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 029

ECG 029


Basic rhythm

Sinus rhythm, regular at 105 bpm.

P waves


PR interval



First complex of the trace: normal duration and axis. Enlarged QRS complex for the sinus complexes at the end of the trace. Runs of wide complex tachycardia with inversion of the polarity of the QRS complexes (positive at the beginning and negative at the end of the run).

ST segment, T waves

Diffuse and signifcant changes in the terminal phase.

QT interval

Extremely marked prolongation above 600 ms.


Long QT interval.
Torsades de pointes.


Torsade de pointes with long QT syndrome.


It is the inversion of the polarity of the QRS complexes during the run (from positive to negative, or from negative to positive depending on the leads) which is characteristic of this type of ventricular tachycardia and it always occurs in the context of a prolonged QT interval. The extrasystole that sets off the tachycardia, even though it is late (420 ms after the end of the preceeding QRS complex), occurs right in the middle of an extraordinarily long repolarisation phase. Long QT syndrome can cause this type of polymorphic tachycardia whatever its origin. The prolongation of the QT interval is most often a side effect of medication, in this case of antiarrhythmic drug treatment with quinidine.


Prolongation of the QT interval


Reading level

1 / 3