ECG Directory

Welcome to this interactive ECG course.

Although it is one of the oldest paraclinic exams, dating back to the late 19th century, the ECG is still of crucial clinical use. This examination often still poses problems of interpretation to the medical practitioner.

This course aims to help the student, the practicing physician and even the trained cardiologist to improve his knowledge in electrocardiography. It consists of 250 traces of varying complexity with a description of each one by experts. This allows the reader to compare his analysis with that of the experts. In addition, the areas of interest of the ECG can be activated to be clearly highlighted.

We hope that these plots will be useful to readers and will improve their knowledge.

The ECGs are available sorted by keywords and categories.

ECG 098

ECG 098


Basic rhythm

Sinus rhythm at 100 bpm.

P waves

Present in all parts of the trace, always dissociated from the QRS complexes.


Leads I to III, bradycardia with narrow QRS complexes, 48 bpm, left axis deviation.

Leads aVR, aVL, aVF, V1 and V3

Tachycardia with slightly widened QRS complexes, showing atypical right bundle branch block.

Leads V4 to V6

Tachycardia with slightly widened QRS complexes, alternating between the 2 different morphologies.

ST segment

Widespread and non-specific changes in the terminal phase.


Blocked P wave.
Pseudo RBBB aspect.
A-V dissociation.
QRS complexes with 2 different morphologies.


The same trace shows a combination of different tachycardia and conduction disturbances due to digitalis intoxication.


The A-V dissociation indicates a complete A-V block: all the QRS complexes have a ventricular origin: origin in the bundle of His with left anterior hemibranch block for the narrow QRS complexes, and fascicular tachycardia showing pseudo right bundle branch block. Following this there is alternance between the two types of complex typical of bidirectional tachycardia. Digoxinemia: 8.3 mmol/l.


Wide QRS complex tachycardia


Reading level

3 / 3