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 024

ECG 024


Basic rhythm

Irregular wide complex tachycardia with an average rate above 300/min.

P waves

Not visible.

PR interval

Not definable.


With variable duration, but constantly enlarged, left axis deviation.

ST segment, T waves

Diffuse and significant changes.

QT interval

Not definable.


Irregularly irregular wideQRS complexes tachycardia.


Atrial fibrillation with preexcitation through multiple accessory pathways.


The irregularity of the tachycardia indicates that the basic rhythm is an atrial fibrillation. The particularly high rate could have provoked a functional bundle branch block, which would explain the enlargement of the QRS complex. In the present case, the QRS complexes are only suggestive of a bundle branch block but not absolutely characteristic of one. The Fast, Broad and Irregular (iFBIi) triad must immediately suggest the diagnosis of atrial fibrillation with preexcitation through an accessory pathway. The accessory pathways here are multiple, both on the left and the right, and the morphology of the QRS is highly variable. QRS complexes of the same type, which initially seem to be identical, present small variations in morphology and duration depending on the significance of the preexcitation from one QRS complex to another.




Reading level

3 / 3