Which type of QRS deflection is noted in multi-focal PVCs?

Multi-focal premature ventricular contractions (PVCs) originate from multiple ectopic foci in the ventricles, leading to varying QRS complexes on the electrocardiogram (ECG). The nature of the QRS complexes in multi-focal PVCs can be characterized by their width and deflection.

In the case of multi-focal PVCs, the QRS complexes are typically wider than those of normal ventricular depolarization because the electrical impulses generated in the ventricles travel through the myocardial tissue in a non-conductive manner, resulting in a slowing of the ventricular conduction. This broader timeframe for depolarization produces a wider QRS complex.

Moreover, the deflection can be negative, especially when the ectopic foci are located in different areas of the ventricles. As the conduction may not follow the usual pathways, it can result in a variety of QRS morphologies, resulting in some complexes being negatively deflected, particularly in the cases where the ectopic foci are positioned inferiorly or laterally in the ventricles.

Thus, the identification of a negative wide QRS complex as the characteristic of multi-focal PVCs accurately reflects the erratic and varied nature of these contractions as they arise from multiple points of