Tricuspid valve is either absent, hypoplastic or imperforate.

  Presence of an atrial septal defect (
ASD) is a necessity.

Usually, the hypoplastic right ventricle (RV) communicates with the dominant left ventricle

      through a ventricular septal defect (

  During left ventricular ejection, some of the blood enters hypoplastic RV through this VSD

      and then it is directed to the pulmonary artery.

ECG in tricuspid atresia

  Right atrial abnormality (RAA).

Left axis deviation.

  Left ventricular hypertrophy.

  Left atrial abnormality (not necessarily).

ECG 1. The ECG above belongs to a 6 years-old boy. He had undergone Fontan circulation operation
for tricuspid atresia and right ventricular hypoplasia 6 months ago. Left axis deviation and left atrial abnormality is seen.

Pediatric cardiologist Dr. Mahmut Gokdemir has donated the above ECG to our website.

Click here for a more detailed ECG