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| REVIEW ARTICLE |
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| Year : 2018 | Volume
: 15
| Issue : 1 | Page : 11-14 |
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Mitral valve prolapse
Nekkanti Venkat Rayudu
Cardiology Department, Apollo Hospitals Enterprises Ltd., Hyderabad, Telangana, India
| Date of Web Publication | 2-Apr-2018 |
Correspondence Address:
Nekkanti Venkat Rayudu
Room No 9055, Apollo Hospitals, Jubilee Hills, Hyderabad - 500 033, Telangana
India
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/am.am_32_17
Mitral valve prolapse, Click murmurs syndrome, Barlow's syndrome is one of the common cause of mitral valve disease with or without mitral regurgitation. Barlow gave full clinical description of the disorder in 1963. It has large clinical spectrum from asymptomatic auscultatory or Echodopler finding to frank mitral regurgitation needing valve surgery.
Keywords: Mitral valve prolapse, mitral regurgitation, myxomatous leaflets
How to cite this article:
Rayudu NV. Mitral valve prolapse. Apollo Med 2018;15:11-4 |
Mitral valve prolapse (MVP), Click murmurs syndrome, and Barlow's syndrome is one of the common causes of mitral valve disease with or without mitral regurgitation (MR). Barlow gave a full clinical description of the disorder in 1963. It has a large clinical spectrum from asymptomatic auscultatory or Echo-Doppler findings to frank MR needing valve surgery. Most often, it is a benign disorder and sometimes associated with dysautonomic symptoms such as fatigue, giddiness, anxiety, neurosis, left-sided chest pain, palpitations, and hypochondriasis(excessive feeling about heart disease). Sometimes, the symptoms follow the routine clinical echo observations.
Many patients with MVP with click and without murmur do not need any further treatment. Some patients with mild-to-moderate MR may progress to severe MR as they age and after 50 years may need mitral valve surgery. In the large group of patients with MVP only a few patients develop symptoms of MR such as dyspnea, fatigue, cardiac dilatation, heart failure (decompensation), and need surgery. Common extracardiac symptoms are anxiety, phobia, neurosis and hypochondriosis. Symptoms may vary intensity and duration from time-to-time [Figure 1]. | Figure 1: LEFT PANEL: The spectrum and progression of MVP. Most of the MVP cases are above the dotted line, while progressive mitrial valve dysfunction cases occupy the area below the dotted line. RIGHT PANEL: The large circle - the total number of MVP patients. Black circle - Patients with symptoms due to mitrial valve dysfunction. Cross hatched circle – Symptom due to autonomic dysfunction
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Mitral valve apparatus consists of the fibrous annular ring on which the leaflets are attached. The anterior mitral leaflet (AML) is long and sail like with short annular attachment. The posterior mitral leaflet (PML) is short with broad and C-shaped attachment to annulus. The junctions of the AML and PML are called commissures (anteriolateral and posterolateral). The leaflets closer is governed by 120 rope-like structures called chordate tendineae, which are attached to two papillary muscles of left ventricular (LV) myocardium. All these structures have to work as a unit to regulate the closer of the valve leaflets. Any in the coordination of these structures causes improper closer of the valve and cause valve deformity in systole with or without MR (mitral valve leak). The accumulation of mucopolysaccharides in the middle layer of leaflets (Spangiosa) results in thickening, redundancy (excessive tissue) and folding of the valve called classic MVP [Figure 2]. | Figure 2: LEFT PANEL: Cross section of left atrium and left ventricle showing normal and abnormal coaptation of mitrial valve leaflets. RIGHT PANEL: Histopathological diagram showing accumulation of mucopolysaccharides in the middle layer of mitrial valve
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MVP is classified as primary and secondary etiology. Causes of primary MVP are (1) Familial and nonfamilial (autosomal dominant), (2) Marfan Syndrome, (3) Ehler– Danlos syndrome, (4) Pseudoxanthoma elasticum, (5) osteogenesis imperfecta. Secondary causes areas follows; (1) Rheumatic heart disease, (2) Dilated cardiomyopathy, (3) Coronary artery disease, (4) Echocardiographic abnormality [Table 1].
In primary classic MVP, most often the body or tip of middle scallop of the posterior leaflet prolapse in systole and best seen in parasternal long axis view of trans thoracic echo cardiogram with or without Doppler evidence of MR. The MR jet is directed (conducted) anteriorly and on auscultation heard at the apex and along left sternal border medially. On the other hand, MR due to other causes (rheumatic) is conducted to axilla and back of the left chest. Furthermore, the leaflets in primary MVP are thick, long, and redundant whereas rheumatic and other causes they are shorter and fibrosed.
