Valvular Heart Disease

Valvular Heart DiseaseValvular Heart Disease

Basic ScienceBasic Science

March 22, 2006March 22, 2006

1. Information on valves may be 1. Information on valves may be accurately obtained by:accurately obtained by:

A.A. CXRCXR

B.B. Transthoracic echocardiography Transthoracic echocardiography (TTE)(TTE)

C.C. Transesophageal echocardiography Transesophageal echocardiography (TEE)(TEE)

D.D. CT scanCT scan

E.E. Cardiac catheterizationCardiac catheterization

TEE is more sensitive than TTE, TEE is more sensitive than TTE, especially for aortic and mitral valve especially for aortic and mitral valve lesions; even more so for mitral lesions; even more so for mitral regurgitation.regurgitation.

Cardiac catheterization can give detail on Cardiac catheterization can give detail on mitral/aortic valve areas, calculated by the mitral/aortic valve areas, calculated by the Gorlin formula.Gorlin formula.

2. What is true concerning the 2. What is true concerning the anatomy of the mitral valve?anatomy of the mitral valve?

A.A. The normal mitral valve has two The normal mitral valve has two leaflets; the lateral and medial leaflets.leaflets; the lateral and medial leaflets.B.B. The chordae tendineae attach the The chordae tendineae attach the leaflets to two papillary muscles.leaflets to two papillary muscles.C.C. The two leaflets are identical mirror The two leaflets are identical mirror images of each other, forming a tight images of each other, forming a tight closure.closure.D.D. There is a fibrous continuity between There is a fibrous continuity between the mitral and aortic valves.the mitral and aortic valves.

The two leaflets are anterior and posterior.The two leaflets are anterior and posterior.

The two leaflets have the same surface The two leaflets have the same surface area but very different shapes. The base area but very different shapes. The base of the anterior leaflet accounts for 1/3 of of the anterior leaflet accounts for 1/3 of the circumference of the mitral annulus the circumference of the mitral annulus and the posterior leaflet accounts for 2/3.and the posterior leaflet accounts for 2/3.

3. What is true concerning mitral 3. What is true concerning mitral stenosis?stenosis?

A. Principal cause is rheumatic fever.A. Principal cause is rheumatic fever.B.B. The normal cross-sectional area of the The normal cross-sectional area of the mitral valve is 4-6 cmmitral valve is 4-6 cm22, and moderate stenosis , and moderate stenosis occurs at 2 cmoccurs at 2 cm22 and severe stenosis occurs at 1 and severe stenosis occurs at 1 cmcm22..C.C. There is normally a 5 mm Hg pressure There is normally a 5 mm Hg pressure gradient across a normal valve, with symptoms gradient across a normal valve, with symptoms occurring once the gradient increases to greater occurring once the gradient increases to greater than 10 mm Hg.than 10 mm Hg.D.D. Symptoms usually occur with bradycardia Symptoms usually occur with bradycardia and the heart’s inability to supply adequate and the heart’s inability to supply adequate cardiac output to overcome the pressure gradient cardiac output to overcome the pressure gradient across the valve.across the valve.

There is normally no pressure gradient There is normally no pressure gradient across the mitral valve. A pressure across the mitral valve. A pressure gradient of 20 mm Hg is needed to gradient of 20 mm Hg is needed to maintain adequate left ventricular filling maintain adequate left ventricular filling across a 1 cmacross a 1 cm22 stenotic valve. stenotic valve.Contribution of an adequate left atrial Contribution of an adequate left atrial “kick” is important in mitral stenosis, and “kick” is important in mitral stenosis, and loss of this contraction (with exertion or loss of this contraction (with exertion or atrial fibrillation) often leads to symptoms.atrial fibrillation) often leads to symptoms.

4. Mechanical relief of mitral 4. Mechanical relief of mitral stenosis should be considered stenosis should be considered

when:when:

A.A. The valve size is 2 cmThe valve size is 2 cm22 or smaller. or smaller.

B.B. The patient becomes symptomatic.The patient becomes symptomatic.

C.C. Pulmonary hypertension develops.Pulmonary hypertension develops.

D.D. With worsening Left ventricular With worsening Left ventricular hypertrophy and dilatation.hypertrophy and dilatation.

E.E. Endocarditis develops in the valves.Endocarditis develops in the valves.

Mechanical correction should be Mechanical correction should be considered when the valve is 1 cmconsidered when the valve is 1 cm22 or less or less in area.in area.

Left ventricular hypertrophy is not Left ventricular hypertrophy is not expected with isolated mitral stenosis.expected with isolated mitral stenosis.

Other causes for repair include systemic Other causes for repair include systemic embolization (usually from a-fib).embolization (usually from a-fib).

