Mitral regurgitation (MR) is caused by the retrograde flow of blood from the left ventricle (LV) into the left atrium (LA) through the mitral valve (MV), causing a systolic murmur heard best at the apex of the heart with radiation to the left axilla. MR is the most common valvular abnormality worldwide, affecting over 2% of the total population and has a prevalence that increases with age.¹
Mitral Insufficiency:
- chronic, slow LV volume overload, dilatation, and hypertrophy → fatigue and dyspnoea upon decompensation
- cardiomegaly, holosystolic precordial murmur → axilla
- acute pulmonary oedema
- reduce pre- and after-load
- ± surgery
Based on the acuity of presentation, MR can be acute or chronic. However, acute MR has a very specific set of etiological reasons such as rupture of the chord/papillary muscle from trauma or ST-segment elevation myocardial infarction (STEMI), or infective endocarditis (IE) leading to leaflet perforation or rupture of the chords.²
Differential Diagnosis:
- tricuspid incompetence – large V-waves, pulsatile liver, right heart failure
- mitral valve prolapse – late systolic murmur
- papillary muscle dysfunction – ischaemic / HOCM
- ventricular septal defect
For primary chronic MR, surveillance and timely intervention are key factors for better outcomes. Early surgical intervention has shown better survival rates over conservative medical management in patients with a flail mitral leaflet. Surgery is recommended for chronic severe primary MR in patients with symptoms and EF more than 30%, in asymptomatic patients with LV dilatation and EF of 30% to 60%, and patients with severe MR undergoing cardiac surgery for other indications. It is also indicated in the presence of severe primary MR with resting pulmonary hypertension, new onset of atrial fibrillation, progressive increase in LV cavity size, or decline in LV ejection fraction. Preference to mitral valve repair over replacement has been given depending on regional anatomy, the involvement of leaflets, and the chance of a successful repair.²
- Douedi S, Douedi H. Mitral Regurgitation. [Updated 2020 Aug 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553135/.
- Chaudhari SS, Chokkalingam Mani B. Mitral Valve Insufficiency. [Updated 2020 May 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557898/.
- Ibrahim, Bassem Sobhi.”Right ventricular failure.” e-Journal of Cardiology Practice 14(32); Dec 12, 2016.
