"INTERNAL MEDICINE"

AORTIC VALVE DISEASE

1. Highlights

a. In aortic setenosis (AS), once symptoms of heart failure, syncope or angina develop, patient should be operated on.

b. Rule of 55: in asymptomatic aortic regurgitation, operate if end-systolic dimension>55 mm or ejection fraction (EF)<55%.

c. Rule of 60-45: in asymptomatic mitral regurgitation (MR), operate if end systolic dimension > 45 mm or EF<>

Aortic Stenosis

2. Highlights

a. An absolute indication for surgery in AS is the presence of symptoms.

b. A small valve gradient on echocardiography does not absolutely rule out severe AS.

c. In the face of symptoms and moderate AS on echocardiography, catheterization to rule out coronary artery disease (CAD) and verify valve gradient can be helpful.

3. Aetiology

a. Degenerative (in elderly).

b. Bicuspid (<70>

c. Rheumatic (less common).

4. History

a. Usually none.

b. Indications for intervention :-

(1) Chest Pain

(2) Syncope.

(3) Congestive heart failure (CHF)

c. Association with gastrointestinal (GI) arteriovenous malformation (GI bleed.

5. Physical Examination

a. Plus parvus and tardus carotid pulse is slow to rise with reduced intensity.

b. Systolic murmur :-

(1) Second right intercostals space.

(2) Coarse, harsh, grunt like.

(3) Crescendo-decrescendo.

(4) Increases with squatting.

(5) Decreases with Valsalva manoeuvre.

(6) Radiates to carotids.

(7) Gallavardin phenomenon, radiation to apex may mimic MR.

(8) Late peaking murmur S, thrill, paradoxical S, splits suggest severe AS.

6. Tests

a. ECG

(1) Left ventricular hypertrophy (LVH).

b. Chest X Ray

(1) Clacific aortic valve

(2) Signs of CHE

c. Echocardiography

(1) Peak and mean valve gradient :-

(a) Low gradient can still represent severe AS in rare cases.

(b) For the same valve area, left ventricular (LV) dysfunction can lower gradient, while severe aortic regurgitation (AR) can increase it.

(2) Aortic valve area.

(3) Definition of severe AS by echocardiography :-

(a) Peak aortic velocity > 4.5 m/second.

(b) Mean pressure gradient > 50 mm Hg.

© Valve area < 1.0 cm².

d. Catheterization

(1) Peak gradient and valve area (Table 21.1);-

(a) Peak gradient in catheterisation is usually lower than in echocardiography.

(b) Hakki formula: aortic valve area (AVA) = cardiac output/(square root of the mean gradient).

(2) Examine the coronary arteries: left heart catheterization.

(3) Examine the pulmonary artery pressures, wedge, cardiac output and so on: right heart catheterization.

7. Table 21.1 (Severity of AS by catheterization)

Severity	Mean gradient (mm Hg)	AVA (cm2)
Mild	<25	>1.5
Moderate	25-50	1.0-1.5
Severe	>50	<1.0
Critical	>80	<0.7

TREATMENT

8. Medical a. Antibiotic prophyaxis for disease b. Treat atrial fibrillation aggressively

c. Avoid vasodilators :

(1) Calcium channel blocker, angiorensin-converting enzyme (ACE) inhibitors and nitroglycerine.

d. Precutaneous valvuloplasty indications limited to :-

(1) Congential AS (age <>

(2) Palliation in the elderly.

(3) Bridge to aortic valve replacement (AVR) in critically ill patients.

(4) 50% restenosis at 6 months.

9. Surgical

a. Survival in AS drops sharply when symptoms develop (Table 21.2) :-

(1) Angina

(2) Syncope

(3) CHF

b. If patients are symptomatic and refuse surgery, 75 % mortality in 3 years, (Schwarz F et al, Circulation 1982; 66:1105.)

c. As combined with CAD has a worse prognosis than AS alone.

d. Indications for valve replacement :-

(1) American College of Cardiology/American Heart Association (ACC/AHA) recommendations :-

(aa) Class 1:

i. Symptomatic severe AS.

ii. Asymptomatic sever AS and undergoing other cardiac surgery.

