Mitral regurgitation

Question 1

etiology

Answer 1

rheumatic heart disease and a prolapsing mitral valve.

Other causes include:
Rheumatic fever - dilatation of mitral valve ring / damage to valve cusps & chordae
Result of valvotomy or valvuloplasty of mitral stenosis
Mitral valve prolapse
Coronary artery disease, cardiomyopathy - dilatation of mitral valve ring
Endocarditis - damage to valve cusps & chordae (perforation of the valve leaflets - important cause of acute mitral regurgitation)
Myocardial infarction - damage to papillary muscle (transient – during ischemia)

Question 2

types MR

Answer 2

Organic – involvement of cusps
Functional –relative – involvement of orifice

Question 3

Pathophysiology

Answer 3

Chronic regurgitation - gradual left atrium dilatation with little increase in pressure (relatively few symptoms)

Left ventricle – slow dilatation: left ventricular diastolic & left atrial pressures gradually increase - chronic volume overload ventricle (breathlessness & pulmonary edema)

Acute regurgitation - rapid rise in left atrial pressure (normal left atrial compliance) – with symptoms

Question 4

hemodynamic changes

Answer 4

• Incomplete closure of the valve leaflets results in regurgitation of the bl frm the LV to LA during ventricular systole
• A large volume of bl thus accumulated in LA and it is dilated
• LV also filled with excess amount of bl which also causes its dilation and compensatory hypertrophy
• Excess distension of atrium increases the blood press inside it and stimulates hypertrophy of myocardium
• Later, as the contractile power of LV decreases, press in LA increases and this press transmitted retrogradely to pulmonic vein, capillaries and arterioles
• As press in lesser circulation increases and dystrophy develops in myocardium, its contractile power decreases and congestion in greater circulation develops
• increased pressure in pulmonary veins → spasm of arterioles in lesser circulation( Kitaev‘s reflex) → increased pressure in pulmonary artery→ intensify load in RV → RV hypertrophy.

Question 5

clinical picture - symptoms, signs

Answer 5

Symptoms
- The increased stroke volume is sensed as a ‗palpitation‘.
- Dyspnoea and orthopnoea. Fatigue and lethargy.
- late stages, symptoms of right heart failure lead to congestive cardiac failure. subacute infective endocarditis.

• Pulse is of high volume & tachycardic & in later stages might be irregular pulse due to atrial fibrillation. Jugular veins are dilated. later might develop right heart failure with edema & ascites development.
• cough either dry or with sputum containing traces of blood
• Heart pain can be boring, stabbing and pressing
• Hepatic congestion, Central cyanosis/peripheral cyanosis, facies mitralis
• Systolic thrill palpate at cardiac apex
• Epigastric pulsation

Percussion: upper border shifted up
- Lateral displacement of the hearts borders due to dilation of LV

Question 6

Investigation (ECG, Ultrasound, X-ray)

Answer 6

1. Chest X-ray
   - left atrial and left ventricular enlargement. mitral valve calcification may seen.
2. Electrocardiogram
   - left atrial delay (bifid P waves) and left ventricular hypertrophy - tall R waves in leads I and V6, and deep S waves in leads V1 and V2. Atrial fibrillation may be present. hypertrophy of LA - P wave elongates
   - shows dilated LA and LV, specific features of chordal/ papillary mitral rupture