Left ventricular outflow tract obstruction in the transposition of great arteries defined by transthoracic three-dimensional echocardiography.

We assessed the feasibility of transthoracic three-dimensional reconstruction of the pulmonary valve and subpulmonary left ventricular outflow tract in two patients with transposition of great arteries, ventricular septal defect, and obstruction to the left ventricular outflow tract. Three-dimensional reconstruction of the pulmonary valve could be displayed as "en face" through a three-dimensional generated "pulmotomy view," allowing an overview of the pulmonary aspect of the valve from a surgeon's perspective. In similar fashion, reconstruction of the subpulmonary outflow tract could be displayed along its longitudinal axis as seen through a left ventriculotomy. Unique views could be obtained equivalent to surgical or autopsy dissections, allowing more complete understanding of the morphology and severity of left-sided obstructive lesions.