The angiographic study of right ventricular outflow tract and pulmonary artery anatomy in tetralogy of Fallot

Objective: The objective of the study is to determine various anatomic variations in the pulmonary vasculature and associated cardiac defects in patients with tetralogy of Fallot (TOF). Methods: This was a cross-sectional descriptive study conducted at Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore from January 2009 to December 2017. A total of 100 patients irrespective of age and gender, who were subjected to cardiac catheterization were enrolled in the study which included all age groups. Measurement of pulmonary valve annulus, main pulmonary artery, right pulmonary artery (RPA), left pulmonary artery (LPA), and descending aorta was taken and corresponding z scores were calculated. McGoon ratio and Nakata index were also calculated. Results: The age group in our study varied from 9 months to 49 years of age. Male-to-female gender ratio was 3:2. All patients had subvalvar (infundibular) stenosis and 82% of patients had stenosis at the valvar level. Seven patients had discrete stenosis, another seven patients had disconnection of RPA or LPA and six patients had supravalvar stenosis in the form of diffuse hypoplasia of one of the pulmonary arteries (PA). Significant communicating major aortopulmonary collaterals arteries (MAPCAs) were seen in 5% of patients and 16% of the patients had a persistent patent ductus arteriosus (PDA). Persistent left superior vena cava was present in 9 patients and 13% of the patients had coronary anomalies. Conclusion: Subvalvular stenosis, confluence of PA, discrete, disconnected, and diffuse stenosis of LPA and RPA were the most common PA abnormalities found in patients with TOF. Significant-associated cardiac lesions including communicating MAPCA, PDA, and coronary anomaly were more commonly observed in these patients.