Valvular Heart Disease I: The mitral valve

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Valvular Heart Disease IThe mitral valve

• Laura Wexler, M.D.
• 475-6383
• wexlerl_at_ucmail.uc.edu

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Reference Sources for Valvular Heart Disease

• Reading Harrison, 14th Edition p 1311-1323
• Computer
• Umedic Aortic stenosis, aortic regurgitation,
  mitral stenosis, mitral regurgitation
• Instructional Programs
• Heart Sounds and Murmurs

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• Case 1
• A 55 year old woman is brought to the emergency
  room with acute onset of severe dyspnea which
  began earlier the same evening and has progressed
  rapidly. She is found to be in acute pulmonary
  edema by physical examination and chest X-ray. An
  ECG shows atrial fibrillation with a rapid
  ventricular response. She is treated with oxygen
  and an intravenous diuretic. Digoxin is
  administered and her heart rate decreases from
  120 bpm to 90 bpm. Her symptoms improve and she
  is able to give more history.

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• She acknowledges that she hasnt felt right for
  several years. She has been able to perform
  adequately at her sedentary job but she has
  gradually cut back on her usual recreational
  activities and more recently even on her
  housework and shopping because of fatigue and
  slowly progressive dyspnea on exertion. She
  denies chest pain or dizzy spells. She does
  notice occasional swelling of her feet and ankles
  at the end of the day. She denies hypertension
  or diabetes and her cholesterol level has was
  reported as normal when checked 5 years ago. In
  childhood, she had acute rheumatic fever
  characterized by fever and joint pains but was
  well subsequently. She had two uncomplicated
  pregnancies in her 20s and underwent menopause
  at age 51. She takes hormone replacement therapy
  but no other medications. She has no family
  history of heart disease.

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Physical Examination

• Thin middle aged woman sitting up in bed and
  breathing deeply and rapidly. BP-120/70, P-90
  irregularly irregular, RR-20, T-98.6F
• JVP 8 cm
• Carotids Normal upstroke and volume
• Lungs Bibasilar rales 1/2 way up the lung
  fields
• Heart Palpable RV impulse at the L
  parasternal border
• Minimal PMI 5th ICS, MCL
• S1 loud, S2 physiologically split, P2
  is prominent.
• S2 followed by opening snap and a mid
  to late diastolic murmur at
  the apex
• Abdomen Unremarkable
• Extremities 1 pedal edema bilaterally

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Chest Xray Normal heart
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Chest Xray
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ECHO Mitral Stenosis
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Mitral Stenosis

• Rheumatic in the majority of cases but only
  50 will have history of ARF
• Other (lt1)
• Congenital
• Mitral annular Ca
• Endocarditis with huge vegetations

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Cardiac physiology
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Mitral Stenosis
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Diagnostic Studies

• ECG LA enlargement or atrial fibrillation
• Chest X-ray RV, LA enlargement.,
• Echocardiogram Mitral valve thickening and
  restricted motion, large LA. Increased velocity
  of flow across the mitral valve
• Cardiac cath Pressure gradient across mitral
  valve (LA gt LV diastolic pressure). Variable
  degree pulmonary hypertension.

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Natural History of Mitral Stenosis

• Progressive dyspnea, PND, orthopnea
• Atrial fibrillation
• Acute pulmonary edema, especially
• Onset of atrial fibrillation
• Acute volume overload (e.g., pregnancy)
• Thromboembolism (stroke)
• Pulmonary (arterial) hypertension ? RV failure
  ?fatigue and edema
• Hemoptysis
• Hoarseness

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Pulmonary Hypertension in Mitral Stenosis

• Passive obligatory increase in PA pressure to
  maintain forward flow into high pressure
  pulmonary veins.
• Reactive (40) medial hypertrophy and intimal
  fibrosis of pulmonary arterioles. Increase
  arteriolar resistance decreases blood flow to the
  pulmonary capillaries.

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Management of Mitral Stenosis

• Diuretics
• Maintenance of NSR or rate control in Afib
• Endocarditis prophylaxis
• Anticoagulation
• Mitral commissurotomy
• Percutaneous transvenous mitral valvuloplasty
• Mitral valve replacement

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Mitral Commissurotomy
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Mitral Valvuloplasty
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Contraindications to Mitral Valvuloplasty

• Mitral regurgitation
• Heavily Ca mitral valve
• Clot in left atrium

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• Case 2
• A 56 year old man who is active and in good
  health consults you after being told he has a
  heart murmur at an insurance physical exam. He
  denies and symptoms of dyspnea. exercise
  intolerance or chest pain. He reports being told
  of an innocent murmur at the time of his
  military draft physical in 1968 but it has not
  been commented on since. He has no history of
  hypertension or other coronary disease risk
  factors and no family history of heart disease.

