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Primary cause of mitral valve prolapse syndrome is a congenital connective tissue disease, its exact cause is unknown. Can occur in all age groups have a higher incidence in women, to women aged up to 14 to 30. One-third of patients without structural heart disease and other clinical manifestations of mitral valve prolapse only, also found in Marfan syndrome, systemic lupus erythematosus, nodular artery go far more patients, leaflet prolapse after more common. In some patients with hereditary abnormal collagen, electron microscopy showed decreased production of type collagen fibers and fracture, connective tissue fibers of the central degeneration of collagen, cellulose deposition; elastic fibers break off and dissolved. Pathological features of mitral valve prolapse is mitral myxoid degeneration, proliferation and invasion of a sponge layer fiber layer, sponge layer thickened with proteoglycan accumulation, heart valve leaflet surface thickening, surface fibrin and platelet deposition . Prolapse of the mitral valve leaflet chordae part-bulging toward the left atrium was hemispherical valve leaflets bulge uplift, variable-length area increased valve leaflets, severe mitral ring expansion. Meanwhile, the chordae become thin, long, twisted, followed by fibrosis and thickening. Abnormal chordae to leaflet at the worst affected as significant, since abnormal chordae, mitral valve stress uneven, causing the leaflets stretch and stripping the organization mucus degeneration;


increased tension tendons rupture tendons can occur. Cardiac papillary muscle and its vicinity may be due to over-stretch, the friction caused by ischemia and fibrosis. Calcified valve annulus enlargement and further increase the degree of prolapse. Part of the mitral valve prolapse may be secondary to rheumatoid inflammation or viral infection, the previous leaflet prolapse more common. In addition, also found in coronary heart disease, cardiomyopathy, congenital heart disease, mitral valve prolapse in patients with hyperthyroidism fairly frequently. Under normal circumstances the pathogenesis of ventricular contraction, papillary muscles immediately contract, pulling the tendons, the mitral valve leaflets with each other and near. When left ventricular systolic ventricular pressure continues to rise, the left atrial prolapse valve leaflets, papillary muscle contraction synergy is tight tendon to prevent the valve leaflets Solar eversion into the left atrium, close to the valve leaflets, mitral valve closed. At this point the valve leaflets do not exceed the level of valve annulus. When the mitral valve leaflets or chordae, or papillary muscles or annular lesions occur, the relaxation of the valve leaflets in the mitral valve is closed off to the left atrium and further, resulting in mitral regurgitation. Mitral valve prolapse, left ventricular systolic dysfunction is also seen that the segmental contraction, can chordae and the leaflets are slack off, causing and aggravating its too long, so that the late systolic mitral valve prolapse occurs. Mitral valve prolapse mitral regurgitation caused by left ventricular contraction, the left atrium and left ventricle diastolic load load increased. Clinical symptoms no obvious symptoms in most patients, symptoms are intermittent, recurrent and transient characteristics. Common symptoms are: 1. Chest pain incidence of 60% to 70%, in the heart of the former area can be presented dull pain, sharp pain or a knife-like pain, usually to a lesser extent, duration minutes to hours, and fatigue or mental factors unrelated to sublingual nitroglycerin can not be relieved by. 2. Palpitations in 50% of patients, for unknown reasons. May be related to arrhythmias such as frequent premature ventricular contractions, paroxysmal supraventricular tachycardia or ventricular tachycardia related, but Holter monitoring and the atrioventricular bundle electrogram inspection found that some patients with palpitations and arrhythmia is not related high. 3. A sense of dyspnea and fatigue, 40% of patients complained of shortness of breath, fatigue, and often the symptoms onset. Some cases without heart failure patients, exercise tolerance decreased. Severe mitral valve back hydraulic pressure may occur in the performance of left ventricular dysfunction. 