A Seminar presentation on

Diseases of the Aortic valve

Pratap Sagar Tiwari, Resident, Internal Medicine, NGMC

Contents• Anatomy of Aortic valve/variants• Aortic Regurgitation • Aortic Stenosis

Anatomy of Aortic Valve

The AV is located betwn the LVOT and the ascending aorta. It forms the centerpiece of the heart and closely approximates many other important cardiac structures; specifically, the PV anteriorly, MV posterolaterally, and TV posteromedially.[1]

Ref: 1. Anderson RH. Clinical anatomy of the aortic root. Heart. Dec 2000;84(6):670-3.

Picture : Aortic Valve.[1]

Picture ref: Anderson RH. Clinical anatomy of the aortic root. Heart. Dec 2000;84(6):670-3.

Picture : Aortic Valve.[1]

Picture reference: Anderson RH. Clinical anatomy of the aortic root. Heart. Dec 2000;84(6):670-3.

Pathophysiologic VariantsBicuspid aortic valve• Bicuspid aortic valves are the most common

cardiac valvular anomaly, occurring in 1- 2% of the general population.

• It is twice as common in males as in females.[1]

Ref:1. Tzemos N, Therrien J, Yip J et al (September 2008). "Outcomes in adults with bicuspid aortic valves". JAMA 300 (11): 1317–1325

Aortic Regurgitation: overview• AR is a condition due to inadequate closure of the

aortic valve leaflets leading to abnormal retrograde flow of blood through the aortic valve during cardiac diastole.

• It can be induced either by damage to and dysfunction of the aortic valve leaflets or by distortion or dilatation of the aortic root and ascending aorta

• In the developing world, the most common cause of AR is rheumatic heart disease. However, in developed countries, AR is most often due to aortic root dilation or a congenital bicuspid aortic valve .[1]

Ref: 1. Maurer G. Aortic regurgitation. Heart. Jul 2006;92(7):994-1000.

Causes of Aortic RegurgitationLeaflet abnormalities Aortic root or ascending aorta

Rheumatic fever Systemic hypertension

Endocarditis Aortitis (eg, syphilis)

Trauma Reactive arthritis

Bicuspid aortic valve Ankylosing spondylitis

Rheumatoid arthritis Trauma/ Dissecting aneurysm

Myxomatous degeneration Osteogenesis imperfecta

Ankylosing spondylitis Marfan syndrome/ EDS

Acromegaly Inflammatory bowel disease

AR is seen more commonly in men than in women. As in the Framingham study, AR was found in 13% of men versus 8.5% of women.[1] The greater prevalence of AR in men may reflect, in part, the male preponderance of underlying conditions such as Marfan syndrome[2] or bicuspid aortic valve[3] .

Ref:1. Singh JP, Evans JC, et al. Prevalence and clinical determinants of mitral, tricuspid, and AR (the Framingham Heart Study). Am J Cardiol. Mar 15 1999;83(6):897-902. 2. Keane MG, Pyeritz RE. Medical management of Marfan syndrome. Circulation. May 27 2008;117(21):2802-13. 3. Ortiz JT, Shin DD, Rajamannan NM. Approach to the patient with bicuspid AVand ascending aorta aneurysm. Curr Treat Options Cardiovasc Med. Dec 2006;8(6):461-7.

Pathophysiology

LV wall stress

↑ LV Volume

LV Hypertrophy

Law of laplace

Pathophysiology : Acute ARSudden large regurgitant volume

imposed on LV of normal size with normal compliance

1. Rapid ↑ LVEDP and ↑ LAP 2. LV attempts to maintain CO with ↑HR and ↑

Contractility

Angina↓ Coronary perfusion

↑demand myocardial O2

Attempts to maintain forward SV/CO may be inadequate

Cardiogenic Shock↓ Forward SV/CO

Pulmonary edema↑ LVEDP and ↑ LAP

Pathophysiology: Chronic AR Regurgitant Volume Load

Compensatory Mechanisms:1. ↑LV dilatation ↑ LVED vol and ↑chamber

compliance2. ↑ LV hypertrophy

Angina↓ Coronary perfusion pressure &

marked LVH

Decompensation

Steadily increasing regurgitant volume loadFurther ventricular dilatation ↑ wall stress

Inability to continue further hypertrophy Contractile dysfunction ↓ EF/SV/CO

CHF symptomsDue to both congestion and

↓ CO

Findings are a/w hyperdynamic pulse

deMusset's sign

A head bob occurring with each cardiac cycle

Mueller's sign Systolic pulsations of the uvula.

