Cardiomyopathy in children
Cardiomyopathy (CMS) is a disease of the heart muscle. Definition means "cardio" in Latin - "heart", "myo" - "muscle", "patio" - "disease." This is not one disease, but a group of pathological conditions with different causes of development, each of which affects the heart muscle. They can affect the shape of the heart, the size and thickness of the muscle walls, as well as the transmission of signals through the heart chambers.
Cardiomyopathy affects the functioning of the heart, thereby reducing its ability to pump blood throughout the body. Damage to the myocardium depends on the type of cardiomyopathy developed in a particular person.
Various methods of investigation are used in the diagnosis of the ILC, but the most informative methods are instrumental. To understand what cardiomyopathy is and how it affects the cardiovascular system, you need to know a little about the heart and how it works.
Video: Cardiomyopathy is a general characteristic
Heart: structure and functions
The heart is the center of the circulatory system in humans. It pumps blood throughout the body, facilitating the transfer of oxygen, which is the source of energy for all cells and organs of the body. With sufficient oxygenation, they can work effectively.
The heart is a powerful muscle pump. It has four chambers: two on the right and two on the left. These pairs of chambers are separated by a wall called a septum.
Two atria (upper chambers) collect blood flowing towards the heart. The right atrium receives blood from the body, while the left atrium receives blood from the lungs. Atrial walls thin and elastic.
Two ventricles (lower chambers) receive blood from the atriums located above. They push blood from the heart: the right ventricle directs blood to the lungs, and the left - to all parts of the body. The walls of the ventricles are thick and powerful, they can dislodge blood from the heart during their contraction. The left ventricle has the thickest wall, since it must supply blood to most of the organs and systems of the body. The ventricles are most often affected by cardiomyopathy.
In the heart there are four valves that help the blood flow in only one direction, through the cardiac chambers and further along the vessels.
The heart pumps blood throughout the body through rhythmic relaxation and contraction of the myocardium (heart muscle). At the same time, electrical impulses synchronously with contractions propagate along the heart, which normally should be transmitted throughout the heart in a regular, rhythmic and orderly manner. This ensures that the various chambers of the heart are compressed and relaxed in the required order. As a result, the blood flow passes in the right direction: from the heart to the lungs to take oxygen, and back to the heart so that it can pump blood to the rest of the body.
When the cardiomyopathy develops, this balance is broken. Depending on the type of cardiomyopathy, there are certain changes in the heart, eventually leading to a violation of the process of removing carbon dioxide, liquid and other metabolic products from the body.
Types of cardiomyopathy
Different types of cardiomyopathy are described according to how they affect the cardiac muscle.
Dilated cardiomyopathy (DCM) - the left ventricular muscle becomes enlarged. The walls of the chamber seem to stretch, become thinner and weaker, as a result of which the ventricle not so qualitatively pumps blood from the heart into the vessels.
Hypertrophic cardiomyopathy (HCMC) - the ventricular muscle thickens (called "hypertrophy"), which makes the chamber cavity of the ventricle smaller. Thickening of the muscle is not associated with an increase in the load on the
Heart, since the primary cause is cardiomyopathy. If the thickening is in the region of the septum, it can affect the flow of blood from the heart (the so-called hypertrophic obstructive cardiomyopathy).
Arrhythmogenic cardiomyopathy of the right ventricle (AKMP RV, also known as arrhythmic cardiomyopathy) is characterized by cell death followed by replacement with scar tissue or fat. This causes the heart muscle to stretch, become thinner and weaker, which makes it unable to push blood out of the heart.
Restrictive cardiomyopathy (RCMD) - the heart muscle becomes stiff and can not relax properly, making it difficult to fill the chamber with blood. In later stages of development, the affected cells expand and blood can not flow out normally from it.
Noncompact left ventricular myocardium (NLMM) - the heart muscle does not develop normally in the fetus. Muscle cells are not compact (not densely located), which contributes to the formation of a "spongy" myocardium. This change in the structure of the heart muscle affects the overall work of the organ.
Takotsubo syndrome or "broken heart" syndrome - this rare cardiomyopathy usually develops during very severe stress (which is why the disease was called "broken heart"). The left ventricle becomes enlarged and
weakened. Pathology often occurs temporarily, as a result of which the patient becomes better.
