mechanisms, such as double-chambered right ventricle, and acquired causes including prior infective endocarditis. Comprehensive multimodality imaging is essential to define coronary anatomy and hemodynamic severity before considering intervention.
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