Mitral valve prolapse

Mitral valve prolapse

1. MITRAL VALVE PROLAPSE DR ANEES KURIKKAL MD Internal medicine resident

2. INTRODUCTION Mitral valve prolapse (MVP), first identified and characterized in the 1960 is the most common abnormality of the mitral valve Mitral valve prolapse initially was documented angiographically by Criley in 1966 Estimated to occur in 2.4 % of the population. The spectrum of MVP ranges from an isolated systolic click in an asymptomatic individual to full-blown, severe mitral regurgitation necessitating mitral valve replacement (floppy valve syndrome) Affected individuals may have a variety of symptoms such as palpitations, atypical chest pain, or dyspnea , anxiety, fatigue, and occasionally syncope MVP is known by names like BARLOWS SYNDROME , FLOPPY VALVE SYNDROME , CLICK MURMUR SYNDROME, BILLOWING MITRAL LEAFLET SYNDROME

3. Non cardiac abnormalities associated with MVP include hyperadrenergic states and thyrotoxicosis Patients with MVP can have wide variety of supraventricular and ventricular tachyarrhythmias and bradyarrhythmias MVP can be inherited as an Autosomal Dominant condition . Its common in connective tissue disorders like Ehlers-Danlos syndrome, Marfan's syndrome, pseudoxanthoma elasticum, osteogenesis imperfecta, and the von Willebrand syndrome

4. PATHOPHYSIOLOGY The basic defect of MVP appears to be an alteration in the composition of the mitral valve tissue and chordae. Normal dense collagen fibers (fibrosa) is replaced by less sturdy connective tissue (spongiosa) The resultant myxomatous transformation may affect individual scallops or an entire mitral cusp. One or both leaflets may be involved. The mitral leaflet tissue itself is often thickened, redundant, and excessive During systole individual scallops or an entire leaflet billow excessively into the left atrium.

5. Mitral regurgitation occurs when there is true prolapse of the mitral leaflet due either to protrusion of the redundant valve tissue or to abnormally long and lax chordae. The greater the distortion of leaflet apposition, the greater the severity of the mitral leak. Mitral regurgitation when present is typically confined to late systole and occurs at the time that the size of the left ventricular chamber has decreased maximally Both mitral leaflets can be affected in MVP, but the posterior (mural) cusp is more commonly involved. Degeneration of collagen and myxomatous changes within the central core of the chordae tendineae , with associated decreases in tensile strength, are primarily responsible for chordal rupture, which often occurs and may intensify the severity of MR

6. ETIOLOGY MVP occurs as a primary condition that is not associated with other diseases and can be familial or nonfamilial Familial MVP is transmitted as an autosomal dominant trait MVP syndrome is more in young women, have a benign course, Severe myxomatous disease is more common in older men,may require surgery Secondary MVP occurs in disorders like Marfans (90%), Ehlers Danlos (6%) , osteogenesis imperfecta ,pseudoxanthoma elasticum, HCM

7. CLINICAL FEATURES Clinical presentations of the MVP syndrome are diverse Most patients are asymptomatic Can affect at any age and both sexes MVP is the most common cause of isolated MR requiring surgical treatment in the United States and the most common cardiac condition predisposing patients to infective endocarditis

8. SYMPTOMS Vast majorty are asymptomatic Non specific symptoms include fatiguabilty ,palpitations ,postural hypotension ,anxiety Chest discomfort may be typical of angina pectoris but is more often atypical in that it is prolonged, not clearly related to exertion , and punctuated by brief attacks of severe stabbing pain at the apex Syncope, presyncope , palpitations, chest discomfort can be seen In patients with MVP and severe MR, the symptoms of MR (fatigue, dyspnea , and exercise limitation) may be present

9. ON CLINICAL EXAMINATION General appearance : familial MVP : red haired and fair skinned Thin and asthenic with long extremities Pectus excavatum is common( pectus carinatum: less common) Scoliosis ,loss of normal dorsal thoracic kyphosis and reduced AP diameter of chest gives a STRAIGHT BACK appearance Hypomastia (small breasts ) in women Carotid pulse and JVP No detectable abnormality in most patients If severe MR , arterial pulse may be brisk and collapsing Also if there is RV failure , V wave of TR will be present BP : lower side  orthostatic hypotension

10. AUSCULTATION: Use the diaphragm of the stethoscope and has to be pressed hard Examine the patient in supine, left decubitus, and sitting positions The most important finding is a nonejection systolic click at least 0.14 second after S1 It occurs after the beginning of the carotid pulse upstroke. (excludes aortic ejection click) Multiple mid- and late systolic clicks are audible, most readily along the lower left sternal border. Clicks are produced by sudden tensing of the elongated chordae tendineae and of the prolapsing leaflets. With posterior leaflet prolapse , the jet of MR is directed anteriorly and the murmur will radiate to the base of the heart. With anterior leaflet involvement , the jet of MR is directed posteriorly and the murmur will radiate to the axilla and back.

