What is ventricular tachycardia?
Ventricular tachycardia (VT) is an arrhythmia (abnormal heart rhythm) that is quite rare in children. It can occur in children with cardiomyopathy, following some heart surgeries, and with inherited diseases that affect the heart’s electrical system (e.g. Long QT syndrome, Brugada’s syndrome).
An arrhythmia is an abnormal heart rhythm caused by a problem in the heart’s electrical system, also called the conduction system. When a child has VT, the heart rhythm is driven by the lower chambers – the ventricles- instead from the upper chambers-the atria. During an episode of VT, the heart rate is fast, sometimes in excess of 200 beats per minute. The heart also pumps less effectively since the upper and lower chambers are no longer beating in synchrony with each other.
What are the effects of this problem on my child's health?
The possible health effects of VT vary widely. Some forms, especially if they are slow, may not cause symptoms nor require treatment.
Other forms of VT can be quite serious, possibly causing fainting or even sudden cardiac death.
How is this problem diagnosed?
Symptoms: Possible symptoms include palpitations (i.e. sensation of "heart racing" or "skipping" heart beats), lightheadedness, chest pain (during episodes), and/or fainting.
Physical findings: The exam is normal when the child is not having an episode. If the child has other heart problems, the exam will may reflect those problems.
Medical tests: One of the first tests usually done is an electrocardiogram (ECG). A device called a transtelephonic ECG recorder is often used to record an ECG at the time of symptoms. Other tests that may be done include a Holter monitor, echocardiogram, and/or exercise test. If further information is needed a special type of heart catheterization called an electrophysiologic study may be done.
How is the problem treated?
The treatment of VT depends on many factors. Possible treatments include heart medication, radiofrequency ablation, and a cardioverter-defibrillator (ICD). If the VT is triggered by a very slow heart rate, a pacemaker may be needed. Sometimes, in children with complex heart problems, another operation is needed.
What are the long-term health issues for these children?
The outlook for children with VT depends on the nature of the underlying causes. Overall, given advances in medical care, the outlook is quite good.
SBE prophylaxis: Children with heart defects along with VT are at increased risk for subacute bacterial endocarditis (SBE). This is an infection of the heart caused by bacteria in the blood stream. Children with heart defects are more prone to this problem because of the altered flow of blood through the heart and or abnormal heart valves. It can occur after dental work or medical procedures on the GI or respiratory tract because these procedures almost always result in some bacteria entering the blood. SBE can usually be prevented by taking an antibiotic before these procedures. SBE prophylaxis is not needed if the person only has VT and an otherwise normal heart.
Exercise guidelines: Exercise guidelines are best made by a patient’s doctor so that all relevant factors can be included. Children with ventricular tachycardia are often restricted from competitive sports although in some cases this may be allowed.
Clinics
Care and services for patients with this problem are provided in the Arrhythmia Clinics and Congenital Heart Clinics at the University of Michigan Medical Center in Ann Arbor.
References
Dick M, Russell MW. Ventricular Tachycardia. in Cardiac Arrhythmias in the Neonate, Infant, and Child, edited by Wolff G, Deal B, Gelband H. Futura Publishing Company, Armonk NJ, 1998, p181-222.
Written by: S. LeRoy RN, MSN, CPNP
Reviewed September, 2012