Causes, symptoms and treatment of mitral valve prolapse

What it is

Mitral valve prolapse (hereinafter - MVP) is the most common valvular heart disease. The disease affects approximately 2.5% of the world's population. It is often found in children and adolescents. The overwhelming majority of patients are women and girls.

MVP is isolated separately from valvular heart disease for two reasons. First, the anomaly has a different nature of occurrence. Secondly, unlike heart defects, this pathology is benign, but it can also have unpleasant consequences. Often, a person does not know about its presence: MVP becomes an "accidental find" during a medical examination or examination for another disease.

To understand the essence of this disease, it is important to understand the valve process. The human heart has 4 cavities, or chambers. Normally, blood circulates in only one direction: from the atria to the ventricles, then to the large vessels (aorta and pulmonary artery). This is possible thanks to the synchronized operation of the valves, which open and close at the right time. Closed valves prevent regurgitation - the direction of blood flow in the opposite direction.

With MVP, its main function is violated. In the systole phase, when the left ventricle contracts, the valve cusps cannot withstand blood pressure and begin to protrude into the left atrial cavity. The main problem is that some of the blood returns to the left atrium. This is called regurgitation. All the resulting adverse consequences of MVP are associated with this process. Severe regurgitation can lead to disability.

Causes of the defect

By origin, mitral valve prolapse is of two types:

• primary;
• secondary.

Primary MVP is caused by genetic defects. And although the gene mutations responsible for the development of the pathology have not yet been precisely determined, there is evidence of the hereditary nature of the disease in the form of frequent cases of prolapse in close relatives.

Therefore, if any of your parents or siblings have been diagnosed with MVP, it is highly likely that you also have it.

Primary prolapse is subdivided into types:

• actually MVP as an independent disease;
• MVP as a manifestation of impaired connective tissue development.

The latter refers to hereditary diseases caused by a defect in the formation of collagen protein. Such diseases include the Marfan and Ehlers-Danlos syndromes, as well as frequently occurring undifferentiated connective tissue dysplasias. In addition to MVP, these pathologies are characterized by different clinical manifestations:

• increased vulnerability and hyper-extensibility of the skin;
• frequent subluxations and dislocations;
• hypermobility of joints - a person is able to bend the elbows and knees in the opposite direction, touch the forearm with his thumb, close his palms, putting his hands behind his back;
• chest deformities - keeled, funnel-shaped;
• curvature of the spine - scoliosis, kyphosis;
• flat feet;
• early myopia;
• aneurysms of the interatrial septum and aorta;
• early development of varicose veins of the lower extremities, hemorrhoids;
• diaphragmatic and vertebral hernia;
• frequent nosebleeds;
• prolapse of internal organs - stomach (gastroptosis), intestines (colonoptosis), kidneys (nephroptosis).

Secondary prolapse, as the name implies, develops against the background of other diseases. MVP occurs due to the expansion of the heart cavities, stretching of the fibrous ring of the valve, due to wrinkling, inflammation of the valve leaflets or the deposition of calcium salts in them.

Reasons for secondary prolapse:

• cardiac ischemia;
• cardiomyopathy;
• myocarditis;
• congenital and acquired heart defects;
• chronic rheumatic heart disease.

Separately, I would like to highlight the "harmless or physiological" MVP, which develops due to the immaturity of the valve itself (annulus fibrosus, leaflets) and the subvalvular apparatus (tendon filaments or chords and papillary muscles). During ventricular systole, the papillary muscles contract and tighten the chords that keep the valve leaflets from sagging.

It often happens that in the growing body of a child, some structures of the heart develop earlier, and others later.

The consequences of this:

• the formation of too long valves or chords;
• large diameter of the annulus fibrosus;
• insufficient contraction of the papillary muscles.

This can lead to prolapse of the mitral valve leaflets. However, physiological prolapse is not without reason called "harmless". By the age of 18–20, all structures of the heart fully mature, and the valve functions as in a healthy person.

Frequent symptoms

Most people with "harmless" mitral valve prolapse, especially children and adolescents, have an asymptomatic course of the disease, they are not worried about anything. Sometimes patients only complain of mild chest discomfort. I want to note that the clinical picture may in no way correspond to the degree of pathology.

