BackgroundThe objective of study was to determine pulmonary artery variations and other associated cardiac defects in patients with Tetralogy of Fallot. This cross-sectional, descriptive study was carried out at The Children's Hospital and the Institute of Child Health, Lahore, from January 2006 to December 2012. All patients with Tetralogy of Fallot, who underwent cardiac catheterization during this period, were included. Standard cine-angiograms were done to record the pulmonary artery sizes and associated cardiac defects.DescriptionA total of 576 patients with Tetralogy of Fallot were catheterized. Pulmonary Artery abnormalities were present in 109 (18.92%) patients. The commonest abnormality was isolated Left Pulmonary Artery stenosis (n = 60, 10.4%) followed by supra-valvular stenosis (n = 9, 1.6%). Left Pulmonary Artery was absent in seven patients(1.2%), while 1 patient (0.2%) had both absent right and left Pulmonary Arteries with segmental branch pulmonary arteries originating directly from Main Pulmonary Artery. Associated cardiac lesions included right aortic arch in 72 (12.5%), additional muscular Ventricular Septal Defect in 31 (5.4%), Patent Ductus Arteriosus in 31 (5.4%), bilateral Superior Vena Cava 36(6.2%), Atrial Septal Defect 4(0.7%) and Major Aortopulmonary Collateral Arteries in 75(13%) patients. Significant coronary artery abnormalities were present in 28(4.9%) children.ConclusionPulmonary artery abnormalities were present in 18.92% of patients with Tetralogy of Fallot. Isolated Left Pulmonary Artery origin stenosis was the most common abnormality. Significant associated cardiac lesions including Patent Ductus Arteriosus , additional muscular Ventricular Septal Defect, coronary artery abnormalities, bilateral Superior Vena Cava, Atrial Septal Defect and Major Aortopulmonary Collateral Arteries were present in one-third of the patients.