The Usual Causes of Left Ventricular Outflow Tract Obstruction Below the Aortic Valve in Normal Ventriculoarterial Connection: Review of the Physiopathology and Surgical Implications

Subaortic narrowing leading to left ventricular outflow tract obstruction (LVOTO) is a significant pathology that may be encountered pre- or postoperatively in both acquired or congenital cardiac disease. Through a review of the morphological features and mechanisms in the different clinical situations, the anatomic, dynamic and mixed forms of subaortic obstruction are emphasized. Knowledge of the substrate of LVOTO, its physiopathology and natural history allows to plan accordingly the surgical repair and the postoperative management.