Symptoms of mitral valve prolapse:

• pain in the left side of the chest or behind the sternum: stitching, pressing, squeezing, moderate intensity. The duration varies from a few seconds to a day. Pain can occur both during a strong experience or exercise, and spontaneously, for no apparent reason. Often, an unpleasant sensation is accompanied by a feeling of lack of air, the appearance of cold clammy sweat, anxiety and even the fear of death;
• dizziness due to low blood pressure;
• palpitations, sensations of "interruptions, rolling, fading" in the chest;
• frequent light-headedness, in which a person experiences a feeling of lightheadedness and nausea, accompanied by the flickering of flies in front of the eyes and blurred vision;
• with severe and prolonged mitral regurgitation, signs of congestive heart failure join - difficulty breathing, rapid onset of fatigue, swelling in the legs, especially in the evening, heaviness in the right side due to an enlarged liver.

Also, in people with mitral valve prolapse, more often against the background of hereditary connective tissue disorders, I observe symptoms of autonomic dysfunction:

• constant pressure drops;
• fainting;
• excessive sweating;
• neurotic disorders - such patients are usually anxious and suspicious, suffer from various phobias, hypochondriacal and obsessive-compulsive neuroses, they often invent non-existent diseases for themselves;
• Chilliness and cold fingers and toes;
• hypersensitivity to cold;
• vegetative crises, more commonly known as panic attacks.

Types and degrees of mitral valve prolapse

Echocardiography (ultrasound of the heart) is the main research method for diagnosing MVP. With its help, the severity of prolapse is assessed: the degree of leaflet prolapse and regurgitation. Prolapse refers to how much the valve leaflets flex into the left atrial cavity.

Table. Mitral valve prolapse classification

Distinguish pathologies:

• with regurgitation;
• without regurgitation.

Violation is also assessed on ultrasound of the heart, but in Doppler mode.

There are 4 degrees:

• 1 degree - the reverse blood flow penetrates into the cavity of the left atrium at a distance of up to 20 mm;
• Grade 2 - penetration to the middle of the atrium;
• 3 degree - more than half of the atrium passes through the blood flow;
• Grade 4 - regurgitation to the opposite atrial wall.

Approximately 30% of people with MVP, which developed against the background of hereditary connective tissue diseases, additionally have tricuspid valve prolapse, and 4–5% have aortic valve prolapse.

Diagnosis criteria

To make an accurate diagnosis, I use specially developed criteria:

1. The main ones.
2. Additional.
3. Non-specific.

The first are:

• late systolic click / click, late systolic murmur at the apex of the heart on auscultation. Sometimes, in order to better listen to the noise, I resort to some tricks: I ask the patient to do 10 squats or lie on his left side;
• displacement of the valves at the time of ventricular systole, prolapse (deflection) of the valves is more than 3 mm.

Additional criteria:

• neurotic disorders;
• the presence of MVP in close relatives (father, mother, grandmothers, grandfathers, siblings);
• the appearance of the patient - tall, thin physique, long arms and legs, malocclusion, deformities of the chest or spine.

Non-specific criteria include:

• patient complaints - pain in the heart, difficulty breathing, heart palpitations, panic attacks;
• changes on the ECG film - negative T wave in leads II, III, aVF, frequent extrasystoles and slowing of intraventricular conduction.

The presence of 2 main criteria or one main and 2 additional ones make it possible to reliably diagnose mitral valve prolapse. In addition, these criteria help to carry out differential diagnostics, i.e. to distinguish MVP from acquired heart defects.

Is treatment required

Factors to help determine if mitral valve prolapse needs treatment:

• symptoms;
• the degree of prolapse and regurgitation;
• the presence or absence of complications.

If a person has a hemodynamically insignificant MVP of grade 1, and he does not experience any unpleasant sensations, then treatment is not required. For such people, I only recommend giving up smoking, drinking too much coffee, and also undergo regular examinations by a cardiologist and echocardiography (1 time in 3 years).

