Newly Developed Signal-Averaged Vector-Projected 187-Channel Electrocardiogram Can Evaluate the Spatial Distribution of Repolarization Heterogeneity

Nakai, Kenta; Miyake, Fumihiko; Kasanuki, Hiroshi; Shoda, Morio; Futagawa, Keisuke; Takahashi, Atsushi; Matsuda, Yuko; Nishizaki, Takashi; Tsuboi, Junichi; Okabayashi, Hitoshi; Itoh, Masatoshi; Kawata, Hiroshi

doi:10.1536/ihj.49.153

Cited by 16 publications

(19 citation statements)

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“…[14][15][16] We hypothesized that AF cycle length may be correlated locally with atrial refractoriness and globally with the degree of atrial organization. In the present study, we developed body surface spectral maps of AFIB and AFL using 187ch VP-ECG, and verified the significance of the accuracy by 64ch MCG.…”

Section: Discussionmentioning

confidence: 99%

“…13) Recently, we developed a 187 channel vectorprojected ECG (187ch VP-ECG) that could evaluate 2-dimensional (2D) characteristics of recovery time dispersion and high frequency late potentials. [14][15][16] We hypothesized that AF cycle length may be correlated locally with atrial refractoriness and globally with the degree of atrial organization. In the present study, we developed body surface spectral maps of AFIB and AFL using 187ch VP-ECG, and verified the significance of the accuracy by 64ch MCG.…”

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confidence: 99%

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

et al. 2012

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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...

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Section: Discussionmentioning

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

et al. 2012

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“…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.…”

Section: Subjectsmentioning

confidence: 99%

“…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. 7,8) In brief, values of dispersion were calculated by the difference of the maximum and minimum of corrected RTc intervals and Tp-e intervals after Bazzet correction shown in Figure 1.…”

Section: Subjectsmentioning

confidence: 99%

“…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.…”

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

et al. 2013

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SummaryThere is no reliable method of screening for pregnant women at high risk of developing severe myocardial disorders. In this study, we used vector-projected 187 channel electrocardiography (DREAM-ECG) and serum biochemical markers to evaluate peripartum myocardial burden in pregnant women. Forty-one pregnant women were examined at 36-37 weeks gestation (GW36), 7 days postpartum (PPD7), and 1 month postpartum (PPM1). Ten non-pregnant control women were assessed at a single time point. Heart rate, sympathetic index, and repolarization index (RTc dispersion) were quantified using the DREAM-ECG system, and serum levels of NT-proBNP, cardiac troponin T, estrogen, and progesterone were determined. Heart rate and the sympathetic index decreased from GW36 to PPM1 (P = 0.0031). The repolarization index decreased over time and was greater than in non-pregnant controls (31 ± 13 ms). Estrogen and progesterone at PPD7 and PPM1 were significantly lower than those at GW36 (P < 0.0001, P < 0.001). NT-proBNP at PPD7 was greater than at GW36 (median 29 pg/mL at GW36, 86 pg/mL at PPD7), and decreased at PPM1 in comparison to PPD7 (median 18.5 pg/mL). Troponin T was in the normal range during the whole period (< 0.003 ng/mL). In conclusion, these results indicate that the peripartum myocardial burden in pregnant women does not return to normal nonpregnant levels by PPM1. We propose that both repolarization indexes such as RTc dispersion by DREAM-ECG and serum biochemical markers may identify pregnant women at high risk of developing severe myocardial damage in the peripartum period. (Int Heart J 2013; 54: 140-145)

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Novel algorithm for identifying T-wave current density alternans using synthesized 187-channel vector-projected body surface mapping

Nakai

Takahashi

Suzuki³

et al. 2010

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The noninvasive evaluation of ventricular T-wave alternans (TWA) in patients with lethal ventricular arrhythmias is an important issue. In this study, we propose a novel algorithm to identify T-wave current density alternans (TWCA) using synthesized 187-channel vector-projected body surface mapping (187-ch SAVP-ECG). We recorded 10 min of 187-ch SAVP-ECG using a Mason-Likar lead system in the supine position. A recovery time (RT) dispersion map was obtained by averaging the 187-ch SAVP-ECG. The TWCA value was determined from the relative changes in the averaged current density in the T-wave zone (Tpeak ± 50 ms) for two T-wave types. We registered 20 ECG recordings from normal controls and 11 ECG recordings from nine subjects with long QT syndrome (LQT). We divided LQT syndrome subjects into two groups: group 1 provided 9 ECG recordings without visually apparent TWAs, and group 2 provided 2 ECG recordings with visually apparent TWAs. The QTc interval values in the LQT groups were higher than those in the control (515 ± 60 ms in LQT G-1, 600 ± 27 ms in LQT G-2 vs. 415 ± 19 ms in control, P < 0.001). The RTendc dispersion values among the LQT subjects were higher than those of the control subjects (48 ± 19 ms in LQT G-1, 65 ± 30 ms in LQT G-2 vs. 24 ± 10 ms in control, P < 0.01). The mean TWCA value was significantly higher in the LQT G-2 group with visually apparent TWCAs (0.5 ± 0.2% in control, 2.1 ± 1.2% in LQT G-1, and 32.3 ± 6.9% in LQT G-2). Interestingly, the two-dimensional distribution of TWCA in LQT was inhomogeneous and correlated with the distribution of increased RT dispersion. We conclude that a novel algorithm using 187-ch SAVP-ECG might provide new insights into body surface TWCA.

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Newly Developed Signal-Averaged Vector-Projected 187-Channel Electrocardiogram Can Evaluate the Spatial Distribution of Repolarization Heterogeneity

Cited by 16 publications

References 25 publications

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

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

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

Novel algorithm for identifying T-wave current density alternans using synthesized 187-channel vector-projected body surface mapping

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