Mitral Valve Diseases PDF

Mitral Valve Diseases By Prof. Ahmad Wafa Intended Learning Outcomes (ILOs): 1. Understand the structure and function of the mitral valve apparatus. 2. Recognize the causes, pathology, and hemodynamics of mitral stenosis (M...

Mitral Valve Diseases By Prof. Ahmad Wafa Intended Learning Outcomes (ILOs): 1. Understand the structure and function of the mitral valve apparatus. 2. Recognize the causes, pathology, and hemodynamics of mitral stenosis (MS). 3. Learn how to diagnose MS and identify clinical signs. 4. Understand the complications and differential diagnosis of MS. 5. Learn about the treatment options for MS. Mitral Valve Apparatus: The mitral valve is a complex structure that ensures proper closure during systole. It includes: Leaflets (cusps) Chordae tendinea Papillary muscles Mitral valve ring (annulus) Proper closure requires normal function of all components. Mitral Stenosis (MS) Causes of MS: Rheumatic heart disease (most common). Less common causes: o Congenital abnormalities. o Left atrial (LA) myxoma. Pathologic Evolution of Rheumatic Mitral Stenosis: Acute Valvulitis: Initial inflammatory process. Slow Scarring Process: Over 10-30 years, leading to a funnel-shaped valve orifice (fish mouth or buttonhole appearance) with calcium deposits. 1 Hemodynamics of Mitral Stenosis: Pathophysiological Changes Impact Progressive narrowing of the mitral valve Elevated LA pressure Elevated pulmonary venous and capillary pressure Protective mechanism Pulmonary HTN, RV overload Prevents pulmonary edema Stages of Mitral Stenosis: Stage Pathology Functional Impact Stage 1 Narrow mitral valve Complete compensation Stage 2 Elevated pulmonary venous pressure Pulmonary congestion Stage 3 Elevated pulmonary artery pressure Pulmonary hypertension + RV hypertrophy Stage 4 Systemic venous congestion Right-sided heart failure Symptoms: Absent in mild cases (discovered accidentally). Congestive lung symptoms: Cough, dyspnea in pulmonary hypertensive cases. Low COP Symptoms: with gradual decease of Congestive Lung Symptoms in Pulmonary Hypertensive cases. Systemic congestion symptoms: Swelling, fatigue, and signs of right heart failure. Symptoms of Complications General signs of MS: o Absent in mild and congestive cases. o Pulmonary hypertensive cases o signs of low cop. o Neck veins: Prominent A wave o Malar Flush (on checks). o Peripheral signs of Right sided HF. o Signs of complications 2 3 Cardiac Signs of MS: Precordial Examination Stages: Stage Findings Stage I & II (mild & congestive cases) - Apical impulse: at its site, hurried & slapping. - Diastolic thrill: ending in palpable accentuated S1 over apex. Stage III (With developed PH) - Signs of enlargement of PA - Signs of RV hypertrophy (Apex shifted outwards) - Precordial bulge (if RVH starts at a young age). Stage IV (marked RVH) - Apex shifted outward. - Systolic thrill of TR may be felt. Auscultation: First Heart Characterized as loud, short, and snappy. Sound (S1) Opening A distinct, clicky sound that occurs after S2 during the isometric relaxation phase. The Snap interval between S2 and the opening snap (S2-OS interval) decreases as the severity of mitral stenosis increases. Mid- A mid-diastolic rumbling murmur with pre-systolic accentuation, localized to the apex Diastolic and most clearly heard with the bell of the stethoscope when the patient is in the left Murmur lateral position. This murmur may not be detectable unless the patient has undergone physical exertion. Complications of MS: Complications Long standing complications - Left atrial dilatation, arrhythmia - Rt side HF Acute Complications - Hemoptysis - Pulmonary edema - Atrial fibrillation (sudden irregular palpitation) - Embolization (hemiplegia) - Endocarditis Mitral Valve Complications - Calcification (affects the approach to relieve valve obstruction) - Infective endocarditis (less common than in MR) - Activation of rheumatic process Investigations: 1. ECG: May show LA enlargement, atrial fibrillation. 