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 128

ECG 128


Basic rhythm

Sinus rhythm at 75 bpm.

P waves

Negative in the left part of the trace in leads II, III and aVF. Spikes present before the P waves. In the right part of the trace the P waves are normal.

PR interval




QT interval



Normal P waves.
Negatives P' waves in II,III and aVF initiated with a spike.


AAI pacemaker working normally.


The negative P waves in II, III and aVF are caused by an AAI pacemaker working correctly and programmed to a minimum rate of 75 bpm. As soon as the sinus rhythm is over 75 bpm (right part of the trace) the pacemaker goes into rest mode. The negative P wave in the lower leads proves that the pacemaker catheter is located in the right atrium.




Reading level

2 / 3