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
What is the usual cause of disease in the pulmonic valve?
Most disorders are congenital (least likely to be acquired)
What is the incidence of congenital pulmonary stenosis?
0.5 per 1000 live births
What is congenital pulmonary stenosis associated with?
Usually an isolated lesion but can be associated with ToF, transposition of the great arteries, and double-outlet RV
What valvular diseases are seen with Noonan syndrome?
Genetic syndrome involving pulmonary stenosis and aortic stenosis
What is subvalvular pulmonary stenosis caused by?
Usually secondary to fibromuscular narrowing or RV hypertrophy
What is supravalvular pulmonary stenosis caused by?
Narrowing of the pulmonary artery or its branches
What is the most common morphology of pulmonary stenosis?
Dome-shaped with a central, narrowed orifice; 3 symmetric, mobile valve leaflets with fusion at the sites of the commissures
What does a dysplastic phenotype of pulmonary stenosis look like?
Myxomatous thickening with poor leaflet mobility without commissural fusion
What type of PV is seen with Tetralogy of Fallot?
Unicuspid or bicuspid pulmonic valves are typical of ToF
What are echo findings for pulmonary stenosis?
Evidence of RV hypertrophy + RV pressure overload (flattening of the IV septum) + domed and thickened PV leaflets + high-velocity turbulence through PV + max PV velocity > 4 m/s
What do you see on CVP tracing with severe pulmonary stenosis?
Prominent jugular venous a wave as the atrium contracts against a thickened and noncompliant RV
When would you do a surgical PV replacement over a balloon valvuloplasty?
Dysplastic valvular leaflets (i.e. Noonan syndrome) + hypoplastic pulmonary annuli + severe PR (sometimes after BAV)
What is the most common cause of pulmonary regurgitation?
Rarely congenital (unless it is absence of a PV); usually mixed valvular disease seen with other genetic disorders or iatrogenic from a procedure; can happen from dilation of the PV annulus or pulmonary artery
What is a common symptom of pulmonary regurgitation?
Dyspnea on exertion; can also see hepatic congestion due to RV failure
How can do you diagnose pulmonary regurgitation?
Via echo or MRI; Mri is preferred because it can also look carefully at RV remodeling and dysfunction
What are the treatment options for pulmonary regurgitation?
Surgical intervention + Transcatheter PVR (Melody and Sapien XT)
What is a Melody valve and when do we use it?
Made from bovine jugular vein and used for pulmonary regurgitation due to dysfunctional conduits or failing bioprostheses
What is a Sapien XT and when do we use it?
Made from bovine pericardium and used for failing conduits
What is the most common form of congenital heart disease?
Tetralogy of Fallot
What are the findings in ToF?
Overriding aorta + VSD + RVOT obstruction + RV hypertrophy
Which of the findings of ToF is most associated with the degree of cyanosis?
RVOT obstruction; the more severe the obstruction, the more cyanosis
What is a palliative measure for ToF in infants who can’t undergo major surgery yet?
Blalock-Thomas-Tausig shunt; a shunt that connects the subclavian artery to the pulonary artery to bypass the RVOT obstruction
What are the two approaches to complete surgical repair for ToF?
Transventricular: single incision across the anterior RV wall to fix both the VSD and the RVOT obstruction; Transatrial-transpulmonary: two incision, one to fix the VSD and one to fix the RVOT obstruction
What is commonly seen in patients who have ToF with pulmonary atresia?
Major aortopulmonary collaterals may exist
What are some common complications following ToF repair?
- Pulmonary regurgitation
- Heart failure (predominantly sub-pulmonary RV dysfunction from long-standing PR which can progress to left-sided HF)
- Aortopathy (usually aortic root and ascending aorta dilation)
- Others (residual VSD, TR, RVOT obstruction or aneurysm, branch PA stenosis)
What is the leading cause of morbidity and mortality in repaired ToF?
Arrhythmias; Atrial arrhythmias from the atriotomy scar (reentry arrhythmias like atypical flutter or even typical flutter) and Ventricular arrhythmias from VSD patch and/or outflow patch
What is the cause of a tet spell in ToF and what is the treatment?
Cyanosis due to decreased pulmonary blood flow; to increase the Qp, the direction of the shunt through the VSD needs to be left to right so you should increased SVR, administer fluid, or give a beta-blocker (reduces RV infundibular spasms)
What percentage of congenital heart disease is due to truncus arteriosus?
1-2% of CHD
What is truncus arteriosus?
Single semilumar valve and annulus from a common outflow trunk of the ventricle + large, misaligned VSD
What are the four types of truncus arteriosus?
