I Am 72 And In Good Health And Get Plenty

I am 72 and in good health and get plenty of exercise. However, I have noticed that when I my heart rate speeds up to approximately 140 on an elliptical machine I develop pain in my chest, but experience no unusual shortness of breath. When it occurs, I ease off on the exercise. Today, I experienced the same pain while playing tennis. Once again, I feel fine and do not experience any unusual shortness of breath. Fifteen years ago I experienced similar pain, but it was ultimately diagnosed as work tension (treated successfully with atenolol which I no longer take in retirement) after a series of tests, including a cardiogram, which I passed with flying colors. The doctor was concerned about an irregularity noted under high stress while taking a stress test. He determined that the left (i think left) ventricle was not vacating totally, but after all the tests were negative, he felt this condition was not life threatening. However, he continued to have me periodically take sonar and other heart related tests for the next ten years with never any problems detected. My cardiologist has now retired and my current doctor is not a cardiologist. I am not excited about undertaking a new set of tests when the previous tests were all negative. Should I be concerned enough to get a referral to a cardiologist?