Aortic stenosis by epifani d. Armedilla

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  • Review the anatomy and physiology of the cardiovascular system

  • Describe the pathophysiology of aortic stenosis

  • Identify the causes of aortic stenosis

  • Recognize the signs and symptoms of aortic stenosis

  • Discuss the imaging studies used in detecting the severity of aortic stenosis

  • Review the treatment for aortic stenosis

The Cardiovascular System



Causes of Aortic Stenosis

  • Congenital

  • Rheumatic fever

  • Degenerative calcification of the aortic cusps – most common

  • Obstructive infective vegetations

  • Paget’s disease of the bone

  • Systemic lupus erythematous

  • Rheumatoid disease

  • Irradiation

Congenital AS

Calcified AS

Senile or degenerative AS

Aortic Stenosis

Clinical Findings in Aortic Stenosis

  • Typical murmur and thrill for slightly narrowed, thickened, or roughened valves

  • Systolic ejection murmur at the aortic area transmitted to the neck and apex for mild or moderate cases

  • Palpable left ventricular heave or thrill, a weak to absent aortic second sound, or reversed splitting of the second sound are present in severe cases of AS because of prolonged ejection time

  • S4 is common and reflects increased atrial contribution to ventricular filling

Symptoms of Aortic Stenosis

  • AS is asymptomatic until the valve orifice has narrowed to approximately 0.5 cm²/m² body surface area of adults

  • Patients remain asymptomatic for a long period of time

  • The condition is first diagnosed based on detection of a systolic murmur on auscultation that can be explained by the gradual process of obstruction

Three Cardinal Symptoms of AS

  • Exertional dyspnea

  • Exertional angina

  • Exertional syncope

Exertional Dyspnea

  • Is a result of elevation of the pulmonary capillary pressure secondary to reduced compliance and/or LV dilatation

Exertional Angina

  • Usually develops later and reflects an imbalance between the augmented myocardial oxygen requirements and reduced oxygen availability

Exertional Syncope

  • Caused by arrhythmias (usually ventricular tachycardia and bradycardias), hypotension, or decreased cerebral perfusion resulting from increased blood flow to exercising muscles without compensatory increase in cardiac output

Imaging Studies

  • ECG

  • Chest radiography

  • Echocardiography

  • Dobutamine echocardiography

  • Cardiac catheterization


  • LV hypertrophy – classic finding

  • Other nonspecific changes are left atrial enlargement, left axis deviation, and left bundle-branch block

  • Not a reliable test because of the wide variations seen in AS and other cardiac conditions

ECG – LV Hypertrophy

  • Large S wave in V1

  • Large R wave in V5

Chest Radiograph

  • Normal or enlarged cardiac silhouette

  • Calcification of aortic valve

  • Dilatation and calcification of ascending aorta


  • Useful in assessing the severity of AS, the degree of coexisting aortic regurgitation, LV size and function

  • Helpful in estimating pulmonary systolic pressure and in identifying other cardiac abnormalities

  • TEE – displays the obstructive orifice extremely well

Dobutamine Echocardiography

  • Indicated in patients with moderate aortic stenosis and LV dysfunction to predict the reversibility of LV dysfunction after AVR

  • Pts. With AS, LV dysfunction, and relatively low gradients have better outcome when management decisions are based on the results of dobutamine echocardiogram (Schwammenthal, et al, 2001)

Cardiac Catheterization

  • Indicated for hemodynamic evaluation whenever there is discrepancy between the clinical picture and echocardiography

  • Indicated for young, asymptomatic patients with noncalcific congenital AS, to define the severity of obstruction to LV outflow

  • Indicated for patients in whom it is suspected that the obstruction to LV outflow may not be at the aortic valve but rather in the sub or supra-valvular regions

  • Also indicated to evaluate the coronaries in AS patients at risk for coronary artery disease

Grading of Aortic Stenosis

  • The aortic valve area must be reduced to one-fourth of its normal size before significant changes in the circulation occur

  • AS is graded based on the aortic valve area

    • Mild - >1.5 cm²
    • Moderate – 1.1 to 1.5 cm²
    • Severe - <0.75 to 1 cm²

Management of Aortic Stenosis

Pharmacological Management

  • Medical treatment has no role in preventing the progression of the disease process

  • But with the onset of LV systolic dysfunction, the use of inotropic agent may be advocated

Surgical Management

  • AVR is indicated for symptomatic patients

  • AVR improves survival in patients with depressed as well as normal LV function

  • The risks of surgery and prosthetic valve complications outweigh the benefits of preventing sudden cardiac death and prolonged survival in asymptomatic patient

Types of Valves

  • Bioprosthesis (Porcine)

  • Mechanical (St. Jude)

  • Homograft

Bioprosthesis vs. Mechanical Valves

  • Bioprosthesis valves are less durable than mechanical valves and begin to deteriorate after 5-6 years; usually do not require long-term coagulation

  • Mechanical valves are durable but require lifelong anticoagulation to control thromboembolism

  • Mechanical valve was associated with significantly lower 15 year mortality compared with bioprosthesis valve (66% vs. 79%) (Hammermeister, et al, 2000).

  • Mechanical valves are less obstructive than stented bioprosthesis valves of the same size (Bech-Hanssen, et al, 1999).

  • Despite a better survival rate with mechanical valve, the choice of valve should be tailored to the patient’s needs.


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      • Bech- Hassen, O., Caidahl, K., Wall, B., Myken, P., Lason, S., & Wallentin, I. (1999). Influence of aortic valve replacement, prosthesis type, and size of functional outcome and ventricular mass in patients with aortic stenosis. Journal of Thoracic Cardiovascular Surgery. 118(1):57-65.
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