2. Chest X-ray: Shows LA enlargement and pulmonary congestion. 3. Echocardiography: Key for diagnosis, showing valve anatomy and hemodynamics, chamber enlargement. 4 Treatment of Mitral Stenosis: A. Prophylactic Treatment: Rheumatic Fever Prevention: Prevent the occurrence and recurrence. Infective Endocarditis Prevention. B. Curative Treatment: 1. Medical Treatment o Aims:  Reduce Symptoms of Pulmonary Congestion (e.g., pulmonary edema): Use of diuretics, beta-blockers (BB), and Digoxin.  Prevent Arterial Embolism (cerebral or peripheral arterial embolism): Employ anticoagulation therapy. 2. Balloon Catheter Dilatation o Intervention to relieve valve obstruction without surgery. o Indications: Recommended for patients with severe Mitral Stenosis (Mitral Valve Area (MVA) less than 1 cm²) and favorable valve morphology. o Contraindications: Not recommended in the presence of a Left Atrial (LA) Thrombus and in heavily deformed or calcified valves. 3. Surgical Treatment Mitral Valve Surgery 1. Mitral Valvotomy Closed Mitral Valvotomy (CMV): A minimally invasive procedure to separate the fused mitral valve leaflets. Open Mitral Valvotomy (OMV): An open heart procedure to manually separate the mitral valve leaflets. 2. Mitral Valve Replacement Indications for MV Prosthesis: o Associated Mitral Regurgitation (MR). o Deformed Calcified Mitral Valve (MV). Types of Valve Prosthesis: o Tissue-origin prosthesis. o Synthetic-origin prosthesis. Postoperative Care: o Lifelong oral anticoagulation is required with artificial valve prosthesis to prevent blood clots. 5 Mitral Regurgitation (MR) Definition: Inadequate closure of the mitral valve leaflets, causing blood to flow backward from the left ventricle to the left atrium during ventricular systole. Causes: Mitral Regurgitation may result from anatomical issues in any part of the complex mitral valve apparatus: Mitral valve ring affection Mitral leaflets affection Chordae tendineae affection Papillary muscles dysfunction Hemodynamics of MR: The clinical presentation and circulatory changes depend on the onset speed and MR severity: Chronic MR Progresses over time, often tolerated for years. Acute MR Results in severe sudden volume overload, leading to pulmonary edema. 6 Symptoms: Chronic MR: Mild cases may be asymptomatic, while severe cases present with low cardiac output and congestive lung symptoms. Acute MR: Presents with acute severe dyspnea or pulmonary edema. Clinical Signs: General signs: No characteristic abnormalities. Precordial Examination: o Systolic thrill over the apex. o Signs of LV hypertrophy in moderate and severe cases Auscultation: o Weak or muffled first mitral sound o S3 gallop. o Pan-systolic murmur that radiates to the axilla. Complications: Left atrial thrombosis and emboli. Left ventricular failure. Infective endocarditis. Pulmonary congestion and right-sided heart failure. Investigations for MR: 1. ECG: May show LA and LV hypertrophy. 2. Chest X-ray: LA and LV enlargement, pulmonary congestion. 3. Echocardiography: Assesses valve function and chamber sizes. 7 Treatment of MR: Acute MR: Urgent evaluation with Doppler echocardiography. Surgical intervention with mitral valve replacement may be necessary. Chronic MR: Medical treatment: o Antibiotics: To prevent infective endocarditis. o Diuretics and vasodilators: To reduce afterload. o Anticoagulation: In cases with atrial fibrillation. Surgical Treatment: o Indicated for severe MR with symptoms or progressive cardiomegaly. o Options include mitral valve repair or replacement. 8