Double inlet left ventricle
Double inlet left ventricle (DILV) describes a congenital cardiac anomaly in which both atrioventricular valves are associated with a single ventricle which demonstrates left ventricular morphology.
Epidemiology
This uncommon entity constituents 1% of all congenital cardiac anomalies, and is one of the more common variants of a univentricular heart .
Associations
- ventricular septal defect
- transposition of the great arteries
- subaortic stenosis
Pathology
Features include a single, dominant ventricle with an elliptical shape, smooth septal endocardium lacking associated papillary muscles, defining left ventricular morphology . Atrioventricular valves may lack sufficient anatomical features to define their morphology in mitral/tricuspid valves, and are commonly stenotic or hypoplastic. A rudimentary outflow chamber (right ventricle) may be identified at the cardiac base. The location of the septum may be left/anterior, defining the L-loop orientation, or right/anterior defining the less common D-loop orientation. Further classification is based upon the relation of the great arteries :
- type I
- normal arterial relations
- type II
- rightward/anterior aortic location
- type III
- leftward/anterior aortic location
- type IV
- leftward/posterior aortic location