ECG recording sites for improving signal-to-noise ratio during atrial depolarisation

The objective of this study was to identify optimal recording sites for a bipolar ECG lead that would improve signal-to-noise ratio during atrial depolarisation. Body surface potential map (BSPM) data, recorded using the Dalhousie 120-lead system and transformed into 352-node BSPMs, were used for the study. The absolute median for every sample of a subject´s p-wave was calculated across all 352-nodes to determine the point in time where the greatest p-wave amplitude occurred. Normalised p-wave values at this point in time were then extracted across all 352-nodes for each subject. The median of the potentials on each node across all 45 subjects was then calculated to establish a median BSPM from which an optimal ECG lead could be identified. The p-wave amplitudes recorded in this population based optimal ECG lead achieved a median of 83.53% of each subject´s attainable maximum attainable p-wave amplitude. In comparison standard Lead II achieved a median of 71.53%.