Figure 6.(.

A) Premature ventricular contractions (PVCs) uniform in morphology and “bigeminy” in frequency, without any other poor prognostic features in the examination, considered “benign.” (B) Triplet monomorphic PVCs (also called ventricular tachycardia (VT)) at a slow rate. (C) Four to six PVCs in polymorphic “Salvo” form, requring careful evaluation. (D) Multiform (polymorphic) PVCs in 2 different morphologies. They became more frequent and finally evolved into polymorphic VT in the exercise test and are considered “malignant.” (E) An interpolated PVC requires more attention, as the probability of coinciding with the T wave in front of it increases (“R on T” phenomenon). (F) Another PVC with a malignant feature; a very short coupling interval causes the “R on T” phenomenon, initiating polymorphic VT.