Overview
It refers to the prolapse of the anterior mitral valve leaflet into the left atrium during ventricular systole.
In mild cases, symptoms are not obvious, while in severe cases, symptoms such as chest tightness, dyspnea, chest pain, palpitations, etc. may be present.
Causes include genetic factors, connective tissue disease, viral myocarditis, coronary artery disease, cardiomyopathy, congenital heart disease, and hyperthyroidism.
Including regular follow-up, medication, surgery, etc.
Definition
Prolapse of the anterior mitral valve leaflet is defined as prolapse of the anterior mitral valve leaflet into the left atrium during ventricular systole (expansion toward the left atrial side), with or without mitral valve closure insufficiency.
Classification
Primary mitral valve prolapse
Mostly due to genetic factors, one-third of patients have no other organic heart disease.
Secondary anterior mitral valve prolapse
Mostly due to rheumatic or viral infections, coronary artery disease, congenital heart disease, cardiomyopathy, hyperthyroidism and other diseases [1].
Morbidity
Mitral valve prolapse is a common condition with a prevalence of about 2% to 3%, affecting more than 176 million people worldwide [2].
Mitral valve prolapse is twice as common in women as in men, but tends to be combined with severe mitral valve closure insufficiency in older men (>50 years).
Etiology
Pathogenic causes
Primary anterior mitral valve prolapse
The etiology is unknown and may be genetically related, with mucoid degeneration and redundancy of the valve, in all age groups, with a predominance of females between 14 and 30 years of age [3].
Secondary anterior mitral valve leaflet prolapse
This is usually due to restriction of closure of the contralateral leaflet, resulting in “relative” or “pseudoproptosis” of the normally closed anterior leaflet.
It is common in hereditary connective tissue diseases, viral infections, coronary artery disease, cardiomyopathy, congenital heart disease, and hyperthyroidism.
Pathogenesis
When the anterior leaflet of the mitral valve is diseased, the relaxed leaflet prolapses further into the left atrium after orifice closure, resulting in mitral valve closure insufficiency [4].
Prolapse of the anterior mitral leaflet is also seen in abnormal left ventricular systolic function, i.e., segmental contractions, which can place the tendon cords and valve leaflets in a state of relaxation, causing and aggravating period of prolongation, which causes prolapse of the anterior mitral leaflet late in the contraction.
Prolapse of the anterior mitral leaflet causes mitral regurgitation during left ventricular systole, which increases left atrial load and left ventricular diastolic load.
Symptoms
Main Symptoms
Patients with mild anterior mitral valve prolapse are often asymptomatic.
The following manifestations may occur as the disease progresses, including atypical chest pain, palpitations, dyspnea, fatigue, dizziness, syncope, vasovagal migraine, transient cerebral ischemia, and neuropsychiatric symptoms such as anxiety and tension, and panic attacks [5].
Other symptoms
Symptoms accompanied by cyanosis, fatigue, dyspnea, skeletal development and growth deformities, pteroid erythema on the face, and arthralgias can be seen in connective tissue diseases, such as Marfon’s syndrome and systemic lupus erythematosus.
Accompanied by chest tightness, chest pain, palpitations, dyspnea, fatigue, pallor and other symptoms can be seen in cardiovascular diseases such as coronary heart disease, myocarditis, cardiomyopathy, congenital heart disease and so on.
Symptoms such as agitation, irritability, hyperphagia, and fear of heat can be seen in endocrine system diseases, such as hyperthyroidism.
Complications
Heart failure
In combination with severe mitral valve insufficiency, congestive heart failure can occur in the late stage, acute severe mitral valve prolapse due to tendon cable rupture, acute left heart failure and pulmonary edema [6].
Infective endocarditis
Most commonly seen in patients with significant valvular structures and closure insufficiency, but the overall incidence is not high.
Arrhythmias
Mostly benign, with ventricular arrhythmias and paroxysmal supraventricular tachycardia being the most common.
Sudden Death
Sudden death from mitral valve prolapse alone is rare.
Consultation
Department of Medicine
Cardiovascular medicine
If you have suffered from coronary heart disease, myocarditis, or cardiomyopathy in the past, we recommend that you consult the Department of Cardiovascular Medicine if you experience symptoms such as chest tightness, chest pain, palpitations, dyspnea, fatigue, or pallor.
