Echocardiographic features and influencing factors of pulmonary hypertension of total anomalous pulmonary venous connection in adults

Background: Patients with total anomalous pulmonary venous connection (TAPVC) generally have symptoms during the neonatal period and infancy, and the fatality rate is extremely high. Most patients do not survive to adulthood. This study analyzed the clinical and transthoracic echocardiographic (TTE) manifestations of adult patients with TAPVC, summarized the echocardiographic characteristics of TAPVC, and identified the factors influencing pulmonary hypertension.

Methods: Data from adult patients with TAPVC from Beijing Anzhen Hospital, China, were retrospectively collected for analyses, including sex, age, history of gestation, clinical manifestations, echocardiographic parameters, and blood oxygen levels. Patients were grouped for comparative analyses based on their pulmonary artery systolic pressure (PASP) (≥60 vs. <60 mmHg); 32 atrial septal defect (ASD) patients were included as a control group.

Results: (I) Sixteen patients were identified with TAPVC (11 women and 5 men; mean age: 32.2±9.5 years), including 8, 4, and 4 patients with supra-cardiac, mixed, and intracardiac type TAPVC, respectively. Furthermore, 10 patients had moderate or severe tricuspid regurgitation, and 6 had a PASP of ≥60 mmHg. Echocardiography misdiagnosed 2 patients with an ASD. (II) The TAPVC group patients had a smaller left atrium (LA) and a lower aorta/pulmonary artery ratio than ASD-only group patients. However, the right ventricular diameter (RVd) and right atrium were larger in patients with TAPVC than in those with only ASD. (III) The RVd was larger and the LA was smaller in patients with a PASP of ≥60 mmHg than in those with a PASP of <60 mmHg. (IV) Of those with a PASP of ≥60 mmHg, TAPVC patients had a smaller LA and a larger RVd than those with only ASD. (V) Pregnancy affected the PASP (adjusted odds ratio: 15.000, 95% confidence interval: 1.031-218.300, P=0.047). (VI) Echocardiography indicated that TAPVC patients with ASD had a right to left shunt at the atrial level and the pulmonary vein (PV) was not connected to the LA.

Conclusions: Searching for the PV by TTE is necessary for patients with ASDs, which may help avoid misdiagnosis. Moreover, pregnancy affects the PASP. Patients with TAPVC may present with a larger right heart, smaller LA, and lower aorta/pulmonary artery ration than those with only ASD.