A few weeks ago, I was having some shortness of breath, and went to my OB's office to get it checked out. The nurse took my pulse, then had another nurse come in to take it, then a third nurse, during which I said, "I know I'm not dead, but you guys are scaring me a little." Turns out they were just verifying that they'd all heard some "skipped beats."
They sent me to a cardiologist, who told me the so-called skipped beats were not actually skipped, but premature ventricular contractions, where the ventricle tries to initiate the heartbeat, interrupting the normal rhythm of the heart. He said it was a minor thing — I could have had it my whole life, or it was stress and pregnancy-induced, or some combination of the three, and recommended I come back for a cardiac echo just to make sure my heart didn't have some underlying structural problem we should know about. He also suggested I relax and cut out caffeine. Ha and ha.
The cardiac echo revealed nothing more than a benign murmur ("Your heart is very strong") and the cardiologist sent me on my way ("See you when you're old, and maybe not even then.")
I am fine, and I am lucky.