Arrhythmia | Definition | Practice Drills

Welcome to our Arrhythmia Training Center providing definitions, practice drills, quizzes, lessons and interactive guides.

Arrhythmia Definition

A heart arrhythmia is an irregular heart beat: the beat may be too fast, too slow, or the rhythm may be irregular.


Arrhythmias can be classified by their origin (atria or ventricles) and by heart rate.


tachycardia ekg tracing example

A fast (over 100 beats per minute) heart rate is called tachycardia. Tachycardias can originate in the atria or ventricles.

Supraventricular arrhythmias include:

  • Atrial fibrillation, which is a chaotic, fast heart rhythm. Fairly common. Risk of developing atrial fibrillation increases with age.
  • Atrial flutter, a rapid heart beat, but not as chaotic as atrial fibrillation.
  • Supraventricular tachycardia, originating above the ventricles. It can last for seconds to hours. Several types of supraventricular tachycardia can be diagnosed.
  • Wolff-Parkinson-White syndrome, is a second electrical pathway between atria and ventricles that bypasses the atrioventricular node. It can cause supraventricular tachycardia.

Ventricular arrhythmias include:

  • Long QT syndrome is an abnormal EKG pattern that reflects disorder of the heart's electrical signals resulting in fast and chaotic heartbeats. During exercise or stress, long QT syndrome can cause dangerous arrhythmias.
  • Premature ventricular contractions are abnormal (and extra) heartbeats that originate in the ventricles. This abnormality is also called PVC or Premature Ventricular Complex. It is fairly common abnormality.
  • Ventricular fibrillation is a rapid and chaotic cardiac rhythm. The ventricles quiver rather than pump, which diminished blood pressure and flow. Ventricular fibrillation demands immediate emergency medical attention.


bradycardia ekg tracing example

Bradycardia describes slow heart rates (under 60 beats per minute). A slow heart rate may be normal, for example, in athletes. In other patients, it may be a sign of an abnormal heart condition. Problems in the heart's electrical conduction system cause abnormalities such as:

  • Heart Block, which is an interruption of the heart's electrical signals moving to the ventricles. Heart block may be congenital or caused by heart disease or due to aging.
  • Sick Sinus Syndrome, which is due to a failure of the sinus node to generate reliable electrical impulses.
  • Tachy-brady syndrome describes a heart sometimes beating too fast and sometimes beating too slowly.

Premature Beat

Premature Beat is a term that describes an extra beat, occurring earlier than normal.

Arrhythmia Signs and Symptoms

Common arrhythmia signs or symptoms include:

  • An irregular heartbeat
  • Palpitations, which are feelings that the heart has skipped a beat or is fluttering, or is beating too fast or too vigorously)
  • A slow heartbeat

Other signs and symptoms include:

  • Dizziness and light-headedness
  • Fainting or nearly fainting
  • Weakness
  • Sweating
  • Shortness of breath
  • Chest pain
  • Anxiety

Additionally, many arrhythmias do not create easily noticed signs or symptoms

Arrhythmia Symptoms - EKG Training

Several types of tests may be employed to reveal certain arrhythmia symptoms and to diagnose arrhythmias: electrocardiograms, holter monitors, event monitors, stress tests, echocardiograms, electrophysiology studies, head-up-tilt-table tests and cardiac catheterization. Here we provide training tools focused on electrocardiograms. We provide these training tools:

  • Arrhythmia Introduction Course
  • Practice Drills
  • Graded Quiz

Training - Introduction

A good starting point 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 practice drills allow students to build skills interactively.

EKG Basics

Practice Drills

The heart arrhythmia practice drills provide a test EKG tracing and users are asked to identify the type of arrhythmia. 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.

Practice Drills


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

External References