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Physical Exam

• BP 135/85 P 70bpm, reg RR 12/min
  T 98.6F
• JVP lt5
• Carotids Normal upstroke and volume
• Lungs Clear
• Heart PMI 3 fb in the 4th ICS just lateral to
  the MCL.
• S1 normal. S2 physiologically split. No S3 or
  S4
• 3/6 holosystolic murmur at the apex, radiating
  to the axilla
• Abdomen Liver not palpable, no ascites
• Extremities No edema

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Diagnostic Studies

• ECG LA enlargement, LVH
• Chest X-ray LA enlargement, clear lungs
• Echocardiogram Mitral insufficiency, LA
  enlargement, LV slightly enlarged, estimated EF
  65

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• After discussing the diagnosis of chronic
  mitral regurgitation with the patient, you inform
  him of the need for close follow-up and teach him
  the principles of endocarditis prophylaxis. You
  see him every six months for the next 5 years he
  remains active and asymptomatic and his exam does
  not change. Serial echocardiograms continue to
  show moderate mitral regurgitation. There is a
  gradual increase in LA size but no further
  increase in left ventricular size and the
  estimated ejection fraction remains high at
  60-65.
• When you next see him for his scheduled
  followup, he reports that he feels well but on
  close questioning about his activities, he admits
  that he has given up singles tennis because he
  was getting too winded and that he is also
  feeling more fatigued than usual. He denies any
  specific intercurrent illnesses.

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Physical Exam Changes

• PMI 6th ICS, 3 cm lateral to the MCL. Diffuse
  (4fb)
• S1 soft, followed by a 4/6 holosystolic murmur.
• There is an S3, followed by a short low-pitched
  diastolic murmur.
• ECG NSR. Increased LV voltage.
• Chest X-ray Cardiomegaly with LV prominence
• Pulmonary venous congestion.
• Echocardiogram
• LA, LV enlargement. Estimated EF 45

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Sources of Mitral Regurgitation
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Mitral Regurgitation

• Valve defects (congenital, rheumatic, infection,
  tears)
• Mitral valve prolapse
• Mitral annular dilation, Ca
• Chordal scarring, rupture, elongation
• Papillary muscle dysfunction, rupture
• Impaired contraction of LV muscle supporting the
  papillary muscle

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Acute vs. Chronic Mitral Regurgitation
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Pathophysiology of AcuteMitral Regurgitation

• Acute LA pressure overload
• Acute pulmonary edema

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Pathophysiology of Chronic Mitral Regurgitation

• Gradual increase in LA volume
• Reduced forward stroke volume
• Diastolic LV volume overload
• Progressive LV dilatation and hypertrophy
• Enhanced ejection fraction initially
• Late LV systolic failure

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Cardiac Findings in ChronicMitral Regurgitation

• Large left ventricular impulse, laterally
  displaced
• Soft first heart sound
• Holosystolic apical murmur radiating to the apex
• Louder with hand grip
• (Severe)Third heart sound
• (Severe)Diastolic filling rumble

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Diagnostic Studies in Chronic Mitral Regurgitation

• ECG LA enlargement, LVH
• Chest X-ray Cardiomegaly (LV,LA enlargement)
• Echocardiogram
• Cardiac catheterization with contrast left
  ventriculogram
  

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Mitral Regurgitation
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Natural History of Chronic Mitral Regurgitation

• Long asymptomatic period
• Atrial fibrillation
• Risk of endocarditis
• Fatigue and exercise intolerance
• Onset of LV dysfunction, worsening MR dyspnea,
  congestive heart failure
• Eventual right heart failure

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Natural History Rheumatic Mitral Regurgitation
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Management of Chronic Mitral Regurgitation

• Reduce LA pressure (diuretics, maintain NSR)
• Promote forward flow (lower systemic vascular
  resistance)
• Close surveillance of LV function on serial echo
• Repair or replace mitral valve BEFORE there is
  significant LV dysfunction
• - Mortality MV repair 2-4
• - Mortality MV replacement 5-10

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Mitral Valve Prolapse

• Incidence Up to 2 of the normal population
• May be associated with rare connective tissue
  disorders
• Marfans Syndrome
• Erlers-Danlos Syndrome
• NOTE Pseudoprolapse in slender women with
  disproportion between small LV cavity and
  oversized MV

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Mitral Valve Prolapse variable murmur
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Physical Findings in MVP

• Mid-systolic click
• Late systolic murmur
• Click-murmur moves with LV volume changes

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Mitral Valve Prolapse

• Natural History
• Benign, asymptomatic
• Progressive MR
• Chordal rupture with acute MR
• Endocarditis
• Peripheral (platelet) emboli
• Atrial/ventricular arrhythmias

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Management of Mitral Valve Prolapse

• Reassurance
• Endocarditis prophylaxis if there is MR
• Serial follow-up for evidence of progressive MR
• Aspirin if there are neurologic symptoms