Pathophysiology

  Tricuspid valve is either absent, hypoplastic or imperforate.

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

 
Usually, hypoplastic right ventricle (RV) communicates with dominant left ventricle through a (ventricular septal defect (VSD).

  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





ECG 2. The ECG above belongs to a cyanotic newborn with tricuspid atresia.
Only limb leads were recorded.
Left axis deviation and right atrial abnormality in a cyanotic newborn may suggest the diagnosis of tricuspid atresia.

Pediatric cardiologist Dr. Sancar Eminoglu has donated the above ECG to our website.

Click here for a more detailed ECG