11. Clicks may be followed by mid- to late crescendo systolic murmur that continues to A2. Duration of the murmur is a function of the severity of the MR. In early stages of MR associated with MVP, the murmur will be in late systole and in severe MR the murmur will be holosystolic There can be variability in physical findings Some pts have mid systolic click and mid to late systolic murmur Some has either one Others have click at one occasion and murmur at another occasion Other conditions associated with mid systolic clicks include tricuspid valve prolapse atrial septal aneurysms

12. DYNAMIC AUSCULTATION The auscultatory findings of MVP are sensitive to physiologic and pharmacologic interventions The mitral valve begins to prolapse when the reduction of LV volume during systole reaches a critical point at which the valve leaflets no longer coapt ; at that instant, the click occurs and the murmur commences Any maneuver that decreases LV volume (e.g., decreased venous return, tachycardia, decreased outflow impedance, increased contractility ) worsens the mismatch in size between the enlarged mitral valve and LV chamber, resulting in prolapse earlier in systole and movement of the click (C) and murmur (M) toward the first heart sound

13. When prolapse is severe and/or LV size is markedly reduced , prolapse may begin with the onset of systole ( click may not be audible and murmur will be holosystolic) During the straining phase of the Valsalva maneuver and on sudden standing , cardiac size decreases, and the click and onset of the murmur occur earlier in systole Sudden change from the standing to the supine position, leg raising, squatting , maximal isometric exercise and will delay the click and the onset of the murmur

14. HOCM V/S MVP During the strain of the Valsalva maneuver , the murmur of HCM increases in intensity, whereas the murmur of MVP becomes longer but usually not louder After a premature beat, the murmur of HCM increases in intensity and duration, whereas that caused by MVP usually remains unchanged or decreases The presence of an S4, the absence of a click, and exaggeration of the murmur following a PVC strongly favour hypertrophic cardiomyopathy

15. ECHO For diagnosis of MVP , the two-dimensional echocardiogram must show that one or both mitral valve leaflets billow by at least 2 mm into the left atrium during systole in the long-axis view Thickening of the involved leaflet to more than 5mm support the diagnosis (classic MVP) Findings of more severe myxomatous disease include increased leaflet area, leaflet redundancy, chordal elongation, and annular dilation TEE provides additional details regarding integrity of the mitral valve apparatus, such as rupture of the chordae tendineae 2D echocardiography has revealed prolapse of the tricuspid and aortic valves in approximately 20% of patients with MVP

16. Doppler echocardiography frequently reveals mild MR Moderate to severe MR is present in approximately two thirds of patients with posterior leaflet prolapse and in approximately 25% of patients with anterior leaflet prolapse

17. ECG Usually normal in asymptomatic patients with MVP ECG shows inverted or biphasic T waves and nonspecifc ST-segment changes in leads II, III, and aVf and occasionally in the anterolateral leads (in symptomatic pts) Arrhythmias : atrial and ventricular premature contractions and supraventricular and ventricular tachyarrhythmias, as well as bradyarrhythmias Paroxysmal supraventricular tachycardia is the most common sustained tachyarrhythmia in patients with MVP Incidence of MVP is high in patients with WPW syndrome

18. ANGIOGRAPHY Is not recommended for the diagnostic evaluation of MVP The right anterior oblique projection is most useful for defining the posterior leaflet of the mitral valve and the left anterior oblique projection is most useful for studying the anterior leaflet. Most important Sign : extension of the mitral leaflet tissue inferiorly and posteriorly to the point of attachment of the mitral leaflets to the mitral annulus. Other findings : scalloped edges of the leaflets , LV dilation, decreased systolic contraction and calcifcation of the mitral annulus. Can be done to rule out CAD

19. DISEASE COURSE Got excellent outlook ,large majority remain asymptomatic, need observation and reassurance Serious complications occur in 1/100 pt years ( need for cardiac surgery, CVA, acute infective endocarditis) Progressive MR, gradual increase in left atrial and LV size, AF, pulmonary hypertension, congestive heart failure : the most frequent serious complication Occurs in approximately 15% of patients over a 10- to 15-year period, with age and initial MR severity being the primary predictors of progression Acute hemiplegia, transient ischemic attacks, cerebellar infarcts, amaurosis fugax, and retinal arteriolar occlusions are more common in MVP patients Risk of sudden death is twice normal in pts with MVP

20. MANAGEMENT Patients suspected to have MVP should undergo transthoracic echocardiography. Diagnosis of MVP requires definitive ECHO findings Asymptomatic pts with no evidence of MR ,arrhythmia have excellent prognosis and they should be reassured, advise lifestyle modification and follow up every 3-5 yrs Pts with long systolic murmur should be evaluated more frequently , at intervals of 12 months Endocarditis prophylaxis is not recommended for MVP pts unless they have prior history of IE Patients with a history of palpitations, lightheadedness , dizziness, or syncope, or those who have ventricular arrhythmias or QT prolongation on a routine ECG, should undergo ambulatory (24-hour) electrocardiographic monitoring and/or exercise electrocardiography to detect arrhythmias

21. Beta blockers for palpitations , chest discomfort and self terminating SVT Radiofrequency ablation of atrioventricular bypass tracts for frequent or prolonged episodes of supraventricular tachycardia. Aspirin should be given to patients with MVP who have had a documented focal neurologic event MVP and severe MR pts may require surgery ( repair without replacement is possible in 90 % cases) Resection of the most deformed leaflet segment, most often the middle scallop of the posterior leaflet, and insertion of an annuloplasty ring is the most common procedure. Repair of anterior leaflet prolapse is very difficult Average operative mortality is 1.6%,

22. REFERENCES ESSENTIALS OF CARDIAC PHYSICAL DIAGNOSIS , JONATHAN ABRAMS BRAUNWALD’S HEART DISEASE :A TEXTBOOK OF CARDIOVASCULAR MEDICINE ,10 E HARRISONS PRINCIPLES OF INTERNAL MEDICINE, 20E

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