ELECTROPHYSIOLOGIC DIAGNOSIS OF PATIENTS WITH SINUS NODE DYSFUNCTION: WITH SPECIAL REFERENCE TO A MODIFIED METHOD FOR CALCULATING SINOATRIAL CONDUCTION TIME

抄録

The diagnostic value of maximum corrected sinus node recovery time (CSNRT) and sinoatrial conduction time (SACT) was assessed in I 5 patients with clinical evidence of sinus node (SN) dysfunction and I 6 control subjects. The SACT was calculated by a modified method using only those sinus cycles with A 1-A 1 intervals falling within one standard deviation of the mean. We also obtained a maximum SACT and a ratio of maximum/mean SACT. We found that the maximum/mean SACT ratio being useful for identifying patients with sinus arrest or sinoatrial block. Abnormal value of the ratio (⩾ 1 .85) was also more frequently observed in patients with syncope or dizzy spells than those without (55.6% vs. 33.3%). By applying mean SACT and maximum/mean SACT ratio, calculated by the modified method, together with maximum CSNRT, all patients with SN dysfunction could be completely isolated from the normal subjects.