(bb) Class 11a

i. Asymptomatic moderate AS undergoing other cardiac surgery.

ii. Asymptomatic severe AS and LV dysfunction.

iii. Abnormal exercise response.

Table 21.2 (Survival in AS with development of symptoms

Symptom	5 % mortality at
Congestive heart failure	2 years
Syncope	3 years
Angina	5 years

CHRONIC AORTIC REGURGITATION

1. Highlights

a. Always differentiate acute from chronic aortic regurgitation (AR).

b. Determine whether AR is due to a valve problem or a dilated aorta.

c. Wide pulse pressure.

d. Surgery if symptomatic (rule of 55) :-

(1) Aorta>5.5 cm.

(2) LV end systolic dimension> 55 mm.

(3) LVEF<55%.

2. Aetiology

a. Root dilatation :-

(1) Marfan’s syndrome.

(2) Syphilis.

(3) Ankylosing spondylitis.

(4) Aneurism.

(5) Dissection.

b. Valvular :-

(1) Rheumatic heart disease.

(2) Endocarditis.

(3) Calcific.

c. Hypertension.

3. History and Physical Examination

a. Dyspnoea and angina.

b. Look for signs suggesting secondary causes (e.g ankylosing spondylitis, Marfan’s).

c. Wide pulse pressure.

d. Peripheral signs.

(1) Corrigan’s waterhammer’ pulse (rapid distension and quick collapse).

(2) Bisferious pulse (carotid pulse has two systolic beats).

(3) Quincke’s pulse (nail bed pulsation)

(4) De Musset’s sign (bobbing of the head with each heart beat).

(5) Duroziez’s sign (bruit over femoral artery on light compression).

e. Decrescendo diastolic murmur in chroni AR :-

(1) Best heart at third left interspace (Erb’s space).

(2) If loudest at right sternal border, suspect aortic dilatation as the source.

f. Austin Flint murmur (MS like murmur due to premature closure of mitral valve secondary to regurgitant volume.

4. Test

a. ECG

(1) LVH

b. Chet X Ray

(1) Cardiomegaly : cor bovinum (heart of a cow).

(2) Enlarged aorta.

(3) Classification of aortic valve.

c. Echocardiography

(1) Always rule out dilated aorta as aetiology.

(2) Determine dimensions to guide surgery :-

(a) LV end systolic

(b) LV end diastolic.

(c) LVEF

d. AR severity based on :-

(1) Size of AR colour jet :-

(a) The width or area of AR jet /LV outflow tract ratio :-

i. >60% = severe.

ii. <>

(2) Deceleration slope of AR jet :-

(a) On continuous wave Doppler pressure half time (PHT) (milliseconds):

i. < style="mso-spacerun:yes"> = severe

ii. >400 = mild

(3) Effective regurgitant orifice’ (ERO) by proximal isovelicity surface area (PISA) :

(a) > 0.3 cm square = severe.

(b) < style="mso-tab-count:1"> = mild

(4) Degree of flow reversal in aorta.

e. Catheterisation (Table 21.3) Angiographic grade of AR

Severity	Grade	Description
Mild	1+	Clears with each beat no opacification of LV
Mild to moderate	2+	Does not clear with each beat faintly opacifies LV
Moderate	3+	Complete opacification: equal dye intensity to aorta after several beats
Severe	4+	LV opacifies with one beat

5. Treatment

a. Medical

(1) Vasodilator :-

(a) Calcium-Channel blocker.

(b) ACE inhibitor.

b. Surgical decision of when to operate

(1) Make sure AR is severe or moderate to severe.

(2) If symptomatic (NYHA Class III or IV) : operate.

(3) If symptomatic :-

(a) Look at echocardiogram (‘rule of 55’): if end systolic dimension > 55 mm or EF <> 75 mm): operate. If aortic root > 5.5-6.0 cm: operate (> 5.0 cm in Marfan’s syndrome).

(4) If patient does not fit the above criteria, follow up echocardiography within 2-3 months, then every 6-12 months for severe AR (depending on severity of AR/LV dimension).