5. What is true concerning balloon 5. What is true concerning balloon mitral valvuloplasty?mitral valvuloplasty?

A.A. Treatment of choice in patients with pliable Treatment of choice in patients with pliable valves, without calcification or deformation of the valves, without calcification or deformation of the chordae tendineae.chordae tendineae.B.B. Contraindications include thickened, Contraindications include thickened, calcified mitral leaflets and absence of any mitral calcified mitral leaflets and absence of any mitral regurgitation.regurgitation.C.C. Balloon inflation should increase the valve Balloon inflation should increase the valve area to greater than 4 cmarea to greater than 4 cm22..D.D. Mortality rate is 0.5-2% with total Mortality rate is 0.5-2% with total complication rate of 3-6%.complication rate of 3-6%.E.E. Results compare favorably with surgical Results compare favorably with surgical valvuloplasty in appropriately selected patients.valvuloplasty in appropriately selected patients.

Moderate mitral regurgitation is a Moderate mitral regurgitation is a contraindication for valvuloplasty.contraindication for valvuloplasty.An area of 2 cmAn area of 2 cm22 should be achieved, should be achieved, resulting in a significant decline in left atrial resulting in a significant decline in left atrial pressure with 20% increase in CO.pressure with 20% increase in CO.Complications include systemic embolism, Complications include systemic embolism, cardiac perforation, and creation of mitral cardiac perforation, and creation of mitral regurgitation (1-2% complication rate for regurgitation (1-2% complication rate for each).each).

6. What is true concerning mitral 6. What is true concerning mitral valve replacement?valve replacement?

A.A. The mitral valve should be replaced if The mitral valve should be replaced if dense calcification precludes balloon dense calcification precludes balloon valvuloplasty or open commissurotomy.valvuloplasty or open commissurotomy.B.B. Should be openly replaced if there is Should be openly replaced if there is concomitant mitral regurgitation.concomitant mitral regurgitation.C.C. The chordae tendineae should be divided, The chordae tendineae should be divided, especially when excessively shortened or especially when excessively shortened or scarred.scarred.D.D. Operative mortality is 1-2%.Operative mortality is 1-2%.E.E. The 5 year survival rate is 50-60%.The 5 year survival rate is 50-60%.

Efforts should be made to preserve the Efforts should be made to preserve the posterior, and in some cases the anterior posterior, and in some cases the anterior leaflets and chordae tendineae; studies leaflets and chordae tendineae; studies have shown an advantage to left have shown an advantage to left ventricular function with preservation.ventricular function with preservation.

Operative mortality is 2-10%.Operative mortality is 2-10%.

Five year survival rate is 70-90%.Five year survival rate is 70-90%.

7. Mitral regurgitation may be 7. Mitral regurgitation may be caused by:caused by:

A.A. Rheumatic fever.Rheumatic fever.

B.B. Trauma.Trauma.

C.C. Myocardial infarction.Myocardial infarction.

D.D. Endocarditis.Endocarditis.

E.E. Hypertension.Hypertension.

F.F. Diseases of collagen formation.Diseases of collagen formation.

Rheumatic fever remains the #1 cause Rheumatic fever remains the #1 cause worldwide.worldwide.

Chordal rupture can occur with trauma, MI, Chordal rupture can occur with trauma, MI, endocarditis and collagen disorders.endocarditis and collagen disorders.

Hypertension is not a known etiology of Hypertension is not a known etiology of mitral regurgitation.mitral regurgitation.

8. Left ventricular ejection fraction 8. Left ventricular ejection fraction typically:typically:

A.A. Increases with mitral regurgitation.Increases with mitral regurgitation.

B.B. Decreases.Decreases.

C.C. Remains the same.Remains the same.

Because the left ventricle is ejecting into Because the left ventricle is ejecting into the aorta and left atrium, the EF is the aorta and left atrium, the EF is increased, but the left ventricle ultimately increased, but the left ventricle ultimately fails from chronic volume overload. Thus fails from chronic volume overload. Thus relatively normal parameters of systolic relatively normal parameters of systolic function (i.e. 40% EF) could indicate function (i.e. 40% EF) could indicate significant contractile dysfunction.significant contractile dysfunction.

9. Management of mitral 9. Management of mitral regurgitation includes:regurgitation includes:

A.A. Diuretics to decrease volume.Diuretics to decrease volume.

B.B. Inotropes to increase cardiac output.Inotropes to increase cardiac output.

C.C. ACE inhibitors to decrease afterload.ACE inhibitors to decrease afterload.

D.D. Nitroprusside in the setting of heart Nitroprusside in the setting of heart failure from acute regurgitation.failure from acute regurgitation.

E.E. Tylenol for the fevers.Tylenol for the fevers.

