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 066

ECG 066


Basic rhythm

Sinus rhythm, regularly irregular at 68 bpm.

P waves

Normal. Two prolonged PP intervals (1680 ms).

PR interval



Normal axis, duration and morphology.

ST segment


T waves


QT interval



Pause without P wave.


Second degree type 2 sinoatrial block.


The duration of the prolonged PP intervals (1750 ms) is exactly twice as long as the shortest PP intervals (875 ms). This indicates that in the middle of the long interval, there is an interruption in the sinoatrial conduction, suppressing the cardiac cycle which should normally occur at that time.


Conduction abnormalities


Reading level

2 / 3