i have been experiencing heart palpitations for the past two weeks. no chest pain. no short of breath. no lightheadness. just annoying. I take Toprol xl 50 mg for the palpitations but they seem to be frequent. I also take synthroid .75mcg. just had blood work & thyroid was within normal range. I am usually a stressful person but nothing out of the ordinary. I smoke occasionally, do not use any caffeine. I am under the care of a cardiologist for the palpitations. I am 62 yrs old. not overweight & exercise daily with no problems. should I be concerned.