The classical auscultatory findings are mid or late systolic click with late systolic murmur heard at the apex. The murmur varies with loading conditions and postures (position). The click and murmur are earlier to start and the best heard on standing or sitting position. Murmur diminishes in loudness and shorter in duration on lying down and on squatting. The best way to appreciate the variability of murmur by auscultating the patient on squatting position and stand along with patient while continuing auscultation. Sometimes, click may be heard clinically in sitting position and echo on lying down position may not show prolapse [Figure 3]. Changing the body position are by giving sublingual nitrate or by doing valsalva echo prolapse may be brought out. Other causes of auscultatory clicks or atrial or ventricular septal aneurysms, tricuspid valve prolapse, absent pericardium, or pneumothorax. | Figure 3: The classical auscultatory findings are mid or late systolic click with late systolic murmur heard at the apex. The murmur varies with loading conditions and postures (position). The click and murmur are earlier to start and the best heard on standing
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Electrocardiography (ECG) most often shows sinus tachycardia, nonspecific ST and T changes in L2, L3 (inferior leads), premature beats (atrial or ventricular), prolonged QT interval. Holter analysis may show premature beats, episodes of nonsustained ventricular tachycardia (VT) and rarely sustained VT and bradycardia due to excessive vagotonia. Echo Doppler is the diagnostic tool for diagnosis, severity, detection and quantifying MR, identifying high-risk patients, the chamber enlargement and other complications. M-mode echo by its temporal resolution (time specificity) shows posterior displacement of PML in late systole. Two-dimensional echo by its spatial resolution (space clarity), shows hairpin bending of PML (mild MVP) to gross prolapse (flial leaflet). Color Doppler classifies mild-to-severe degree MR. Two millimeters are more superior and posterior displacement of PML or AML or both leaflets is taken as diagnostic criterion. Leaflet thickness more than 5 mm is considered as myxomatous and redundant [Figure 4]. | Figure 4: LEFT PANEL: ECG showing inferior wall changes. MIDDLE PANEL: 2D Echo showing bi-leaflet prolapse and Doppler echo showing late systolic mitrial regurgitation. LAST PANEL: Filial Transient posterior mitrial leaflet
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High-risk patients are more prone to complications. They are
- Click and murmur by auscultation
- MVP patients with H/O syncope or family history sudden cardiac death
- Patients with exertional dyspnea and or chest pain
- ST segment changes in ECG or long QT interval or atrial fibrillation
- Complex ventricular arrhythmias
- 5 mm or more thick leaflets and redundant leaflets [Figure 5]
- Flail leaflets
- Chamber (left atrial [LA]/LV) dilatation
- Moderate-to-severe MR
- Ejection fraction 60% or less
- LV and systolic volume 60 ml or more
- Evidence of pulmonary arterial hypertension.
 | Figure 5: Classification of mitrial valve prolapse according to thickness and symptoms
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| Natural Course | |  |
Most of the patients with MVP have benign course and mortality, and morbidity is same as the general population. High-risk groups may have transient ischemic attacks (TIA), episodes of giddiness, transient blindness (amaurosis), or strokes with hemiplegia. One of the causes of recurrent stroke in different vascular territories in young people is MVP. Endocarditis (valve infection) is another worrisome complication, especially in patients with thick valves and MR [Table 2]. Most of the MVP patients develop complications after the age of 50 years [Figure 6] and [Figure 7]. | Table 2: Recommendation for Antibiotic Endocarditis Prophylaxis for Patients with MVP undergoing procedures associate with Bacteremia
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 | Figure 6: The course and possible complications of MVP in most patients MVP syndrome has benign prognosis. (Ref 3). CNS :- Central Nervous System, OPTH:- Ophthalmologic
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 | Figure 7: The relation-ship between cardiac structure, between Age and complication in MVP syndrome (Ref 4)
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| Treatment | | |
Patients with mild degree prolapse need reassurance about the benignity of the condition. Patients with palpitation, anxiety, chest pain will benefit from beta blockers such as propranolol. Patients with thick leaflets and regurgitation need endocarditis prophylaxis. Those who have TIA need aspirin therapy. Patients with AF and more than 65 years require anticoagulation. Symptomatic patients with moderate-to-severe MR and [Table 3] or with LA/LV enlargement has to undergo mitral valve surgery [Figure 8].
Most often, valve repair with or without annuloplasty ring is the treatment of choice. Quadrangular resection of middle scallop of PML, chordal repair, ring annuloplasty will decrease and cure MR. Patients with both leaflet prolapse and AML prolapse, fibrosed leaflets are difficult to repair and may need mitral valve replacement with prosthetic valve [Figure 9]. | Figure 9: Surgical view of mitrial valve and classification of scallops (Ref 5)
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In summary, MVP is unique and interesting clinical disorder and one of the common causes of MR. The variability of the symptoms and auscultatory findings along with autonomic symptoms change the clinical line of treatment. Echo Doppler is the best tool for diagnosis, identifying high-risk group of patients. Most often, MVP runs a benign course and need reassurance, beta blockers, and aspirin therapy. Very few patients need complex management, and some may require mitral valve surgery.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]
[Table 1], [Table 2], [Table 3]
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