Causes of cardiomyopathy
Cardiomyopathy can occur in any person at any age. It is estimated that the disease affects about 160,000 people in the UK, this is 1 in 500 people. Although many people are born with cardiomyopathy, the symptoms
can develop up to adulthood, and in some, this state is not manifested in any way and especially does not progress.
Cardiomyopathy is often defined as a genetic disease. This means that a mutation (change) has occurred in the human DNA, which affects the development of the heart and how it works. Some mutations arise spontaneously when the child develops in the uterus, and some are transmitted (inherited) from the parent. Since cardiomyopathy can be inherited, in some families there is a high likelihood of developing CMP. For this reason, if cardiomyopathy is considered genetic, it is recommended that close relatives of the patient, such as parents, brothers, sisters, children (known as first-line relatives), be checked for the presence of the disease.
Other causes of cardiomyopathy include:
- viral infections that have tropism to the heart muscle;
- autoimmune diseases (which affect the immune system);
- some drugs (including those used to treat cancer) or toxins (eg, alcohol, drugs or smoking).
During the examination of a patient, doctors usually ask him questions about the medical history and his life, and also, if necessary, do some tests to find out the cause and type of cardiomyopathy.
Symptoms of cardiomyopathy
Signs of cardiomyopathy can be associated with one or more mechanisms of the disease:
- Disturbance of electrical conduction of the heart.
- Reduction or violation of blood flow to the heart.
- Poor supply of oxygen and nutrients to the body.
- Poor removal of metabolites from the body.
Although different types of cardiomyopathy affect cardiac function in different ways, there are common symptoms that occur in different variants of cMYP.
Symptoms of cardiomyopathy in children may include the following.
- Fatigue - due to the deterioration of circulation and the level of oxygen in the blood, cells and organs do not receive it in sufficient quantity, which reduces the "strength" of the body.
- Shortness of breath - because of the accumulation of fluid (called edema) in the lungs, breathing becomes difficult.
- Edema in the abdomen and ankles - develop against the backdrop of an increase in the amount of fluid in the body.
- Palpitation (the feeling that the heart beats too fast, hard or "fluttering") is caused by abnormal heart rhythms (arrhythmias) when the heart beats too fast or erratically. This may be due to electrical impulses that control the normal rhythm of the heart, as a result of which the conductivity is disturbed.
- Chest pain or a feeling of "tightness" in the chest - although the cause of the symptom is not always completely clear, it can be associated with a decrease in blood flow from the heart. Also, this can happen when the heart is under increased pressure (for example, during training), as it is forced to work harder to supply the body with oxygen.
- Dizziness or fainting is caused by a decreased level of oxygen or blood supply in the brain. In some cases, it leads to loss of consciousness or fainting.
If older children can say that they are concerned, then very small, who can not speak yet, can not do this. in such cases helps the attention of parents who may notice that the baby has become capricious, often "hysterical" for no reason, crying a lot or just whimpering. Breastfeeds gain weight poorly, sometimes because of serious heart pathology refuse to suck.
Diagnosis of cardiomyopathy
If there is a suspicion that a child may have cardiomyopathy, usually refer to a pediatrician or a pediatric cardiologist. At the reception the doctor will ask questions about the symptoms, will study the medical and family history, will conduct some studies to find out if there is cardiomyopathy.
Conventional diagnostic tests for suspected cardiomyopathy
- ECG (electrocardiography) - the method allows you to study the electrical activity of the heart and determine arrhythmias (abnormal heart rhythms). The ECG can be performed during exercise (if the exercises usually lead to symptoms), or a portable "Holter monitor" is installed, which can record the heart rate within 24 hours.
- Echocardiography (echocardiography) is an ultrasound scan that is based on the use of sound waves to create 2- and 3- dimensional images. This test allows you to consider the structure of the heart and is used to see if the size of the body is enlarged and whether there is a thickening of the heart muscle. Images move, so you can also see how the heart works. Doppler echocardiography determines the speed and flow of blood through the heart chambers, which also helps to check its functioning.
- MRI (magnetic resonance imaging) - this type of scanning makes it possible to obtain high-quality images and is used to study the detailed structure of the heart and how the blood flows through its cavities. MRI can also be used to measure any areas of a thickened myocardium.
Video: Cardiomyopathy of newborns
Other diagnostic methods may be used, the need for which is considered depending on the test results given above. In general, all efforts are directed to diagnosing cardiomyopathy or looking for another cause of the symptoms.
