Spatial Pattern of P Waves in Paroxysmal Atrial Fibrillation Patients in Sinus Rhythm and Controls

Abstract

Atrial depolarization is characterized by a single dipole with time-varying amplitude and orientation with significant differences in dipole trajectory between patients with PAF and HCs.

Non-invasive localization of atrial ectopic beats by using simulated body surface P-wave integral maps

“…All the experimental studies based on the analysis of the ECG and BSPM [1–7,13] highlighted the need to localize the origin of the ectopic foci non-invasively and provided a first-hand knowledge of the changes on P-wave characteristics and potential distribution on the torso surface when the atrial tachycardia origins at different atrial regions. These studies drew interesting conclusions: i) P-wave morphology in lead V1 was the most informative for the diagnosis of left atrial rhythms [1]; ii) when depolarization starts from a focus within the RA and coronary sinus, the resultant P-waves consistently assumed an orientation determined by the site of stimulation [3]; and iii) P-wave dipole evolution may correlate the dipole trajectory with specific RA-paced regions [13], but when the ectopic site is localized in the LA, the poles changed its position and amplitude very fast giving rise to big jumps forward and backwards.…”

“…Those approaches provided dense maps of P-wave signals, triggered from stimulation catheters placed at a few locations inside the atria that allowed characterising the signals and analysing their distribution on the torso surface. More recently, a combination of BSPM with surface wavefront propagation maps [12], and with the spatial evolution of the electrical dipole [13] have been proposed to get an insight into the determination of the ectopic focus origin that maintains the arrhythmia and the dynamics of the dipole of atrial depolarization prior to the ablation procedure. However, none of those approaches based on the forward problem have provided an efficient and systematic method to localize the specific origin of the ectopic excitation.…”

Three-dimensional Multiscale Modelling and Simulation of Atria and Torso Electrophysiology

“…They provided a first-hand knowledge of the changes on P-wave characteristics and potential distribution on the torso surface when the atrial tachycardia origins at different atrial regions. These studies drew interesting conclusions: i) P-wave morphology in lead V1 was the most informative for the diagnosis of left atrial rhythms (Harris et al 1968); ii) when depolarization starts from a focus within the RA and CS, the resultant P-waves consistently assumed an orientation determined by the site of stimulation (Leon et al 1970); and iii) P-wave dipole evolution may correlate the dipole trajectory with specific RA-paced regions (Giacopelli et al 2012), but when the ectopic site is placed in the LA, the poles changed its position and amplitude very fast giving rise to big jumps forward and backwards. However, several shortcomings prevented authors from clearly relating torso surface electrical phenomena to atrial myocardial events: a) the techniques used were not much accurate mainly with P-waves with low amplitudes or isoelectric in surface leads; b) it was always emphasized the necessity of using intracardiac intervention to measure the atrial depolarization times; and c) the isopotential map characterized by a single maximum and/or a single minimum did not show a direct correlation with the origin of the atrial ectopic foci.…”

“…All the experimental studies based on the analysis of the ECG and BSPM (Harris et al 1968;Massumi et al 1969;Leon et al 1970;Mirvis 1980;Kawano et al 1983;Kawano et al 1989;Ishihara et al 1997;Giacopelli et al 2012) highlighted the need to localize the origin of the ectopic foci non-invasively. They provided a first-hand knowledge of the changes on P-wave characteristics and potential distribution on the torso surface when the atrial tachycardia origins at different atrial regions.…”

“…Those approaches provided dense maps of P-wave signals, triggered from stimulation catheters placed at a few sites inside the atria that allowed characterising the signals and analysing their distribution on the torso surface. More recently, a combination of BSPM with surface wavefront propagation maps (M. S. , and with the spatial evolution of the electrical dipole (Giacopelli et al 2012) have been proposed to get an insight into the determination of the ectopic focus origin that maintains the arrhythmia and the dynamics of the dipole of atrial depolarization prior to the ablation procedure. However, none of those approaches based on the forward problem have provided an efficient and systematic method to localize the specific origin of the ectopic excitation.…”