Ventricular Extrasystoles - ECG
Ventricular extrasystoles are common findings and when isolated, they mean no clinical significance and may be found in completely healthy individuals. In the ECG curve we may find one or more abnormally shaped QRS complexes. The QRS complex corresponding to the ventricular extrasystole is dilated (above 120ms). The ventricular extrasystole is followed by a full compensatory pause*. The shape of the QRS complex can tell us a lot about the place of the origin of the extrasystole. When it originates from the right ventricle, it has a shape similar to LBBB and when it originates from the left ventricle, it is formed similarly to RBBB.
*Full compensatory pause means that distance of the QRS complex before the ventricular extrasystole and QRS complex after the extrasystole equals two RR as RR is the distance of any two common QRS (see the picture below).
In this one-lead recording we see an isolated ventricular extrasystole with a wide QRS complex (blue). The full compensatory pause is present as the distance between QRS complexes is equal to two RR (red).
Conclusion: The significance of ventricular extrasystoles rises with their numbers. The more there are present, the more probable is a heart disease. Occasional extrasystoles are not important; multiple extrasystoles may be related to ischemia, acute infarction, valvular heart disease, etc.
There are multiple ventricular extrasystoles present in this ECG. In the long recorded shape below, I have marked them by blue rectangle. The extrasystoles alternate with the normal rhythm QRS complexes (red ellipses). This situation is referred to as bigeminy and it is a much more serious finding than isolated ventricular extrasystoles.