Mitral insufficiency – Mitral regurgitation


Mitral insufficiency is a lack of hermetic closure of mitral valve during ventricular systole, allowing regurgitation of the blood from the left ventricle to the left atrium. This reflux of blood from the atrium to the left ventricle to the atrium during systole depends on the mitral orifice area that remains open because the gradient pressure between these two cavities is high.

Mitral_InsufficiencyThe mitral apparatus consists of:

  • actual valves;

  • mitral rings;

  • chordae tendineae;

  • papillary muscles;

  • Ventricular myocardium which is inserted.

Changing any constituent structures cause mitral regurgitation.

Causes of mitral insufficiency

Mitral insufficiency can be the result of many pathological entities.

Causes of mitral valve damages are:

  • Myxomatous degeneration of the mitral valve – the lesion is commonly found;

  • acute rheumatic fever;

  • systemic lupus erythematosus;

  • mitral valve prolapseMitral valve prolapse;

  • Congenital anomalies;

  • Degenerative changes – Atherosclerosis;

  • Trauma;

  • Hypertrophic cardiomyopathy.

Valvular ring may be affected by:

  • Enlarging by dilating the ventricular cavity (functional mitral insufficiency);

  • Calcification.

Rupture or elongation of the chordae (more commonly the posterior):

  • mitral valve endocarditisinfectious endocarditis;

  • Myocardial infarction;

  • Necrosis chordae tendineae.

Papillary muscles (more commonly the posterior) can be affected by:

  • Rupture at this level in case of a heart attack;

  • Ischemic dysfunction;

  • Papillary muscle necrosis.

A particular form of mitral regurgitation is mitral valve prolapse.

Pathophysiological mechanism

During systole (contraction) one part of the left ventricle ejects blood into the aorta normally, but another part will regurgitate into the left atrium due to the defect closure of the mitral valve. Due to the large pressure gradient between the ventricle and the atrium, regurgitated blood column will produce at the level of the left atrium dilation (“jet lesion”).

In acute mitral regurgitation left atrium has no time to adapt (dilate) the pressure in the left ventricle, sending it to the venous-capillary pulmonary network, with the appearance of dyspnea, up to acute pulmonary edema.

Left atrium in chronic mitral insufficiency gradually expands, increasing the pressure inside it reducing the blood volume regurgitated. In diastole (relaxation time) left ventricle will receive a larger amount of blood resulting from the current and regurgitated volume in the previously systole, which will lead to hypertrophy (increase in volume) and its dilation.

If blood flow resistance is small, a large part of this volume will be ejected, regurgitation being smaller. The increase resistance in the arterial system leads to increased regurgitated blood volume and overloading the pulmonary circulation. In advanced stages, through decreasing the left ventricular contraction function, prolonged pulmonary venous-capillary stasis, will have repercussions and over the right ventricle, leading to global heart failure.

Signs and symptoms of mitral insufficiency

In forms with mitral regurgitation small to medium subjective symptoms may be absent, in severe forms appears the decompensation of the left ventricle.

In acute mitral insufficiency clinical manifestations are acute pulmonary edema or cardiogenic shock. The onset is sudden, with the following symptoms:

  • Dyspnea (difficulty breathing) paroxysmal;

  • orthopnea (the patient can breathe only in the sitting position, intolerant to decubitus);

  • Cough and frequently frothy expectoration, with bloody streaks.

The patient is cyanotic (bluish color of the facies), orthopneic, with crepitation rales in both lung fields, especially at their base.

The heart rate is fast, weak pulse; blood pressure is low and the jugular become turgescent.

In acute mitral insufficiency, patients are more common in sinus rhythm than in atrial fibrillation, the left atrium dilatation is minimal or absent, missing mitral valve calcification and mitral stenosis associated, in many cases, the left ventricle dilatation is minimal.

From the clinical point of view, mitral insufficiency is characterized by: holosystolic murmur (the duration of systole, contraction), which is maximum at the apex, with radiation in the armpit and occasional to the basis, a hyperdynamic shock of the left ventricle, a rapid upward slope of the carotid pulse and three strong noises.

