Transcript Congenital Aortic Stenosis

Congenital Aortic Stenosis
Echo Conference
January 7, 2008
Anne B. Riley
Outline
Subvalvular
Valvular
Supravalvular
• Morphology
• Epidemiology/
Genetics
• Clinical Presentation
• Associated
syndromes
• Treatment options
Subvalvular:Morphology
• Caused by an
accumulation of
fibroelastic tissue
• Thin, crescent shaped
membrane just below
the aortic valve
• Thick fibromuscular
ridge
• Tunnel or tubular: long
narrow fibromuscular
channel along the
LVOT
Imaging
Courtesy: Yale School of Medicine Atlas of Echocardiography
SUBvalvular
Echocardiogram- PLA
SUBvalvular
Echocardiogram- 5 Ch
SUBvalvular
SUBvalvular
Epidemiology
• Second most common form of Congenital AS
• More common in males (67-75% of cases)
• Accounts for 8-30% of LVOT obstruction
• Isolated SubAS is felt to be an acquired lesion- not seen
in newborns
• Reports published of familial occurrence (? Morphologic
abnormalities of LVOT lead to predisposition for cell
proliferation)
SUBvalvular
Clinical Presentation
• Lesion often found in children/young adults
when evaluating for other cardiac defects
• Presentation in the adult is usually in evaluation
of a heart murmur
• Tends to be a progressive lesion
• Aortic valve at risk (high velocity jet slams into
aortic valve)
• Symptoms depend on degree of obstruction:
fatigue, dyspnea on exertion, chest pain,
syncope
• High risk for developing infective endocarditis
SUBvalvular
Clinical Presentation
• Associated with other defects in 60% of
cases
– Multilevel LVOT obstruction
– VSD
– Coarctation of the aorta
– PDA
– Left superior vena cava
– Valvular aortic stenosis
SUBvalvular
Shone Syndrome
• Left ventricular inflow and outflow obstruction
• Parachute mitral valve (single pap muscle),
supravalvular mitral ring, subaortic stenosis,
coarctation
• Treated with surgery often in first year of life
• 15-year survival 89%
• Deaths secondary to severe mitral valve
disease, need for multiple surgeries
Brown et al. Operative results and outcome in patient with Shone’s anomaly.
Ann Thorasic Surgery 2005 April 79(4).
SUBvalvular
Evaluation
• Echocardiography: assess anatomy,
measure gradient with continuous wave
doppler
• Cardiac cath: further define mechanism
and extent of subaortic obstruction
(particularly if suspect multiple levels of
obstruction)
SUBvalvular
Treatment
• Definitive therapy: Surgical correction
• Timing is controversial because of high
recurrence rate (~20%)
• Suggested indications in adults
Peak gradient >50 mmHg, mean gradient >30
mmHg
Progressive mod-severe AR, EF <55%, or
LVESD 50 mm
Symptomatic from obstruction
• Membranectomy +/- myomectomy, KonnoRastan procedure (reconstruct LVOT)
ACC/AHA 2008 Guidelines for Management of Adults with CHD
Valvular Aortic Stenosis
• Unicuspid,
– acommissural
– unicommissural
• Bicuspid (most common)
• Trileaflet valve
– Miniature
– Dysplastic
– Fusion of commissures
• Quadricupsid
(usually incompetent, rarely stenotic)
Valvular Aortic Stenosis
• 14 year old boy referred for aortic stenosis
and regurgitation
• MRI showed …
Valvular AS
Unicuspid
Diagnosis and Management of Adult Congenital Heart Disease
Case
• 30 year old Guatemalan man with mild
shortness of breath on exertion and harsh
holosystolic murmur at left sternal border
and systolic murmur heard at base
• Echo shows …
Echo showed
• Quadricuspid aortic valve, mild AI, no AS
(peak velocity 1.3 m/s)
• Paramembranous VSD
• Large secundum atrial septal defect
Valvular AS
Bicuspid Valve Morphology
• Right-Left Commissures
– Gives anterior and posterior
cusps
– RCA and LMCA both from
anterior cusp
– False raphe also on anterior
cusp
• Anterior-Posterior Commissures
– Gives left and right cusps
– RCA from right cusp and
LMCA from left cusp
– Often have a false raphe, on
right cusp
Right-Left Commissures
R
L
N
Courtesy: Yale University School of Medicine Atlas of echocardiography
Valvular AS
Bicuspid
Valvular AS
Valvular AS
Valvular AS
Epidemiology
• Bicuspid valve accounts for 95% of cases
of congenital AS, occurs in 1-2% of
general population
• More common in males (3:1)
• Case reports of familial inheritance of
bicuspid valves, tends to be autosomal
dominant with variable penetrance
Valvular AS
Clinical Presentation
Initially asymptomatic
Abnormal folding
Turbulent flow
Restricted motion
-66% develop aortic stenosis
-Only 15% of patients have a
normally functioning valve in
the 5th decade
Scarring, calcification,
stenosis, regurgitation
Valvular AS
Bicuspids and the Aorta
• Often have abnormalities of the aortic
media
• Increased risk for dilatation, dissection (59x) and rupture of ascending aorta
• Previously thought to be secondary to
“poststenotic turbulence”
• Abnormalities of ascending aorta occur
irrespective of degree of stenosis or
regurgitation
Valvular AS
Monitoring and Treatment
• Dilated aortic root (>4 cm): yearly imaging of aorta (echo,
CT?, MRI?)
