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 142

ECG 142


ECG carried out on the same patient as ECG no. 141.

Basic rhythm

Sinus rhythm at 92 bpm.

PQ interval

Prolonged. Every second P wave is not conducted to the ventricles. The PP interval shows variation of approximately 40 ms.



QT interval



Blocked P wave.


Second degree A-V block 2:1.


On this trace it is not possible to say whether the A-V block is a Mobitz type I or Mobitz type II block. The previous trace answers this question, since it allows the block to be located to the A-V node with an extremely reduced Wenckeback period of only 2 QRS complexes. The variation of PP interval is called a ventriculophasic variation.


Conduction abnormalities


Reading level

2 / 3