The mainstay of medical treatment is The mainstay of medical treatment is diuretics and ACE inhibitors.diuretics and ACE inhibitors.

Afterload reduction is key, since the blood Afterload reduction is key, since the blood will flow down the path of least resistance.will flow down the path of least resistance.

There is no role for inotropes or tylenol in There is no role for inotropes or tylenol in mitral regurgitation (although tylenol is still mitral regurgitation (although tylenol is still ok for fevers).ok for fevers).

10. Indications for surgery in mitral 10. Indications for surgery in mitral regurgitation include:regurgitation include:

A.A. Ongoing symptoms despite medical Ongoing symptoms despite medical management.management.B.B. An identified structural abnormality, An identified structural abnormality, such as a ruptured chorda tendinea.such as a ruptured chorda tendinea.C.C. An EF of 20% or less.An EF of 20% or less.D.D. An end-systolic diameter (ESD) of 60 An end-systolic diameter (ESD) of 60 mm or greater.mm or greater.E.E. Development of pulmonary Development of pulmonary hypertension.hypertension.

An EF of less than 60% suggests An EF of less than 60% suggests myocardial dysfunction and operative myocardial dysfunction and operative mortality increases. An ESD of 45 mm or mortality increases. An ESD of 45 mm or more makes for a worse prognosis after more makes for a worse prognosis after surgery.surgery.

Thus even in the absence of symptoms Thus even in the absence of symptoms patients should be referred for surgery if patients should be referred for surgery if the EF is <60% or ESD is >45mm.the EF is <60% or ESD is >45mm.

11. What is true regarding the 11. What is true regarding the anatomy of the aortic valve?anatomy of the aortic valve?

A.A. The valve consists of three cusps.The valve consists of three cusps.B.B. Coronary arteries arise from each of the Coronary arteries arise from each of the three sinuses of Valsalva.three sinuses of Valsalva.C.C. The coronary leaflets form commissures The coronary leaflets form commissures over the anterior leaflet of the mitral valve and over the anterior leaflet of the mitral valve and the bundle of His.the bundle of His.D.D. The leaflets are divided into the left, The leaflets are divided into the left, right, and posterior coronary leaflets.right, and posterior coronary leaflets.E.E. The normal area of the valve is 1-2 cmThe normal area of the valve is 1-2 cm22..

11. What is true regarding the 11. What is true regarding the anatomy of the aortic valve?anatomy of the aortic valve?

A.A. The valve consists of three cusps.The valve consists of three cusps.B.B. Coronary arteries arise from each of the Coronary arteries arise from each of the three sinuses of Valsalva.three sinuses of Valsalva.C.C. The coronary leaflets form commissures The coronary leaflets form commissures over the anterior leaflet of the mitral valve over the anterior leaflet of the mitral valve and the bundle of His.and the bundle of His.D.D. The leaflets are divided into the left, The leaflets are divided into the left, right, and posterior coronary leaflets.right, and posterior coronary leaflets.E.E. The normal area of the valve is 1-2 cmThe normal area of the valve is 1-2 cm22..

There are two coronary arteries that arise from There are two coronary arteries that arise from the sinuses: the left and right.the sinuses: the left and right.Thus the aortic leaflets are named after the Thus the aortic leaflets are named after the coronary arteries: the left coronary leaflet, the coronary arteries: the left coronary leaflet, the right coronary leaflet, and the noncoronary leaflet.right coronary leaflet, and the noncoronary leaflet.The commissure between the left and The commissure between the left and noncoronary leaflets sits over the anterior leaflet noncoronary leaflets sits over the anterior leaflet of the mitral valve, while the commissure between of the mitral valve, while the commissure between the right and noncoronary leaflets sits on the left the right and noncoronary leaflets sits on the left bundle of His.bundle of His.Normal valve size is 3-4 cmNormal valve size is 3-4 cm22. Symptoms usually . Symptoms usually arise at 1 cmarise at 1 cm22 with critical stenosis at 0.7 cm with critical stenosis at 0.7 cm22..

12. Aortic stenosis may be caused 12. Aortic stenosis may be caused by:by:

A.A. Hypertension and the resultant left Hypertension and the resultant left ventricular hypertrophy.ventricular hypertrophy.

B.B. Rheumatic fever.Rheumatic fever.

C.C. Idiopathic.Idiopathic.

D.D. Congenital valvular deformities.Congenital valvular deformities.

E.E. Chronic steroid use.Chronic steroid use.