Rheumatology
If you have a history of rheumatologic and immunologic diseases such as systemic lupus erythematosus, ankylosing spondylitis, etc., and have sudden symptoms such as fatigue, palpitations, chest tightness, dyspnea, etc., it is recommended that you visit the Department of Rheumatology and Immunology.
Endocrinology
If the patient is accompanied by symptoms such as agitation, irritability, hyperphagia, fear of heat, etc., it is recommended to go to the Endocrinology Department in time.
Emergency Department
If the patient has sudden onset of fainting or shock, it may indicate the presence of severe mitral regurgitation and should be referred to the Emergency Department.
Preparation
Preparing for a visit: registering, preparing information, and common problems.
Tips
Avoid emotional distress.
It is best to have someone accompany you to the hospital.
In the event of fainting or syncope it is recommended to take the patient to the hospital immediately, or call 120 emergency.
Preparation List
Symptom list
Especially need to pay attention to the time of symptom onset, special performance, etc.
What is the discomfort? How long has the discomfort lasted?
Are there any symptoms such as chest pain, chest tightness, etc.?
Are there any symptoms such as palpitations, fatigue, etc.?
Is it accompanied by dyspnea? Is it associated with activity?
When did the symptoms start to appear?
What aggravates these symptoms and how can they be relieved?
List of medical history
Any previous history of chronic diseases such as hypertension, diabetes mellitus, hyperlipidemia, etc.?
Any previous coronary heart disease, viral myocarditis, cardiomyopathy, congenital heart disease?
Any history of hyperthyroidism?
Any previous connective tissue disease, such as Marfan syndrome, systemic lupus erythematosus, etc.?
Checklist
Test results of the last 6 months, which can be brought to the doctor’s office
Laboratory tests: macrobiotics, markers of myocardial injury, erythrocyte sedimentation rate, serum thyroid and related hormone measurements, B-type natriuretic peptide levels, etc.
Imaging tests: echocardiography, chest X-ray, coronary CT angiography, left ventriculography, etc.
Electrocardiogram
Medication list
Medications used in the last 3 months, if available in boxes or packages, bring them with you to the doctor’s office
Beta receptor antagonists: metoprolol, bisoprolol, etc.
Calcium channel blockers: verapamil, diltiazem, etc.
Antiplatelet drugs: Aspirin, Tegretol, etc.
Statins: Rosuvastatin, Atorvastatin, etc.
Glucocorticoid: prednisone, methylprednisolone, etc.
Immunosuppressants: cyclophosphamide, methotrexate, etc.
Diagnosis
Diagnosis is based on
Medical history
Past history of connective tissue diseases such as equine syndrome and systemic lupus erythematosus.
Past or recent history of cardiac disease such as viral myocarditis, coronary artery disease, cardiomyopathy, congenital heart disease.
Past history of hyperthyroidism.
Abnormal blood pressure, blood glucose, and blood lipids.
Chronic smoking or alcoholism.
Clinical manifestations
Symptoms
Most patients have no symptoms. As the disease progresses, mitral valve prolapse with moderate to severe regurgitation may have the following manifestations.
Atypical chest pain, which varies in nature and degree and is not easily relieved by nitroglycerin.
Palpitations, often associated with arrhythmias of various types (e.g., frequent ventricular pre-systole, paroxysmal supraventricular tachycardia, or ventricular tachycardia), may be present in half of the patients.
Dyspnea and malaise, mainly seen in severe mitral regurgitation can be complicated by left heart insufficiency.
Autonomic dysfunction, including anxiety, emotional stress and agitation, malaise, and hyperventilation.
Others, such as dizziness, syncope, and transient ischemic attack.
Physical signs
May be accompanied by straight back, scoliosis or proptosis, funnel chest, etc [7].
Auscultation reveals a mid- to late-systolic non-jetty click in the apical region or its medial aspect, which is caused by a sudden tightening of the tendon cords and an abrupt termination of leaflet prolapse; this is followed by a late-systolic blowing murmur, which is often of an incremental type, and in a few cases may be a full-systolic murmur, and mask the click.
