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 143

ECG 143


Basic rhythm

Sinus, 85 bpm

P waves

Normal. After the 8th beat there is a pause broken by a P wave that is slightly different from the preceding waves, clearly visible at aVL. P wave blocked in preceding T wave.

PR interval




QT interval



Sinus pause with atrial escape rhythm.


Sinus pause with blocked atrial extrasystole. Atrial escape beat.


This tracing shows how important it is to study the morphology of the different waves (P and T in the present case). The different morphology of the P wave terminating the prolonged PP wave may be the effect of atrial activation starting in the lower part of the sinus node or the expression of atrial escape. Sinus pause (sinus arrest) is secondary to a blocked atrial extrasystole which can be seen in the preceding T wave.


Conduction abnormalities


Reading level

1 / 3