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 017

ECG 017


Basic rhythm

Sinus rhythm at 80 bpm.

P waves

Normal (first and third QRS complexes in the peripheral leads, second and fourth QRS complexes in the precordial leads) or in the form of runs of atrial extrasystoles, with a rate of 260 bpm.

PR interval

Normal after the sinus P wave, A-V block of variable degrees during the runs.


Normal axis and morphology.

ST segment


T waves


QT interval



Blocked P' wave.
Run of atrial tachycardia.


Run of atrial extrasystoles (with A-V block).


The runs of atrial extrasystoles always precede a sustained atrial tachycardia of short duration, which can become classical atrial fibrillation. This atrial arrhythmia originates from ectopic foci located in the junction between the pulmonary veins and the left atrium (in this case, the left pulmonary veins, considering the vertical axis of the extrasystoles).




Reading level

2 / 3