Mitral valve prolapse with acute left heart failure may have a sharp rise in blood pressure, auscultation of both lungs can be heard wet rales, occasionally accompanied by rales; with shock, blood pressure drops suddenly or even undetectable, there may be cold extremities, weak pulse and other signs.
Laboratory Tests
Blood tests
Check the white blood cell count, neutrophil count, red blood cell count, platelet count, hemoglobin concentration and other conditions.
Other diseases can be excluded.
Blood biochemistry
Tests liver and kidney function, fasting blood sugar, blood ion levels, blood lipid levels, cardiac enzyme levels, homocysteine, etc.
It can clarify the cause of the disease, the severity of the disease, prepare for treatment, or exclude other diseases.
Myocardial injury markers
Including cardiac troponin I (cTnI) or T (cTnT), creatine kinase isoenzyme (CK-MB), myoglobin (Myo) and so on. They are used to determine whether myocardial injury is present and the severity of the injury.
Abnormalities occur in myocardial injury, which in combination with an electrocardiogram can indicate acute myocardial infarction, and are suggestive of the etiology of acute anterior mitral valve leaflet prolapse [8].
Erythrocyte sedimentation rate
It is the rate of erythrocyte sedimentation under certain conditions.
It can be suggestive of the active phase of certain connective tissue diseases, acute inflammation, etc.
B-type natriuretic peptide level (BNP, NT-ProBNP)
Can clarify whether patients with mitral valve prolapse have combined heart failure, and is also an important indicator in the risk assessment of clinical events.
A normal B-type natriuretic peptide level in an untreated patient can largely rule out a diagnosis of heart failure, while a high B-type natriuretic peptide level in a treated patient suggests a poor prognosis.
Note: Renal insufficiency, liver cirrhosis, infection, sepsis, advanced age, etc. can cause B-type natriuretic peptide to be elevated, so its specificity is not high.
Imaging
Echocardiography
Echocardiographic performance allows assessment of valve thickness (≥5 mm is considered valve thickening), mobility, annulus and tendon cords, origin and orientation of the regurgitant bundle (indirectly suggesting the site of prolapse), and quantification of the degree of regurgitation.
Transthoracic echocardiography often underestimates the degree of regurgitation. Transthoracic echocardiography allows precise evaluation of the degree of regurgitation, valve structure, extent and zonation of prolapse, possibility of repair, and helps in preoperative surgical planning.
Chest X-ray
Observe whether the patient has skeletal deformity, enlarged heart shadow, patchy shadow of lungs and pleural effusion.
It can understand the degree of progression of the disease, whether it is combined with left heart failure and pulmonary stasis, and distinguish it from other lung diseases.
Coronary CT imaging
It is used to clarify the degree of stenosis in the coronary arteries, whether there is occlusion or thrombosis.
It is suggestive of the cause of prolapse of the anterior mitral leaflet.
Left ventriculography
Can clarify whether the valve leaflets are prolapsed or not, and can be used to semi-quantify mitral regurgitation.
Helps in the diagnosis of anterior mitral valve leaflet prolapse, but is not a routine test.
Electrocardiogram
Monitors the electrical activity of the heart.
In some patients with anterior mitral valve prolapse, the ECG may show ST-T segment depression or T-wave inversion in the inferior wall leads, and in some cases, various arrhythmias.
It can also indicate the etiology of the disease, such as myocardial infarction, viral myocarditis, cardiomyopathy and so on.
Diagnostic criteria
Diagnosis can be confirmed on the basis of typical mid-late systolic clicks in the apical region and late systolic blowing murmurs, as well as electrocardiogram and echocardiogram.
Physical signs
Late systolic clicks
Auscultation reveals a late systolic non-jetty click in the apical region or medial to it.
A click that occurs 0.08 seconds after the first heart sound is called a mid-systolic click, and a click that occurs more than 0.08 seconds later is called a late systolic click.
Late systolic wind-like murmur
The late systolic wind murmur is characterized by a high pitch, coarse tone, and intensity of grade 3/6 or above, which is transmitted to the left axilla or left subscapular region, and is weakened during inspiration and strengthened during expiration, and is more pronounced in the left lateral position.
