Mitral Valve Prolapse: Clinical Examination, Diagnosis, and Treatment
Clinical Examination
Physical examination remains the optimal method for detecting mitral valve prolapse, and in the absence of physical findings in the supine, sitting, and standing positions, echocardiography is of little use as the primary diagnostic tool. 1
Key Auscultatory Findings
The hallmark finding is a nonejection midsystolic click that represents sudden tensing of the mitral valve apparatus as the leaflets prolapse into the left atrium during systole, best heard at the apex with possible radiation to the axilla. 2, 3
The click may occur as a single sound or multiple clicks, and its timing moves within systole with changes in left ventricular dimensions. 2, 3
In mild-to-moderate MVP with regurgitation, expect a late systolic murmur that begins after the midsystolic click and extends to S2, best heard at the apex. 2, 3
In severe MVP with regurgitation, a loud holosystolic murmur may be heard at the apex, though this is less common. 2, 3
Normal intensity and splitting of S2 is typically preserved in mild MVP. 2, 3
Dynamic Maneuvers (Critical for Diagnosis)
Standing from squatting or Valsalva maneuver decreases left ventricular volume, causing the click to occur earlier in systole and the murmur to become longer and louder. 2, 3
Squatting or leg raising increases left ventricular volume, causing the click to occur later in systole and the murmur to become shorter and softer. 2, 3
Failing to examine in multiple positions (supine, sitting, standing) may miss MVP, as these positions are optimal for detection. 1, 2, 3
Signs of Hemodynamic Severity
An early diastolic filling sound (S3) may be present in severe mitral regurgitation with significant volume overload. 2, 3
Normal left ventricular and left atrial examination findings suggest that severe chronic mitral regurgitation is unlikely, even if echocardiography suggests otherwise. 2, 3
Signs of pulmonary congestion may be present in severe regurgitation with hemodynamic compromise. 2, 3
Critical Pitfall in Late-Systolic Prolapse
- A very late soft systolic murmur without diastolic filling sounds indicates that regurgitation occurs only in very late systole, which is frequently overestimated by echocardiography because calculations do not account for the short duration of late systolic regurgitation. 4, 2, 3
Diagnosis
Indications for Echocardiography
Echocardiography should be performed for diagnosis, assessment of hemodynamic severity, leaflet morphology, and ventricular compensation in patients with physical signs of MVP. 1
Class I indication: Diagnosis and assessment in patients with a nonejection click and/or murmur. 1
Class IIa indication: Risk stratification in patients with physical signs of MVP or known MVP. 1
Class IIa indication: To exclude MVP in patients who have been diagnosed but without clinical evidence to support the diagnosis. 1
Class III indication (not recommended): Exclusion of MVP in patients with ill-defined symptoms in the absence of clinical symptoms, physical findings suggestive of MVP, or positive family history. 1
Echocardiographic Criteria
Diagnosis of prolapse should be made in the parasternal long-axis view or apical long-axis view, not in the apical four-chamber view, because the saddle-shaped annulus may lead to false positive diagnosis. 1
Mitral valve prolapse is defined as valve prolapse of 2 mm or more above the mitral annulus in the long-axis parasternal view. 1
The echocardiographic report should identify leaflet thickening, LV dilatation, and provide clues on the likelihood of valve repair. 1
Assessment of Mitral Regurgitation Severity
Echocardiography is essential to assess the etiology of mitral regurgitation, valve anatomy, function, and severity using an integrative approach. 4
Severe primary MR is defined as effective regurgitant orifice area (EROA) ≥0.4 cm² and regurgitant volume ≥60 mL. 4
A flail leaflet, ruptured papillary muscle, or large coaptation defect is specific for severe MR. 1
Treatment
Asymptomatic Patients with Mild MVP
Asymptomatic patients with mild MVP require only regular monitoring with clinical follow-up every 12 months and echocardiography every 2 years. 4
- No specific medical treatment is needed except reassurance and endocarditis prophylaxis in patients with a pansystolic or end-systolic murmur. 5
Asymptomatic Patients with Moderate MR
- Clinical follow-up every 6 months with annual echocardiography is recommended. 4
Asymptomatic Patients with Severe MR
Surgical intervention is recommended for asymptomatic patients with severe primary MR and left ventricular ejection fraction <60% or left ventricular end-systolic dimension ≥40 mm. 4
Surgery should be considered in asymptomatic patients with severe MR if any of the following are present: left ventricular dysfunction, new onset atrial fibrillation, or pulmonary hypertension. 4
Clinical evaluation every 6 months with annual echocardiography is recommended. 4
Symptomatic Patients with Severe MR
Surgery is recommended for symptomatic patients with severe MR, regardless of left ventricular function. 4
Medical Therapy
There is no evidence supporting the use of vasodilators, including ACE inhibitors, in chronic MR without heart failure. 4
ACE inhibitors have benefit and should be used in patients with advanced MR and severe symptoms who are not surgical candidates. 4
Beta-blockers should be considered for patients with chest pain and symptomatic arrhythmias. 6
Beta-blockers and spironolactone should be considered as appropriate for heart failure management. 4
Anticoagulant therapy with target INR between 2-3 is recommended for patients with permanent or paroxysmal atrial fibrillation, history of systemic embolism, or evidence of left atrial thrombus. 4
Surgical Management
Mitral valve repair is strongly preferred over replacement when technically feasible. 4
For focal posterior leaflet flail, focal triangular resection with annuloplasty ring is recommended. 4
For anterior leaflet prolapse or bileaflet prolapse, nonresection techniques using PTFE neochord reconstruction or chordal transfer with annuloplasty ring are preferred. 4
For diffuse posterior leaflet myxomatous disease, sliding leaflet valvuloplasty with annuloplasty ring is recommended. 4
Outcomes depend significantly on surgeon experience and center volume. 4
For patients at high surgical risk, percutaneous edge-to-edge repair may be considered. 4
Management of Arrhythmias
Patients with ventricular tachycardia should receive antiarrhythmic therapy. 6
Treatment with beta-blockers is indicated for frequent ventricular extrasystoles of more than 30 per hour, usually associated with bigeminy, runs or polymorphism, ventricular tachycardia, and ventricular fibrillation. 5
Patients with abnormal resting ECGs or frequent ventricular premature beats should be further tested because of increased risk of sudden death. 6
Post-Surgical Follow-up
- A baseline ECG, X-ray, and echocardiography should be established post-repair/replacement for future comparison. 4