Transesophageal determination of SNRT and SACT in paroxysmal supraventricular tachyarrhythmias.

The paper tested the hypothesis that supraventricular tachyarrhythmias (SVT) could represent the first clinical manifestation of the sick sinus syndrome (SSS). Absolute sinus node recovery time (SNRT) and sinoatrial conduction time (SACT) were determined through transesophageal approach in 16 patients with paroxysmal SVT, but without bradycardic episodes between crises. The values considered normal were: SNRTa less than or equal to less than or equal to 1500 ms; SNRTc less than or equal to 525 ms; SACT less than or equal to 150 ms. SNRTa, SNRTc and SACT were normal in all subjects (SNRTa: 1077 ms; SNRTc: 400 ms; SACT: 111 ms) and suggest the absence of a notable sinusal disfunction in these patients. We concluded that SVT unassociated with bradycardia do not usually represent a manifestation of SSS. Consequently the administration of sinusal depressant drugs in such patients could be permitted without restrictions.