: Most patients are asymptomatic and MVP is an incidental auscultatory finding. Beta-blockers may markedly attenuate or abolish the symptoms, a fact that is important to remember while evaluating a patient who is receiving these agents. Findings are more marked when patients are examined in the outpatient department rather than in the inpatient setting, reflecting the contributory role of adrenergic state. Chest pain occurs in 10% of patients diagnosed with MVP and may be caused by any of the following factors: Excessive stretching of the chordae tendineae, leading to traction on papillary muscles Coronary microembolism from platelet aggregates and fibrin deposits in the angle between the left atrium and the posterior mitral leaflet Inappropriate tachycardia and excessive postural changes and physical and emotional stresses Hyperadrenergic state, which increases myocardial oxygen demand Coronary artery spasm Palpitations Palpitations are present in 7.4% of patients. Occurrence may be related to cardiac arrhythmia, although this is not proved conclusively. Fatigability and dyspnea These often develop on exertion. The cause may be alterations in centrally modulated breathing cycle control. Neuropsychiatric Panic attacks may occur. Nervousness, presyncope, and syncope occur in 0.9% of patients. Thromboembolism, arrhythmia, or vasodepressor-vasovagal problems may be involved. Pulse Findings usually are normal. Pulse occasionally is irregular in the presence of premature contractions. Exaggerated tachycardia (high-volume in severe MR) following exertion is not unusual Skeletal abnormalities are observed in two thirds of patients. These do not fit into any of the recognized connective tissue disorders, although an occasional patient may have Marfan or other related syndromes. Common findings are as follows: Hypomastia Thin children Height-to-weight ratio greater than normal Arm span greater than height (dolichostenomelia) Arachnodactyly Scoliosis Narrow anteroposterior chest diameter (straight back) Pectus excavatum or pectus carinatum Cathedral palate Crowding of teeth Joint hypermobility Auscultation Apical midsystolic nonejection click and late systolic murmur are the hallmarks, but either may occur alone. Heart sounds usually are normal, but the first heart sound (S1) may be accentuated when prolapse occurs early in systole, due to the summation of S1 and mitral click. Multiple clicks occur when prolapse of different leaflets occurs at different times during the systole and may resemble pericardial friction rub. In patients with redundant floppy mitral valves and significant MR, the murmur may be holosystolic and the click absent. Where the posterior mitral valve leaflet is prolapsing, the murmur may radiate along the left sternal border to the aortic area, thus mimicking left ventricular outflow tract murmur. If the anterior leaflet prolapses, the murmur radiates to the axilla and the spine. Dynamic auscultation In the sitting or standing position in late systole, the click may appear earlier and the murmur may be more prominent. The systolic click moves towards S1 on standing, often merging with S1 if marked postural tachycardia occurs, and new clicks may appear. If an exaggerated heart rate response occurs, the murmur becomes longer and often louder to holosystolic. Occasionally the murmur is present only in the upright posture. When squatting from standing position, the click and murmur may move back to late systole. Continuous auscultation, while the patient is standing from squatting position, reveals the click and murmur moving back to early systole on a beat-to-beat basis as the heart rate accelerates. Occasionally, a systolic precordial honk or whooping sound may be heard with the murmur. Often these are heard only in the sitting or standing position and may be limited to a few beats immediately after standing. Dynamic auscultatory changes reflect alterations in the timing of the MVP, the timing and extent of the MR, the expected changes in left ventricular volume, myocardial contractility, and heart rate. In the upright posture, venous return decreases and so does the left ventricular volume. The reflex tachycardia that occurs in the upright position will further reduce left ventricular volume. Timing and degree of the prolapse are determined by the position of the mitral leaflets at end diastole, which in turn is dependent on the distance from the mitral valve annulus to the attachment of the chordae to papillary muscles. Low left ventricular end-diastolic volume shortens the mitral annular papillary muscle distance, allowing the leaflets to prolapse earlier in systole. Prompt squatting from standing position increases venous return and left ventricular volume; thus, the systolic click and murmur may become late systolic. Squatting, however, may also be associated with an increase in peripheral vascular resistance, which in turn increases the tension on the mitral valve apparatus, directing blood flow preferentially into the left atrium, rather than to the peripheral circulation. The late systolic click and murmur then become accentuated in the squatting position. Other maneuvers are possible as follows, but none is as practical and helpful as a systematically performed postural dynamic auscultation. Leg elevation Isometric hand grip exercise Valsalva maneuver Application of tourniquets to the extremities Lower body negative pressure or amyl nitrate inhalation Causes: Heritable disorders of connective tissue Marfan syndrome Ehlers-Danlos syndrome types I, II, IV Stickler syndrome Polycystic kidney disease, adult type Osteogenesis imperfecta Fragile X syndrome Martin-Bell syndrome Pseudoxanthoma elasticum Periarteritis nodosa Skeletal abnormalities Asthenic habitus Straight back syndrome Pectus excavatum Pectus carinatum Cardiac abnormalities Atrial septal defect (ostium secundum), including atrial septal aneurysm, tricuspid valve prolapse, aortic valve prolapse, and Ebstein anomaly of tricuspid valve Holt-Oram syndrome Accessory atrioventricular pathways Coronary artery anomalies Hypertrophic cardiomyopathy Other disease Graves disease Thyroiditis Sickle cell disease Muscular dystrophy Myotonic dystrophy Von Willebrand disease Several reports suggest magnesium deficiency underlies the disease in some patients. Most patients with MR (mitral regurg. have dizzy spells).