What causes atrial tachycardia in children?
Atrial tachycardia in children (also know as atrial ectopic tachycardia or AET) is an arrhythmia, or abnormal heart rhythm that causes a fast heart rate. Normal electrical conduction in the heart starts with the generation of electricity in the sinus node in the upper portion of the right atrium. Electricity moves from the sinus node through the atrium. From there, it is transmitted to the AV node to the ventricles. At electricity passes to the ventricles, the heart muscle contracts.
Tachycardia means a faster than normal heart rate. Atrial tachycardia is a specific type of tachycardia that involves the atrium, the upper two chambers of the heart. With atrial tachycardia, electricity is fired from a source in the atrium other than the sinus node at a very fast rate. In babies, atrial tachycardia may be as fast as 250-300 beats per minute. In older children and teenagers, the heart rate is often in the range of 150-180 beats per minute.
What are the signs and symptoms of atrial tachycardia in children?
The danger of atrial tachycardia, or any tachycardia for that matter, involves the degree of stress placed on the heart muscle. When the heart rate is very fast, or even when the heart rate is not so fast but continues for a prolonged period of time, the heart muscle tires out. This may lead to ineffective pumping and the development of congestive heart failure.
Babies with atrial tachycardia may have no symptoms at all. The problem is often detected when a faster than normal heart rate is heard during a routine examination. If the problem has gone on long enough, symptoms of heart failure may result. In an infant, these include rapid breathing, sweating, irritability, poor feeding, and poor weight gain.
Children with atrial tachycardia often experience palpitations. They typically complain of their heart racing. Symptoms of congestive heart failure in older children with atrial tachycardia are uncommon.
How is atrial tachycardia in children diagnosed?
Typically atrial tachycardia is suspected when the patient presents with symptoms or an abnormal heart rhythm is heard on examination. Diagnosis is usually confirmed by an ECG or Holter monitor study.
How is atrial tachycardia in children treated?
Atrial tachycardia can develop in both babies as well as older children. In babies it tends to spontaneously resolve, often by 8-12 months of age, and sometimes much sooner. Treatment with medication is often necessary to suppress the abnormal tissue and allow the normal sinus node to take over. In some instances, it may be impossible to completely suppress the abnormal tissue and the goal becomes simply to keep the heart rate relatively slow to prevent the heart muscle from tiring out.
In older children, atrial tachycardia often does not spontaneously resolve. In this situation, treatment with medication is often effective, but many may opt for a more definitive procedure, a radiofrequency ablation. In this procedure, the abnormal focus of tissue is ablated, or destroyed with high frequency energy. This often cures the individual of the problem permanently.
In summary, atrial tachycardia in children is relatively uncommon. Fortunately most episodes can be treated effectively with either medication or a definitive procedure.