Treatment of cardiomyopathy in children
Treatment of cardiomyopathy is aimed at reducing and eliminating any symptoms of the disease and reducing the likelihood of developing various complications. Therapy depends on the type of cardiomyopathy and clinical manifestations. If the child does not have any symptoms, then the treatment may not be carried out at all. But children who are determined manifestations of the disease must undergo special treatment.
Depending on the symptoms and characteristics of a particular child, a treatment regimen is drawn up, most often with the use of medications.
- ACE inhibitors (angiotensin-converting enzyme inhibitor) - reduce the need of the heart in oxygen and facilitate the process of pumping blood.
- Angiotensin II receptor blockers reduce the need for oxygen in the heart and facilitate the pumping of blood. They can be used in place of ACE inhibitors.
- Antiarrhythmic drugs control the rhythm of the heart and help to eliminate arrhythmias (abnormal heart rhythms).
- Anticoagulants ("blood thinners") prevent the formation of thrombi and are used in the presence of atrial fibrillation (an abnormal heart rhythm that causes uneven blood flow through the chambers of the heart).
- Beta-blockers reduce the burden on the heart and can help with chest pain, dyspnea and palpitations.
- Calcium channel blockers reduce the force of contracting the heart. Some drugs reduce blood pressure by reducing the rigidity of the arteries, while others eliminate pain in the chest and arrhythmias.
- Diuretics - reduce the formation of edema due to increased excretion of water with urine. They also reduce blood pressure.
The Boston Scientific device (Image courtesy of Boston Scientific, © 2017 Boston Scientific Corporation).
Pacemakers control the rhythm of the heart due to its constant electrical stimulation. This ensures that the heart beats normally (the so-called "sinus rhythm" is maintained). Some pacemakers, called biventricular pacemakers, are used for cardiac resynchronization therapy, send electrical signals to both sides of the heart, which helps the cameras to contract together.
Implantable cardioverter defibrillators monitor the heart rhythm and, if a dangerous arrhythmia occurs, send an electric pulse to the heart, which allows to restore a normal rhythm. Some devices are also pacemakers.
Auxiliary device for the left ventricle are artificial pumps that help the heart pump blood. Devices are used only if there are very serious problems with the function of the heart. Such patients are mainly waiting for heart transplantation.
Surgical methods of treatment can be used in the presence of hypertrophic cardiomyopathy, where a thickened cardiac muscle prevents the ejection of blood from the heart. This obstruction can be reduced surgically or by injecting medical alcohol into the area of thickening (called alcohol ablation of the septum). In surgical intervention, part of the thickened muscle is cut off, that is, the so-called surgical myectomy is performed.
In a small number of cases, heart transplant may be required. Such risks are most often increased in children with restrictive cardiomyopathy than with other types of CML. Nevertheless, heart transplantation is rarely necessary and most children do not need it.
Complications of cardiomyopathy
Sometimes cardiomyopathy leads to complications that develop due to impaired cardiac function. Some methods of treating cardiomyopathy are aimed at reducing the likelihood of complications, but in a number of cases they still have to be observed.
The most frequent complications of CMS
- Arrhythmias are abnormal heart rhythms that cause the heart to beat too fast, too slowly or irregularly. Some arrhythmias are temporary and do not cause long disturbances. However, some of them are dangerous and therefore urgent treatment is required (since they can promote the formation of blood clots or cause cardiac arrest).Arrhythmias are treated with antiarrhythmic drugs or implanted devices that control the heart rhythm.
- Blood clots, or clots , can form in the heart, when the blood circulates poorly. For example, in arrhythmias, called "atrial fibrillation," the heart muscle does not contract properly, making the bloodstream atrial turbulent, which can cause blood clots. Blood clots moving with blood flow lead to the development of a stroke, so drugs can be used to normalize the rhythm of the heart (antiarrhythmic drugs) and dilute blood to reduce the risk of clot formation (anticoagulants).
- Cardiac arrest is a sudden cessation of cardiac activity, as a result of which blood ceases to circulate through the body. This can occur because of dangerous arrhythmias, such as ventricular fibrillation. Such cases are sometimes called sudden death. People who are at risk of cardiac arrest should have an implanted defibrillator that controls the heart and normalizes it in any dangerous arrhythmias and shock conditions.
Thus, such an unfavorable disease as cardiomyopathy in children can take on menacing forms of development, therefore it is extremely important to contact a doctor without delay if the first suspicious symptoms appear.