Mitral Valve Disease

Valvular Heart Disease Bernardo D. Morantte Jr. M.D. Dept. of Medicine College of Medicine Pamantasan Ng Lungsod Ng Maynila

Cardiac valves Anatomy  There are 4 cardiac valves  2 semilunar valves_ aortic and pulmonic  2 AV valves _ mitral and tricuspid Valve structure: AV _ papillary muscle, chordae, leaflets

Left Heart

Aorta

VA = 2cm2

EKG LA Mitral valve 2

1 VA =4 cm2

Aortic valve 1

Mitral Stenosis Aortic Stenosis

2

LV

Intracardiac pressures  Diagramatic mm HG  LA= 10  

RA= 5 LVEDP = 10 RVEDP= 5

RVEDP = RV endiastolic pressure LVEDP = LV endiastolic pressure

Mitral Stenosis  Narrowed mitral valve orifice < 4 cm2 with obstruction to the blood flow from LA to LV  Presence of a pressure gradient across the mitral valve < 4 cm2 pressure gradient occurs with exercise  < 2 cm2 pressure gradient occurs at rest

Mitral Stenosis EKG LA Mitral valve

Aorta 2

Aortic valve Mitral Stenosis

1

VA = < 4 cm2

LV

Normal Pressures 100 LV

50 LA A C

V

0 EKG

mm HG

P

QRS

T

Mitral stenosis 100 LV Presurre gradient LA

A

50

V

0 EKG

mm Hg

p

QRS

T

Valve area calculaton  Gorlin’s formula:   Mitral valve = valve flow in ml / sec V* x 44.3 (mean gradient) 1/2

  

* V is a variable V = 0.85 for mitral valve V = 1 for aortic valve

Etiology  Congenital  Valvular  Subvalvular ring  Supravalvular ( cor tri-atriatum)  Rheumatic heart disease

Rheumatic fever Jones Criteria       

Major Migrating polyarthritis Carditis Sydenham chorea Subcutaenous nodules Erythema marginatum

Minor Clinical fever arthralgia Laboratory acute phase reactants prolonged PR interval

  

Criteria: 2 major or 1 major + 2 minor Plus A recent group A strep infection, + rapid antigen detection test, or + ASO titer

Pathophysiology in Mitral Stenosis  Increase pulmonary wedge pressure > 12 mm Hg  Reduced cardiac output (CO)  Moderately Severe MS _slow rise in CO with exercise  Severe MS _no increase CO or CO drops

Severity of Mitral Stenosis based on valve area (VA)  Mild Mitral stenosis_ VA < 4 cm2 but > 2cm2  Moderate _ VA 1.5 cm2 _ 2 cm2  Moderately severe _ VA 1.1 cm2_ 1.5 cm2  Severe_ VA 1 cm2 or less

Symptoms         

Easifatigability Dyspnea at rest / exertion Orthopnea Paroxysmal nocturnal dyspnea Palpitations Edema Cough Hemoptysis Exertional syncope ( uncommon)

Key physical examination findings  Opening snap (OS) and diastolic rumbling murmur at the apex



P2

 A2 - OS interval is inversely proportional to the severity of MS

Other PE findings     

Thrill at the apex Sternal pulsation (RV enlargement) Cardiac arrhythmia _ A-fib S1 increased Mild apical systolic murmur (gr I-II)

 Signs of congestive heart failure  Jugular venous distention  Dullness on chest percussion  Fine rales  Hepatomegaly and ascites  Pedal or sacral edema

pleural effusion

Associated Valve lesions  Mitral regurgitation  Tricuspid stenosis / regurgitation  Aortic regurgitation

Differential Diagnosis           

Severe Mitral regurgitaton (MR) * Loud systolic murmur ( Gr III/VI or >) Presence of S3 Atrial septal defect Fixed wide splitting of S2 Absence of LA enlargement on EKG and CXR Aortic regurgitation ( Austin Flint murmur) Maneuvers with amyl nitrate, exercise Atrial myxoma Changing murmur with change in position

Echocadiogram        

Calcified mitral valve Coving of the anterior mitral leaflet Reduced EF slope in the M- mode echo Anterior motion of the posterior mitral leaftlet in diastole Left atrial enlargement Presence of mural thrombus On doppler presence of a diastolic gradient across the MV. narrowed mitral valve area

Other Diagnostic Studies  EKG  atrial fib  left atrial hypertrophy  

RV hypertrophy RA hypertrophy

 Chest x-ray  left atrial enlargement  prominent PA   

Kerley B lines pleural effusion and alveolar infiltrates pulmonary edema

Complications  Congestive Heart Failure  Atrial fibrillation  Systemic embolism  Bacterial endocarditis

