Hi, I am having some episodes of a very low heart rate. Although generally healthy, I am not in good shape. Recently I had severe gastroparesis, and lost about 35 pounds in 3 months, but that has stabilized as of a month ago or so. My heart rate has been running in the low 50s, and at times drops into the upper 40s. This afternoon it dropped to 45 and remained below 50 for 10 minutes. I tend to feel somewhat dizzy when this happens. Yet, I have a normal exercise response (walking for an hour at 4 mph my heart rate rises to 122). Any ideas why my pulse is so low?