This happens from time to time and is not usually because they have been so overtaken by the Holy Spirit that they swoon. It seemed a little more serious than that, and indeed was.
Despite the fact that I had been thinking during the week that I needed to do a bit more/better sermon preparation in order that the receivers might be able to have a chance of receiving it well...and I was a little bit more conscientious...I just decided that it was best to jettison it in mid-stream.
Not much else you can do when all eyes and ears are elsewhere.
We always need to be coy about how much of the preaching exercise depends on we preachers any way.
Perhaps the incident was a sermon in itself. I was able to draw out a 30 second reflection after the ambulance had been and gone that what I was actually talking about was the presence of Christ in the world, and that so often we didn't cope well with things like a medical emergency during worship because we have invested so much energy in making worship a cocoon against the approach of the world.
Any way, A was taken off to hospital and says (in her nineties) that she plans to live for another 20 years!