Dr. Richard Page answers the question: 'Defibrillator Firing Saved My Life?' — -- Question: If my defibrillator fires does that mean it just saved my life from a life threatening heart rhythm ...

After tapping Set Up Now on the first page, you’ll get an explanation of what Irregular Heart Rhythm Notifications looks for, specifically using Fitbit sensor data to detect signs of AFib.

An EP procedure is a medical test that evaluates heart rhythm. A doctor who specializes in heart rhythms, or an electrophysiologic (a type of cardiologist), will typically perform the procedure.

When you have AFib, then your heart goes back to normal rhythm, it’s called paroxysmal atrial fibrillation. If it lasts longer than 7 days, it’s called persistent AFib.

A version of this article appears in print on Jan. 4, 2023, Section A, Page 19 of the New York edition with the headline: Doctors Say Blow to Chest Could Alter Heart Rhythm.