In chronic mitral insufficiency precede physical signs with many years’ from the appearance of the symptoms.

The first symptom is breathlessness on exertion, progressive disease, frequently accompanied by cough. As chronic pulmonary stasis is installed appears also the mucous expectoration.

Pulmonary edema can be precipitated in the following situations:

  • Infective endocarditis;

  • Atrial fibrillationAtrial fibrillation with a rapid rhythm;

  • Fever;

  • Anemia;

  • Hyperthyroidism.

Systemic emboli are much rarer than in mitral stenosis, their frequency has increased after the appearance of infective endocarditis.

Specialized counseling

See your health care professional when the following symptoms occur:

  • Paroxysmal dyspnea with orthopnea;

  • Cough with expectoration.

Your doctor will decide if your symptoms are due to mitral valve or other types of heart problems.

Acute Mitral insufficiency occurs suddenly with:

  • Paroxysmal dyspnea with orthopnea;

  • Tachycardia;

  • Low pulse;

  • Sweating;

  • turgescent jugular;

  • Hypotension.

This is considered a medical emergency and call for an ambulance service.

Recommended medical specialists:

  • family physician,

  • general practitioners,

  • internist physician,

  • Emergency doctor.

After diagnosis, consult a cardiologist who is specialized in heart disease. It will monitor the disease both clinically and biologically, and will decide depending on the severity of valvulopathy if surgery is necessary in order to replace the valve.

Investigations

Usually, each person should do their regular analyzes, depending on the age, health status and risk factors, especially family history factors. Most of valvular insufficiencies are found by the doctor when listening to the heart with a stethoscope. If your doctor discovers mitral insufficiency during a routine examination, in the safest case, the patient’s condition is not severe and will not require emergency treatment.

By the early treatment of the disease, can be years delayed the need of surgical valve replacement. Given the fact that any artificial valve will break and will be re replaced through early treatment will decrease the number of surgeries in this regard. By the examination performed by a doctor, it will determine whether it is or not about mitral insufficiency and whether it is acute or chronic. The doctor will determine the severity of the failure and the existence or not of complications (arrhythmias or cardiac collapse).

Past medical history and physical examination are important parts of any routine examination. Through physical examination is determined mitral insufficiency. Further, more extensive tests, determine the degree of insufficiency. Investigations are necessary and if there are symptoms that can be mistaken for symptoms of other heart diseases as coronary artery disease, heart failure or other cardiac disease. During the physical exam, the doctor will hear a superimposed of cardiac noise (murmur).

If there is a heart murmur will be suspecting a heart failure and will be necessary to carry out more investigations:

  • mitral regurgitation ultrasoundTransthoracic echocardiography. This is used for viewing the valves and regurgitation. Also, it is checked by ultrasound and the capacity of the left ventricle, the left atrium and the diameters of these cavities (usually meets wall thickening due to regurgitation), the pressure in the pulmonary artery and right ventricular function. These measurements are extremely important and useful for establishing the treatment as for the associated injuries recognition. Through ultrasound, the doctor will determine the treatment and the need of surgical replacement of the valve. Transthoracic ultrasound can detect the causative disease process (acute rheumatic fever, prolapse, loose valve) and the Doppler method can estimate the qualitative and semi-quantitative severity of mitral regurgitation. Through this method clinically insignificant regurgitation is detected at many normal individuals, this change must be interpreted in the overall clinical context of the patient.

  • Transesophageal echocardiography can detect due to mitral regurgitation and can detect patients’ candidates for prosthetic valve.

  • Electrocardiogram (ECG) reveals abnormal electrical activity, suggesting that the heart is enlarged or has a high load through regurgitation.

  • Chest radiography shows an enlarged left ventricle. In some cases it may be dilated and the pulmonary artery.

  • Test effort. It may be necessary to see how the heart responses to exercise.

  • Angiography. A flexible tube called a catheter is inserted through the femoral artery and went into the left ventricle. Then is injected a contrast substance and will see the flow through the valve and the pulmonary arterial pressure. Coronary angiography, which visualizes the coronary arteries, will be performed at the same time. Coronary angiography is often indicated before valve surgery to establish the existence of coronary artery disease.

