Questions on mitral regurgitation
Definition
- Q
Epidemiology
- Q
Etiology and Pathophysiology
- What are the causes of MR? a, hs
- What are the causes of acute MR? a, hs
- What are the causes of pansystolic murmur? A
- Is there any MDM in MR? a
Clinical manifestations
- Q
Examinations
- What are the signs of severe MR? a, hs
- Where the murmur radiates following the rupture of chorda tendineae? A
- When does the murmur of MR radiate up the parasternal edge to neck? hs
- How can you differentiate MR and TR clinically? hs
Investigations
- What investigations should be done in MR? a, hs
Diagnosis
- Why your diagnosis is MR? a
- What do you think the cause in this case? A
- What are your differential diagnoses? A
- Why not this is TR? A, hs
- Why not this is VSD? A
- Does the presence of a third heart sound always signifies MR? hs
Treatment
- How to treat MR? a, hs
- What type of valve should be replaced? A
- What are the indications of surgery in MR? a, hs
- What are the types of prosthetic valve? A
- How to detect that the patient has prosthetic valves? A
- How to detect clinically whether the replaced valve is mitral or arotic? a
- How to detect, if prosthetic valve is leaking? A
- What happens, if there is dysfunction of prosthetic valve? A
- What are the advantages and disadvantages of different valves?
- What are the complications of metallic valve? A
- What are the complications of tissue valve? A
- What are the complications of prosthetic valve? A
- How to choose a particular valve? A
- Which prosthesis is used in a woman at child bearing age? a
Complications
- What are the complications of MR? a, hs
- In which lesion of MR or MS, endocarditis id common? hs
Additional
- What is mitral valve prolapse? What are the features? How would you treat? A
Rimikri
SOLVES
What are the causes of MR?
As follows:
- Chronic rheumatic heart disease (rheumatic MR is more common in male)
- Mitral valve prolapse
- Papillary muscle dysfunction (due to acute inferior myocardial infarction)
- Rupture of chordae tendineae (due to infarction, subacute bacterial endocarditis, trauma or spontaneous)
- Infective endocarditis
- Valvotomy or valvuloplasty
- Connective tissue diseases (RA, SLE)
- Ankylosing spondylitis
- Cardiomyopathy (restrictive, hypertrophic and dilated)
- Secondary to left ventricular dilatation (functional MR – hypertension, aortic valve disease)
- Associated with Marfan syndrome, pseudoxanthoma elasticum and Ehlers-Danlos syndrome
- Rarely by drugs (such as fenfluramine, phentermine which are used to treat obesity)
* Short Cases in Clinical Medicine, ABM Abdullah, 5th Edition Page: 79; Short and Long Cases in Clinical Medicine, HN Sarker Page: 42; Long Cases in Clinical Medicine, ABM Abdullah Page: 176
Note:
Rheumatic disease is the principal cause in countries where rheumatic fever is common, but elsewhere, including in the UK, other causes are more important.
* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 618
What are the causes of acute MR?
As follows:
- Acute myocardial infarction (due to rupture of papillary muscle)
- Trauma or surgery (mitral valvotomy)
- Infective endocarditis (due to perforation of mitral valve leaflet or chordae)
- Acute rheumatic fever (due to mitral valvulitis)
- Spontaneous rupture of chorda tendineae or myxomatous degeneration of valve.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 177
What are the causes of pansystolic murmur?
As follows:
- Mitral regurgitation
- Tricuspid regurgitation (TR)
- VSD
* Long Cases in Clinical Medicine, ABM Abdullah Page: 177
Is there any MDM in MR?
Yes, it may be present due to increased flow of blood through mitral valve (or if associated with MS).
* Long Cases in Clinical Medicine, ABM Abdullah Page: 177
What are the clinical features in mitral regurgitation?
Clinical features (and their causes) in mitral regurgitation:
Symptoms
- Dyspnoea (pulmonary venous congestion)
- Fatigue (low cardiac output)
- Palpitation (atrial fibrillation, increased stroke volume)
- Oedema, ascites (right heart failure)
Signs
- Atrial fibrillation/flutter
- Cardiomegaly: displaced hyperdynamic apex beat
- Apical pansystolic murmur ± thrill
- Soft S1, apical S3
- Signs of pulmonary venous congestion (crepitations, pulmonary oedema, effusions)
- Signs of pulmonary hypertension and right heart failure
* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 618
What are the signs of severe MR?
Severe MR is suggested by the following findings:
- Soft first heart sound
- Large left ventricle (apex is shifted, thrusting)
- Presence of third heart sound
- Presence of mid diastolic flow murmur (due to rapid filling of the left ventricle)
- Signs of pulmonary venous congestion (crepitations, pulmonary oedema, effusions)
- Signs of pulmonary hypertension
* Long Cases in Clinical Medicine, ABM Abdullah Page: 177; Short and Long Cases in Clinical Medicine, HN Sarker Page: 43
Where the murmur radiates following the rupture of chorda tendineae?
