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 070

ECG 070


Basic rhythm

Sinus rhythm at 90/min, QRS at 47/min.

P waves

Appear normal.

PR interval

Prolonged (220 ms); every second P wave is blocked.


Wide(120 ms) rSR' pattern in V1. Enlarged S wave, thickened in I. Normal axis.

ST segment

Oblique descending depression, outlined in V1 and V2.

T waves


QT interval



Blocked P wave.
rSR' aspect typical for rigth bundel branch block (RBBB).


Mobitz type 2 second degree A-V block, 2:1 conduction; right bundle branch block.


The conduction is permanently blocked on the right branch of the bundle of His. The prolongation of the PR interval is caused by conduction being slowed on the left branch, which becomes a complete block on every second beat (P waves blocked). This intermittent conduction disturbance is intranodal (on both branches of the bundle of His); if it became permanent, the escape rhythm would be very slow and difficult to tolerate. Implantation of a permanent pacemaker is indicated.


Conduction abnormalities


Reading level

2 / 3