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 107

ECG 107


Basic rhythm

Sinus rhythm, regular at 120 bpm.

P waves

Negative in leads I and aVL.

PR interval



Normal morphology and duration. Axis: - 170°.

ST segment

Depression in V5 and V6.

T waves

Negative in V5 and V6.

QT interval



Negative P wave.
Negative QRS complex.


Incorrect positioning of electrodes on the arms.


The inversion of the electrodes placed on the two arms cause the trace to be completely inverted in the peripheral leads, with inversion of the P waves, QRS complexes and T waves. This explains the extreme axis deviation. A left atrial rhythm would invert the P waves in I and aVL without changing the QRS axis. The changes in the ST segment are non-specific in this case.


Various cardiopathy


Reading level

1 / 3