Managing a Child With Heart Palpitations
The most worrisome arrhythmia in children is ventricular tachycardia (VT). It is a life-threatening arrhythmia. Fortunately, it is the most uncommon. Nonetheless, people who treat children have to be aware of conditions that are a setup for this kind of arrhythmia.
Hypertrophic cardiomyopathy is one such condition. It is a genetic condition leading to abnormality of the ventricular muscle. The abnormality produces a structural change with thickening of the heart muscle in an asymmetric fashion. The thickness may cause obstruction of the left ventricular outflow tract. In addition, such an individual is prone to VT. The presenting symptom for such individuals tends to be loss of consciousness or a fainting episode with the arrhythmia, generally occurring in the setting of vigorous physical activity. It can be a silent condition, fainting or collapse being the first symptom for some patients. Diagnosis is made by a combination of tests, including echocardiogram and ECG. Genetic testing is now available for the condition but does not help with practical management issues.
If a child is reporting other problems, such as constant fatigue and/or symptoms with minor daily activities, it suggests the possibility of myocarditis, usually related to viral infections. The heart of a child with such an infection becomes dilated and does not contract well. These patients are prone to VT. While some children with myocarditis recover, others may suffer permanent damage. The heart may remain dilated and prone to VT.
Another rare condition to include in your differential diagnosis is prolonged QT interval syndrome. The condition is genetic in nature and tends to run in families. The mechanism involves gates or ion channels in cell membranes that normally regulate the influx of sodium, potassium, and calcium. In a child with the syndrome, the gates remain open too long, thereby allowing too much sodium or calcium to enter the cells, and VT can ensue. ECG tracings and a history of syncope can be diagnostic. Genetic testing is available and helpful.
Ventricular tachycardia is very worrisome because it can be fatal within minutes. Therefore, VT is an emergency in most instances, although there are some benign forms that are well tolerated. The distinction can sometimes require an electrophysiology study. The placement of automatic external defibrillators in public places has enhanced the chances of survival in patients who experience rapid VT.