4. Others may have dizziness, syncope, vascular migraine, transient cerebral ischemia, as well as anxiety, tension, irritability, fear and neuropsychiatric symptoms such as hyperventilation. Signs 1. Inside the heart auscultation apex or contraction could be heard and s advanced non-jet-like sound, the sound in 0.14 seconds or more after the first heart sound appeared to be suddenly taut chordae or prolapsed leaflets of a sudden suspended due. s can be heard immediately following the contraction of the late blowing sound like noise, often incremental type, small for all systolic murmurs, s, and cover up the sound. Sometimes you can hear a high profile at the apex contraction loud music late noise, similar to the kind of whooping cough, or yang. Systolic murmur occurs earlier, the longer it appears that the more severe mitral regurgitation. Where can reduce the resistance of the left ventricular ejection, reducing venous return, increased cardiac contractility leaving end diastolic volume or drugs to reduce the physiological measures, such as standing position, breath, tachycardia, inhalation of amyl nitrite, etc., can the early systolic s in sound and noise; the other hand, where the resistance can increase left ventricular ejection, increased venous return, decreased left ventricular myocardial contraction end diastolic volume increase leaving the physiological factors that are squatting or drugs, bradycardia, receptor blockers, vasopressors, etc., can make sound and systolic murmur Kara delay. 2. Other signs of heart beat was twofold mid systolic and s in audio form, while the heart suddenly out of the heart beat back a sudden halt. Patients are mostly unable to type of shape, may be associated with straight back, scoliosis, or lordosis, pectus excavatum and so on. Diagnosis of clinical diagnosis was based on typical contraction of the apex in the late late systolic s tone and hair-like noise, drugs and the impact of noise and movement on the diagnostic value ECG, echocardiography can confirm the diagnosis. (A) X-ray examination the majority of patients with heart shadow was normal. Severe mitral insufficiency significantly increased the left atrium and left ventricle. The most common thoracic skeletal abnormalities. Left ventricular angiography showed mitral valve prolapse and regurgitation, right anterior oblique projection after mitral valve systolic see sample broke into the left atrium was lip; left ventricular asymmetry, or the middle of a strong basal ventricular contraction, was inward depression of the "ballet foot," like change. (B) the majority of patients with ECG electrocardiogram can be normal. Some patients showed , , aVF lead biphasic or inverted T waves, and nonspecific ST segment changes, this change in the inhalation of amyl nitrite or after exercise is more evident. ST-T wave changes may or papillary muscle ischemia, or increased tension on left ventricular valve prolapse and hyperthyroidism on the sympathetic nervous. QT interval prolongation seen. Common variety of arrhythmias, including atrial premature beats, ventricular premature beats, supraventricular or ventricular tachycardia, sinus node dysfunction and various degrees of atrioventricular block. WPW syndrome can also be found. (C) echocardiography in the diagnosis of mitral valve prolapse is of special significance. Two-dimensional echocardiography on parasternal long axis before and after the leaves suddenly visible to the left systolic atrial mitral valve, and more than annulus level. In addition, the visible balloon mitral valve showed a change in valve leaflet thickening, long, ring expansion valve, left atrial and left ventricular dilatation, chordal thinning extended or broken. M-mode ultrasound visible contraction of the late mitral valve closure line (CD section) arched backwards after ultrasound 2mm and the whole systolic shift ultrasound 3mm. Meanwhile, the systolic period before and after the valve leaflets or valve leaflets showed a hammock-like changes. Differential diagnosis is generally believed that mitral valve prolapse is not a heart disease, but a mitral valve lesions. Mitral valve prolapse can be normal or pathological mitral valve prolapse. It is divided into physiological and pathological. Most patients with no typical symptoms of physiological and therefore respond to physiological and clinical pathological mitral valve prolapse were identified: 1, physiological mitral valve prolapse patients, conventional echocardiography before and after the leaves are part of the performance of prolapse, sublingual isosorbide dinitrate 10mg15min underwent echocardiography, left ventricular long axis, four chamber observation, showed a different degree of symptoms before and after the leaflet prolapse. Some cases, conventional echocardiography mitral valve prolapse is not clear. Ultrasound examination can clearly show the first leaflet prolapse or prolapse of the posterior lobe, associated with thoracic deformities. 