I did once make that very joke to an Asian Doctor (at the time he was operating a heart scan device on me) who, complete with waggling head, said "I am thinking you are having acute angina" to which I replied .... "I bet you say that to all the girls" .... he didn't get it but the nurse burst out laughing at which said Doctor looked even more puzzled...... "And some fell on stoney ground" I thought. Hopefully the nurse explained it after I had gone.
It doesn't pay to make jokes with the medics I have discovered. Their average level of humour never seems to advance beyond dressing up as nurses and pushing a bed down the High Street during Rag Week.