Becker's sign Visible pulsations of the retinal arteries and pupils.

Quincke's pulses

visible Capillary pulsations in the nailbeds after holding the tip of the nail.

Duroziez's sign

A systolic and diastolic bruit heard when the femoral artery is partially compressed.to and fro murmur

Traube's sign A pistol shot murmur (systolic and diastolic sounds) heard over the femoral arteries.

Mayne's sign More than a 15 mmHg decrease in DBP with arm elevation from the value obtained with the arm in the standard position.

Hill's sign Popliteal cuff systolic pressure exceeding brachial pressure by more than 60 mmHg.

Rosenbach's sign

Systolic pulsations of the liver.

Gerhard's sign

Systolic pulsations of the spleen.

• The diastolic murmur of AR begins immediately after A2 .

• It is high pitched, often blowing in quality, and may be sustained in intensity or decrescendo.

• It may be soft and barely audible, often appreciated only when the patient is sitting up, leaning forward, and holding his or her breath in expiration.

• Patients with a longer diastolic murmur, a displaced left ventricular impulse, a wide pulse pressure, and the peripheral findings of a wide pulse pressure are considered to have severe AR.

Note: When the Diastolic murmur of AR is louder in the 3rd /4th RICS than in the 3/4th LICS ,the AR is likely to result from Aortic root dilatation than deformitiy of leaflets alone.Ref: ACC/AHA Guidelines 2006

• In a review of the literature, the presence of an early diastolic murmur, as heard by a cardiologist, was the most useful finding for establishing the presence of AR (positive likelihood ratio 8.8 [ie, the odds of AR are increased 8.8 fold]) and its absence the most useful finding for eliminating the presence of AR (negative likelihood ratio 0.2 to 0.3 [ie, the odds of disease are reduced by a factor of 0.2 to 0.3]) .[1]

Ref: 1. Choudhry NK, Etchells EE. The rational clinical examination. Does this patient have aortic regurgitation? JAMA 1999; 281:2231.

Laboratory Studies• Laboratory testing in patients with aortic

regurgitation should be guided by the clinical scenario.

• For example, in patients with AR due to suspected infective endocarditis, peripheral blood counts and cultures may help clarify the diagnosis and identify the causative organism.

• Specific serologic tests may assist in the diagnosis of rheumatological causes.

Imaging studies : Echo• Aortic valve structure and morphology (bileaflet versus

trileaflet, flail, thickening)• Presence of vegetations • Severity of AR• Color Doppler jet width • Vena contracta width• Regurgitant volume, fraction, and orifice area• Premature closure of the mitral valve (seen in severe AR)

• Associated lesions of the aorta, including dilation, aneurysm, dissection

• LV structure and function• LV hypertrophy and dilation• EF and end-systolic dimension are key determinants of

outcome

Severity of AR: Echo grading MILD MOD SEVERE

Structural parameters

Left ventricular size N N or dilated Dilated, except acute AR

Aortic leaflets N or abnormal N or abnormal Abnormal/flail, or wide coaptation defect

Doppler parameters

Color Doppler jet width

Central jet, width <25 percent of LVOT

Central jet, width 25 to 65 percent of LVOT

Central jet width >65 percent of LVOT

Doppler vena contracta width

<3 mm 3 to 6 mm >6 mm

Quantitative parameters

Regurgitant volume <30 mL/beat 30 to 59 mL/beat ≥60 mL/beat

Regurgitant fraction <30 percent 30 to 49 percent ≥50 percent

Regurgitant orifice area

<0.10 cm2 0.10 to 0.29 cm2 ≥0.30 cm2

Severe chronic AR is typically a/w c/f including a longer diastolic murmur, a displaced LVI, a wide PP, and the peripheral findings of a wide PP.

Echo staging of Decompensation.[1,2,3,4,5,6,7,8]