Type 1. Main PA comes off the truncus arteriosus and branches into RPA and LPA; Type 2 and 3. No main PA, RPA and LPA come off the truncus arteriosus; Type 4. No PA at all, blood is supplied to the lungs via major aortopulmonary collateral arteries
What is used to determine the PVR to SVR ratio in truncus arteriosus?
The Qp:Qs (pulmonary blood flow to systemic blood flow); if PVR increases, more blood goes systemically but bypasses the lungs so you get desaturations and vice versa
What are treatment options for truncus arteriosus?
Repair: VSD closure + division of truncus with truncal valve used as the aortic valve + RV to PA conduit with or without valve; Palliation: PA banding to balance Qp:Qs
What are common complications from truncus repair?
Conduit stenosis + PA stenosis + neo-aortic valve (truncal) insufficiency
What is the most common congenital deformation of the TV?
Ebstein’s anomaly (0.3-0.5% of CHD)
What is the cause of Ebstein’s anomaly?
The failure of delamination of the septal and posterior leaflets of the TV from the underlying myocardium -> results in hypoplastic septal and posterior leaflets of TV and a large, sail-like anterior leaflet
What are some classic findings of Ebstein’s anomaly?
Large, sail-like anterior leaflet of the TV + attrialization of the RV (the septal and posterior leaflets are inferiorly displaced so this moves the TV away from the AV junction) -> this causes parts of the RV to be functionally hypoplastic (atrialized ventricle balloons and is not functional as it should be)
Which CHD is most associated with arrhythmias?
Ebstein’s anomaly
What are common arrythmias seen with Ebstein’s anomaly?
SVT usually secondary to WPW accessory pathways; usually secondary to dilated RA and atrialization of the RV
How do you repair Ebstein’s anomaly?
The cone repair: creation of a neo-valve (cone) which is a circumferential repair with mobilization of all 3 leaflets of the TV + plication of the atrialized RV; if this is too hard, simply do a TV replacement with a bioprosthetic valve
What causes cleft MV leaflets?
Failure of fusion of the endocardial cushions
What causes dysfunction of the subvalvular apparatus during development?
Derangements in delamination and abnormal fusion of myocardial trabeculae
What is mitral atresia seen with?
Hypoplastic left heart syndrome or transposition of the great arteries
Is MR or MS more common with congenital mitral valve disease?
MR (72%), MS (13%), and both (15%)
What is a mitral cleft?
Division of one of the leaflets (usually anterior) resulting in MR
What do you see with a partial AV canal defect?
Clefting of the MV + Primum ASD
What do you see with a transitional AV canal defect?
Clefting of the MV with MR + Primum ASD + Restrictive VSD
What do you see with a complete AV canal defect?
AV valve bridges both the left and right side of the heart + clefting of the MV with MR + Primum ASD + Nonrestrictive VSD
What are the different types of congenital mitral stenosis?
- Typical 2. Hypoplastic 3. Supramitral ring 4. Parachute mitral valve
What is the most common form of congenital mitral stenosis?
Typical; characterized by thickening MV leaflets + short thickened chords with obliteration of interchordal space + underdeveloped papillary muscles with reduced interpapillary distance
What is typical congenital mitral stenosis commonly associated with?
Coarctation of the aorta and aortic stenosis
What are the two forms of typical congenital mitral stenosis?
Arcade MV (papillary muscles come together and insert dirrectly into the leading edge of the anterior mitral leaflet) + Hammock MV (shortened and thickened chords insert directly into the muscular mass of the posterior wall)
What is the second most common type of congenital mitral stenosis? What is it associated with?
Hypoplastic; all the components are smaller -> always associated with severe LVOT abnormalities (usually hypoplastic left heart syndrome)
What is a supramitral ring?
Complete, circumferential, or partial ring of connective tissue supra-annularly, originating from the atrial surface of the MV leaflets just above the mitral annulus distal to the opening of the LAA
What is a supramitral ring commonly associated with?
Multilevel obstruction of the left side of the heart (like Shone’s complex)
What do you need to distinguish a supramitral ring from?
Cor triatriatum sinister: fibromuscular membrane that is clearly separated from the MV located proximal to the LAA and divides the LA into two parts
What is the least common form of congenital mitral stenosis?
Parachute mitral valve
What is a parachute mitral valve?
All chordae are thickened, shortened, and attached to a single central papillary muscle (usually posteromedial while the anterolateral is often absent or hypoplastic)
What is the most common cardiac valvular anomaly in developed countries?
Mitral valve prolapse
What is the most common cause of MV prolapse?
Replacement of the dense fibrous collagen layer of the MV apparatus with loose, myxomatous connective tissue resulting in MR
