Is there a problem if my heart-rate goes higher instead of lower with deep breathing? i feel like i get some benefit from deep (belly) breathing, but my heart rate actually gets higher or stays about the same even though i'm taking deep, slow breaths.

Heart : Heart rate variability - or heart rates that speed up and slow down with breathing- tends to be most prominent in people who are otherwise young and healthy. Typically with slow slow, deep breathing, the heart rate slightly increases as we inhale and then slightly decreases as we exhale. This is primarily due to interactions of the nerve sensors in our chest and the autonomic nervous system or vagal nerve that runs throughout our body. The older we become, typically this variability becomes less noticeable. Also many medications and medical conditions such as diabetes can affect or blunt this heart rate variability response.