What Variance in RR Intervals Must Be Present to Be

Question

What variance in RR intervals must be present to be considered sinus arrhythmia?
A) more than 20%
B) more than 10%
C) more than 40%
D) more than 30%

Accepted Answer

Sinus arrhythmia is considered present when there is more than a 10% variance in RR intervals, which is a normal variation in heart rate during a breathing cycle.