Atrial Fibrillation

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 - heart illustration

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.

Rhythm Irregular
Rate Very fast (> 350 bpm) for Atrial, but ventricular rate may be slow, normal or fast
P Wave Absent - erratic waves are present
PR Interval Absent
QRS Normal but may be widened if there are conduction delays
atrial fibrillation ekg strip

EKG Training

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.

EKG Basics

EKG Practice Drills

The heart arrhythmia practice drills provide a test EKG tracing and users are asked to identify the type of arrhythmia. Many of these drills include tachycardia EKG tracings. Each answer is immediately evaluated and the correct classification of the EKG tracing is provided, along with a detailed explanation. A directory of arrhythmias is also provided.

Arrhythmia Practice Drills

ECG Quiz

The quiz is structured like a classroom exam. The quiz present twenty EKGs. Users answer each question and at the end of the quiz, a fully graded report is provided. This graded report provides scoring as well as the correct answer to each question. Top scores and mean scores are also provided. This quiz draws its questions from a library of over 300 EKGs, allowing users to take the quiz multiple times.

ECG Quiz

ECG Monitor Challenge (beta version)

Try the beta version of our ECG monitor challenge. This quiz uses a simulated patient monitor with moving waveform instead of a paper tracing. As with the quiz described above, twenty questions are presented, then a graded report is available.

ECG Monitor Challenge