Valvular Heart Disease: The Mitral Valve
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Transcript of Valvular Heart Disease: The Mitral Valve
Valvular Heart Disease:The Mitral Valve
Case
• A 45 year old man presents to establish care. He was told many years ago that he needed antibiotics prior to dental work because there was a problem with a heart valve. He has occasional palpitations. On exam he has brisk carotid upstrokes and a holosystolic murmur is heard best at the apex along with an S3 and a diastolic rumble.
Case
• What is the next best step?– Do nothing, this murmur is benign– Do an exercise stress test because the patient may
have CAD and ischemic heart disease– Do nothing, exam findings suggest mild disease– Order an echocardiogram – Refer the patient to a cardiologist for further
evaluation
Case
• An echocardiogram shows moderately dilated left atrium, a normal appearing left ventricle with am EF of 55%, a prolapsing posterior mitral leaflet and severe MR. Now you should:– Tell the patient to continue antibiotic prophylaxis
prior to the dental work– Have the patient follow up with a annual echo– Refer the patient for valve surgery– Refer the patient for a defibrilator to prevent
sudden death from MVP
What Makes A Heart Murmur?
• High blood flow through a normal or abnormal orifice
• Forward flow through a narrowed or irregular orifice
• Backward flow through an incompetent valve
These Murmurs Are Benign
• Mid systolic murmur at the left sternal border with grade 2 or less with a normal S1 and S2 and no other abnormal findings in an otherwise asymptomatic patient
• Associated with normal or increased blood flow across normal valves
These Murmurs Need Further Evaluation
• Diastolic Murmurs• Continuous Murmurs • Systolic
– Loud– Early systolic– Late systolic– Holosystolic
Strategy For The Evaluation Of Cardiac Murmurs
Bonow. JACC. 2006.
When To Order An Echo
• Class I– Diastolic, continuous, holosystolic, late systolic,
clicks, radiation to neck or back– Symptoms of underlying cardio-pulmonary disease– Grade 3 or louder mid systolic murmurs
• Class III– Mid systolic mumur grade II or less thought to be
innocent
Mitral Valve Disease: From Many Structures
• Mitral leaflets• Chordae• Papillary muscles• Mitral anulus
Otto. NEJM, 2001.
Etiology of Mitral Regurgitation
• Organic (Primary pathology of the leaflets)– Degenerative– Rheumatic– Endocarditis– Congenital
• Functional (Secondary to myocardial process)– Ischemic – Dilated cardiomyopathy– Hypertrophic cardiomyopathy
Enriquez-Serano. Contemporary Cardiology, 2009.
Mitral Regurgitation: Epidemiology
• Prevalence: >5,000,000• Incidence: >650,000 new cases/year in the US• Most common discharge diagnosis• Most common cause of readmission < 60 days• Cost: > 34.8 billion annualy
Rosamond. Circulation, 2008.Braunwald. 2007.
Pathophysiology• Volume overload ->
– LV dilation– LA dilation
• Acute: Rapidly increasing LA/PV pressures-> pulmonary edema
• Chronic: Slow enlargement of the LA with low pressures
• Left ventricular dilation and increased EF followed by LV deterioration
Foster. NEJM, 2002.
Hemodynamic Stages of Mitral Regurgitation
Libby. Braunwald’s Heart Disease. 8th Ed.
Natural History of Severe MR
Libby. Braunwald’s Heart Disease. 8th Ed.
Degenerative Mitral Valve Disease: Mitral Valve Prolapse
• Most common organic mitral valve disease
• Incidence about 2-3% • Usually results in mitral
valve prolapse • Variable histology
– Increased extracellular matrix
– Thickened and redundant– Chordal elongation
Sanders. Forensic Science International, 2007.
Complications• Chordal rupture and flail leaflet
– 12% of patients– Most common in older men
• Heart failure• Sudden death• AF• Endocarditis
– Most common compliation, but rare (100cases/100,000 patient years)
– Higher risk with flail leaflet
Mitral Regurgitation: Mitral Valve Prolapse
Foster. NEJM. 2010.
Echocardiogram: Flail Mitral Leaflet
Foster. NEJM. 2010.
Endocarditis
• Destruction of tissue by infection
• About 5% of severe MR
Mitral Regurgitation From Connective Tissue Disease
Functional Mitral Regurgitation
• Affects 15-20% with HF, 12% 30 days post MI
• Leaflets are normal• Coaptation is
incomplete• Can also be associated
with papillary muscle rupture
Marasco. Heart, Lung and Circulation, 2008.
Prosthetic Valve Failure
Alexander. Circulation, 1995.
Prosthetic Valve Failure
Novarro. JASE, 2000.
