Preatrial activity recorded by intracavitary and transthoracic techniques

Two methods to record preatrial activity, that is, sinus node potential are presented. One, during right atrial catheterization through an electrode catheter, and the other, using transthoracic recordings with a high amplification and derivation of the electric signals. The sinus node potential duration represents the sino-atrial conduction time (SACT), a useful parameter for the sinus node function evaluation.