Treatment

The treatment of mitral regurgitation depends on the symptoms and on the heart muscle integrity. Other factors, that play an important role in the decision of the treatment is age (older people have a higher risk of complications); the risks associated with surgery and experienced doctor who performed the procedures.

If there are symptoms, surgery may be required. If symptoms are acute (acute mitral insufficiency) requires immediate surgery.

Acute mitral insufficiency seconds following conditions require emergency surgery:

  • Endocarditis;

  • Myocardial infarction;

  • Ruptured chordae tendineae.

Some patients may be stabilized with vasodilator treatment or through intra-aortic balloon counterpulsation which reduces regurgitant flow by decreasing systemic vascular resistance.

Your doctor will determine the cause and severity of mitral regurgitation initially and is functional status of the heart. Therefore, in addition to preliminary tests – blood tests and electrocardiography will be performed and exercise test (also known as the exercise ECG) to see if symptoms occur during exercise.

After these investigations is resorting to transthoracic echocardiography to determine ejection fraction (as a result it is appreciated the function of contraction of the heart) which is a measurement of the ventricular filling and emptying.

With this determination, the doctor will determine if and when is needed surgery.
If impairment is mild and no symptoms are present, treatment will consist only of medicines. It will be given antibiotics before certain procedures, such as dental work and surgical procedures to prevent an infection. In the case of acute rheumatic fever antecedents, it may be necessary to take antibiotics every day for the next 5-10 years, depending on the heart condition.

If failure is moderate to severe, may be prescribed:

  • Calcium channel blockers;

  • Angiotensin – converting enzyme inhibitors ;

  • Angiotensin II – receptor blockers;

  • Vasodilators.

These medicines are usually prescribed for high blood pressure; have been shown to slow the progression of mitral regurgitation and removes the need of the mitral valve replacement.

Because the heart is overloaded, it will be necessary lifestyle changes. It will be necessary to quit smoking, with the possibility that your doctor prescribe medications helpful in this regard. Some studies show that a combination of smoking cessation therapy, medication and supportive therapy increases the success rates of smoking cessation.

We recommend a cardio-protective diet. If there are no symptoms, the doctor will recommend regular exercise and mild (for example: walking), but you should start a fitness program without medical advice.

A proper dental hygiene and regular dental checkups are important, as long as poor dental hygiene can lead to the spread of bacteria.

A proper dental hygiene and regular dental checkups are important, as long as poor dental hygiene can lead to the spread of bacteria.

Any symptoms like fainting or shortness of breath should be reported to the physician.

It will trace the evolution of symptoms over the next 2-3 months.

Treatment if the condition gets worse

If regurgitation is getting worse and the heart fails to cope with the overload, the doctor will recommend valve replacement surgery, even if no symptoms.

At this point, the patient does not have symptoms; they appear only after cardiac function is impaired. Other risk factors (age, rate of deterioration of valves and general health) are considered for deciding the timing of surgical valve replacement. Once symptoms appear, the mitral valve replacement surgery is the only curable treatment for mitral regurgitation.

Some people may have other overlapping diseases, which makes valve replacement surgery to be dangerous. Others may opt for surgical treatment for personal reasons. For example, they may find that they do not have to live long enough so that surgery mustn’t be done. Symptomatic patients who do not use valve replacement surgery will have a progressive evolution towards cardiac collapse and average life expectancy of 2-4 years. This probably means that valvular insufficiency will cause death.

To remember!

Patients with chronic lesions may remain asymptomatic for many years. Surgery is needed if there appears physical activity limitation or if the left ventricular function deteriorates progressively. In non-rheumatic lesions, there was a growing success of valve reconstruction that avoids the complications of valvular prosthesis.

Furthermore, the left ventricular function is better preserved if the subvalvular structures are kept intact through valvuloplasty. For this intervention may benefit some patients with poor ventricular function and severe mitral insufficiency. Increasingly more mitral valve surgery benefits from thoracoscopic approach, much less invasive.


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2 Responses

  1. Puneet says:

    Wat should be the Diet Chart for the persons in valve leak condition.

  1. March 22, 2015

    […] Mitral insufficiency. […]

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