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 198

ECG 198


Baseline rhythm

Regular at 150 bpm.P-waves: normal.PR interval: variable.QRS: broadened but with 2 morphologies.ST segment: depressed in the precordial leads.T-waves: negative from V2 to V6.QT interval: normal.


Alternance of short and normal PR interval. Intermittent ∂ wave.
Alternance of a QRS complex with pre excitation and normal QRS complex with right bundle branch block.


Sinus tachycardia with RBBB alternating with pre-excitation


This tracing shows sinus tachycardia with a RBBB morphology for every second complex (QRS 2,4,6) with an rSR’ in V1. The other QRS complexes are broad and exhibit pre-excitation with a short PR and a ∂-wave. This is therefore intermittent pre-excitation (WPW syndrome). The refractory period of the accessory pathway is not too short otherwise the pre-excitation would be constant. Note that analysis of the pre-excited QRS is more difficult due to the underlying RBBB in sinus rhythm. Finally, the ST depression is of no significance, because in the presence of a depolarization abnormality, there is also a repolarization abnormality.




Reading level

2 / 3