What is Mitral Regurgitation?

Mitral regurgitation (MR) is understood to be an unusual reversal of blood flow from the left ventricle (LV) to the left atrium (LA). It’s caused by interruption in any area of the mitral valve (MV) equipment. The most common etiologies of MR contain MV prolapse (MVP), rheumatic heart disease, infective endocarditis, annular calcification, cardiomyopathy, and ischemic heart disease.

Mitral regurgitation (MR) happens when the mitral valve doesn’t close correctly, causing the strange leaking of blood from the left ventricle during the mitral valve and back to the left atrium when the left ventricle contracts.

MR might be primary or secondary:

Primary MR:

  • Intrinsic lesions influence 1 or several elements of the mitral valve.
  • Together with the decreased incidence of rheumatic fever, degenerative MR is now the most common cause.
  • Acute MR may result from papillary muscle rupture, infective endocarditis or trauma.

Secondary MR (also called functional MR):

  • Secondary MR may be due to idiopathic cardiomyopathy or ischaemic heart disease (when it is also called ischaemic mitral regurgitation).

 

MR Signs and symptoms

When linked with coronary artery disease (CAD) and acute myocardial infarction (MI), significant acute MR is accompanied by the following symptoms:

  • Dyspnea
  • Exhaustion
  • Orthopnea
  • Pulmonary edema (frequently the original manifestation)

The following may be noticed with continual MR:

  • Some patients may remain asymptomatic for years
  • Patients could have normal exercise fortitude until systolic LV dysfunction develops, at which point they may experience symptoms of a reduced forward cardiac output
  • Patients may sense chest palpitations if AF develops because of persistent atrial dilatation

Palpation may reveal these:

  • Lively carotid upstroke and hyperdynamic cardiac impulse
  • Notable LV filling wave

Auscultation may show the following:

  • Diminished S1 in acute MR and continual severe MR with defective valve leaflets
  • Wide dividing of S2 as a direct result early closing of the aortic valve
  • S3 as a consequence of LV dysfunction or increased blood circulation across the MV
  • Accentuated P2 if pulmonary hypertension is present
  • Characteristic murmur

Mitral Regurgitation Diagnosis

The following findings could be noted on chest radiography:

  • Evidence of LV enlargement as a result of volume overload (especially in long-term MR), though pulmonary congestion may not be discovered until heart failure has developed
  • Signs of LA enlargement in the anteroposterior perspective

European Society of Cardiology (ESC)/European Association for Cardio-Thoracic Surgery (EACTS) echographic criteria for the definition of severe MR are as follows:

  • Flail leaflet/ruptured papillary muscle/big coaptation defect
  • Very big color flow central jet or eccentric jet sticking, swirling, and reaching the posterior wall of the LA
  • Dense/triangular continuous-wave signal of regurgitant jet
  • Big flow convergence zone

American College of Cardiology (ACC)/American Heart Association (AHA) class I indicators for transthoracic echocardiography (TTE) are as follows:

  • Yearly or semiannual surveillance of LV ejection fraction (LVEF) and end-systolic measurement in asymptomatic patients with moderate-to-intense MR
  • Evaluation of the MV gear and LV function after a change in signals or symptoms
  • Assessment of LV size and function and mitral valve hemodynamics in the original assessment after MV replacing or repair

ACC/AHA class I indicators for serial TTE are as follows:

  • Asymptomatic patients with moderate MR and no evidence of LV enlargement, LV dysfunction, or pulmonary hypertension – Annual observation; serial TTE is not indicated
  • Patients with average MR – Annual TTE
  • Asymptomatic patients with acute MR – TTE and clinical evaluation every 6-12 months to evaluate symptoms and progression of LV dysfunction
  • Appraisal of etiology of acute MR in patients for whom surgery is advisable to determine the feasibility of MV repair
  • Evaluation of mitral valve and related structures when TTE is nondiagnostic

Other evaluations are the following:

  • Electrocardiography (ECG)
  • Brain natriuretic peptide (BNP) appraisal
  • Cardiac catheterization

Treatment of MR

The managing of asymptomatic patients is contentious but operation may be an option in selected asymptomatic patients with acute MR. Surgery is indicated in patients with indications of LV dysfunction.

When operation is proper, early surgery (ie within two months) is connected with better results, because the development of even mild symptoms by the time of surgery is associated with unfavorable changes in cardiac function after surgery.

Medical therapy

In MR, first treatment choices contain nitrates, diuretics, sodium nitroprusside, positive inotropic agents and intra -aortic balloon pump.
When heart failure has developed, angiotensin-converting enzyme (ACE) inhibitors should be considered in patients with advanced MR and serious symptoms, who aren’t appropriate for operation or have residual symptoms following surgery. Beta blockers and spironolactone are also proper.

Serial testing

In certain asymptomatic patients, it has been revealed that severe MR can be safely followed up until symptoms develop or advocated cut-off values for LV dysfunction are reached. Such direction demands attentive and regular follow up.

Asymptomatic patients with average MR and preserved LV function may be followed on a yearly basis and echocardiography should be performed every couple of years.

Asymptomatic patients with acute MR and maintained LV function should be found every six months and echocardiography performed yearly.

Surgery

  • Urgent surgery is indicated in patients with acute severe MR.
  • Rupture of a papillary muscle needs urgent surgical treatment after haemodynamic stabilisation with the intra-aortic balloon pump, positive inotropic agents and, when possible, vasodilators. Valve operation includes valve replacement usually.

Surgery is indicated in patients with acute long-term main MR who have symptoms due to chronic MR, but no contraindications to operation.
Valve repair is considered to be the preferred operative treatment in patients with severe MR.

When repair isn’t possible, mitral valve replacement with preservation of the subvalvular equipment is preferred.

Percutaneous intervention

  • The single process that has been valued in organic MR is the edge-to-edge procedure, which has revealed a success rate of about 75%.
  • It is comparatively safe but reduces MR less effectively than mitral valve operation and recurrence or worsening of MR is prone to happen during follow-up.
  • Percutaneous repair or annuloplasty are not yet regularly advocated