Sustained symptomatic sinus node reentrant tachycardia: incidence, clinical significance, electrophysiologic observations and the effects of antiarrhythmic agents.

The clinical, electrocardiographic and electrophysiologic determinants and effects of antiarrhythmic agents on sustained sinus node reentrant tachycardia remain poorly defined. Of 65 consecutive men undergoing electrophysiologic studies for symptomatic paroxysmal supraventricular tachycardia over a 4 year period, 11 (16.9%), who ranged in age from 39 to 76 years, demonstrated sustained sinus node reentrant tachycardia.

New application of direct sinus node recordings in man: assessment of sinus node recovery time.

Sinus node recovery time (SNRT) is frequently used to assess sinus node function in patients with suspected sick sinus syndrome (SSS). Although SNRT is assumed to reflect sinus node automaticity, this assumption remains unproven. The purpose of this study was (1) to test the hypothesis that SNRT in patients with and without SSS reflects sinus node automaticity, and (2) to assess the role of sinoatrial conduction time in the measurement of SNRT.