The sinus node electrogram in patients with and without sick sinus syndrome: techniques and correlation between directly measured and indirectly estimated sinoatrial conduction time.

44 patients undergoing sinus node electrogram recording, including a subset of 28 patients with successful recordings (12 with sick sinus syndrome and 16 without).

Recording of sinus node electrograms (SNEs) using a standard quadripolar electrode catheter with 10-mm interelectrode distance. Two positioning methods were evaluated: method 1 (catheter close to but not in direct contact with the right atrial endocardium, n=23) and method 2 (catheter in direct contact with the right atrial endocardium, n=21).

Method 1 versus Method 2 for recording success; patients with sick sinus syndrome versus those without for sinoatrial conduction time (SACT); directly measured SACT versus indirectly estimated SACT (by continuous pacing or premature stimulation).

Success rate of obtaining stable sinus node electrograms, directly measured sinoatrial conduction time (SACT), and correlation between direct and indirect SACT.surrogate