Aims: Previous classification of muscular ventricular septal defects (VSDs) visualized on two-dimensional echocardiography relied on artificial divisions of the septum. New visualization of the ventricular septum integrating the third dimension would facilitate communication between cardiologists and surgeons. The objectives of this study were (1) to assess in patients with muscular ventricular septal defects the accuracy of left ventricular three-dimensional echocardiographic reconstructions in demonstrating the position, the size and the tissue rims of the defects; (2) to compare findings by three-dimensional echocardiography with those obtained by surgical and transcatheter approaches.
Methods and results: Twenty-six patients, aged from one month to 40 years, with muscular ventricular septal defects underwent three-dimensional echocardiographic study. From the left ventricular three-dimensional echocardiographic reconstructions, the localization, the maximal diameter and the tissue rim of the defect were analysed and compared with surgical or transcatheter findings. Optimal three-dimensional echocardiographic reconstructions were obtained in 22 patients. Nineteen had a single muscular ventricular septal defect and three had multiple muscular ventricular septal defects. The muscular ventricular septal defect localizations were the inlet septum in three, the outlet septum in three, the mid-muscular septum in 14 and the apex in eighth. In 10 patients who underwent surgical closure, the correlation between three-dimensional echocardiography and surgery for muscular ventricular septal defect maximal diameter was y=0 x 95 x +0.13 (r=0.98; P<0.001). The agreement between three-dimensional echocardiographic and intraoperative findings on muscular ventricular septal defect localization were complete. In five patients who underwent transcatheter closure, the mean difference between three-dimensional echocardiographic maximal diameter and stretched diameter was 1 x 8+/-0 x 5 mm.
Conclusion: The three-dimensional echocardiographic left ventricular views provide a new and easily communicated visualization of various muscular ventricular septal defects. Such new imaging should contribute to the surgical and transcatheter treatments of muscular ventricular septal defects.