AORTIC VALVE Aortic Valve is located at the junction of LV outflow tract and ascending Aorta. Aortic valve consists of 3 components – annulus, cusp and commissure. Aortic valve have 3 cusp – one located on the anterior wall(right coronary cusp)& two located in the posterior wall(left and posterior cusp) Cusp are fold of endocardium with central fibrous core. Each cusp have thick basal border, deeply concave on its aortic aspects and horizontal free margins.

Continue... Behind each cusp aortic wall bulges to form aortic sinus of valsava. Coronary arteries arise form the sinus(right coronary artery – anterior cusp, left coronary artery – left posterior cusp) Aortic valve consisted of annulus but there is no complete collagenous ring supporting the attachment of leaflet Commusures form tall peacked space between the attachment of adjacent cusp and attain the level of aortic sinotubular junction Aortic cusp form central closure line in diastole, in systole the cusp open and close again at the end systole when aortic pressure exceeds the LV pressure

Normal valve area (cm2) _ 2.5 – 3.5cm2 Normal velocity of aorta (m/s) – 1 – 1.7 m/s

AORTIC STENOSIS Narrowing of aortic orifice Aortic stenosis develops slowly except in congenital form Aortic stenosis occurs in three levels Valvular Aortic Stenosis(Causes) Rheumatic Heart Disease Calcific Aortic Stenosis associated with increasing age Congenital Bicuspid Valve(A bicuspid valve is found in 40% of middle aged individual with aortic stenosis and 80% of elderly individual with aortic stenosis Bicuspid Aortic valve is congenital abnormality affecting 1-2% of population and result in cusp which separate normally but usually have eccentric closure line which may lie interiorly or posteriorly.

Continue... Sub Valvular Aortic Stenosis(caused by obstruction proximal to AV) Sub aortic membrane Hypertrophic cardiomyopathy Tunnel Sub aortic obstruction Upper septal bulge – this is due to fibrosis and hypertrophy usually seen in elderly individual Supra Valvular Aortic Stenosis This occur in some congenital condition such as Williams syndrome (which includes hypercalcemia, growth failure and mental retardation)

Normal valve area Peak Velocity (m/s) Peak gradient(mmHg) Mild 1.5 - 2.5 Moderate 0.75-1.5 Severe <0.75 Peak Velocity (m/s) Normal 1.0 Mild 1.0 – 2.0 Moderate 2.0-4.0 Severe >4.0 Peak gradient(mmHg) Normal <10 Mild <20 Moderate 20-64 Severe >64

Valvular Aortic stenosis

Clinical Features Symptoms Mild to Moderate AS is usually asymptomatic Exertional Dyspnea Angina Exertional Syncope Sudden Death Episode of acute Pulmonary Edema Signs Ejection systolic murmer Slow rising carotid pulse Narrow pulse pressure Thirsting apex beat(LV pressure overload) Signs of pulmonary venous congestion

Investigation ECG – LVH, LBBB X-ray - LV enlargment Echocardiogram 2D Echo Cusp may seen thickened, calcific reduced motion or may dome There may be LVH due to pressure overload LV dilatation occur if heart failure has developed Post stenotic dilatation of aorta may be seen Doppler Turbulant flow. Can asses the severity of AS by estimating the pressure gradient across the AV.

Management Patient with symptomatic AS and valve gradient indicative of moderate or severe stenosis(>50 mm Hg)should have valve replacement Aortic Balloon Valvuloplasty is useful in congenital aortic stenosis Anticoagulants are required only if patient have atrial fibrillation or have valve replacement with mechanical prosthesis

Aortic Regurgitation This is leakage of blood from aorta to LV during diastole Causes: # Congenital Bicuspid valve or disproportionate cusp # Accquired Rheumatic Disease Infective Endocarditis Trauma Aortic Dilatation(Marfan syndrome, anneurysm, dissection, syphyllis)

Clinical Features Symptoms Mild – moderate AR often asymptomatic Awareness of heart beat “pulsation” Severe AR – Breathlessness, Angina Signs Pulse Large volume or collapsing pulse Bounding peripheral pulse Capillary pulsation in nail bed _Quineke’s Sign Femoral bruit Head nodding with pulse Murmur early diastolic murmur systolic murmur Austin flint murmur (soft mid diastolic) Other Signs Displaced rocking apex beat Fourth heart beat sound Pulmonary Venous Conjestion

INVESTIGATION ECG – LVH X-ray – Cardiac Dilatation, features of LVH Echocardiogram M mode and 2D Echo – LV dilatation with severe AR, progressive dilatation with symptoms or left ventricular end systolic diametre in excess of 5.5cm Pulse Vave Doppler Can give idea of severity by seeing how far into the LV cavity the AR jet reaches Mild AR remains within the area of AV Moderate AR remains between the LVOT & level of mitral valve above papillary muscle level Severe AR extend to LV apex Continuous Wave Doppler The slope of deccelaration rate of the doppler signal of AR can give an indication of severity

Doppler High velocity turbulent flow in diastole because of aliasing direction of flow is not seen correctly but dominant doppler signal are above the base line.

Management Treatment for endocarditis AVR indicated if AR causes symptoms Vasodilators have been shown to prevent left ventricular dilatation When aortic root dilatation is cause of AR aortic root replacement may be necessary