FIRST IRAQI EXPERIENCE IN SINUS NODE ELECTROGRAM RECORDING AND ITS ROLE IN THE DIAGNOSIS OF SINUS NODE DYSFUNCTION (A STUDY WHICH IS CARRIED IN THE CARDIAC CARE UNIT IN AL-KADHIMIYA TEACHING HOSPITAL)

Abstract

Background: Measurement of Sinoatrial Conduction time from the sinus node electrogram record is an accurate and useful method. It gives idea about the function and integrity of the sinus node.Objective: To record normal sinus node electrogram as a first experience in Iraq, and obtain normal values of Sinoatrial Conduction Time (SACT), which is measured directly from sinus node electrogram. Then to make a correlation between directly measured SACT from sinus node electrogram and indirectly measured SACT from premature atrail stimulation.Method: The study was conducted during the period between June 2005 to October 2006 on 70 patients suffering from syncopal or palpitation attacks attending the Cardiac Care Unit in Al-Kadhimia Teaching Hospital. In 62 patients sinus node electrograms were successfully recorded and Sinoatrial conduction time was measured indirectly by both Strauss Method (Premature Atrial Stimulation method), and Narula Method (Continuous Aatrial Pacing Method).Results: Seventy subjects were undergone cardiac electrophysiological study. Sinus Node Electrogram (SNE) was recorded successfully in 62 subjects and the Sinoatrial Conduction Time (SACT) was measured. In the control group with normal sinus node function (N=33),mean SACT was 81.2 ± 11.6 msec (mean ± SD). In patients (N=29) with sinus node dysfunction, 16 out of 29 mean SACT was 88.2 ± 6.3 msec. In the rest 13 patients the mean SACT was 206.8 ± 14.8 msec., which is significantly prolonged. In 33 subject of the control group, SACT had been measured indirectly using continuous atrial pacing (Narula method) in addition to premature atrialstimulation technique (Strauss method). The mean SACT were 83.5 ± 13.1 msec. and 82.4 ± 11.7 msec. by Strauss and Narula methods respectively, which indicates no significant differences between the indirect method (Strauss and Narula), from the direct method measured from the SNE (p>0.01).Conclusion: SNEs that were recorded for the first time in Iraq, in subjects with apparently normal sinus node function, were comparable to the measured values obtained by different world wide laboratories. The significant correlation between the indirect methods [continuous atrial pacing (Narula method) and premature atrial stimulation technique (Strauss method)] and the direct method (SNE) makes SNE a precise method for the measurement of SACT.