Mitral valve prolapse of grade 1 with regurgitation of grade 1 and mitral valve prolapse of grade 2, and even more signs of rhythm disturbance and circulatory failure - this is an indication for the appointment of specific drug therapy: drugs from the group of beta-blockers (Metoprolol, Bisoprolol).

These pharmacological drugs are excellent for treating pain, normalizing heart rate and blood pressure levels. They slow down the progression of the degree of regurgitation, prevent dangerous tachyarrhythmias. Also, with the help of beta-blockers, you can compensate for the phenomena of heart failure. If they fail, then I use calcium channel blockers (Diltiazem, Verapamil).

However, it is important to remember that there are contraindications to the use of these drugs:

• severe bradycardia, i.e. slow heart rate (less than 55 beats per minute);
• atrioventricular block of 2 and 3 degrees;
• low blood pressure (below 100 mm Hg).

In the fight against hypotension, "biogenic stimulants" help:

• eleutherococcus;
• ginseng;
• lemongrass.

To treat anxiety, I first prescribe herbal sedatives - valerian, motherwort, hawthorn. With severe neurotic disorders and for the prevention of panic attacks, stronger drugs are needed (Diazepam, Phenazepam). To get a prescription for them, I refer patients to a neurologist, psychiatrist, or psychotherapist for consultation.

If chronic heart failure develops, I prescribe ACE inhibitors (Perindopril) and potassium-sparing diuretics (Spironolactone). In case of severe heart rhythm disturbances that cause a deterioration in well-being, I use antiarrhythmic drugs (Amiodarone, Propafenone). I use anticoagulants (Warfarin) to prevent blood clots from atrial fibrillation.

In the later stages of prolapse with grade 4 mitral regurgitation or severe circulatory failure, surgery is required - plastic or valve replacement.

Separately, it is worth considering the issue of pregnancy with MVP. Medical treatment is not fundamentally different. If severe regurgitation occurs (3-4 degrees) and serious complications develop, further actions depend on the period:

• up to 22 weeks - medical termination of pregnancy or vacuum aspiration;
• after 22 weeks - caesarean section and placement of the child in a special incubator to save life.

In the future, surgical treatment of prolapse is carried out. Such drastic measures are due to the high danger to the mother and fetus: a fatal outcome is likely.

Does the prognosis change in people with MVP?

Mitral valve prolapse is a benign pathology.

But the forecast directly depends on the following factors:

• the degree of prolapse;
• regurgitation is present or absent;
• are there any complications.

With minor prolapse (grade 1 without regurgitation or with grade 1 regurgitation), the prognosis is favorable. This pathology does not affect life expectancy.

In case of prolapse with degree 2 regurgitation, the patient, in addition to taking medications, is important to observe a restrictive regimen. For example, boxing, weightlifting, and professional running are contraindicated in patients. Young people have limitations of fitness for military service. At the military medical commission, depending on the presence of complications, they are assigned categories "B", "C", and "D".

Possible and negative consequences

Despite the seeming harmlessness, mitral valve prolapse is dangerous complications that can become a real threat to the patient's life.

The adverse effects of MVP include:

• chronic heart failure - due to regurgitation, part of the blood does not enter the aorta, so the left ventricle is forced to compensatory hypertrophy (thicken). Over time, this will lead to its dysfunction and deterioration of blood circulation throughout the body;
• heart rhythm disturbances (atrial fibrillation, prolongation of the QT interval, paroxysmal supraventricular and ventricular tachycardias). Regurgitation leads to stretching and expansion of the left atrial cavity, in the wall of which foci of pathological electrical activity can occur;
• ischemic stroke - a vortex blood flow is created in the enlarged cavity of the left atrium, which contributes to its thickening and the formation of blood clots;
• acute mitral regurgitation - with a pronounced degree of prolapse and regurgitation, the tendon sutures that are attached to the valves are strongly stretched. As a result, their rupture and a sharp overload of the parts of the heart located on the left are possible;
• infective endocarditis - during some medical procedures (tooth extraction, catheter placement, bronchoscopy), a small amount of bacteria enters the general bloodstream. With prolapse, they can settle on the valve flaps and begin to multiply. To prevent this, people with MVP are advised to take antibiotics before the procedure.

These complications can quickly lead to the death of the patient.