In this situation, the depolarization wave conducts down the left bundle branch and then through the ventricles aberrantly, resulting in an abnormally wide QRS complex.
So if we get a more zoomed out look at the ECG, some of these P waves have a QRS complex right after them, and some don't and are followed by escape beats.
Alright, as a quick recap - Premature ventricular contractions are abnormal heartbeats that originate in the ventricles, and show up as tall and wide QRS complexes on an ECG.
The QRS wave, which is sometimes called the QRS complex, represents the spread of the electrical impulse through the ventricles, or ventricular depolarization.
If the ectopic focus originates in the left ventricle, the wave will depolarizing the left ventricle first and then the right ventricle, which produces a QRS complex that looks like a right bundle branch block.
Peaked T-waves, ST segment elevation, and alterations to the terminal portion of the QRS complex are the early changes of acute myocardial infarction secondary to complete occlusion of a coronary arterial vessel.
If the ectopic focus originates in the right ventricle, the wave will depolarize the right ventricle first and then the left ventricle, and this produces a QRS complex that looks like a left bundle branch block.
In a given ECG lead, T waves are generally concordant with the QRS complex so that in a lead with a dominant R wave such as v6 the T waves are normally upright.
This is followed by elevation of the ST segments above the eyes of electric line in these leads and this in turn is followed by alterations to the terminal portion of the QRS complex.