• Recent data to suggest that ARBs slow the rate of
progression of aortic root dilatation in Marfan’s patients
Brooke et al. Angiotensin II Blockade and Aortic root dilation in Marfan’s Syndrome. NEJM 2008
Valvular AS
Intervention
• Valve replacement surgery indicated for patients
with severe stenosis who are symptomatic or are
developing LV dysfunction (EF<50%) or LV
dilatation
• Consider surgery who have moderate stenosis
with moderate AR or dilated ascending aorta
• Repair/replacement of the ascending aorta when
5 cm or expanding at a rate >5 mm/yr
Supravalvular Aortic Stenosis
• Least common lesion of the LVOT
Hourglass
vs
Diffuse
narrowing
Courtesy: Yale University School of Medicine Atlas of Echocardiography
SupraValvular
Associated Abnormalities
• Aortic valve leaflets: thickened, redundant,
bicuspid
• Coronary artery stenosis
• Coarctation of the aorta or stenoses of
carotid, renal, iliac
• Pulmonary artery stenoses
SupraValvular
Classification
• Williams syndrome
• Autosomal dominant form without features
of Williams syndrome
• Sporadic
SupraValvular
Williams syndrome
•
•
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•
•
•
•
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Affects 1/10,000 individuals
Supravalvular AS (70%)
Mental retardation
Elfin facies
Cocktail personality
Renovascular hypertension
Stellate iris
MRI
Mechanisms and treatment of cardiovascular disease in Williams-Beuren syndrome
SupraValvular
Genetics and Pathology
• Mutation in or deletion of the elastin gene
located on chromosome 7q11.23
• Aortic Media is affected:
– a reduction of elastic tissue with disorganized
elastin fibers
– Decreased elasticity, increased shear stress->
smooth muscle hypertrophy and collagen
deposition
Therapy: Surgery
• Surgical enlargement of sinotubular area
and ascending aorta
• Recommended with symptoms (angina,
dyspnea, syncope) or mean pressure
gradient of >50mmHg, or peak >70 mmHg
• Excision and end-end anastamosis
• Patch enlargement of sinotubular junction
Thank you
Special thanks to
Eli (for suggesting this topic) and
Anne Marie Valente of the BACH program
References
Aboulhosn et al. Left Ventricular Outflow Obstruction: Subaortic Stenosis,
Bicuspid Aortic Valve, Supravalvuar Aortic Stenosis, and Coarctation of the
Aorta. Circulation 2006:114, 2412-2422.
Brooke et al. Angiotensin II Blockade and Aortic root dilation in Marfan’s
Syndrome. NEJM 2008.
Brown et al. Operative results and outcome in patient with Shone’s anomaly.
Ann Thorasic Surgery 2005 April 79(4).
Holt et al. Quadricuspid Aortic Valve with Aortic Insufficiency: case report and
review of the literature. J Card Surg 2007: 22, 224-239.
Pober et al. Mechanisms and Treatment of Cardiovascular Disease in
Williams-Beuren syndrome. J of Clin Investigation: 2008:5, 1606-1615.
ACC/AHA 2008 Guidelines for Management of Adults with Congenital Heart
Disease.
Diagnosis and Management of Adult Congenital Heart Disease. Gazoulis.
2003, Elsevier Limited.
The Clinical Recognition of Congenital Heart Disease. Perloff. 1987, WB
Saunders.
Yale School of Medicine Atlas of Echocardiography