Left ventricular hypertrophy is a result of aortic Left ventricular hypertrophy is a result of aortic stenosis, as the body compensates for the stenosis, as the body compensates for the increased pressure gradient across the valve. increased pressure gradient across the valve. There are unfortunately detrimental effects There are unfortunately detrimental effects including increased myocardial mass, increasing including increased myocardial mass, increasing oxygen demand, decreased ventricular oxygen demand, decreased ventricular compliance leading to increased wall tension, compliance leading to increased wall tension, and thus decreased coronary artery flow. This all and thus decreased coronary artery flow. This all leads to chronic ischemia, cell death, and leads to chronic ischemia, cell death, and fibrosis.fibrosis.Steroids have no known role in causing aortic Steroids have no known role in causing aortic stenosis (and if there is I apologize, as I just stenosis (and if there is I apologize, as I just made this up).made this up).

13. The principle symptoms of 13. The principle symptoms of aortic stenosis are:aortic stenosis are:

A.A. Headache.Headache.

B.B. Angina.Angina.

C.C. Palpitations.Palpitations.

D.D. Syncope.Syncope.

E.E. Nightmares.Nightmares.

F.F. Dyspnea.Dyspnea.

The three principal symptoms are angina, The three principal symptoms are angina, syncope, and congestive heart failure, syncope, and congestive heart failure, usually seen as dyspnea.usually seen as dyspnea.

14. Viable treatment options for 14. Viable treatment options for symptomatic aortic stenosis in a symptomatic aortic stenosis in a

relatively healthy patient are:relatively healthy patient are:

A.A. Balloon angioplasty of the valve.Balloon angioplasty of the valve.

B.B. Open valvuloplasty Open valvuloplasty (commissurotomy).(commissurotomy).

C.C. Minimally invasive laser valvulotomy.Minimally invasive laser valvulotomy.

D.D. Replacement of the valve.Replacement of the valve.

E.E. Medical management.Medical management.

Surgical replacement of the valve is the Surgical replacement of the valve is the only solution with an acceptable long term only solution with an acceptable long term outcome.outcome.

““The only potential role of aortic balloon The only potential role of aortic balloon valvuloplasty may be in aged, frail, and valvuloplasty may be in aged, frail, and possibly senile patients whose long-term possibly senile patients whose long-term survival is poor.”survival is poor.”

Answer C is complete nonsense.Answer C is complete nonsense.

15. Aortic insufficiency may be 15. Aortic insufficiency may be caused by:caused by:

A.A. Mixoid degeneration of the aortic Mixoid degeneration of the aortic root.root.

B.B. Trauma.Trauma.

C.C. Rheumatic fever.Rheumatic fever.

D.D. Endocarditis.Endocarditis.

E.E. Annuloaortic ectasia.Annuloaortic ectasia.

Mixoid degeneration in Marfan’s, Ehlers-Mixoid degeneration in Marfan’s, Ehlers-Danlos, and cystic medial necrosis.Danlos, and cystic medial necrosis.

Annuloaortic ectasia is an idiopathic Annuloaortic ectasia is an idiopathic dilatation of the aortic root and annulus, dilatation of the aortic root and annulus, and is the most reason for aortic and is the most reason for aortic insufficiency despite normal leaflet insufficiency despite normal leaflet morphology.morphology.

16. Treatment options for aortic 16. Treatment options for aortic insufficiency include:insufficiency include:

A.A. Observation and close monitoring for Observation and close monitoring for patients with mild to moderate regurgitation who patients with mild to moderate regurgitation who are asymptomatic.are asymptomatic.B.B. Medical treatment with diuretics and Medical treatment with diuretics and afterload reduction agents in symptomatic afterload reduction agents in symptomatic patients.patients.C.C. Valve replacement before the left ventricle Valve replacement before the left ventricle reaches 55 mm Hg in end-systolic volume.reaches 55 mm Hg in end-systolic volume.D.D. Valve replacement once the end systolic Valve replacement once the end systolic volumes have reached 90 mL/mvolumes have reached 90 mL/m22 or greater. or greater.E.E. Valve replacement in symptomatic Valve replacement in symptomatic patients.patients.

Pts with mild to moderate regurgitation have a Pts with mild to moderate regurgitation have a 10 yr survival rate of 85-95%. These pts can be 10 yr survival rate of 85-95%. These pts can be followed with serial echocadiography or nuclear followed with serial echocadiography or nuclear studies.studies.They should be maintained on diuretics and They should be maintained on diuretics and afterload reducers, but once symptoms develop, afterload reducers, but once symptoms develop, it means that the multiple compensatory it means that the multiple compensatory mechanisms have failed and medical mechanisms have failed and medical management is not enough.management is not enough.To achieve optimal results valve replacement To achieve optimal results valve replacement should take place before the left ventricle has should take place before the left ventricle has undergone irreversible dilitation.undergone irreversible dilitation.

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Valvular Heart Disease

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