07/08/2026
Long case mechanical prosthetic mitral valve with AF
Dr Mohamad Ahmad
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Below is an exam-oriented long case for a patient with a mechanical prosthetic mitral valve and atrial fibrillation (AF), suitable for cardiology clinical examination.
Long Case: Mechanical Prosthetic Mitral Valve + AF
1. Identification
A ___-year-old patient, known to have rheumatic mitral valve disease, underwent mechanical mitral valve replacement ___ years ago and is on long-term anticoagulation, presenting with palpitations / dyspnea / fatigue / edema.
2. History
A. Presenting symptoms
Ask about:
Dyspnea: NYHA functional class.
Orthopnea and PND.
Palpitations: onset, duration, regularity.
Chest pain.
Dizziness or syncope.
Fatigue and reduced exercise tolerance.
Symptoms of heart failure: leg swelling, abdominal distension, weight gain.
B. Symptoms suggesting prosthetic valve dysfunction
New or increasing dyspnea.
Reduced exercise tolerance.
Change or disappearance of mechanical valve click.
New murmur.
Symptoms of pulmonary hypertension.
Fever → consider prosthetic valve infective endocarditis.
Acute pulmonary edema → consider prosthetic valve thrombosis or severe prosthetic regurgitation.
C. History of AF
Ask about:
First detected or longstanding AF.
Persistent vs paroxysmal.
Previous cardioversion or ablation.
Previous thromboembolism/stroke.
Rate-control medications.
Symptoms during rapid ventricular response.
D. Anticoagulation history — very important
For a mechanical mitral valve, ask specifically about warfarin/VKA:
Dose and duration.
Compliance.
Recent INR values.
Target INR.
Any bleeding: epistaxis, gum bleeding, GI bleeding, hematuria, hematoma.
Any thromboembolic symptoms.
Key exam point: A mechanical mitral prosthesis requires lifelong VKA anticoagulation. DOACs such as apixaban, rivaroxaban, dabigatran and edoxaban are not appropriate substitutes for anticoagulation in patients with mechanical valves.
3. Examination
General examination
Look for:
Pallor.
Cyanosis.
Jaundice.
Peripheral edema.
Signs of infective endocarditis.
Cachexia.
Pulse
In AF:
Irregularly irregular pulse
Assess rate and volume.
Pulse deficit may be present.
Check:
Radio-radial delay.
Radio-femoral delay.
Peripheral pulses.
Blood pressure
Measure BP and look for:
Hypertension.
Hypotension.
Pulse pressure abnormalities.
4. JVP
Assess for:
Raised JVP.
Positive hepatojugular reflux.
Prominent V waves if significant tricuspid regurgitation is present.
5. Precordial Examination
Inspection
Look for:
Previous sternotomy scar.
Visible apex beat.
Precordial bulge.
Palpation
Apex beat:
Location.
Character.
Displacement → cardiomegaly/LV enlargement.
Parasternal heave:
Suggests RV hypertrophy, commonly due to pulmonary hypertension.
Thrill:
May indicate significant prosthetic dysfunction or associated valve disease.
Auscultation
Mechanical mitral prosthesis
Listen for:
Sharp, crisp prosthetic valve closing click.
Compare intensity with previous examinations if available.
A new decrease, muffling, or disappearance of the mechanical click raises concern for:
Prosthetic valve thrombosis.
Prosthetic obstruction.
Structural dysfunction.
Murmurs
Assess:
Timing.
Site.
Radiation.
Intensity.
Look for:
Prosthetic valve obstruction.
Paravalvular leak.
Associated mitral/tricuspid/aortic valve disease.
In AF, S1 intensity varies because ventricular filling varies from beat to beat.
6. Examination of Other Systems
Respiratory
Look for:
Basal crepitations → pulmonary congestion.
Pleural effusion.
Pulmonary hypertension-related findings.
Abdomen
Look for:
Hepatomegaly.
Ascites.
Splenomegaly.
Neurological
Look for evidence of previous:
Stroke.
TIA.
Systemic embolism.
