Mitral Stenosis (OSCE Guide)

1/03/2020

Mitral Stenosis (OSCE Guide)

Mitral stenosis (MS) is a notoriously tricky case at the exam where most of the candidates failing to diagnose it because of the hardly audible low-pitched murmur needing the patient to be auscultated in the left lateral position. So, try to diagnose it even before you auscultate the patient!

Always suspect MS if the patient has irregularly irregular pulse indicative of atrial fibrillation (AF). Although MS patients are usually in AF, every AF is not having MS, and every MS patient is not in AF.

Mitral Valvotomy was carried out via a left lateral thoracotomy incision in the past. Although it is history now, there may be a handful of (elderly) patients who had undergone mitral valvotomy and having mitral restenosis with time. Suspect Before Auscultation!

  • Malar Flush
  • Irregularly Irregular Pulse

The most important finding would be the lateral thoracotomy scar if your clinical diagnosis is MS. If the scar is present you have to present the case as “Mitral Restenosis” instead of “Mitral Stenosis”.

MITRAL STENOSIS – EXAMINATION

GENERAL EXAMINATION

GENERAL EXAMINATION
  • Malar Flush – Indicate low cardiac output (Complication)
  • Running Fever – Suspect Infective Endocarditis (Complication)
  • Stigmata of IE – Clubbing, Splinter Hemorrhages, Osler’s Nodes, Janeway Lesions (Complication)
  • Joint Swelling – Rheumatic Fever (Aetiology)
  • Erythema Marginatum – Rheumatic Fever (Aetiology)
  • Bilateral Pitting Ankle Oedema – RHF (Complication)
  • Evidence of Hemiparesis – Thromboembolism (Complication)
PULSE
  • Irregularly Irregular – Underlying Atrial Fibrillation (Complication)
  • Volume – Low volume in severe MS (Severity Marker)
  • Rate – may vary (Slow or Fast AF)
BLOOD PRESSURE
  • Narrow Pulse Pressure (PP) in Sever MS due to low cardiac output (Severity Marker).
JUGULAR VENOUS PRESSURE (JVP)

Elevated JVP – Indicative of Pulmonary Hypertension and RHF (Complication).
If JVP elevated, you should carefully look for other signs of PHTN & RHF later on your examination & mention them in your presentation.

PRECORDIAL EXAMINATION

INSPECTION
  • Midline Sternotomy Scars (Previous Mitral Valve replacement)
  • Mitral Valvotomy Scars in the lateral chest wall (Previous Mitral Valvotomy)
PALPATION
  • Tapping Apex – (Palpable First heart sound) – Underlying Loud S1 (Mobile & pliable Mitral valve leaflets)
  • Parasternal Heave – RVH due to RV pressure overload (Complication)
  • Diastolic Thrill at Apex – Underlying loud diastolic murmur (For Diagnosis)
  • Palpable Second heart Sound (P2) – Pulmonary HTN (Complication)
AUSCULTATION
  • Loud S1 – Mobile & pliable Mitral valve leaflets.
  • Or else Soft S1? – Calcified & Immobile Mitral valve leaflets. (Not Necessarily a Complication)
  • Loud P2 – Pulmonary Hypertension (Complication)
  • Opening Snap – Mobile & pliable Mitral valve leaflets (Refer FAQs).
  • Rumbling Type, Low pitched, Mid-diastolic Murmur at Mitral area – Best heard with the Bell in left lateral position. Presystolic accentuation of the murmur is heard if the patient is in sinus rhythm.
  • Functional Tricuspid Regurgitation – You should actively look for this murmur if you found any features to suggest the patient is having PHTN or RHF (e.g. Elevated JVP, Parasternal heave, Loud p2). There will be a “systolic murmur at Tricuspid area which is louder in inspiration”. This is due to increased resistance in pulmonary vasculature secondary to MS, causing backflow via the tricuspid valve (Severity Marker).
  • Graham-Steel Murmur – This is also an additional murmur hear in severe MS due to increased pulmonary vasculature resistance causing backflow via Pulmonary valve in diastole. It is, in fact, the “Pulmonary Regurgitation murmur heard”. There will be an early diastolic murmur at the pulmonary area (Severity Marker).

EXTENDED EXAMINATION

  • Lung Bases – Bibasal fine crepitations would indicate left heart failure secondary to MS. But these are rarely heard if the patient is on diuretics. (Complication)
  • Tender Hepatomegaly – Would indicate RHF following PHTN secondary to MS (Complication)

MITRAL STENOSIS – CASE PRESENTATION 01

This patient is not having peripheral stigmata of infective endocarditis. There is no malar flush or ankle edema. The pulse irregularly irregular, the volume is normal and normal in character. His BP is (Valve) & JVP is not elevated.

