Racing heart in children

Dr Sandra Williams-Phillips, Contributor

Racing heart, known as palpitations, also occurs in children and can arise simply from the top of the heart, supraventricular tachycardia (SVT).

The most common type is from the bottom of the heart, ventricular tachycardia (VT).

Clinical presentation of palpitation is dependent on age.

Infant's symptoms usually occur by five months of age, and are non-specific, including shortness of breath, poor feeding, irritability and signs of heart failure. Cardiac arrest and heart failure usually occur if palpitation is sustained for more than 24 hours.

Many are misdiagnosed in this age group, especially when episodes occur infrequently.

For older children and adolescents, it usually presents with more clearly and easily recognised symptoms such as chest pain, sticking, beating or beeping in chest, classic symptoms of cardiac failure, weakness, dizziness, syncope (fainting), seizure (fits), poor exercise tolerance and not being able to keep up with peers, excessive sweating and heart racing.

Heart failure is less likely, unless sudden severe episodes occur. If palpitation is not diagnosed and controlled, it can lead to dilatation of the heart.

When dealing with the child, it is important to obtain drug and dietary history, state of hydration, and occurrence of stress.

The family history of sudden infant death syndrome, sudden death under 50 years, palpitations, congenital heart disease, deafness and thyroid disorders provide very important clues, which will help to classify the type of disorder that can be associated with the child's palpitations.

TESTS TO DETERMINE HEART PROBLEMS

Tests that can be done to determine if the child has a heart condition includes, but by no means complete, are:

Blood tests: especially for thyroid-function tests.

Electrocardiogram (ECG): a negative ECG does not mean that the child does not have a SVT.

Echocardiogram (ultrasound of the heart): to rule out cardiac lesions, which may not provide any signs or murmur. A normal echocardiogram does not rule out a disorder.

Holter assessment: where the child's heartbeat is recorded for 24 hours. If no episode occurs during this time, the test may be negative. This does not mean that the SVT is not there. There are devices that can be placed on a child for up to five years, especially in children where it is unable to 'catch' the palpitations on Holter assessment.

Transoesophageal studies (not available in Jamaica): is a very good test for detection with trans catheter electrophysiological studies (EP studies) and ablation, leading to a cure in specific cases.

Treatment will depend entirely on the cause of the palpitations. These include:

The SVT can resolve (go away) spontaneously in a significant number of patients.

SVT can be controlled with medication.

If a child has a thyroid problem, treatment is specific for this disorder, which then controls the SVT.

Restriction of specific activities, such as swimming, until there is control of the SVT.

SVT can be difficult to diagnose and may not respond readily to treatment. Use of a diary of the palpitation events is a simple useful exercise which helps with choice of medication, and provides a guide, to both family and cardiologist, of the level of control.

Dr Sandra Williams-Phillips, MD, FESC, FASE, FAHA. is a consultant paediatric, adolescent and adult congenital cardiologist at Andrews Memorial Hospital: Email: drsandrap@hotmail.com or yourhealth@gleanerjm.com