7. Investigations
ECG
Typical findings:
Atrial fibrillation
Absent P waves.
Irregularly irregular RR intervals.
Variable ventricular rate.
Assess:
Ventricular rate.
QRS duration.
LVH.
Previous MI.
Ischemia.
Echocardiography — most important
Perform TTE, assessing:
Mechanical mitral prosthetic valve function.
Transprosthetic gradients.
Effective or***ce area when appropriate.
Leaflet/disc mobility.
Presence and severity of regurgitation.
Paravalvular leak.
LV size and EF.
LA size.
RV function.
Pulmonary artery pressure.
Tricuspid regurgitation.
Other valve lesions.
TEE is particularly useful when:
Prosthetic valve thrombosis is suspected.
Prosthetic endocarditis is suspected.
Paravalvular leak needs assessment.
TTE images are inadequate.
Laboratory
CBC.
PT/INR.
Renal function.
Liver function.
Electrolytes.
CRP/ESR if infection suspected.
Blood cultures if fever or suspected endocarditis.
Other
Depending on presentation:
Chest X-ray.
Holter monitoring.
Cardiac CT/fluoroscopy for suspected mechanical leaflet obstruction.
Coronary assessment when clinically indicated.
8. Main Differential Diagnosis
In a patient with mechanical MVR + AF who develops dyspnea:
AF with rapid ventricular response
Prosthetic valve thrombosis
Prosthetic valve obstruction
Prosthetic valve regurgitation/paravalvular leak
Prosthetic valve endocarditis
Heart failure
Pulmonary hypertension
LV dysfunction
Recurrent rheumatic valve disease/other valve disease
Pulmonary embolism
9. Management
A. Anticoagulation
Lifelong VKA/warfarin is mandatory for a mechanical mitral valve.
Monitor INR regularly and maintain the target according to:
Valve type/model.
Patient-specific thromboembolic risk.
Local/institutional protocol and current guideline recommendations.
If anticoagulation is interrupted for a significant procedure, bridging with therapeutic heparin may be required, particularly because a mechanical mitral valve carries high thromboembolic risk.
B. AF rate control
Depending on LV function and clinical status:
β-blocker
Digoxin
Non-dihydropyridine calcium-channel blocker such as diltiazem/verapamil in appropriate patients with preserved LV systolic function.
C. Rhythm control
Consider:
Electrical cardioversion.
Antiarrhythmic therapy.
Catheter ablation in selected patients.
Important: In a mechanical valve patient, anticoagulation remains necessary even if sinus rhythm is restored.
D. Heart failure treatment
If heart failure is present:
Diuretics for congestion.
Guideline-directed therapy according to LV function.
Treat the underlying valve/prosthetic problem.
E. Prosthetic valve thrombosis
Management depends on:
Obstructive vs non-obstructive thrombosis.
Size of thrombus.
Symptoms.
Hemodynamic compromise.
Bleeding risk.
Options include:
Optimization/intensification of anticoagulation in selected non-obstructive cases.
Thrombolysis or surgery for selected obstructive prosthetic valve thrombosis.
F. Prosthetic valve endocarditis
Requires:
Blood cultures.
Echocardiographic assessment, often TEE.
Prolonged pathogen-directed IV antibiotics.
Early surgical evaluation when there is prosthetic dysfunction, uncontrolled infection, abscess, or other surgical indication.
Examiner's Summary
A good final presentation could be:
“This is a patient with previous mechanical mitral valve replacement, currently in atrial fibrillation. I would assess the patient for adequacy of anticoagulation, ventricular rate control, heart failure, thromboembolism and, importantly, mechanical prosthetic valve dysfunction including thrombosis, obstruction, regurgitation, paravalvular leak and infective endocarditis. I would confirm the rhythm with ECG, assess prosthetic valve function and cardiac hemodynamics by echocardiography, and check INR and other relevant laboratory investigations.”
High-yield viva questions
Why does a mechanical mitral valve require lifelong anticoagulation?
What is the target INR?
Why are DOACs contraindicated?
Causes of a missing prosthetic valve click?
How do you diagnose prosthetic valve thrombosis?
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