What is the typical appearance of a QRS complex in PVCs?

In the context of premature ventricular contractions (PVCs), the typical appearance of the QRS complex is wide and bizarre. PVCs originate in the ventricles, bypassing the normal conduction pathway through the atria and the His-Purkinje system, resulting in a QRS complex that is wider than normal.

The wide QRS complex occurs because the ventricles contract independently, and the impulse takes longer to travel through the ventricular muscle tissue, which leads to a prolongation of the QRS duration. The term "bizarre" describes the unusual shape and morphology of the QRS complex, which can appear markedly different compared to the usual complexes seen in normal sinus rhythm.

This abnormal morphology can vary between different PVCs and typically stands out significantly against the background of normal heart rhythm complexes on an electrocardiogram. Understanding this appearance helps clinicians identify PVCs in a patient's cardiac rhythm and further assess the patient's overall cardiac function and potential implications for treatment.