On precordial examination, there are no surgical scars suggestive of previous valve replacement or mitral valvotomy. The apex beat is undisplaced & tapping in character. P2 is not palpable and there are no thrills or parasternal heave. The first heart sound is loud whereas the pulmonary component of the second heart sound is of normal intensity. There is an opening snap in early diastole followed by a grade 2 mid-diastolic rumbling type murmur best heard at the apex which increases in intensity with expiration while patient is in left lateral position. Bilateral lung bases are clear & there is no tender hepatomegaly.

MITRAL STENOSIS – CASE PRESENTATION 02

This patient is not having peripheral stigmata of infective endocarditis. There is malar flush and ankle oedema. The pulse irregularly irregular, volume is low and normal in character. His BP is 110/90 mmHg & JVP is elevated.

On precordial examination, there is a lateral thoracotomy scar. The apex beat is undisplaced & tapping in character. P2 is palpable and there is a parasternal heave, but no diastolic thrills palpable. The first heart sound is loud as well as the pulmonary component of the second heart sound. There is grade 2 mid-diastolic rumbling type murmur best heard at the apex which increases in intensity with expiration while the patient is in the left lateral position. Opening snap is not heard. In addition, there is a pansystolic murmur best heard at LLSB (tricuspid area) and an early diastolic murmur best heard at the Pulmonary area, both are louder in inspiration. There are fine crepitations on both lung fields & tender hepatomegaly.

So, this patient has undergone mitral valvotomy in the past and now having severe Mitral restenosis and associated Atrial Fibrillation with evidence of Pulmonary Hypertension leading to congestive cardiac failure. There is functional tricuspid regurgitation & Graham-Steel murmur of Pulmonary regurgitation due to the pressure overload secondary to severe PHTN. The mitral valve leaflets are clinically immobile & calcified.


FREQUENTLY ASKED QUESTIONS

1. Rheumatoid Arthritis 2. Systemic Lupus Erythematosus (SLE) 3. Congenital MS 4. Carcinoid Syndrome 5. Whipple's Disease
1. Atrial Septal Defect (ASD)0 2. Mitral Valve Prolapse 3. Tricuspid Stenosis
1. Left atrial myxoma 2. Austin flint murmur (in Aortic Regurgitation) 3. Carey Coombs murmur (in acute rheumatic carditis)
A murmur heard in between second heart sound and the first heart sound.
It is the accentuated and palpable first heart sound which is best felt at the apex.
Because the valve cusps are widely apart at the onset of systole and suddenly shut with the forceful ventricular contractions.
It is caused by the sudden opening of stenosed mitral valve with left atrial contraction. Usually opening of valves does not cause any sound. But in MS, an opening snap is heard due to increased atrial pressure.
It indicates the valves are still pliable and the patient is suitable for percutaneous transeptal mitral commissurotomy (PTMC). When they are diffusely calcified, the opening snap disappears.
1. The turbulence of flow occurs when it is < 2 square centimeters. 2. Clinically significant MS is when it is < 1.5 square centimeters. 3. Severe mitral stenosis is when it is < 1 square centimeters.
Thickening of valve leaflets, nodularity and ultimately commissural fusion resulting in a “fish-mouth” like valve.
1. Long murmur 2. Narrow gap between S2 and OS
1. Malar Flush (Low cardiac output) 2. Narrow Pulse Pressure (Low cardiac output) 3. Irregularly irregular pulse (Atrial fibrillation) 4. Loud P2 (Pulmonary hypertension) 5. Functional Tricuspid Regurgitation (Severe Pulmonary Hypertension) 6. Graham-Steel Murmur (Pulmonary Regurgitation due to severe PHTN) 7. Paraventricular heave (Right ventricular hypertrophy) 8. Distended neck veins (Increased JVP) 9. Tender hepatomegaly (RHF) 10. Bilateral pitting oedema (RHF)
It is due to development of severe Pulmonary HTN leading to low cardiac output.
1. ECG P mitrale - bifid P waves (due to left atrial enlargement) Irregularly irregular QRS complexes (if AF present) 2. Chest X-ray Double silhouette sign (due to enlarged left atrium) Features of RHF (Upper lobe diversion, Kerly B lines) 3. 2D Echocardiography To confirm the diagnosis
1. Antitussive medication - for bronchitis 2. Low dose diuretics - for dyspnoea 3. Beta-blockers & Calcium channel blockers - to increase exercise tolerance 4. Management of AF - Rate control, Rhythm control, Anticoagulant therapy
1. Symptomatic patients with significant mitral stenosis 2. Patients with pulmonary hypertension regardless of the severity 3. Recurrent thromboembolism despite anticoagulation
1. Balloon valvuloplasty 2. Percutaneous transeptal mitral commissurotomy (PTMC) 3. Open commissurotomy 4. Mitral valve replacement

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