Electrocardiogram
Normal or non-specific ST-T segment changes, QT interval may be prolonged. May be accompanied by various types of arrhythmias and bypass.
Echocardiography
Echocardiography is important to confirm the diagnosis and to clarify the size of the cardiac chambers, the presence or absence of other structural lesions, and to assess cardiac function.
The diagnosis can be confirmed by the presence of a balloon-like mitral valve with thickened and elongated leaflets, an enlarged annulus, enlarged left atrium and left ventricle, thinning and lengthening of the tendon cords or rupture of the tendon cords, a “flail-like” leaflet swing, and mitral leaflet dehiscence of more than 2 mm into the left atrium.
The M-mode echocardiogram shows bowing of the mitral leaflet closure line and hammock-like changes in one segment of the leaflet or in both the anterior and posterior leaflets during systole.
Differential Diagnosis
Mitral stenosis
Similarities
The murmurs are all in the apical region, and the gradual onset of the disease may lead to cardiac insufficiency, resulting in similar symptoms, such as dyspnea, palpitations, and fatigue.
Differences
In mitral stenosis, the first heart sound is hyperacute, the typical murmur is a low-pitched, increasing rumbling murmur in the mid- to late-diastolic period in the apical region, and the mitral valve opening sound can be detected at the left edge of the sternum between the 3rd and 4th intercostal spaces or in the medial aspect of the apical region.
Dilated cardiomyopathy
Similarities
Both can lead to mitral valve closure insufficiency and mitral regurgitation.
Differences
Dilated cardiomyopathy shows enlargement of the cardiac chambers and thinning of the myocardium on echocardiography, resulting in relative mitral insufficiency, but there is no damage to the valvular tendon cords, papillary muscles, or other parts of the valves themselves.
Tricuspid valve prolapse
Similarities
Both are heart valve prolapses, so the auscultation sounds are similar.
Differences
The location of the lesion is different and can be differentiated by echocardiography.
Aortic valve insufficiency
Similarities
Valve regurgitation occurs in both cases, and similar symptoms such as dizziness, chest tightness, palpitations, and dyspnea may occur.
Differences
Aortic valve insufficiency may present with peripheral vascular signs, whereas anterior mitral valve prolapse does not.
Treatment
Aim of treatment: slow down the progress of the disease, improve the heart function, and prevent sudden death.
Treatment principle: Patients with mild anterior mitral valve prolapse are recommended to have regular follow-up, combined with relevant medications to delay ventricular remodeling and reconstruction, improve cardiac function, and have surgery as soon as possible if surgery is indicated.
Follow-up
Asymptomatic patients with normal cardiac function who have anterior mitral valve prolapse with severe regurgitation should be followed up once every six months.
Patients with mitral valve prolapse with stable moderate mitral regurgitation are recommended to have a repeat cardiac ultrasound in about one year.
If there is any change in the condition, consult your doctor and increase the frequency of follow-up.
Medication
Drug therapy is generally non-specific and mainly symptomatic. It is suitable for those who have relevant symptoms but do not meet the indication for surgery, preoperative transitional therapy, postoperative long-term maintenance therapy, and those who are unable to operate due to contraindications.
Beta-blockers
β-blockers control ventricular rate, reduce myocardial oxygen consumption, reduce cardiac load, etc. Commonly used drugs include bisoprolol and metoprolol.
Antiplatelet and anticoagulation therapy
For those with transient cerebral ischemia, antiplatelet agents such as aspirin can be applied to prevent thrombosis.
Those with risk factors for thromboembolism such as left atrial thrombosis, history of embolism, within three months of mitral valve repair, and severe heart failure need anticoagulation. Common medications include warfarin and rivaroxaban.
Improvement of cardiac function
When acute left heart failure is combined with mitral valve prolapse, diuretics, aminophylline and other drugs can be used to reduce the cardiac load and calm the heart. It should be noted that nitrates can aggravate prolapse and should be used with caution.
Digitalis drugs can be used in the treatment of heart failure combined with fast ventricular rate type atrial fibrillation, but acute myocardial infarction is prohibited within 24 hours.
