[Measurement of sinoatrial conduction time]

A prolonged sinoatrial conduction time (SACT) is one of the electrophysiologic characteristics of sick sinus syndrome. Because conduction from the sinus node to the atrium can not be assessed directly, an indirect method for estimating the SACT was developed by Strauss et al.: the premature atrial stimulation technique. The theoretical basis of the method is reviewed and the use of atrial spontaneous premature beats is proposed to estimate the SACT instead of electrical premature atrial stimulation.