Diagnostical mistakes in ablation procedures associated with a high placement of the leads V1-V3.

The misplacement of electrodes for surface electrocardiogram (ECG) recording that we use daily as a reference for mapping precise locations in invasive procedures may, besides inducing diagnostical mistakes, greatly increase the duration of the procedure and making more feasible the incidence of complications, especially in ablation of arrhythmic substrates of ventricular outflow tracts such as premature ventricular contractions (PVC's) and accessory pathways, if the right precordial electrodes (V1-V3) are higher positioned.