Mitral valve prolapse syndrome is also known as Barlow’s syndrome, mid-systolic karate – late systolic murmur syndrome, balloon-like mitral valve syndrome, and valve relaxation syndrome. It is a series of clinical manifestations caused by the protrusion of the mitral valve into the left atrium during left ventricular contraction, resulting in the return of blood from the left ventricle into the left atrium. The onset of the disease is often insidious, and most cases progress slowly and may remain untreated for life. In a few cases, surgery is required.
The cause is unknown. It is idiopathic and has a high familial incidence. Patients with Marfan syndrome, Ehlers-Danlos syndrome, Ebstein’s anomaly, adult polycystic kidney disease, and scoliosis are prone to develop this disease. Patients also have concomitant rheumatic heart disease or congenital heart disease.
The pathology of mitral valve prolapse is characterized by hyperplasia of the mitral valve cavernous layer with mucopolysaccharide accumulation and invasion of the fibrous layer, resulting in collagen fiber rupture, as well as invasion of the tendon cords attached to the valve leaflets by the hyperplastic cavernous layer, resulting in decreased strength of the invaded leaflets and tendon cords, increased leaflet area, and lengthened tendon cords. The valve leaflets were significantly thickened and showed mucus-like degeneration. During left ventricular systole, the mitral leaflets, together with the tendon cords, expand toward the left atrium in a hemispheric bulge. This is followed by valve leaflet fibrosis, distortion of the extended tendon cords, and subsequent fibrosis and thickening. Tendon rupture can occur with increased tension in the tendon cords.
Due to the abnormal tendon cords, the thickened and fibrotic mitral leaflets are unevenly stressed, leading to leaflet coiling, contracture, and calcification, exacerbating mitral regurgitation; the papillary muscles and the myocardial tissue at their roots can be overstretched and rubbed, causing ischemia and fibrosis.
Patients can have a variety of symptoms that vary widely. They generally present with weight loss or emotional abnormalities. They may also present with tachycardia or various arrhythmias; dizziness; vertigo; weakness; palpitations after activity; chest tightness after lying down, and in some patients, chest pain.
Clinical symptoms in patients with mitral regurgitation depend on the degree of mitral regurgitation. Patients with mild mitral regurgitation may be asymptomatic. Patients with severe mitral regurgitation may present with symptoms of congestive heart failure such as lower extremity edema and nocturnal paroxysmal dyspnea.
Most patients are unaffected. Some patients have impaired mobility, decreased quality of life, and in severe cases, life-threatening heart failure.
The clinical diagnosis of mitral valve prolapse is mainly based on the typical mid-systole in the apical region, late karate and late systolic blowing murmur, the effect of drugs and action on murmur and electrocardiogram have auxiliary diagnostic value, and echocardiography can make a clear diagnosis.
1.Electrocardiogram The electrocardiogram can be normal in most patients. Some patients have biphasic or inverted T waves in leads II, III and aVF, as well as ST-T abnormalities. There may be various heart rate changes or arrhythmia manifestations. Various arrhythmias, such as atrial premature beats, ventricular premature beats, supraventricular tachycardia, atrial fibrillation and various degrees of atrioventricular block, are common.
2, chest X-ray Chest X-ray examination of most patients without significant abnormalities in the heart shadow. In mitral valve insufficiency, there may be signs of enlarged left atrium or left ventricle, accompanied by increased pulmonary blood. Some patients may have skeletal abnormalities in the chest, such as scoliosis.
3. Echocardiography is the most effective test for diagnosing mitral valve prolapse. Two-dimensional echocardiography can investigate the relationship between the mitral valve and mitral annulus, as well as the thickness of the mitral leaflets, which is extremely valuable in the diagnosis of mitral valve prolapse. A typical echocardiographic presentation shows a systolic mitral leaflet protruding toward the left atrium and exceeding the highest plane of the annulus. The mitral leaflet is significantly thickened, redundant, and the tendon cords are prolonged or ruptured with enlargement of the left atrium or left ventricle.
Treatment principles
1, the majority of patients with simple mitral valve prolapse, asymptomatic or mild symptoms, do not need treatment, can work and live normally, can be reviewed every 2-3 years heart ultrasound.
