Aortic Stenosis

Aortic Stenosis Bernardo D. Morantte Jr. M.D. Dept. of Medicine College of Medicine Pamantasan Ng Lungsod Ng Maynila

Aortic stenosis  It is the narrowing of the

aortic valve orifice which causes an obstruction to the flow of blood from the left ventricle (LV) to the aorta (Ao).

Left Heart in aortic stenosis EKG LA

VA = 2cm2

Aorta

2

Mitral valve

1 VA =4 cm2

 Aortic valve Aortic Stenosis

LV 2

Etiology of Aortic stenosis 1.

5. 6. 7.

Congenital Valvular _ bicuspid aortic valve (common) Subvalvular Supravalvular Degenerative Rheumatic fever Connective tissue disease or collagen vascular disease _ SLE

Pathophysiology 

Normal aortic valve area is 2 cm2

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The wear and tear effect causes the valve leaftlets to become rigid and calcified

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As the valve orifice narrows, the pressure in the LV rises and a pressure gradient occurs between the LV and the aorta.

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A pressure gradient is the difference in the pressure (mm Hg) inside the LV and the aorta

PATHOPHYSIOLOGY 

LV pressure LVH Reduced CO

LA pressure

CHF

LA dilatation & hypertrophy Pulmonary hypertension Pulmonic regurg

Hypotension RV dilatation Tricuspid regurg

Symptoms of AS  Mild to moderate aortic stenosis are

usually asymptomatic  Angina like chest pain  Easifatigability  Dyspnea/ orthopnea/ PND  Exertional Syncope

Physical Exam  Pulsus tardus in the carotid artery  Thrill

and harsh crescendo-decrescendo systolic murmur at the 2nd RICS  Early systolic click is present if valve is still pliable  Single S2 or paradoxical splitting of S2  S4 present  S3 when LV dilatation and CHF occurs

Diffferential Diagnosis  Hypertrophic obstructive cardiomyopathy  Pulmonic stenosis  VSD  Mitral regurgitation  Carotid artery stenosis  Benign systolic murmur The location and quality of the murmur differentiates it from the above conditions.

Diagnostics  EKG _ LVH, LAH 

LV strain pattern ( ST depression)

 CXR_ normal heart size   

dilated aorta LA enlargement enlarge heart ushers the onset of CHF

Echocardiography Bicuspid aortic valve  Deformed and calcified aortic valve  Reduced aortic valve opening  Left ventricular hypertrophy and left atrial dilatation  Ejection fraction (EF) usually normal (55 % or >) but declines with the onset of CHF On Doppler  Increased velocity at the aortic valve  usually 4 m/ sec or > 

Gradient = 4 V square

Ejection Fraction  

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EF = EDV - ESV % Cross sectional view of Left ventricle (LV)

End diastolic volume (EDV)

End systolic volume (ESV)

Cardiac Catheterization  Clinically significant AS _presence of

pressure gradient of 50 mm Hg or higher at rest in a patient with normal cardiac output  Severe aortic stenosis = Aortic valve area of < 1 cm2 or < 0.75 cm2/m2

Complications  Endocarditis  Congestive Heart Failure  Cardiac arrhythmia  Sudden death

Natural History of Aortic Stenosis from onset of symptoms  Angina pectoris  Syncope  Dyspnea  CHF

Death 3 years 3 years 2 years 1.5 -2 years

Medical Management      

Restriction of sports and strenuous physical activity Importance of fluids or hydration in the absence of CHF Treatment of Cardiac arrhythmias Cautious use of NTG for angina Ace Inhibitors have unproven long term benefits_ risk of syncope! SBE prophylaxis

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Balloon valvuloplasty for severe aortic stenosis with pliable leaflets especially in children and young adults

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DON’TS Digitalis is contraindicated except for control of SVT or A-fib Treadmill exercise test is contraindicated in severe aortic stenosis

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Indications for intervention or surgery  Presence of symptoms assuming that

there are no other explanation for the symptoms  Aortic valve area of < 1

cm2 or less

Surgical Therapy   

Aortic valve replacement for valvular aortic stenosis with: Bioprosthesis Mechanical valves

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Open incision or excision for subvalvular or supravalvular aortic stenosis

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Surgical mortality 8% For patients with reduced EF or CHF, surgical mortality is 20 %

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Survival rate after AVR  60 % 10 year survival   With bioprosthesis 30% requires repeat

valve replacement after 8-10 years

END of Aortic Stenosis

Aortic regurgitation (AR)  It is the backward flow of blood from

the aorta to the left ventricle (LV) in diastole

 It is also known as aortic insufficiency (AI)

Left Heart _ Aortic regurgitation

Aorta

EKG LA Mitral valve

VA = 2cm2 2

Aortic valve

VA =4 cm2

LV

Pathophysiology  Left ventricular volume = Regurgitant

volume from the aorta + forward volume from the left atrium

Pathophysiology of AR 

LV volume LA dilatation

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LV dilatation LA pressure

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LV stroke volume CHF

 

Aortic dilatation

Etiology of aortic regurgitation Acute  Acute / subacute endocarditis  Trauma  Aortic dissection / Marfan’s syndrome

Chronic  Congenital  Rheumatic heart disease  Connective tissue disease such as Rheumatoid arthritis ankylosing spondylitis Lupus Erythematosus  Syphilis

Symptoms Early  Asymptomatic  Awareness of heart beats or palpitation

Late  Easifatigability  Exertional dyspnea  Orthopnea / PND  Edema  Chest pains

Physical examination Systolic hypertension  Wide pulse pressure  Besferiens and waterhammer pulse (Corrigan’s)  Hyperdynamic precordium and apical impulse is displaced to the left and inferiorly  Thrill and a diastolic blowing murmur at the 3rd LICS or 2nd RICS  S3 Plus the findings below in moderately severe to severe AR  Head bobbing  suprasternal notch pulsation (aortic dilatation)  Diastolic murmur at the apex ( Austin flint murmur)  Pistol shot (Traube sign)  Dorosiez sign  Quinke’s pulse  Signs of CHF 

Differential Diagnosis  Pulmonic regurgitation  Coronary sinus AV fistula  Mitral stenosis  Aortic dissection

DIAGNOSTICS  EKG _ LVH, LAH

LBBB  Chest x-ray • • •

cardiomegaly with the apex displaced downward and to the left Left atrial enlargement dilated aorta

Echocardiogram       

Deformed aortic leaflets Presence of calcification suggest a combined AS/ AR lesion Austin Flint phenomena in the mitral valve LV and LA dilatation Initially EF is normal or increased Doppler Presence of regurgitant jet flow from aorta to LV

Chest CT scan  To exclude aortic dissection if patient

presents with chest pains  Markedly dilated aorta  Following severe chest trauma

Cardiac Cath  Aortic root angiography

Backflow of x-ray contrast material from the aorta to the LV Aortic root angiography is relatively contraindicated in the presence of aortic dissection

Other diagnostic studies  RA factor  ANA titer and LE prep  VDRL and RPR  Blood cultures for febrile patients

Medical therapy      

Fluid and salt restriction Ace inhibitors Digoxin Duiretics Treat cardiac arrhythmias if present SBE prophylaxis with appropriate antibiotics

Depending on the history, PE and results of diagnostic test:  Rheumatic fever prophylaxis  Antibiotic therapy for endocarditis  Penicillin therapy for syphilis  Steroid therapy for connective tissue disease

Indications for surgery in AR  Class III-VI functional capacity  EF< 55 %  LV end systolic volume of 55 ml /m2 or > in

the echocardiogram

Surgical therapy  Aortic valve replacement

Bioprosthesis Mechanical valve

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END