When I Play Golf After Two Are Three Holes My

When I play golf after two are three holes my heart starts to skip beats it beat three times then beat twice. This going on for 18holes, when I have stop playing golf my heart still skips for about one hr.,I have no other skips until i do some kinds of hard work, I am 77 years old, had a mild heart attack. in 1997,but I had skips before my heart attack.