An alternative method for correct placement of electrocardiogram electrodes V1 and V2
Abstract
Misplacement of the precordial electrodes V1 and V2 is a common technical error when performing an electrocardiogram. Misplacement may affect interpretation and analysis of an electrocardiogram and is a both a patient safety issue and a cost issue because some conditions may be missed, and false findings may lead to delay in other diagnostics pending a cardiac work-up. The traditional methods to identify the fourth intercostal space has a success rate found in literature between 6% to 90%, with an average success rate less than 50%. An alternative method, the 1/2 – 1/4 method was investigated in this thesis. It was done by attaching the electrodes V1 and V2, by the new method measuring one quarter up on the sternum, in non-urgent patients at St. Olav’s University Hospital, receiving a diagnostic computed tomography of the chest as part of their standard care. The placement of V1 and V2 was confirmed by computer tomography imaging. Fifty consecutive patients were included in the trial. The CT images were also investigated to see if the anatomical proportions of the 1/2–1/4 method were valid. In the electrode trial, 44% had both V1 and V2 placed in the fourth intercostal space. Ninety-two percent of the electrodes were either in the fourth intercostal space or within one intercostal space away from the fourth. The anatomical review of the method found correct location in 95,7% of the patients. Computer tomography imaging appears to be an accurate method to verify electrode placement.