[Left ventricular outflow tract obstruction in transposition of the great arteries. Correlation between anatomic and echocardiographic findings].

INTRODUCTION AND OBJECTIVES Left ventricle outflow tract obstructions in transposition of the great arteries are frequent. We report the correlations between two-dimensional echocardiographic and autopsy findings to draw attention to the usefulness of this diagnostic method in the preoperative evaluation of these anomalies. MATERIAL AND METHODS Of 73 hearts with transposition of great arteries, 26 specimens (38%) with different types of left ventricular outflow tract obstruction were selected to establish the relationship between an anatomical substrate of obstruction and echocardiographic findings in equivalent hearts. Pulsed-wave Doppler studies of velocities at the site of stenosis were done with high-pulse-rate frequency and continuous wave techniques. Eight echocardiographic studies of anatomical specimens and 10 studies in equivalent hearts used for comparison were analyzed to determine correlations. RESULTS Twenty-eight obstructions were found; the most frequent type being left ventricular outflow tract alteration (77%). The most frequent anomalies were posterior deviation of the infundibular septum, cone-like obstruction, pulmonary valve stenosis and septal hypertrophy, followed by congenital mitral valve anomalies (15 %) and anomalies of the tricuspid valve (8%). Two-dimensional echocardiographic studies revealed different types anatomical obstruction. CONCLUSIONS We found precise correlations between the anatomical obstruction and its echocardiographic image. Evaluating electrocardiographic findings is important because these findings can affect the choice of surgical treatment or even the decision to use surgery.