AORTIC STENOSIS 

 ETIOLOGY

 1-Rheumatic heart disease is the most common cause resulting from adhesions and fusions of the commissures and cusps.

2. Congenitally abnormal (bicuspid) aortic valve. The normal valve is tricuspid, the bicuspid valve may be stenotic with commissural fusion at birth but usually not causing serious narrowing of the aortic orifice during childhood. The abnormal architecture induces turbulent flow, which traumatizes the leaflets and leads to fibrosis, increased rigidity, calcification of leaflets, and narrowing of the aortic orifice in adulthood.

3. Senile AS:

SYMPTOMS

Long asymptomatic phase

Symptomatic AS manifests as

Angina

Exercise-induced syncope

Exertional dyspnea  

Syncope attacks:

Syncopal attacks are due to markedly decreased cerebral perfusion that occurs during exertion due to systemic vasodilatation in the presence of reduced cardiac output due to fixed obstruction. Syncope at rest may be due to transient ventricular fibrillation from which the patient recovers spontaneously, transient AF, or transient heart block.

Angina pectoris: –

Angina occurs due to myocardial ischemia Exertional dyspnea:  Exertional dyspnea, orthopnea, and PND are late symptoms in AS and reflect pulmonary venous hypertension

Heart failure:

Heart failure occurs due to both left ventricular systolic and diastolic dysfunction.

Signs 

General physical examination related to AS

Pulse: carotid pulse is low volume and slowly rising  

Palpation of the apex and carotid artery reveals a delay in carotid pulse in severe AS.

Pulse pressure: Narrow in late stages

JVP: prominent a wave due to reduced compliance of right ventricle due to pulmonary hypertension or hypertrophy of the ventricular septum.

Palpation 

Apex beat is not displaced  •Apex beat is heaving in character (forceful) due to left ventricular hypertrophy (as a result of pressure overload)

A double apex beat may be palpable due to a fourth heart sound or atrial contraction.  •

A systolic thrill may be felt in the aortic area or suprasternal notch and is frequently transmitted along the carotid arteries.

Auscultation

Heart sounds  • SI is normal or soft  • S2 is soft because only P2 is audible while A2 is inaudible due to immobility of the aortic valve as a result of calcification.

Reversed splitting of the second heart sound. Normally during inspiration, the splitting of 2 nd heart sound becomes wide. But in this case, it becomes narrow during inspiration and wide during expiration due to delayed closure of the aortic valve.

A prominent fourth heart sound.

Systolic ejection click  

Ejection systolic (mid- systolic) murmur  • Ejection systolic (mid- systolic) murmur is present in the aortic area. The murmur is usually rough in quality and best heard in the aortic area.  • It radiates to the carotid artery and also the precordium to the apex,  Murmurs heard best with the patient leaning forwards and breath held in expiration

INVESTIGATIONS

X-ray chest  • Chest X-ray may be normal in critical AS  • The heart is usually normal in size or slightly enlarged.  • Post-stenotic dilatation of ascending aorta on PA view is commonly seen.

ECG  • Left ventricular hypertrophy.  • Left ventricular strain due to pressure overload (such as depressed ST segments and T wave inversion in leads I, AVL, V5, and V6).

Echocardiogram —  This shows a thickened, calcified, and immobile aortic valve cusp.  Detects left ventricular hypertrophy, its systolic and diastolic function.

Cardiac catheterization is required in patients 40 years and above for coronary angiography and to confirm the gradient across the aortic valve. Coronary angiography is performed to diagnose the cause of angina that may be due to coronary artery disease or aortic stenosis.

TREATMENT

Medical treatment is not effective for aortic stenosis.

Angiography is indicated in patient aged 40 years or above if valve replacement is planned

Surgery is not indicated for asymptomatic patients except those with declining left ventricular function, very severe left ventricular hypertrophy

Medical treatment is given to those patients who are inoperable (usually; due to co-morbidities

Avoid strenuous physical activity.

Angina may be treated with beta-blockers but cautiously because they may lead to shock or heart failure.

Surgical treatment   Aortic balloon valvoplasty