2, pathologic mitral valve prolapse syndrome, rheumatic heart disease associated with mitral insufficiency, ultrasonography, in addition to mitral regurgitation, but also before and after the performance of mitral valve leaflet prolapse. Treatment of asymptomatic or mild symptoms who do not need treatment, work and life can be normal, regular follow-up. A history of syncope, family history of sudden death, complex ventricular arrhythmia, Marfan syndrome, should avoid excessive physical work and strenuous exercise. Chest pain that can be used -blockers reduce myocardial oxygen consumption and ventricular wall tension, heart rate, decreased myocardial contractility, improve the degree of mitral valve prolapse, and thus relieve chest pain. Nitrates can increase the mitral valve prolapse should be used with caution. Of those associated with mitral regurgitation, surgery, dental extraction, childbirth or after invasive procedures, should prophylactic antibiotics to prevent infective endocarditis. Of the arrhythmia with heart palpitations, dizziness, vertigo or a history of syncope, can be used -blockers, phenytoin can be invalid, quinidine, etc., if necessary, combination therapy. A transient ischemic attack, use of aspirin and other anti-platelet drugs, such as invalid, can be used anticoagulant drugs to prevent cerebral embolism. Severe mitral regurgitation combined with congestive heart failure, which require surgery. The tendons extend or fracture, valve ring to expand, but mitral valve thickening without calcification were good sports, should line valve repair; valve repair is not suitable for those with artificial heart valve replacement. Complications (a) severe congestive heart failure caused mitral regurgitation to congestive heart failure, the Department of valve ring to expand and gradually lengthen the tendons, caused more severe mitral regurgitation; may also occur in acute, multi- in the tendons of infective endocarditis complicated by rupture or when. (B) of infective endocarditis more common in men and more than 45 years of age, the occurrence rate of 1% to 10%. Where the only sound persons have isolated systolic s or noise extend the time limit and the noise of unexplained fever, infective endocarditis should be considered possible. Bacterial endocarditis mitral valve prolapse as the underlying cause easily combined endocarditis (11%). Common pathological thickening of valve leaflets, deformation, neoplasm formation, valve rupture, perforation, part of the chordae can be broken. Those with a heart murmur reasonable chance of endocarditis than those without heart disease were higher noise management 35 times. (C) of the arrhythmia and sudden death in patients prone to arrhythmias in mitral valve prolapse, the general had no effect on health. The most common arrhythmia, the occurrence rate of 50%. Paroxysmal supraventricular tachycardia than common. Mechanism is unknown, may be associated with mitral valve papillary traction tendon cable, or elevated sympathetic activity. Even sudden death can occur, the following cases greater risk of sudden death: mitral valve prolapse with severe left ventricular decompensation; complex ventricular arrhythmias; QT interval was significantly prolonged; ventricular late potential; atrial flutter or fibrillation with WPW syndrome; young women in black Mongolian history of syncope associated with breathing difficulties. (D) a transient ischemic cerebral thrombosis and embolism caused by more than the 45 years of age in patients with mitral valve prolapse rate of 40%. Studies show that patients with mitral valve prolapse is often accompanied by increased platelet activity. In addition, the mitral valve and the atrial surface and tendons in the left ventricular wall friction causes endocardial fibrosis, prone to cause thrombosis. Off can cause cerebral embolism and thrombosis, retinal artery embolism, and systemic circulation (coronary, renal artery, splenic artery, superior mesenteric artery and other) embolism. Paroxysmal atrial fibrillation is often a sign of cerebral embolism. (E) mitral regurgitation mitral valve prolapse complicated by mitral regurgitation, mitral valve prolapse syndrome when there is increased valve ring, chordal extension of rupture valve (endocarditis), the , there may have hemodynamic significance of mitral regurgitation. Severe mitral regurgitation should be considered for surgery. Mitral valve prolapse is due to prevention of common sense into the left atrium due to mitral valve prolapse, the main complications of infective endocarditis, the mitral regurgitation, chordal rupture, arrhythmia, embolism and systemic circulation sudden death, but early mortality is not common, the most meaningful echocardiography, to have arrhythmia, should be checked and dynamic ECG ECG examination, treatment can be used propranolol, metoprolol and other drugs.


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