An 84-year-old avid cyclist wonders if his irregular heartbeat is dangerous — here's what doctors say

Dear Doctor Roach: You recently used the term “abnormal irregular heartbeat.” I’ve had an irregular heartbeat for decades without seemingly ill effects. My doctors haven’t put any restrictions on my vigorous cycling or any other activities that I do at 84 years old. Does this mean that I have normal irregular heartbeats? Is there an implied difference by your use of “abnormal”? -- S.B.