Do you understand how the ECG machine even records electrical signals? Here we outline the basics of electrocardiography and prepare to dive into cardiac anatomy by reviewing Limb and Precordial Lead placement.

To master pathological ECG diagnoses we must first appreciate and explain the nuances of normal waveforms. We use the ECG to further explain the physiology of SA, AV and myocardial tissues from an anatomical perspective.

Here we build a base beginning at the cellular level. We breakdown the cardiac action potential, correlating each phase with its corresponding ECG waveforms. We begin to align our understanding of cardiac anatomy to the ECG

Deep dive into AV Node physiology and the association between P waves and QRS complexes. This section outlines the anatomical and electrophysiological differences between First, Second and Third Degree AV Blocks and how to recognize them on ECG.

Early beats come in the form of Premature Atrial, Junctional or Ventricular Contractions. We dive into the anatomy of each so that we can understand exactly how they differ on ECG.

Wide QRS complexes can be from multiple causes, one of which is Right or Left Bundle Branch Blocks. Here we dive into their anatomy and how to identify each on ECG.

The Sinus Node is the pacemaker of the heart. Here we dig into how we can determine if it is functioning appropriately and, if not, what backup rhythms might save the day.

Excessive structural development (hypertrophy) of either the right or left ventricular myocardium can manifest as changes to QRS morphology on ECG. Here we dive into the anatomy that governs those pathological properties.

Atrial depolarization results in the P wave on ECG. In this module, we dive into P wave changes that are associated with pathological enlargement of the right and left atria.

Certain arrhythmias arise from atrial tissue. Here we dive into the anatomy and pathophysiology associated with Ectopic Atrial Rhythms, Wandering Atrial Pacemaker, Atrial Fibrillation and Atrial Flutter and how that explains each of their findings on ECG.

"SVT" comprises a group of rhythms, most commonly AV Nodal Reentry Tachycardia (AVNRT) and AV Reentry Tachycardia (AVRT). We dive into these rhythms in this module, and discuss how Wolff-Parkinson-White (WPW) Syndrome plays a role.

The AV Junction and Ventricular Myocardium do not often produce its own rhythm. Here we dive into ECG findings when they do: Accelerated Junctional and Accelerated Idioventricular Rhythms. 

Monomorphic and Polymorphic Ventricular Tachycardia (VT) as well as Ventricular Fibrillation are critical rhythms that must be accurately identified on ECG. This module details each of their mechanisms and how the ECG gives evidence of each.

STEMI and NSTEMI are "do not miss" diagnoses on ECG. Here we discuss the mechanism of ST segment changes in ischemic tissue. We also touch on the ECG findings of Pericarditis in this module.

Pacemakers are common treatments for AV Block and Sinus Node Dysfunction. Learn how to identify pacemaker patterns on ECG and assess how well the pacemaker is functioning.

Changes to the extracellular (serum) levels of electrolytes causes changes to the cardiac action potential and thus, ECG. Learn about the most common electrolyte imbalances and the mechanism behind the ECG changes of each.

Brugada Syndrome and Arrhythmogenic Right Ventricular Dysplasia (ARVD) are reviewed in this module, as these are inherited conditions that can predispose someone to lethal arrhythmias. Learn how to identify them on ECG.

The Left Bundle Branch gives off fascicles that supply conduction to the Left Ventricle. These, like any other tissue, can become blocked and cause characteristic ECG changes. In this module, we review Left Anterior and Posterior Fascicular Blocks, Bifascicular Blocks and Trifascicular Blocks.

Non-cardiac conditions can cause cardiac manifestations. Here we detail the most common and critical conditions that manifest themselves on ECG. Examples include Cerebral T Waves, Lyme Carditis and Autoimmune conditions.

Now that we understand the cardiac cycle and action potential, it is time to understand antiarrhythmic mechanism of action. We also dive into non-cardiac drugs that can cause electrophysiological side effects (and alter the ECG, of course). 

Test your ECG knowledge with over 100 multiple choice questions and video reviews.

Watch over 150 individual ECG Case Studies. With each case, download the blank ECG handout and watch each 7-10 minute video interpretation of real world ECGs.