Body Surface Two-Dimensional Spectral Map of Atrial Fibrillation Using Vector-Projected 187 Channel Electrocardiography

Abstract

SummaryAtrial cycle length during atrial fibrillation and flutter waves may be correlated with atrial refractoriness and organization. The nature of the frequency by spectral analysis may reflect a profile of atrial cycle length. In this study, we developed a novel body surface 2-dimensional spectral map during fibrillation using vector-projected 187 channel ECG (187ch VP-ECG).The study consisted of 28 patients (24 with atrial fibrillation (AFIB) and 4 atrial flutter (AFL) with valvular heart disease). We performed spectral analysis by maximum entropy modeling (MEM) in 4 second nonaveraged 187ch electrical current waves by 187ch VP-ECG. Body surface spectral features were displayed according to the frequency and power magnitude components. We verified the accuracy of the spectral features by a 64ch magnetocardiography (MCG).The average dominant frequency in AFL by 187ch VP-ECG was lower than those in AFIB (4.6 ± 0.9 Hz in AFL, 7.2 ± 0.9 Hz in AFIB, P < 0.01). Comparison of average dominant frequency between 187ch VP-ECG and 64 ch MCG demonstrated good agreement (y = 0.86x+0.84, r 2 = 0.89, P < 0.0001). Body surface 2-dimensional spectral features demonstrated homogenous spectrum patterns in AFL, and in-homogenous spectrum patterns in AFIB.In conclusion, novel body surface spectral mapping using 187ch VP-ECG may represent a 2-dimensional spectral feature that may be related to atrial refractoriness and organization. (Int Heart J 2012; 53: 5-10) Key words: Atrial fibrillation, Body surface map, Vector projection, Spectral analysis, Magnetocardiography A trial fibrillation (AFIB) was reported to be an independent risk factor for stroke in the Framingham Study. In patients with coronary heart disease or cardiac failure, atrial fibrillation doubled the stroke risk in men and trebled the risk in women.1,2) Left atrial myocardial extension on to pulmonary veins in humans by anatomic observation might be relevant for atrial arrhythmias.3) Certain cases of AFIB may be maintained by small re-entrant rotors that result in a hierarchical distribution of frequencies throughout the atria.4,5) Recent advances in interventional catheter ablation and surgical pulmonary vein isolation, radical treatments have been applied in patients with atrial flutter (AFL) and AFIB. 6,7) Holma, et al reported noninvasive assessment of the atrial cycle length during atrial fibrillation in humans. 8) Sanders, et al reported spectral analysis and frequency mapping identify localized sites of high-frequency activity during AFIB in humans with different distributions in paroxysmal and permanent AFIB.9,10) Determination of the features of cycle length of excitation of atrial fibrillation is important for a therapeutic strategy.Magnetocardiography (MCG) has the potential to detect 3-dimensional (3D) electrical current density and electrical repolarization phenomena because the magnetic field is unaffected by the shape of the lungs and the torso.11,12) Previously, we reported a 3D spectral map of the atrial fibrillation generated by 64ch cardiomagneti...

Vector synthesis high‐resolution electrocardiography, atrial natriuretic peptide and N‐terminal prohormone brain natriuretic peptide for estimation of cardiac load in pregnancy

“…With regard to vector synthesis high‐resolution ECG indices, X‐Y‐Z lead ECG were averaged and processed through a band‐pass filter (finite impulse response [FIR] type, 45–200 Hz), and filtered QRS (fQRS) was measured in vector magnitude waveforms. The inflection points of the P, QRS, and T waves were determined using differentiation . From lead vectors corresponding to the center electrode and 187 electrodes on the body surface (Fig.…”

“…The inflection points of the P, QRS, and T waves were determined using differentiation. [6][7][8]14 From lead vectors corresponding to the center electrode and 187 electrodes on the body surface ( Fig. 1), a 187-channel ECG was synthesized, current density determined, and a "D distribution map of RTc dispersion representing the variation of the repolarization time was prepared ( Fig.…”

“…In 2007, Nakai et al developed an original vector synthesis 187-channel high-resolution ECG based on the vector projection theory by Frank,5 and reported that cardiomyopathy, cardiac load, and fetal ECG can be non-invasively evaluated using this device. [6][7][8][9] The traditional ECG is displayed as a weave form converted from electric potential, but vector synthesis high-resolution ECG can present the recover time (RT) disorientation, which may be helpful in predicting which patients with non-sustained ventricular tachycardia (VT) are likely to have inducible VT by programmed stimulation, and more, detect the spatial distribution of high-frequency late positional and vermicular depolarization, and increased RT dispersion suggestive of a right ventricular outflow region. 6 In 2013, Terata et al succeeded in analyzing the cardiac load of pregnant and post-partum women using vector synthesis high-resolution ECG without echocardiography.…”

Detection of Peripartum Myocardial Burden by Vector-Projected 187 Channel Electrocardiography and Serum NT-proBNP

“…Spectral analysis of R-R variability was performed, and the sympathetic index was calculated as the ratio of the maximum peak of the high-frequency region (around 0.3 Hz) to the maximum peak of the lowfrequency region (around 0.1 Hz) shown in Figure 1. [7][8][9][10] 187-channel ECG was based on vector-projected theory and was obtained from 187 body surface electrode positions. Two-dimensional repolarization function maps (RTc dispersion maps) were determined from the current density map (Figure 1), and the repolarization index (recovery time (RTc) dispersion and Tpeak-end (Tp-e) dispersion) were determined.…”

“…Nakai, et al reported that markers of abnormal repolarization, such as T wave alternans and RTc dispersion, could be successfully assessed as risk stratification for myocardial injury using a vector-projected 187-channel high-resolution electrocardiograph system (DREAM-ECG). [7][8][9] In this study, we evaluated peripartum myocardial burden in pregnant women using the DREAM-ECG system and serum biochemical markers.…”