Medical Management of Mitral Stenosis    

Treatment of Congestive Heart Failure Control of Cardiac arrhythmias Anti-coagulant therapy SBE prophylaxis with antibiotics

Invasive cardiac Intervention:  Percutaneous balloon mitral valvulotomy for non-calcified or pliable leaflets

Natural History of MS based on functional class      

NYHA Class I II III IV

5 year survival rate 97 % 60 % 47 % 0

Surgical Therapy  Closed mitral commisurotomy  Open mitral commisurotomy  Mitral valve replacement (MVR)  bioprosthesis  Artificial valve  5 year survival after MVR_ 89-90 %

Indications for intervention  Class III-IV functional capacity  Severe mitral stenosis _ valve area 1 cm2  or less with symptoms

Mitral Regurgitation  It is the leakage of blood back to the left atrium during systole. The amount of blood that leaks back is the regurgitant volume (RV) RV = LVSV – FSV  LVSV= Left ventricular stroke volume calculated by echo or angiography  FSV = Forward Stroke volume 

FSV= CO / HR * CO = Cardiac output (Fick method) * HR = Heart rate

Types of Mitral Regurgitation  1. Transient _ PVC’s, myocardial ischemia  2. Acute_ sudden as in Acute MI, bacterial endocarditis

 3. Chronic

Left Heart _Mitral regurgitation

Aorta

VA = 2cm2

EKG LA Mitral valve 2

1

Aortic valve

VA =4 cm2

LV

Hemodynamics in MR  LV dilatation  LA dilatation  Pulmonary venous congestion  Pulmonary hypertension  RV dilatation  Tricuspid regurgitation

pulmonic regurgitation

Etiology of Chronic MR  Congenital  Coronary artery disease with papillary muscle dysfunction  Mitral annular calcification  Prolapse of the mitral valve  Rheumatic heart disease  Cardiomyopathy  Collagen vascular disease

Symptoms of MR Acute MR sudden dyspnea

orthopnea palpitations chest pain

fever?

Chronic MR recurrent exertional dyspnea orthopnea, PND palpitations easifatigability RUQ abdominal tenderness pedal edema

Differential Diagnosis of MR**  Aortic stenosis  Ventricular septal defect  Hypertrophic cardiomyopathy  Tricuspid regurgitation **Location, quality, radiation and maneuvers * Echocardiography

Diagnostics Acute MR EKG  Acute MI or ischemia Chest x-ray  pulmonary edema  normal heart size  

Chronic MR  LA and LV enlargement

  

CHF LA and LV enlargement mitral annular calcification

Echocardiogram Acute 2-D echo  LA and LV size usually normal  hyperkinetic LV  wall motion abnormality suggest MI or trauma    

EF usually normal ruptured chordae ruptured papillary muscle bacterial vegetations

Cardiac doppler  Presence of regurgitant jet

Chronic  

LA and LV enlargement RV enlargement

   

Reduced EF Mitral valve thickening and calcification suggesting a concomitant MS Prolapse of MV Associated Congenital anomalies



Presence of regurgitant jet

Medical Therapy Acute MR Vasodilators IV Nitroprusside or Nitroglycerin Ace Inhibitors Hydralazine Nifidipine IV Loop diuretics + K supplement

Chronic MR

Digoxin Anti-coagulants for A-fib Heparin / Warferrin IV antibiotics for acute endocarditis Fluid and salt restriction O2 therapy Ventillator support for PO2 <55 and RR > 40 / min

Digoxin Anti-coagulants for A-fib _ Warferrin

Ace inhibitors Diuretics + K supplement Loop Thiazide K sparing

Fluid and salt restriction O2 therapy Exercise program SBE and RF prophylaxis

Natural History of Chronic MR  3 year survival _ 50 %  5 year survival _ 35 %

Indications for surgical therapy  Severe MR with class III-IV functional capacity  Echocardiogram  Reduced EF < 55%  Progressive LV dilatation  ESD > 45mm  ESV index 55 ml/ m2  Moderate pulmonary hypertension  PA > 50 mm HG  Contraindication: EF < 30 % 

Diagnostic studies prior to surgical intervention  Cardiac catherization large V waves in the LA or PCP pressure pulmonary hypertension  Left ventriculography regurgitation of contrast material to LA  Coronary angiography

Surgical therapy  Mitral annuloplasty with Carpentier ring  Mitral valve replacement  bioprosthesis  artificial valve  The surgical procedure of choice depends on the underlying cause and the pathology