Valvular Heart Disease Aortic Stenosis

Valvular Heart Disease Aortic Stenosis

Aortic Stenosis

• Etiology

• Physical Examination

• Assessing Severity

• Natural History

• Prognosis

• Timing of Surgery

Common Clinical Scenarios

• Younger people

• Functional murmur vs MVP vs bicuspid AV

Innocent Murmurs

• Common in asymptomatic adults

• Characterized by

• Grade I – II @ LSB
• Systolic ejection pattern

An 83 year old man with exertional dyspnea

• Previously well

• Gradual onset Class 2/4 dyspnea

• Occasional lightheadedness with exertion

• O/E: 2/6 ejection murmur

An 83 year old man with exertional dyspnea

• Is there significant valvular heart disease?

• Which valve?

• Is the valve playing a role in his dyspnea?

• How do you distinguish AV sclerosis from stenosis?

• What are the clinical signs of severe AS?

• What tests are appropriate?

• When is surgery indicated?

Aortic Stenosis: Symptoms

• Cardinal Symptoms

• Chest pain (angina)
• Reduced coronary flow reserve
• Increased demand-high afterload
• Syncope/Dizziness (exertional pre-syncope)
• Fixed cardiac output
• Vasodepressor response
• Dyspnea on exertion & rest
• Impaired exercise tolerance

• Other signs of LV failure

• Diastolic & systolic dysfunction

Common Murmurs and Timing (click on murmur to play)

• Systolic Murmurs

• Aortic stenosis

• Mitral insufficiency

• Mitral valve prolapse

• Tricuspid insufficiency

• Diastolic Murmurs

• Aortic insufficiency

• Mitral stenosis

Aortic Stenosis: Physical Findings

Aortic Stenosis: Physical Findings

• Intensity DOES NOT predict severity

• Presence of thrill DOES NOT predict severity

• “Diamond” shaped, harsh, systolic crescendo-decrescendo

• Decreased, delay & prolongation of pulse amplitude

• Paradoxical S2

• S4 (with left ventricular hypertrophy)

• S3 (with left ventricular failure)

Recognizing Aortic Stenosis

An 83 year old man with exertional dyspnea

Aortic Stenosis - Etiology

• Young patient think congenital

• Bicuspid
• 2% population
• 3:1 male:female distribution
• Co-existing coarctation 6% of patients

Aortic Stenosis: Etiology

• Congenital bicuspid valve is the most common abnormality

• Rheumatic heart disease and degeneration with calcification are found as well

Bicuspid Aortic Valve

Severity of Stenosis

• Normal aortic valve area 2.5-3.5 cm2

• Mild stenosis 1.5-2.5 cm2

• Moderate stenosis 1.0-1.5 cm2

• Severe stenosis < 1.0 cm2

• Onset of symptoms

• 0.9 cm2 with CAD
• 0.7 cm2 without CAD

Echocardiogram

• Etiology

• Valve gradient and area

• LVH

• Systolic LV function

• Diastolic LV function

• LA size

• Concomitant regional wall motion abnormalities

• Coarctation associated with bicuspid AV

Figure 1: Principles of the Use of Doppler Ultrasonography and the Continuity Equation in Estimating Aortic-Valve Area. For blood flow (A1 x V1) to remain constant when it reaches a stenosis (A2), velocity must increase to V2. Doppler examination of the stenosis detects the increase in velocity, which can be used to calculate the aortic-valve gradient or to solve the continuity equation for A2. A denotes area, and V velocity

Aortic Stenosis: Prognosis

Natural History of Aortic Stenosis

• Heart failure reduces life expectancy to less than 2 years

• Angina and syncope reduce life expectancy between 2 and 5 years

• Rate of progression  @ 0.1 cm2/year

Operative mortality of AVR in the elderly

• ~ 4-24%/year

• Risk factors for operative mortality

• Functional class
• Lack of sinus rhythm
• HTN
• Pre-existing LV dysfunction

Prosthetic Heart Valves

Caged-Ball Valve

Disc Valve

Bio-prosthetic Valve

Prosthetic Valves

• MECHANICAL

• Durable
• Large orifice
• High thromboembolic potential
• Best in Left Side
• Chronic warfarin therapy