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 054

ECG 054


Basic rhythm

Narrow complex tachycardia, regular at 187 bpm.

P waves

Present in the form of a small negative deflection at the end of the QRS complex in the inferior leads and reflected by a pseudo r' wave in V1.

PR interval


Duration, morphology and axis normal.

ST segment

Depression in most of the leads, especially marked in V3 (5 mm).

T waves


QT interval



ST segment depression.
No visible P waves.
Narrow QRS complexes tachycardia.


Typical atrioventricular nodal reentrant tachycardia.


The P' wave that is often invisible in atrioventricular nodal re-entrant tachycardia (concealed in the QRS complex) can be seen here in the form of a small deflection deforming the terminal portion of the QRS complex. The ST segment depression, which is relatively common in narrow complex tachycardias, has a large amplitude here, but must not be interpreted as a sign of ischaemia.


Narrow QRS complex tachycardia


Reading level

2 / 3