I'm 64 and after riding my bicycle, I sometimes experience heart palpitations.  Should I be concerned, since they tend to subside after several minutes.
D001145:Arrhythmias, Cardiac / Q000145:classification* / Q000209:etiology* / Q000503:physiopathology; D015444:Exercise; D006339:Heart Rate; D006801:Humans; D008875:Middle Aged