ECG features

Last edited 06/2020

Ventricular extrasystoles are the commonest type of arrhythmia that occur after a myocardial infarction.

Features include:

  • ventricular extrasystoles have abnormally wide QRS complexes (>120 ms)

  • ST segment and T wave are usually opposite in polarity to the QRS

  • complete compensatory pause - the underlying sinus rythm continues undisturbed

  • the next P wave has a normal morphology but is usually not conducted through the AVN

Ventricular ectopics are common and usually of no clinical significance. Rarely they have the potential to induce ventricular fibrillation particularly if they coincide with the T wave of a preceding beat - this is described as the 'R on T phenomenon'.

For more details regarding ventricular premature contraction then click here

Reference:

  • Adgey AA, Geddes JS. Lancet. 1977 Apr 30;1(8018):951