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 148

ECG 148


Basic rhythm

Slightly irregular (2 alternating RR intervals at 360 ms and 340 ms) at approximately 150 bpm.

P waves


PR interval



Normal; small positive notch in V1 at the end of the QRS complex. Alternating amplitude, pronounced in V5. Normal axis.

ST segment, T waves

Widespread significant changes in the terminal phase.

QT interval



Narrow QRS complexes tachycardia.
Two RR interval duration.
r' wave at the end of the QRS complex.


Atrioventricular nodal tachycardia with multiple conduction pathways.


The small positive notch at the end of the QRS complex in V1 (pseudo R wave) is in fact the characteristic P wave of atrioventricular nodal tachycardia. The alternating amplitudes of the QRS complexes and alternating RR interval durations are explained by the presence of several antegrade transnodal conduction pathways. This alternance is rare in this type of tachycardia and is usually seen in A-V tachycardia in the accessory pathway.


Wide QRS complex tachycardia


Reading level

3 / 3