As follows:
- Rupture of anterior leaflet of chorda tendineae
- Murmur radiates to axilla and back
- Rupture of posterior leaflet of chorda tendineae
- Murmur radiates to cardiac base and carotid
* Long Cases in Clinical Medicine, ABM Abdullah Page: 177
When does the murmur of MR radiate up the parasternal edge to neck?
When mitral regurgitation is due to posterior mitral leaflet prolapse or rupture.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 43
How can you differentiate MR and TR clinically?
Clinical sign(s) | MR | TR |
Pulse | Normal or jerky (if severe) | Normal |
Jugular venous pressure (JVP) | Normal V wave | Prominent V waves |
Palpation | Apical systolic thrill, Thrusting displaced apex | Parasternal heave |
Auscultatin | Pansystolic murmur Loudest in expiration, radiating to axilla | Pansystolic murmur loudest in inspiration no radiation to axilla |
Liver | Normal | Pulsatile liver |
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 43
What investigations should be done in MR?
ECG
- Left atrial hypertrophy (if not in atrial fibrillation)
- Left ventricular hypertrophy
Chest X-ray
- Enlarged LA
- Enlarged LV
- Pulmonary venous congestion
- Pulmonary oedema (if acute)
Echo
- Dilated LA, LV
- Dynamic LV (unless myocardial dysfunction predominates)
- Structural abnormalities of mitral valve (e.g. prolapse)
Doppler
- Detects and quantifies regurgitation
Cardiac catheterisation
- Dilated LA, dilated LV, mitral regurgitation
- Pulmonary hypertension
- Coexisting coronary artery disease
Figure: Mitral regurgitation: murmur and systolic wave in left atrial pressure. The first sound is normal or soft and merges with a pansystolic murmur (PSM) extending to the second heart sound. A third heart sound occurs with severe regurgitation.
* Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 619
Why your diagnosis is MR?
Because:
- Systolic thrill in mitral area
- First heart sound is soft
- There is a PSM radiating to the left axilla.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 175
What do you think the cause in this case?
Chronic rheumatic heart disease, mitral valve prolapse.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 175
What are your differential diagnoses?
As follows:
- Tricuspid regurgitation (TR)
- Ventricular septal defect (VSD).
* Long Cases in Clinical Medicine, ABM Abdullah Page: 175
Why not this is TR?
In TR, findings are:
- Pansystolic murmur is present in the left lower parasternal area, no radiation to axilla (No systolic thrill).
- Murmur is prominent on inspiration and less on expiration.
- Raised JVP with prominent “V” wave.
- Enlarged, tender and pulsatile liver.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 176
Why not this is VSD?
In VSD, findings are:
- Systolic thrill in left parasternal area (fourth or fifth intercostal space).
- Pansystolic murmur in left parasternal area (fourth or fifth intercostal space), no radiation.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 176
Does the presence of a third heart sound always signifies MR?
The presence of a third heart sound alone in the absence of other signs of severity does not itself imply severe mitral regurgitation.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 43
How to treat MR?
As follows:
- Medical therapy (In mild to moderate case):
- Prophylactic penicillin to prevent endocarditis
- Follow-up every 6 months by echocardiogram.
- Diuretics
- Vasodilators, e.g. ACE inhibitors
- Digoxin if atrial fibrillation is present
- Anticoagulants if atrial fibrillation is present or history of pulmonary embolism
- Surgical treatment (In severe MR or in progressively worsening MR)
- Replacement of valve.
Note:
Mitral valve repair is used to treat mitral valve prolapse and offers many advantages when compared to mitral valve replacement, such that it is now advocated for severe regurgitation, even in asymptomatic patients, because results are excellent and early repair prevents irreversible left ventricular damage.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 177; Davidson’s Principles and Practice of Medicine, 22nd Edition Page: 619, 620
What type of valve should be replaced?
As follows:
- In young patient: metallic valve
- In elderly patient: tissue valve.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 178
What are the indications of surgery in MR?
As follows:
- Patient who are asymptomatic, i.e. New York Heart Association (NYHA) functional class III or IV despite optimum medical therapy.
- Asymptomatic patient with severe MR with mild to moderate left ventricular dysfunction
- Ejection fraction (EF) falls to 55%
- Left ventricular end systolic diameter is greater than 45 mm
- Asymptomatic patient with normal left ventricle and atrial fibrillation or pulmonary hypertension.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 178; Short and Long Cases in Clinical Medicine, HN Sarker Page: 73
What are the complications of MR?
