This could be any number of arrhythmias, like sinus pause, sleep apnea,
Atrioventricular Block (1st degree, 2nd degree (types I or II)...), etc.
And yes, there may not be anything to worry about, but then again, I triaged a patient whose nurse told him the same thing, "Don't worry, sinus arrhythmias are normal, everyone has them to some degree"; he had 3rd degree av block and now has a pacemaker.