Recording of sinus node electrogram: its technique, electrophysiological and clinical importance.

The electric sign of sinus node activity, the sinus node electrogram, was recorded in animal experiments and in 22 patients. In humans the electric sign of the sinus node precedes the atrial activation by 60 msec on the average. Atrial impulse conduction time is somewhat longer than the sinoauricular one. Canine sinus node electrogram is very similar to that recorded in humans but sinoauricular impulse conduction is somewhat quicker in dogs. The pathological importance of the sinus node electrogram is discussed.