What Is Cardiomyopathy in Pediatric Patients?
Worldwide there are almost one in 100,000 children who suffer from cardiomyopathy, and usually, during the first two years of life, the chances of developing this condition are higher. It is a heterogeneous group of disorders leading to fatal conditions in children like heart failure. Even though medicine is very advanced these days, conditions like this still have a high mortality rate. Few of the cases show no symptoms, but some of them show symptoms like heartburn, rapid heartbeat, fatigue, and heart failure.
Cardiomyopathy is differentiated into ischemic and non-ischemic or primary and secondary conditions. An ischemic condition is a congenital abnormality of a coronary artery that causes a decrease in oxygen levels in the blood. Non-ischemic condition is when there is structural damage or functional defects of the heart muscle causing the symptoms like a heart attack. Also, primary cardiomyopathy is a heart failure caused by genetic disorders, infectious disease, and inflammation of the muscles of the heart. On the contrary, when there are secondary complications affecting other organs along with heart failure, it is called secondary cardiomyopathy.
What Are the Types of Cardiomyopathy in Pediatric Patients?
There are five forms of cardiomyopathy, such as:
- Dilated Cardiomyopathy (DCM): It is a muscle disorder where the ventricle is too stretched to pump out the blood to the rest of the body. This type of cardiomyopathy usually occurs due to infections, complications in the last trimester of pregnancy, immunocompromised conditions, obesity, hypertension, arrhythmias (irregular rhythm of the heart), or heart valve diseases. The symptoms of the disease include fatigue, shortness of breath, edema of the ankles and belly, poor growth, chest discomfort, persistent cough, and rapid heartbeat. Also, there are some complications associated with dilated cardiomyopathy, such as leaky heart valves, heart failure, sudden cardiac arrest, and blood clots. The primary goal of treatment is to manage cardiac function in children. Additionally, medications like beta-blockers and ACE inhibitors can be prescribed according to the age and condition of the infant.
- Hypertrophic Cardiomyopathy (HCM): It is a large heterogeneous group of disorders that rarely affects children. Even if it is very rare, its mortality rate is very high. The childhood HCM is caused by inherited metabolic defects, malformation syndrome, and neuromuscular and mitochondrial diseases. HCM is often present without any symptoms or signs in the body in the early stages, so a high suspicion index must be made in those patients. In most cases, it goes undiagnosed till the adulthood of the patient. Some symptoms of hypertrophic cardiomyopathy; are light-headedness, shortness of breath, chest pain, palpitations, excessive sweating, and difficulty feeding. Furthermore, sometimes taking a detailed family history, physical examination, or electrocardiogram can reveal the underlying condition. Drug therapy like beta-blockers and calcium channel blockers help to relax the cardiac muscles. Moreover, patients at high risk of cardiac arrest are prescribed implantable cardioverter-defibrillator and antiarrhythmic medicines.
- Restrictive Cardiomyopathy (RCM): When cardiac muscles become stiff and filled with blood in a relaxation position, it causes a condition like restrictive cardiomyopathy. Due to this condition, there are symptoms like shortness of breath, persistent cough, abnormal heartbeat, poor growth, sweating, and fussiness seen in children. In almost 25 to 30 percent of cases, the underlying cause is a genetic factor, and other than that, excessive iron in the heart, systemic diseases, abnormal protein in heart muscles, or any inherited diseases can cause restrictive cardiomyopathy.
- Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): It is a rare condition where the heart muscle of the bottom right chamber- the right ventricle, is preoccupied with fat or fibrous tissue, and because of that, the heart is not able to pump the blood. Owing to this condition, there are symptoms like irregular heart rhythms, dizziness, fluttering of the chest, or sudden death due to heart failure. Even though there is no medications or treatment with 100 percent success, antiarrhythmic drugs can help to manage the symptoms.
- Left Ventricular Non-Compaction Cardiomyopathy (LVNC): A heart muscle is made of sponge-like muscle fibers; however, with a condition like left ventricular non-compaction cardiomyopathy, the piece of muscle growth inside the left ventricle is called trabeculations. With the development of the heart muscle, trabeculations also developed, making the heart muscle smooth and solid. The symptoms of this disorder include dizziness, abnormal heartbeat, weight gain, shortness of breath, sweating, and poor feeding. Primarily the medication to manage the symptoms and prevent cardiac damage is given. Additionally, blood thinners like Aspirin are given along with beta-blockers.
What Are the Causes of Cardiomyopathy in Pediatric Patients?
Usually, the cause of cardiomyopathy is unknown, but research shows that genetic abnormality can trigger the condition in infants. The defective gene can be inherited from any one of the parents, or it can be a result of a mutation of genes. Moreover, recessive gene disorder occurs when both parents pass the same defective gene to their child. On the contrary, when a child has one abnormal gene inherited and one normal gene, it means that they remain a carrier of the disease but without any signs and symptoms and can pass it along. On the other hand, X-linked disorder is the result of non-working genes on the X-chromosome.
Dilated cardiomyopathy is the result of a generalized genetic disorder and muscular dystrophies. Most inherited genes responsible for dilated cardiomyopathy are either autosomal dominant traits, recessive or x-linked. Hypertrophic cardiomyopathy is the result of either a genetic mutation that is passed onto future generations as an autosomal dominant gene or there is no family history or reason behind the condition. When a patient already has systemic disorders such as sarcoidosis (collection of inflammatory cells causing tiny bumps) or hemochromatosis (extra absorption of iron from food), there are also chances of developing restrictive cardiomyopathy. Additionally, it can also be the result of post-operative open-heart surgery scarring or radiotherapy.
Apart from inherited factors, cardiomyopathy can be caused by a viral infection, toxins, chemotherapy, and metallic and mitochondrial diseases.
What Are the Symptoms of Cardiomyopathy in Pediatric Patients?
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Tachycardia - Increased blood pressure.
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Dizziness.
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Chest pain.
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Fatigue.
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Abdominal swelling.
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Sweating.
How To Diagnose Cardiomyopathy In Pediatric Patients?
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Family history (specifically, look for a genetic abnormality that runs in the family).
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Physical examination.
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Computed tomography.
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Radiography of chest.
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Electrocardiography.
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Cardiac magnetic resonance imaging.
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Radionuclide ventriculogram.
How to Manage Cardiomyopathy in Pediatric Patients?
According to the type, severity, and age of the infant, the treatment plan proceeds. Although there is no cure for cardiomyopathy, their symptoms can be managed.
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Medication: There are some drugs that treat the symptoms; for instance, arrhythmia can be treated with antiarrhythmic drugs, cardiac arrest can be treated with beta-blockers and ACE inhibitors, and for blood clots, Aspirin can be given with age-appropriate dosages.
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An Implantable Cardioverter Defibrillator: It is used to treat the arrhythmia by regulating the heartbeat in children.
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A Heart Transplant: In case of a severe condition, where all the medication and other treatments are ineffective, this mode of treatment is followed.
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Myectomy: This type of surgical treatment is performed in the case of hypertrophic cardiomyopathy (muscle thickening).
Conclusion
Children with this disorder usually face many other complications throughout their life. However, with the support of medication and surgeries, this chronic condition can be managed. Moreover, the caregivers or parents should follow a few restrictions with regular follow-up visits to the hospital with restrictions on a diet, playing sports, or any other activity that requires strength.