Does everyone have respiratory sinus arrhythmia? is it normal? would my doc detect this by having me breathe deep while listening to my heart?

Respiratory sinus arrhythmia is common with slow rates but often the heart rate variability is only detectable on an EKG. The heart beat( R R interval) comes slightly earlier on inspiration and later on expiration. When interpreting an EKG we don't often comment on subtle rate variations but will if the variability is quite prominent. Marked sinus arrhythmia is often due to sinus node dysfunction