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 146

ECG 146


Basic rhythm

Sinus rhythm, regular at 75 bpm.

P waves


PR interval

Prolonged (320 ms).


Wide (120 ms); positive deflection only in V1 (rR' pattern), wide S wave, deep in lead I. Left axis deviation at the start of the ECG recording, and right axis deviation at the end of the ECG recording.

ST segment, T waves

Widespread significant changes in the terminal phase.

QT interval



Rigth axis deviation.
Prolongation of the PR interval.
Left axis deviation.
Rigth bundle branch block (RBBB).


First degree A-V block. Complete right bundle branch block. Alternance between left anterior and left posterior hemiblock (trifascicular block).


There is disturbed conduction on all pathways. Conduction is permanently blocked in the right branch, and alternately blocked in the anterior hemibranch (left axis deviation) and posterior hemibranch (right axis deviation). This is a sign of a trifascicular block. This type of electrocardiogram means a pacemaker needs to be implanted, since a high-degree A-V block is imminent.


Conduction abnormalities


Reading level

3 / 3