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 051

ECG 051


Basic rhythm

Sinus rhythm, regular at 85 bpm.

P waves


PR interval

Prolonged (240 ms).


Enlarged (160 ms); large amplitude S wave in I and aVL; rsR pattern; right axis deviation (+130°).

ST segment


T waves


QT interval



Right axis deviation. Small q waves in II,III and aVF with big R waves.
Profound S waves in I and aVL.
Prolonged PR interval.
Right Bundle Branch Block.


First degree A-V block and bifascicular block (complete right bundle branch block and left posterior hemiblock).


With a right bundle branch block the axis stays within normal limits. The right axis deviation is due to a block on the posterior hemibranch. This bifascicular block is associated with a prolongation of the PR interval, probably related to an attack in the left anterior hemibranch (trifascicular block) or disturbed conduction in the A-V node. This kind of trifascicular block generally precedes a complete A-V block and requires a pacemaker to be implanted.


Conduction abnormalities


Reading level

3 / 3