I have palpitations and premature beats since childhood. Should I be worried?

Hello doctor,

I am a 48 year old male. I have a lean build and do exercises regularly. Since childhood, I had a tendency for heart palpitations and premature beats, mostly when I do not get good sleep or if I am going through some stress. Around 16 years ago, I consulted a cardiologist and had an ECG and echo test done. Both the tests were normal and the doctor said that there is no heart problem and the symptoms were due to anxiety. Since then, palpitations had reduced quite a bit and I only had premature beats sometimes. Four days back, I had not slept well the previous night and in the afternoon, I had a very heavy lunch at work. After that, when I had to walk a little distance, I felt that I was having premature beats. It subsided after four to five minutes. When I returned to my office, I felt the same sensation again. In the evening, I was perfectly fine when I returned home. I even walked up three floors without a problem. On the next day, I did my regular exercise which includes some running, without any problem. A day later, I had to go to work, with only four hours of sleep. In the evening, I had some beer after which I felt the premature beats again. But, they subsided after five minutes. From the last two days, there is no problem at all. There was no other symptom during these episodes. My BP is always normal, which I regularly get checked. I have no other medical illness till date, except for a tendency to worry about my health. Please guide me.