What Causes Abdominal Pressure Along With Racing Heart Beat?

I am a very fit 51 year old male. Lately (over the past two weeks) I have felt a strong tightness or pressure in my abdomen. Along with this is a racing heartbeat (90 - 100 bpm) - at rest. My usual resting heart rate is around 60. I also always have low blood pressure (around 110 over 60). But lately it has been 130 over 70. What is going on?