As follows:
- Acute left ventricular failure (LVF)
- Infective endocarditis
- Systemic embolism
- Atrial fibrillation
- CCF
* Short Cases in Clinical Medicine, ABM Abdullah, 5th Edition Page: 80
In which lesion of MR or MS, endocarditis is common?
Endocarditis is common in MR.
* Short and Long Cases in Clinical Medicine, HN Sarker Page: 43
What are the types of prosthetic valve?
Prosthetic valves are of 2 types:
- Metallic valves:
- Starr-Edward valve (ball-cage valve)
- Bjork-Shiley valve (tilting disc)
- St Jude’s valve (bi-leaflet, double tilting disc).
- Tissue valves:
- Carpentier-Edwards valve
- Hancock porcine valve
- Ionescu Shiley valve (less used).
Note Tissue valve – 2 types:
- Xenograft: made from porcine valve or bovine pericardium. These are less durable and may require replacement after 8 to 10 years. Anticoagulation is not required unless there is AF.
- Homograft: these are cadaveric valves (aortic or pulmonary human valve), particularly useful in young patient and in the replacement of infected valves.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 178
What are the advantages and disadvantages of different valves?
As follows:
- In case of metallic valve:
- Advantage: incidence of valve failure is less and more durable.
- Disadvantage: incidence of thrombosis is usually high, requiring long-time anticoagulant therapy, even life long. There may be microangiopathic hemolytic anemia.
- In case of tissue valve:
- Advantage: incidence of thrombosis is less, hence long-time anticoagulant therapy is not required (short-term anticoagulant is used in postoperative period. Also, anticoagulant is required, if associated with AF). No hemolysis.
- Disadvantage: incidence of valve failure is high due to stiffening and later tearing of valve leaflets over 10 years, and requires repeat valve replacement and is less durable. There is degeneration and calcification in advanced stage.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 179
What are the complications of prosthetic valve?
As follows:
- Thromboembolism: more on metallic valve (common in mitral than aortic). Anticoagulant is necessary (INR should be between 3 and 4.5).
- Primary valve failure: rare in metallic valve (common in tissue valve).
- Valve leaking.
- Dehiscence or detachment of valve from the site or valve ring resulting in paraprosthetic leak.
- Valve obstruction by thrombosis or calcification.
- Mechanical or microangiopathic hemolytic anemia (mainly in aortic valve in 10 to 20% in 10 years. Occurs due to metallic valve.).
- In tissue valve, there may be perforation, rupture, degenerative changes due to calcium deposition.
- Infective endocarditis, especially in dental procedure or catheterisation. Common organism is Staphylococcus epidermidis. Occasionally, treatment may be difficult, high mortality and may require to replace the valve again. If infection occurs within 60 days of valve replacement (early), it is mostly by contamination of intravenous (IV) cannula and if the infection occurs after 60 days (late), it is like other valve endocarditis.
Note
- Ball and cage valve causes hemolysis more than other valve
- Tilting disc is more thrombogenic.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 180
How to choose a particular valve?
In the following way:
- In young patients, if no contraindication for anticoagulant therapy, metallic valve prosthesis is preferred.
- In elderly patient or if there is contraindication to anticoagulant therapy, tissue valve prosthesis is preferred.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 180
What is mitral valve prolapse? What are the features? How would you treat?
It is also called Barlow’s syndrome or floppy mitral valve. In this condition, a mitral valve leaflet (most commonly the posterior leaflet) prolapses into the left atrium during ventricular systole. It is one of the commonest causes of MR. It may be congenital anomaly or due to degenerative myxomatous changes. It may be associated with Marfan’s syndrome, Ehler-Danlos syndrome, thyrotoxicosis, rheumatic or ischemic heat disease, atrial septal defect or hypertrophic cardiomyopathy.
Mitral valve prolapse is more common in thin, young women, may be familial. It may be present in healthy women in up to 10% cases. The most common symptom is atypical chest pain, usually in left submammary region and stabbing in quality. Rarely, it may be confused with anginal pain. There may be palpitation, dyspnea, fatigue, benign arrhythmia or rarely fatal ventricular arrhythmia. Embolic stroke and TIA are rare complications. Symptoms increases with aging.
On examination, the typical features are midsystolic click followed by late systolic murmur. Later, MR may develop and there is PSM. Two-dimensional echocardiography confirms the diagnosis.
Asymptomatic patient only needs reassurance, periodic echocardiography may be done. Atypical chest pain and palpitation are treated with b-blocker. Other antiarrhythmic drugs may be needed. If there is significant MR or AF, anticoagulation is indicated to prevent thromboembolism (aspirin may be given). If MR is severe, mitral valve repair or replacement should be done. Prophylaxis for infective endocarditis in most cases is not recommended. Overall prognosis is good.
* Long Cases in Clinical Medicine, ABM Abdullah Page: 176
