Video Courses Articles
Video Courses Articles For Institutions Log In GET STARTED

About us | Help


Cardiac Conduction: General Principles

In this course, we explain important concepts in the ECG diagnosis of cardiac conduction abnormalities. The principles explained here will facilitate your learning in the area of tachyarrhythmia diagnosis

1.0 x AMA PRA Category 1 Credits™
Available on the Pro Plan



2026In this course, we define the key term ‘aberrant conduction’. We teach you how to identify the likely site of origin, within the heart, of escape rhythms and ectopic beats. We teach you how to recognize normal cardiac conduction on the ECG. We teach you the anatomy of the arterial blood supply of the cardiac conducting system. A knowledge of this vascular anatomy is necessary to understand important ECG abnormalities in ischemic heart disease. The principles and definitions explained here will facilitate your learning in the area of tachyarrhythmia diagnosis.


Planner and Author: Dr John Seery MB PhD

  • Consultant Physician at St. Vincent's University Hospital, Dublin, Ireland
  • Lecturer at the School of Medicine and Medical Science, University College Dublin, Ireland
  • Studied medicine at the University of Cambridge, United Kingdom
  • A Natural Sciences graduate of Trinity College Dublin, Ireland
  • PhD in Cell Biology from University College London, United Kingdom

Planner: Dr Karen Strahan PhD (University of Cambridge), Head of Editorial
Planner: Tommy O'Sullivan, CME Manager

Estimated Time to Complete

1.0 hours

Target Audience

  • Physicians
  • Nurses
  • Nurse Practitioners
  • Physician Assistants
  • Paramedics

Learning Objectives

Upon successful completion of this activity, you will be able to:

  • Explain the concept of latent pacemakers
  • Identify normal versus aberrant conduction on the ECG
  • Determine the likely anatomical site of the origin of an escape rhythm based on ECG analysis
  • Know how to distinguish between atrial and ventricular premature contractions
  • Constantly distinguish between ectopic beats and escape beats on the ECG

Course Content

  • Introduction
  • The Frontal Schematic
  • Normal Cardiac Automaticity
  • Normal Conduction and the QRS Duration
  • Aberrant Conduction
  • Latent Pacemakers and Escape Rhythms
  • Fusion Complexes on the ECG
  • Ectopic Beats
  • Ectopic Beats - Pauses
  • Normal Cardiac Conduction on the ECG
  • Blood supply of the Cardiac Conducting System
  • Quiz

Release date


Expiration date


Instructions for Participation

Participants must complete the online activity during the valid period as noted above.
Follow these steps:

  1. View videos in sequence
  2. Complete quiz
  3. Complete the activity evaluation form to provide feedback for continuing education purposes and for the development of future activities
  4. Download the Certificate of Completion

Relevant Financial Disclosures

Acadoodle adheres to the ACCME's Standards for Integrity and Independence in Accredited Continuing Education. Any individuals in a position to control the content of a CE activity, including faculty, planners, reviewers or others are required to disclose all relevant financial relationships with ineligible entities (commercial interests). All relevant conflicts of interest have been mitigated prior to the commencement of the activity.

Planners and faculty for this activity have no relevant financial relationships with commercial interests to disclose.


Garcia T and Miller G. (2004) Arrhythmia Recognition: The Art of Interpretation. 1st Edition, Jones & Bartlett Learning.

Mangoni ME and Nargeot J. Genesis and regulation of heart automaticity. Physiol Rev. 2008;88(3):919-82.

Futami C et al. The arterial blood supply of the conducting system in normal human hearts. Surg Radiol Anat. 2003;25:42-9.

Williams PL. (1980) Gray’s Anatomy. Williams PL and Warwick R, Eds. Angiology (the coronary arteries) 669-73. 36th Edition, Churchill Livingstone, Edinburgh.

Suyama AC et al. Differentiation between aberrant ventricular conduction and ventricular ectopy in atrial fibrillation using RR Interval scattergram. Circulation. 1993;88(1):2307-14.

Titus JL. Symposium, Cardiac arrhythmias (Part 1). Anatomy of the conduction system. Circulation. 1973;47(1):170-77.

Additional Reading

Yang YC et al. A Case of Complete Heart Block with Diagnostic Challenge and Therapeutic Dilemma. J Investig Med High Impact Case Rep. 2018;6: 2324709618788110.
 doi: 10.1177/2324709618788110.

Jakkoju A et al. Accelerated idioventricular rhythm. Proc (Bayl Univ Med Cent) 2018;31(4):506-7.

ACCME Accreditation Statement

Acadoodle, Ltd is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

Credit Designation Statement

AMA Physician’s Recognition Award

Acadoodle, Ltd designates this enduring material activity for a maximum of 1.0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

DisclaimerPrivacy PolicyTerms of UseData Deletion© Acadoodle 2024