St Jude Mitral Valve
Butany. J Clin Path, 2005
Physical Exam Findings
• Brisk carotid upstrokes, laterally displaced forceful apical impulse
• Murmur: characteristics don’t reliably predict severity– Similar to AS, TR and VSD– Constant intensitiy, holosystolic, loud blowing,
apical with axillary radiation– Dimimished S1, split S2, possible S3 and loud P2– Highly variable depending on structures involved
Dynamic Auscultation
Intervention
Hypertrophic Obstructive Cardiomyopathy Aortic Stenosis
Mitral Regurgitation
Mitral Valve Prolapse
Valsalva ↑ ↓ ↓ ↑ or ↓Standing ↑ ↑ or
unchanged↓ ↑
Handgrip or squatting
↓ ↓ or unchanged
↑ ↓
Supine position with legs elevated
↓ ↑ or unchanged
Unchanged ↓
Exercise ↑ ↑ or unchanged
↓ ↑
Amyl nitrite ↑↑ ↑ ↓ ↑Isoproterenol ↑↑ ↑ ↓ ↑
Libby. Braunwald’s Heart Disease. 8th Ed.
XR Findings
• Prominent left atrial enlargement
• Left ventricular enlargement
• Pulmonary edema in acute MR
Enriquez-Serano. Contemporary Cardiology, 2009.
Atrial Fibrillation Affects 50% of Patients Within 10 Years
Enriquez-Serano. Contemporary Cardiology, 2009.
Acute Mitral Regurgitation Elevated PAP and Large PCWP V Waves
Libby. Braunwald’s Heart Disease. 8th Ed.
Variable Presentations of Mitral Regurgitation
Enriquez-Serano. Contemporary Cardiology, 2009.
Mitral Regurgitation Severity By Echo• Structural
– LA size– LV size– Mitral leaflets and apparatus
• Doppler– Jet area and characterisitics– Mitral inflow– Pulmonary vein flow
• Quantitative– Regurgitant orifice area– Vena contracta– Right ventricle
Zoghbi. JASE, 2003.
Medical Management
• Diuretics to maintain euvolemia• Digoxin and beta blocker for rate control• Medical therapy directed at underlying
ischemia• No benefits to vasodilators• Afterload reduction and inotropic support in
acute mitral regurgitation
Survival: Medical Management of Organic MV Regurgitation
Enriquez-Serano. Contemporary Cardiology, 2009.
MildModerate
Severe
Mitral Valve Prolapse Repair
Foster. NEJM. 2010.
Prosthetic Mitral Valve
Bloomfield. Heart, 2002.
Survival After Surgical Correction By EF
Libby. Braunwald’s Heart Disease. 8th Ed.
Repair vs Replacement
• Repair can be accomplished in 80-90%• Advantages
– Possible lower mortality rates– Possible reduced need for anticoagulation– Lower risk of endocarditis
Foster. NEJM. 2010.
Possible Survival Benefit With Mitral Valve Repair
Shuhaiber. EJCTS, 2007.
Chronic Severe MR
Bonow. JACC, 2006.
Percutaneous Therapies• 1/3 of European patients with severe
valve disease are denied surgery• 1/2 of patients with severe
symptomatic MR
Piazza. JACC, 2009.Feldman. JACC, 2009
Mitral Stenosis• Most commonly from
rheumatic fever: 99%• 2-20 years until symptoms
of MS• Likely worsened by
recurrent RF• Also
– Congenital– CTD, RA– Mucopolysaccharidoses
• Mimicks– Tumors– Infection– membranes
http://www.yale.edu/imaging/echo_atlas/entities/mitral_stenosis.html
Hemodynamics
• Normal valve orifice 4-6 cm2
• Small valve area requires higher pressure gradient
• Symptoms precipitated by fast heart rate– Higher LA-LV pressure gradient– Lower cardiac output
Libby. Braunwald’s Heart Disease. 8th Ed.
Hemodynamics: Why Symptoms Develop
• Increased left atrial pressure• Increase in left ventricular diastolic pressure• Pulmonary hypertension• Everything is worse with exercise• Chronic atrial changes lead to arrhythmia
Clinical Findings• Presentation
– Dyspnea, hemoptysis, chest pain, arrhythmia, embolic events, hoarseness
• Exam findings– Accentuated S1– Opening snap- at the apex with the diaphragm– A2-OS snap good indicator of severity– Findings of pulmonary hypertension– Low pitched rumbling murmur at the apex– Maneuvers that increase mitral flow increase murmur and
decrease A2-OS time
Echo Determinants Of Mitral Stenosis Severity
Baumgartner. JASE, 2009.
Echo Determinants Of Mitral Stenosis Severity
Mild Moderate Severe
Valve Area (cm2) >1.5 1.0-1.5 <1.0
Mean Gradient (mmHg)
<5 5-10 >10
PAP (mmHg) <30 30-50 >50
Mitral Valvuloplasty Score
Baumgartner. JASE, 2009.
Natural History of 159 Patients With Un-Operated Mitral Valve Disease
Mitral stenosis
Mitral regurgitation
Expected survival
Libby. Braunwald’s Heart Disease. 8th Ed.
Management Approach to Mitral Stenosis
Nobuyoshi. Circulation, 2009.
Percutaneous Valvuloplasty
Nobuyoshi. Circulation, 2009.
Long Term Outcome For Percutaneous Valvuloplasty
Libby. Braunwald’s Heart Disease. 8th Ed.
Endocarditis Prophylaxis
• Prosthetic valve material• Prior endocarditis• Congenital heart disease
– Unrepaired cyanotic– For 6 months following repair with prosthetic
material – Following incomplete repair with prosthetic
material• Transplant recipient with abnormal valves