What Causes Fast Heart Beat Post Partial Pancreatectomy?

My husband who is 71 years old had a partial pancreatectomy and spleenectomy three weeks ago. Since then he has experienced a faster than normal heart beat, ranging from 93 - 105. Should we be unduly concerned now? Will it return to normal after he heals? His blood pressure is usually in the normal range, with a few exceptions. Does age affect heart rate and blood pressure?