References:1. ACC/AHA 2006 guidelines2. Gaasch WH, Andrias CW, Levine HJ. Chronic aortic regurgitation: the effect of aortic valve replacement on left ventricular volume, mass and function. Circulation 1978; 58:825.3. Schuler G, Peterson KL, Johnson AD, et al. Serial noninvasive assessment of left ventricular hypertrophy and function after surgical correction of AR. Am J Cardiol 1979; 44:585.4. Borow KM, Green LH, Mann T, et al. End-systolic volume as a predictor of postoperative LVperformance in volume overload from valvular regurgitation. Am J Med 1980; 68:655.5. Henry WL, Bonow RO, et al. Observations on the optimum time for operative intervention for AR. Evaluation of the results of AVR in symptomatic patients. Circulation 1980; 61:471.6. Kumpuris AG, Quinones MA, Waggoner AD, et al. Importance of preoperative hypertrophy, wall stress and end-systolic dimension as echocardiographic predictors of normalization of left ventricular dilatation after valve replacement in chronic aortic insufficiency. Am J Cardiol 1982; 49:1091.7. Gaasch WH, Carroll JD, Criscitiello MG. Chronic AR: prognostic value of left ventricular end-systolic dimension and end-diastolic radius/thickness ratio. J Am Coll Cardiol 1983; 1:775.8. Stone PH, Clark RD, Goldschlager N, et al. Determinants of prognosis of patients with aortic regurgitation who undergo aortic valve replacement. J Am Coll Cardiol 1984; 3:1118.9. Bonow RO, Rosing DR, McIntosh CL, et al. The natural history of asymptomatic patients with aortic regurgitation and normal left ventricular function. Circulation 1983; 68:509.10. Bonow RO, Lakatos E. Serial long-term assessment of the natural history of asymptomatic patients with chronic AR and normal left ventricular systolic function. Circulation 1991; 84:1625.11. Siemienczuk D, Greenberg B, Morris C, et al. Chronic aortic insufficiency: factors associated with progression to aortic valve replacement. Ann Intern Med 1989; 110:587.

Procedures: Cardiac Cath

Class I indications for CC under current ACC/AHA guidelines include the following:[1]

• Assessment of coronary anatomy prior to aortic valve surgery in patients with risk factors for coronary artery disease.

Ref: 1. Bonow RO, Carabello BA, Chatterjee K, de Leon AC Jr, Faxon DP, Freed MD. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease..

Exercise testing in AR[1]

Class IIa - The weight of evidence or opinion is in favor of efficacy of the following tests in patients with AR in the above settings.

Ref: 1. Bonow RO, Carabello BA, Chatterjee K, de Leon AC Jr, Faxon DP, Freed MD. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with VHD.

Medical care• In acute severe AR, surgical intervention is usually

indicated, but the patient may be supported medically with dobutamine to augment cardiac output and shorten diastole and sodium nitroprusside to reduce afterload in hypertensive patients.

• In chronic severe AR, vasodilator therapy may be used in select conditions to reduce afterload in patients with systolic hypertension to minimize wall stress and optimize LV function; in normotensive patients, vasodilator therapy is not likely to reduce regurgitant volume (preload) significantly and thus may not be of clinical benefit.[1]

Ref: 1. Bekeredjian R, Grayburn PA. Valvular heart disease: aortic regurgitation. Circulation. Jul 5 2005;112(1):125-34.

Medical Care continue…• The acute administration of Na Nitoprusside ,

hydralazine, nifedipine or felodipine ↓PVR and results in an immediate augmentation in forward CO and a ↓ in regurgitant volume.

• With nitroprusside and hydralazine ,these acute hemodynamic changes lead to a consistent ↓in EDV and an ↑in EF.

References:1. Miller RR, Vismara LA, .Afterload reduction therapy with nitroprusside in severe AR: improved cardiac performance and reduced regurgitant volume. AmJ Cardiol 976;38:564–72. Greenberg BH, DeMots H. Beneficial effects of hydralazine on rest and exercise hemodynamics in patients with chronic severe aortic insufficiency. Circulation 1980;62:49–553. FiorettiP, BenussiB.Afterload reduction with nifedipine in aortic insufficiency. AmJ Cardiol 1982;49:1728–32

Medical Care Continue…..• Reduced EDV and ↑EF have also been observed

in small number of pts receiving long term oral therapy with hydralazine and nifedipine for a period of 1-2 yrs. With nifedipine these effects are A/W ↓ in LV mass.[1,2]

• Reduced BP with enalapril and quinapril has been A/W ↓ in EDV and mass but no change in EF.[3,4]

References:1. Scognamiglio R, Fasoli G. Long-term nifedipine unloading therapy in asymptomatic patients with chronic severe AR. J Am Coll Cardiol 1990; 16:424–9.2. Greenberg B, Massie B, et al. Long-term vasodilator therapy of chronic AI: a randomized double-blinded, placebo-controlled clinical trial. Circulation 1988;78:92–103.3. Lin M, Chiang HT,etal.Vasodilator therapy in chronic asymptomatic AR: enalapril versus hydralazine therapy. J Am Coll Cardiol 1994;24:1046–53.4. Schon HR, Dorn R. Effects of 12 months quinapril therapy in asymptomatic patients with chronic AR. J Heart Valve Dis 1994;3:500–9.

