Comparison of Sinoatrial Conduction Time Measured by Holter method and Premature Stimulation Method

BACKGROUND: The reliability of noninvasive Holter method for the calculation of sinoatrial conduction time (SACT) has not been confirmed by results of invasive electrophysiological studies of sinus nodal function. The aim of this study was to compare the values of SACT obtained by Holter method with values estimated by premature atrial stimulation method. METHODS: The study population consisted of 61 patients, in whom the 24-hour ambulatory ECG monitoring had shown the occurrence of atrial premature beats. All these subjects were undergoing electrophysiological study including programmed atrial and ventricular stimulation. The measurements of SACT were obtained using spontaneous atrial premature beats (Holter method) and high right atrial stimulation (Strauss method). RESULTS: There was a good correlation between measurements of SACT by Holter method and Strauss method (r = 0.79; P < 0.001). There was no significant difference between values of SACT estimated by two compared methods. However, in certain patients, there were appreciable differences and SACT measured using spontaneous premature beats was shorter in 34 and longer in 23 patients than that estimated by the Strauss method. The values of SACT calculated by Holter method and Strauss method were significantly (P < 0.001) higher in patients with sick sinus syndrome than in those without evidence of sinus node dysfunction. CONCLUSIONS: Good correlation between values of SACT obtained by two compared methods suggests that single measurement performed using Holter method may be adequate for reliable calculation of SACT.