Type: 1
Location: outflow of the right ventricle (RV), in the conal or outlet septum
Synonyms: conal, subpulmonary, infundibular, supracristal
Comment: higher frequency in Asians (33%) vs non-Asians (6%); spontaneous closure uncommon
Type: 2
Location: membranous septum, adjacent to the septal leaflet of the tricuspid valve and adjacent to the aortic valve
Synonyms: peri or paramembranous, conoventricular
Comment: most common defect (about 80%)
Type: 3
Location: lower part of the right ventricle, adjacent to the tricuspid valve
Synonyms: inlet
Comment: associated with Down's syndrome
Type: 4
Location: central, apical, anterior, posterior
Synonyms: muscular (surrounded by muscle)
Comment: spontaneous closure common; may be multiple
