You need to be concerned if, when your pulse is slow, you develop symptoms such as blurry vision, lightheadedness, dizziness, passing out or near passing out spells. Otherwise, it may simply be a marker of high vagal tone, and not associated with adverse effects. But just to make sure at least have a 12 lead electrocardiogram reviewed by your PCP or cardiologist to make sure there are not underlying conduction problems.
i think thats awful low myself. mine has been inthe 50 but 35 really low i would call your dr.