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 144

ECG 144


Basic rhythm

Regular at 100 bpm.

P waves

2:1 P wave to QRS ratio.

P wave frequency 200/min.

PR interval

Normal for the conducted P wave (2nd blocked P wave).


Prolonged. Small spike at the start of the QRS complex visible in V3. Left axis.

ST segment, T waves

Widespread changes in the terminal phase.

QT interval



Electrostimulated QRS complex with a spike at the beginning of each QRS complex.
Atrial tachycardia with 2:1 AV block (2 P' waves for 1 QRS complex).


Atrial tachycardia or atrial flutter with second degree A-V block and 2:1 conduction. Cardiac pacing of the ventricles.


The regular, high-frequency P waves are a sign of atrial tachycardia with 2:1 conduction (every second P wave is blocked). According to the interpretation of the atrial complex given (P or F) the diagnosis should be one of atrial tachycardia or atrial flutter with 2:1 conduction. The ventricles are paced, causing the QRS complex to be prolonged, with Q waves in leads I and aVL and a QS pattern in leads V1 to V5 which should not be attributed to an infarction. The pacemaker is working correctly in DDD mode in accordance with the programmed parameters.


Wide QRS complex tachycardia


Reading level

3 / 3