2, with mitral regurgitation, can lead to arrhythmias, heart enlargement or heart failure, must be reviewed every year echocardiography. Prophylactic antibiotics should be taken before and after minor surgery, dental procedures, childbirth, or invasive examinations (e.g., colonoscopy, cystoscopy, etc.) to prevent infective endocarditis.
3. Those with a history of syncope, family history of sudden death, complex ventricular arrhythmias, and Marfan syndrome should avoid excessive physical work and strenuous exercise. Any symptoms that appear should be taken seriously and handled with care.
Drug treatment
For chest pain, β-blockers can be used to reduce myocardial oxygen consumption and ventricular wall tension, slow down the heart rate, increase left ventricular volume, and reduce the degree of mitral valve prolapse, thus relieving chest pain. For those who cannot tolerate beta-blockers, calcium channel blockers, such as isoptin or diltiazem, can be applied. Nitrates can aggravate mitral valve prolapse and should be used with caution.
In case of transient cerebral ischemia, anti-platelet aggregation drugs such as aspirin should be used, and if they are ineffective, anticoagulant drugs can be used to prevent cerebral embolism.
Surgical treatment
Severe mitral valve insufficiency combined with congestive heart failure requires surgical treatment. For those with extended or ruptured tendon cords, enlarged annulus, thickened mitral valve but good motion without calcification, valve repair is appropriate; for those who are not suitable for valve repair, prosthetic valve replacement is performed.
In recent years, because of the remarkable effect of mitral valve repair, for those with significant mitral valve prolapse without mitral regurgitation, valve repair is also recommended to avoid arrhythmias and heart failure.
The prognosis of patients with mitral valve prolapse depends on the severity and progression of mitral valve prolapse, the severity of mitral regurgitation, and the presence or absence of various complications.
The vast majority of patients have slow progression of the disease and do not require treatment and have a near normal quality of life.
In patients with severe mitral regurgitation, it can lead to progressive congestive heart failure, which is caused by the gradual aggravation of mitral regurgitation; it can also occur acutely, mostly when the tendon cord is ruptured or when it is complicated by infective endocarditis. Surgical treatment should be considered.
In the presence of arrhythmias, there is generally no impact on health. The prognosis depends on the malignancy of the arrhythmia and the response to treatment.
In cases of infective endocarditis, the prognosis depends on the effectiveness of anti-infective therapy and the presence of recurrence.
In cases of transient cerebral ischemia and embolism of the body circulation, the prognosis depends on the effectiveness of anticoagulation therapy.
Precautions
1. Avoid heavy physical labor and strenuous exercise.
2.Restrict water and sodium intake.
3.Maintain cardiac function.
4.Increase nutrition to improve body resistance and reduce the occurrence of various complications.
Disease prevention
Because the cause of mitral valve prolapse syndrome is unknown, there are no targeted preventive measures. However, various measures can be taken to prevent various complications. The main complications include infective endocarditis, progressive mitral valve insufficiency, tendon rupture, arrhythmias, embolism of the body circulation, and sudden death. Mitral valve prolapse echocardiography is the most valuable, and after diagnosis, β-blocker therapy is started as early as possible with drugs such as ponerol and betalactone.
For those with mitral regurgitation, avoid heavy physical work, maintain cardiac function, prevent and treat heart failure, and operate as soon as possible if surgery is indicated. For those with arrhythmias, ECG examination and dynamic ECG examination should be done and early drug treatment should be given. Improve body resistance, pay attention to personal hygiene, and avoid infective endocarditis. Those with manifestations of cerebral ischemia and embolism of body circulation should be alerted and anticoagulation therapy should be started as early as possible to prevent cerebral embolism.
Nowadays, some patients with mitral valve prolapse often show two misconceptions. Some of them know they have heart murmur, but they do not follow up regularly and come to the clinic when they have severe heart failure, and the treatment effect is often unsatisfactory. Other patients are extremely sensitive, which affects their life and work. Patients therefore need to know.
1, mitral valve prolapse is the most common heart valve disease.
2, Most patients with mitral valve prolapse can be asymptomatic and do not require treatment.
3, mitral valve prolapse can have palpitations or weakness.
4, echocardiography can confirm the diagnosis of mitral valve prolapse
5, mitral valve prolapse should be regularly rechecked ultrasound
6, mitral valve prolapse patients need to take antibiotics to prevent infective endocarditis before undergoing various minor surgeries.