Congenital Flashcards
What is the hollow conotruncus?
The primary outflow tract that twists to become the heart
What gives rise to the right and left leaflets of the semilunar valves?
The extensions of the conotruncal septum
What forms the anterior and posterior pulmonic leaflets?
Two smaller endocardial cushions, not the primary extensions of the conotruncal septum
What occurs if you have a defect in the rotation of the conotruncal septum?
Transposition of the great arteries
What occurs if you have an anterior deviation that diminishes the pulmonary valve orifice and RVOT?
Tetralogy of Fallot
What occurs if you have improper endocardial cushion development?
Primary semilunar valve dysfunction; most common are bicuspid aortic valves and pulmonary valve stenosis
What is the site of formation of the AV valves?
The AV canal
What forms the AV canal septum?
The inferior and superior AV endocardial cushions; separates the tricuspid and mitral orifices
What forms the septal leaflets of the AV valves?
The edges of the AV canal septum; forms the anterior leaflet of the MV and the septal leaflet of the TV
What forms the mural AV valve leaflets?
The lateral endocardial cushions; forms the posterior MV leaflet and the posterior and anterior TV leaflets
What is the cause of MV/TV stenosis or atresia?
Defects in endocardial cushion fusion (lateral cushions or the AV canal septum)
What is the cause of a common AV valve?
Failure of the AV endocardial fusion
What is delamination?
The process of AV valve leaflet formation; the ventricular myocardium underlying the endocardial cushions remodel into myocardial tethers (chordae tendinae) and anchoring trabeculae (papillary muscles)
What is the most common congenital heart defect?
Bicuspid aortic valve (0.5-2% prevelance)
What is the genetic pattern for bicuspid AV?
Autosomal dominant with incomplete penetrance and variable expressivity
Male or female more likely for a bicuspid AV?
Males (3:1 ratio)
What genetic syndromes include a bicuspid AV?
Turner syndrome (30% of patients) and Loeys-Dietz syndrome (10% of patients)
What is the Siever’s Classification System?
System used to describe bicuspid Avs and relative incidences
What is a Type 0 bicuspid AV?
No raphe (no real fusion between 2 of the 3 leaflets, you are just born with 2 leaflets)
What is a Type 1 bicuspid AV?
Fusion of 1 raphe (most commonly left and right cusps fused, then right and non-coronary, and rarely non-coronary and left)
What is a Type 2 bicuspid AV?
Fusion of 2 raphes (usually left and right cusps and right and non-coronary cusps)
Which two AV cusps are most likely to be fused with bicuspid AV?
Left and right cusps
What can bicuspid AV be associated with?
Usually an isolated lesion but can be associated with subvalvular or supravalvular stenosis + VSD + Sinus of Valsalva aneurysm + coarctation + anomalous coronary takeoff + left coronary artery dominance (not an anomaly)
What other congenital cardiac lesions are bicuspid AV associated with?
Coarctation (50-85% of patients) + Shone complex (71% of patients) + Hypoplastic left heart syndrome
What do you also see with patients with bicuspid AV?
Ascending aortic dilation (40-50%) in younger patients + rapid rate of increase + associated with higher risk of dissection
What do you see on aortic tissue histology in patients with a bicuspid AV?
Cystic medial necrosis
What complications are more common with bicuspid AV?
Severe AI (more frequently in men) + severe AS (more frequently in women) + endocarditis (17x more likely)
What are treatment options for a bicuspid AV?
- Balloon valvuloplasty
- AV repair (suture plication, reconstruction with pericardium - Ozaki procedure, commissuroplasty)
- Ross Procedure
- AV replacement
- TAVR
What is the Ross Procedure?
Pulmonic autograft in the aortic position and a homograft in the pulmonic position
What is subaortic stenosis often seen with?
VSD, PDA, bicuspid AV, coarctation, pulmonary stenosis and Shone complex (or other left-sided obstructive lesions)
What is Shone complex?
Rare congenital cardiac malformation with 4 obstructive lesions of the heart (both inflow and outflow obstruction of the LV): supravalvular mitral ring + parachute mitral valve + muscular/membranous subaortic stenosis + coarctation
What is subaortic stenosis?
Membranous: thin, fibrous membrane within the LVOT attached ot the ventricular septum; Muscular: muscular, diffuse tunnel-like obstruction
What does supravalvular aortic stenosis commonly present as?
A discrete thickening at the STJ creating an “hourglass” deformity; can also be an extension from the STJ to the more distal ascending aorta
What genetic component is affected in supravalvular aortic stenosis?
Genetic disturbance of the elastin gene
What is Williams-Beuren syndrome?
Multisystem genetic syndrome with a deletion in the elastin gene; associated with supravalvular aortic stenosis + pulmonary artery stenosis + coronary artery stenosis
What is the treatment for supravalvular aortic stenosis?
Surgical relief of obstruction; enlarging the STJ and affected aorta
What is the Konno procedure?
Aortoventriculoinfundibuloplasty; enlarging the aortic root by anterior approach; used to treat diffuse subaortic stenosis
What are the surgical criteria for treatment in supravalvular aortic stenosis?
> /= 50 mmHg gradient or symptoms or lower EF or coronary ischemia caused by lesion