When mitral valve prolapse is combined with chronic heart failure, therapeutic drugs mainly include diuretics, β-receptor antagonists, renin angiotensin aldosterone system inhibitors, sodium-glucose cotransporter protein 2 (SGLT-2) inhibitors and so on.
Representative drugs include furosemide, spironolactone, metoprolol, sacubitril valsartan, dagliflozin, etc [9].
Antiarrhythmic therapy
In the presence of arrhythmia, such as supraventricular tachycardia and ventricular tachycardia, antiarrhythmic drugs such as propafenone and amiodarone can be used in order to control the ventricular rate and to avoid the occurrence of lethal arrhythmia.
Anti-infection
Mitral valve prolapse combined with severe mitral valve insufficiency is easily associated with infective endocarditis, and antibiotics can be applied prophylactically if necessary.
Surgery
Indications for Surgery
Acute severe mitral valve insufficiency due to prolapse of the anterior mitral leaflet usually requires emergency surgery, and in cases where papillary muscle rupture is the causative agent, valve replacement is usually required.
Indications for surgery for chronic mitral valve closure insufficiency due to prolapse of the anterior mitral leaflet include.
Presence of symptoms.
Asymptomatic severe mitral valve closure insufficiency combined with evidence of left ventricular insufficiency: a left ventricular ejection fraction of 30% to 60% or a left ventricular end-systolic internal diameter ≥40 mm.
Asymptomatic severe mitral valve closure insufficiency without evidence of left ventricular insufficiency with atrial fibrillation or pulmonary hypertension (pulmonary artery pressure >50 mm Hg) favors surgical treatment.
Patients with severe left ventricular systolic dysfunction (ejection fraction <30%) are at high risk for surgery.
Surgical Procedures
Mitral valve repair (mitral annuloplasty)
The preferred procedure, which avoids the complications of thromboembolic bleeding from prosthetic valves as well as the risk of infection, better maintains valve physiology and left ventricular function, and has a lower perioperative mortality rate and better long-term prognosis [10].
Mitral valve replacement with or without preservation of subvalvular structures
Mitral valve replacement with preservation of subvalvular tissue should be performed whenever possible when no repair of the mitral valve is possible to facilitate postoperative cardiac function.
Percutaneous Coronary Sinus Prosthetic Ring Implantation
This is a minimally invasive, non-conventional procedure that is not yet widely available and is mainly performed in patients with high risk or contraindications to surgery.
Prognosis
Cure
Overall, most patients with anterior mitral valve prolapse have a favorable prognosis and remain symptom-free for many years.
The prognosis is generally poor if the patient fails to comply with regular medication and follow-up, resulting in complications such as heart failure, arrhythmia, or even sudden death.
Hazards
Patients with mild anterior mitral valve prolapse have no obvious symptoms and are not at risk.
In patients with severe mitral valve prolapse combined with severe mitral valve insufficiency, it may cause a series of complications such as acute congestive heart failure, arrhythmia, etc., and in severe cases, it may jeopardize the patient’s life and lead to sudden death.
Daily
Daily Management
Dietary management
Eat a light diet with plenty of fresh fruits and vegetables, soy products, grains, and foods rich in dietary fiber.
Avoid spicy and stimulating foods.
Avoid coffee, strong tea, energy drinks and other beverages.
Life management
Patients in the acute stage should avoid activities and take bed rest.
Live a regular life, ensure adequate sleep and avoid staying up late.
Maintain ideal body weight.
Adhere to regular medication as prescribed by the doctor.
Quit smoking and drinking.
Prevention
For those who suffer from coronary heart disease, cardiomyopathy, congenital heart disease, etc., it is recommended to actively carry out the treatment, take the relevant medication as prescribed by the doctor, follow up regularly, do a good job in daily management, and improve medication adherence.
Change your lifestyle, maintain a regular routine, avoid staying up late, get enough sleep, quit smoking and drinking, and avoid coffee and strong tea.
For obese people, it is recommended to carry out scientific weight reduction and regular diet under the guidance of professional physicians in a timely manner, so as to control the weight in the ideal range.
Maintain optimism and pleasant emotions, avoid overwork and emotional excitement, and pay attention to the combination of work and rest.
Regular medical checkups are recommended once a year to detect related diseases as early as possible.