Equation of Mandel et al for Spontaneous Sinus Cycle Length and Maximum Sinus Node Recovery Time

 

According to Josephson:

 

maximum normal sinus node recovery time in msec =

= (1.3 * (spontaneous sinus cycle length in msec)) + 101

 

This is credited to Mandel et al., who gives an equation that describes the mean for P-P interval before pacing vs maximum sinus pause:

 

maximum sinus pause in msec =

= (1.3 * (P-P interval in msec)) + 46.12

 

The normal range is this line +/- 2 SD. The shaded area in Figure 3 of Mandel et al is +/- 1 SD. If 101 - 46.12 = 2 SD, then 1 SD is 27.4 msec.