How is AFib Diagnosed?
Your physician can diagnose AFib with certain tests of the heart, including:

Echocardiogram, which uses ultrasound to evaluate heart size, pumping strength, and how well valves function
EKG, which records the heart’s electrical impulses (heart beats) on graph paper
Holter Monitor, in which patient wears a device that provides one to two days of continuous EKG readings to see how the heart works when doing normal daily activities
Stress Test, which assesses effect of stress on the heart brought on by exercise.