Welcome to our atrial fibrillation reference page.
This page provides a definition followed by an synopsis of EKG features.
Links to our practice drills, quizzes, lessons and interactive guides can be found below.
Definition of Atrial Fibrillation
Atrial fibrillation is an irregular heartbeat which is frequently rapid.
It occurs when the atria (upper heart chambers) beats chaotically.
This atrial beating is out of sync with the ventricles (lower chambers of the heart).
Symptoms of atrial fibrillation can include shortness of breath, exercise intolerance, heart palpitations and weakness.
These symptoms may persist or reoccur.
Atrial Fibrillation Electrophysiology
Atrial Fibrillation occurs when multiple electrical impulses occur within within the atria.
This chaotic electrical activity results in a chaotic wave form between the QRS complexes.
P waves are absent. They are replaced by lower case "f" waves.
No P waves means there is no PR interval measurement.
This rapid electrical activity overwhelms the AV node causing impulses to enter the ventricular conduction system at irregular points.
This results in irregular R to R intervals.
Atrial Fibrillation Rhythm Strip
The following table summarizes the key features of an atrial fibrillation EKG rhythm strip.
||Very fast (> 350 bpm) for Atrial, but ventricular rate may be slow, normal or fast
||Absent - erratic waves are present
||Normal but may be widened if there are conduction delays
A good starting point for learning EKG interpretation is our EKG Basics training course. The course provides training on the key features of an EKG tracing. These features include observing P-wave forms, measurement of EKG intervals and segments, assessment of rhythm, calculating heart rate, and the evaluation of other relevant wave segments. The arrhythmia practice drills allow students to build skills interactively.