Supraventricular tachycardia.

Supraventricular tachycardia (SVT) is a common cardiac rhythm disturbance; it usually presents with recurrent episodes of tachycardia, which often increase in frequency and severity with time. Although SVT is usually not life-threatening, many patients suffer recurrent symptoms that have a major impact on their quality of life. The uncertain and sporadic nature of episodes of tachycardia can cause considerable anxiety - many patients curtail their lifestyle as a result, and many prefer curative treatment. SVT often terminates before presentation, and episodes may be erroneously attributed to anxiety. Sudden-onset, rapid, regular palpitations characterise SVT and, in most patients, a diagnosis can be made with a high degree of certainty from patient history alone. Repeated attempts at electrocardiographic documentation of the arrhythmia may be unnecessary. Treatment of SVT may not be necessary when the episodes are infrequent and self-terminating, and produce minimal symptoms. When episodes of tachycardia occur frequently, are prolonged or are associated with symptoms that affect quality of life, catheter ablation is the first choice of treatment; it is a low-risk procedure with a high success rate. Long-term preventive pharmacotherapy is an alternative approach in some patients.