Supraventricular tachyarrhythmias involving the sinus node: clinical and electrophysiologic characteristics.

Supraventricular tachyarrhythmias occur quite commonly and are now evaluated more often because of technological advances in the field of electrophysiology. Arrhythmias that involve the sinus node, namely, the syndrome of inappropriate sinus tachycardia and sinus node reentry, are rare. Because of their origin in the sinus node, the surface electrocardiogram (ECG) in these patients can present a diagnostic challenge to the clinician and in fact may elude recognition as an abnormal heart rhythm. Presented in this review are the clinical characteristics of these arrhythmias, as well as the mechanisms of action. Pharmacotherapy may be therapeutic in certain patients in preventing recurrences; however, radiofrequency catheter ablation offers a lifelong curative effect for these patients.