Recognising supraventricular tachycardia in children: An arrhythmia not to miss

Abstract

Supraventricular tachycardia (SVT) is the most common symptomatic arrhythmia in children that demands urgent medical attention. This article describes the caveats in diagnosing and managing children with SVT in the pre-hospital setting. It is important that the paramedic team arranges urgent transfer of a child with SVT to the emergency department. The prehospital management should include obtaining an electrocardiogram (ECG), administering oxygen and attempting vagal manoeuvres such as carotid sinus massage while en route to hospital. It is also important that the paramedic team should actively look for clues for the sudden onset of SVT in a child such as the presence of illegal drugs at home, a history of accidental ingestion of parents’ medicines, and a family history of arrhythmias. The clinical presentation of SVT varies with the child’s age, and can be difficult to diagnose in infants and young children. It is important that paramedic teams consider a diagnosis of SVT in young children with histories of poor feeding, lethargy, irritability, excessive sweating or pallor and in older children with a history of palpitations, dizziness, chest pain, syncope or shortness of breath. Tachycardia is a common symptom, encountered in children presenting to the emergency services. In the majority of cases, tachycardia can occur in response to pain, emotional distress (crying), hypovolaemia (fluid loss) and fever. It can, however, also be a primary tachyarrhythmia with potentially serious consequences. It is therefore important that the paramedic team remains aware of the commonly encountered types of arrhythmia and institute appropriate management when faced with these cases (Karpas, 2006). SVT is defined as an abnormally rapid heart rhythm originating above the ventricles often, although not exclusively, with a narrow QRS complex. It is important that health professionals remain aware of the normal ranges of heart rates in children as this varies with age unlike in adults (Table 1). In this article we present a case of a two-year-old boy who was diagnosed with SVT followed by a discussion of the condition itself. Some practical points are provided which will be helpful in managing children with SVT in the prehospital setting.