Mitral Regurgitation — Symptoms, Causes and Treatment in Hyderabad
Mitral regurgitation (MR) — also called mitral incompetence or mitral insufficiency — occurs when the mitral valve does not close completely, allowing blood to leak backward from the left ventricle into the left atrium with each heartbeat. It is the most common valve disease globally and a frequent cause of heart failure, atrial fibrillation, and progressive cardiac deterioration if untreated.
Types of mitral regurgitation
| Primary (degenerative) MR | The valve leaflets or supporting structures are intrinsically abnormal. Most common cause in Western populations — mitral valve prolapse (Barlow's disease, fibroelastic deficiency). The leaflets billow into the left atrium during systole, preventing complete closure. |
| Secondary (functional) MR | The valve leaflets are structurally normal but the left ventricle is dilated — from ischaemic heart disease or dilated cardiomyopathy — pulling the leaflet attachment points apart and preventing closure. MR is a consequence of the ventricular disease, not a primary valve problem. |
| Rheumatic MR | Leaflet thickening, retraction, and commissural fusion from rheumatic fever. Common in India alongside or separately from mitral stenosis. |
| Acute MR | Sudden severe regurgitation from papillary muscle rupture (complicating heart attack), chordae rupture, or endocarditis. A cardiac emergency requiring urgent surgery or catheter-based repair. |
Symptoms
- Breathlessness on exertion — The primary symptom caused by elevated pulmonary venous pressure.
- Fatigue and reduced exercise tolerance — Occur due to reduced forward cardiac output.
- Palpitations — Commonly associated with atrial fibrillation occurring alongside mitral regurgitation.
- Orthopnoea and paroxysmal nocturnal dyspnoea — Seen in severe decompensated mitral regurgitation, especially during advanced heart failure.
- Asymptomatic for many years — Chronic severe mitral regurgitation may remain silent for a decade or longer before symptoms appear, during which time irreversible ventricular damage can develop gradually.
Why serial echocardiography matters
Asymptomatic patients with moderate or severe MR need annual or biennial echocardiography to monitor left ventricular size and function. The threshold for intervention is guided by ventricular dimensions — surgery or MitraClip before the EF falls below 60% or the end-systolic diameter exceeds 40 mm prevents irreversible ventricular damage.
Grading
| Mild MR | Trace to small jet on colour Doppler. No haemodynamic significance. Annual monitoring. |
| Moderate MR | Moderate jet. Left atrial and ventricular enlargement beginning. 6–12 monthly echocardiography. |
| Severe MR | Large regurgitant jet, vena contracta above 7 mm, ERO above 40 mm². Significant volume overload. Intervention threshold approaches. |