I suffered an episode of atrial fibrillation, having never had one before. It started in the early morning on Friday and resolved spontaneously on Saturday evening. In between was a visit to the E.R. and an appointment with my cardiologist. Also a couple of new meds: a blood thinner and a CCB.
In the meantime I went for a couple of walks, which were fine, and tried jogging but didn't get more than about 100 yards before gasping for breath.
The meds will hopefully help prevent a recurrence of the a-fib. They may adversely affect performance, we'll have to see.