Dilated Cardiomyopathy
Introduction:
Dilated Cardiomyopathy (DCM) is a disease of the heart muscle. In DCM, the bottom chamber (left ventricle) of the heart becomes enlarged (dilated), thinning the walls of the ventricle, reducing the ability for the heart to squeeze effectively and pump blood efficiently.
In many cases, DCM occurs without reason.
When the cause can be determined, more common reasons include:
- a viral infection of the heart causing muscle inflammation (myocarditis), which weakens the heart muscle
- a genetic condition
- a metabolic disorder
- a problem with the coronary arteries, present at birth or acquired
Signs and Symptoms:
DCM usually presents with signs and symptoms of congestive heart failure.
Infants may have:
- fast breathing and sweating during feedings
- feedings that take longer than normal
- lethargy or inactivity
- poor weight gain
Children and Adolescents may have:
- shortness of breath (starts with exercise, but over time occurs at rest)
- shortness of breath when lying flat
- fatigue
- persistent cough
- swelling in face, abdomen, legs or feet
- unexplained weight gain
- dizziness or lightheadedness
- fainting or passing out (syncope)
- abnormal heartbeats
- nausea and vomiting
- decreased appetite
Diagnosis:
Diagnosis of DCM is based on the medical and family history, physical exam, and cardiac testing.
Cardiac Testing:
- An ECG to evaluate the amount of enlargement as well as the rhythm of the heart
- An echocardiogram will help measure the dilation of the ventricles and the overall squeeze of the heart
- A chest X-ray can show an enlarged heart and extra fluid in the lungs
- An exercise stress test to see how the heart reacts to exercise or stress
- A stress echocardiogram, which uses ultrasound and heart-rate monitoring to assess heart function before and after exercise
- A Holter monitor to screen for abnormal heart rhythms
- A cardiac catheterization may be performed to evaluate pressures in each chamber of the heart and look at the coronary arteries. Sometimes a biopsy is needed to assist with the diagnosis. These heart muscle biopsies are helpful in evaluating for possible infections or certain metabolic abnormalities of the heart
Treatment:
Clinical management of DCM depends on the severity of the disease and the patients symptoms. Medications can be used to help improve heart function and minimize symptoms and complications. Medications can used to:
- dilate blood vessels allowing the heart to pump easier (angiotensin converting enzyme (ACE) inhibitors)
- slow the heart rate down and protect against abnormal heart rhythms (beta blockers and other antiarrhythmic medications)
- help the body get rid of extra fluid that can build up if the heart is not squeezing well (diuretics)
- help strengthen the squeeze of the heart and reduce symptoms of heart failure (digoxin)
- prevent blood clots that can result from poor heart function (blood thinner)
- prevent the development of scar in the heart muscle (aldosterone antagonist)
When these medications no longer work, advanced heart failure therapies may be considered in certain patients:
- intravenous medications
- implantation of an implantable cardioverter defibrillator (ICD) for certain patients deemed at risk for life-threatening arrhythmias.
- implantation of a cardiac resynchronization pacemaker (CRT pacemaker) or biventricular pacemaker in order to restore the normal timing pattern of the heartbeat. This type of pacemaker hopes to improve the coordination of the squeeze of the heart muscle and improve the function of the heart.
- implantation of a ventricular assist device or VAD can be used to support the heart while waiting for heart transplantation. This is a pump attached to the heart that helps the heart pump and increases blood flow to the body.
- heart transplantation if the condition is severe
Lifestyle changes:
Some children with DCM may be restricted from certain sports and activities. “Intense” physical activity may be a risk for a child with a weakened heart muscle. Children with DCM should never “push through” a symptom if they are feeling tired, dizzy, or have difficulty breathing with an activity. They should remain well hydrated at all times and rest when needed. It will be important to discuss the sports and activities that are safe and appropriate for your child and to focus on what CAN be done and how to stay safe when participating in activities. Children with DCM should also follow a healthy, well balanced diet.