3D transthoracic echocardiography to assess pulmonary valve morphology and annulus size in patients with Tetralogy of Fallot.

Summary Background Accurate evaluation of the pulmonary valve (PV) is crucial before surgical repair of Tetralogy of Fallot (TOF). Aims To assess PV and pulmonary annulus (PA) morphology using three-dimensional (3D) transthoracic echocardiography (TTE) in infants referred for surgical repair of TOF. Also, to compare PA measurements obtained by 3D TTE with those from other imaging modalities, including two-dimensional (2D) TTE and computed tomography (CT), with reference to surgical measurements. Methods 3D zoom mode was used to assess PV morphology. 2D TTE and CT PA diameters were compared to both vertical and horizontal diameters obtained from 3D datasets. Surgical PA diameters were measured using Hegar's dilators. Results A total of 29 patients with TOF (median [range] age 6 [3–24] months) were included and all successfully underwent 2D and 3D TTE; 22 also underwent CT. The number of pulmonary leaflets could be visualized in 24 patients (82.8%), with complete concordance with surgical findings. Vertical diameter was significantly longer than horizontal diameter ( P Conclusion 3D TTE is accurate to assess PV morphology and PA size in patients with TOF. 2D TTE and CT underestimate PA diameter with reference to surgical diameter, however 3D mean and maximum diameters did not differ significantly.