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 114

ECG 114


Basic rhythm

Sinus rhythm, regular at 60 bpm.

P waves


PR interval

Shortened (120 ms).


Wide (180 ms), preceded by a spike, with atypical morphlogy in all parts of the trace.

ST segment, T waves

Widespread changes in the repolarisation.

QT interval



Spike with ventricular pacing.
Normal P wave.


Ventricular pacing.


The double chamber (DDD) cardiac pacemaker detects atrial activity and stimulates the ventricles. Usually, the catheter is placed at the apex of the right ventricle or, even better, in the interventricular septum, and the appearance of the QRS is of an atypical left bundle branch block. In this case, the catheter is implanted in the septum, which explains the unusual look of the QRS complex and the short PR interval.




Reading level

2 / 3