ACC/AHA GL on Vasodilator therapy:

• Indicated for long-term therapy in patients with chronic, severe AR and symptoms of LV dysfunction but who are not candidates for surgery.( CLASS I: LOE-b)

• Is reasonable for short-term therapy in patients with severe LV dysfunction and HF symptoms to improve their hemodynamic profile before proceeding with surgery.(CLASS IIa: LOE-c)

• Is acceptable for long-term therapy in asymptomatic patients with severe AR and LV dilation with normal EF. (CLASS IIb: LOE-b)

Ref: 1. Bonow RO, Carabello BA, Chatterjee K, de Leon AC Jr, Faxon DP, Freed MD. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease.

Note: LOE = Level of Evidence

Prophylaxis for IE• Antibiotic prophylaxis prior to dental procedures is

no longer routinely recommended for all patients with AR under current ACC/AHA guidelines.[1]

Ref:1. Bonow RO, Carabello BA, Chatterjee K, de Leon AC Jr, Faxon DP, Freed MD. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease

Surgical care• Surgical treatment of AR usually requires

replacement of the diseased valve with a prosthetic valve, although valve-sparing repair is increasingly possible with advances in surgical technique and technology.

Current ACC/AHA guideline for AV Sx [1]

• Patient is symptomatic.• Patient is asymptomatic, with a resting EF of ≤

55%.• Patient is asymptomatic, with LV dilation (LV end-

systolic dimension >55 mm).

Ref: 1. Bonow RO, Carabello BA, Chatterjee K, de Leon AC Jr, Faxon DP, Freed MD. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease.

Mechanical Vs bioprosthetic AV• For patients undergoing AV replacement, careful

consideration should be given to the relative risks and benefits of mechanical vs bioprosthetic valves.

• Mechanical valves : more durable but require long-term anticoagulation with warfarin due to increased risk of thrombosis.

• Bioprosthetic valves carry a greater risk of long-term deterioration and risk of reoperation but avoid the need for long-term warfarin.[1]

Ref: 1. Bonow RO, Carabello BA, Chatterjee K, de Leon AC Jr, Faxon DP, Freed MD. 2008 focused update incorporated into the ACC/AHA2006 guidelines for the management of patients with valvular heart disease..

Further inpatient care• Inpatient care is required for most patients with

acute severe aortic regurgitation (AR), particularly with symptoms or evidence of hemodynamic decompensation.

Further outpatient CareESD EDD Stable Dimension Incresing

Dimension

<45 mm < 60 mm Evaluate 6-12 mn Repeat Echo in 12 mnth

3mnth3 mnth

45-50 mm

60-70 mm Evaluate 6 mn Repeat Echo in 12 mnth

3 mnth3 mnth

50-55 mm

70-75 mm Evaluate in 6 mn Repeat Echo 6 mnth

3 mnth3 mnth

>55 mm > 75 mm Surgery

Complications• Left untreated, acute severe AR is likely to lead to

considerable morbidity and mortality from either the underlying cause (typically infective endocarditis or aortic dissection) or from hemodynamic decompensation of the LV.

• Potential complications in patients with chronic severe AR include progressive LV dysfunction and dilation, CHF, MI, arrhythmia, and sudden death.

PrognosisThe prognosis for patients with severe AR depends on the presence or absence of LV dysfunction and symptoms, as follows:[1]

• In asymptomatic patients with normal EF1. Rate of progression to symptoms &/or LVD = < 6% per yr2. Rate of progression to asymptomatic LVD = < 3.5% per yr3. Rate of sudden death = less than 0.2% per yr• In asymptomatic patients with decreased EF, rate of

progression to symptoms = >25% per year.• In symptomatic patients, mortality rate = >10% per yr.The strongest predictors of outcome are echocardiographicparameters (EF and LV end-systolic dimension).Ref:1. Bonow RO, Carabello BA, Chatterjee K, de Leon AC Jr, Faxon DP, Freed MD. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease.

Thankyou

References:1. 2008 update on ACC/AHA 2006 Guideline on

VHD.2. Harrison’s Principle of Internal Medicine ,18th ed.3. Washington manual; Cardiology Subspeciality

Consult ,2nd ed.4. Cardiology Secrets by Glenn L Levine, 3rd ed.5. Uptodate 19.1 .Last literature review sep 30

2011.6. Emedicine “7. Mayo Clinic