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Locati ET, Pappone C, Heilbron F, van Dam PM. CineECG provides a novel anatomical view on the normal atrial P-wave. EUROPEAN HEART JOURNAL. DIGITAL HEALTH 2022; 3:169-180. [PMID: 36713023 PMCID: PMC9708036 DOI: 10.1093/ehjdh/ztac007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/09/2022] [Accepted: 02/03/2022] [Indexed: 02/01/2023]
Abstract
Aims Novel CineECG computed from standard 12-lead electrocardiogram (ECG) correlated the ventricular electric activity to ventricular anatomy. CineECG was never applied to reconstruct the spatial distribution of normal atrial electric activity into an atrial anatomic model. Methods and results From 6409 normal ECGs from PTB-XL database, we computed a median beat with fiducial points for P-and Q-onset. To determine the temporo-spatial location of atrial activity during PQ-interval, CineECG was computed on a normal 58-year-old male atrial/torso model. CineECG was projected to three major cardiac axes: posterior-anterior, right-left, base-roof, and to the standard cardiac four-chamber, left anterior oblique, and right anterior oblique (RAO) views. In 6409 normal subjects, during P-wave, CineECG moved homogeneously from right atrial roof towards left atrial base (-54 ± 14° in four-chamber view, 95 ± 24° RAO view). During terminal PQ-interval, the CineECG direction was opposite, moving towards left atrial roof (62 ± 27° in four-chamber view, 78 ± 27° RAO view). We identified the deflection point, where the atrial CineECG changes in direction. The time from P-onset to deflection point was similar to P-wave duration. Conclusion CineECG provided a novel three-dimensional visualization of atrial electrical activity during the PQ-interval, relating atrial electrical activity to the atrial anatomy. CineECG location during P-wave and terminal PQ-interval were homogeneous within normal controls. CineECG and its deflection point may enable the early detection of atrial conduction disorders predisposing to atrial arrhythmias.
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Affiliation(s)
- Emanuela T Locati
- Department of Arrhythmology and Electrophysiology, IRCCS Policlinico San Donato, Milano, Italy
| | - Carlo Pappone
- Department of Arrhythmology and Electrophysiology, IRCCS Policlinico San Donato, Milano, Italy,University San Raffaele Vita & Salute, Milano, Italy
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Arumughan J, Bhardwaj A, Sivaraman J. Stability analysis on the effects of heart rate variability and premature activation of atrial ECG dynamics using ARMAX model. Phys Eng Sci Med 2020; 43:1361-1370. [PMID: 33165820 DOI: 10.1007/s13246-020-00940-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/26/2020] [Indexed: 10/23/2022]
Abstract
The cellular action potential of cardiac muscles generates Electrocardiogram (ECG) signals. Disturbances in cardiac cells are determined by analyzing the stability of ECG intervals. The PTa Interval (PTaI) of ECG represents the atrial Action Potential Duration (APD) and the evaluation of the causes of PTaI instability can predict the onset of arrhythmia. This study developed an Autoregressive Moving Average with Exogenous Input (ARMAX) model to explore the roles of Heart Rate Variability (HRV) and Premature Activation (PA) in PTaI dynamics using PTaI and PP Interval (PPI) as exogenous inputs. Minute ECG signals were collected from twenty Normal Sinus Rhythm (NSR) and ten Atrial Tachycardia (AT) volunteers. The EDAN PC ECG system was used in the Modified Limb Lead (MLL) configuration to evaluate instability. The instabilities of PTaI were found at the minimum model orders (Amin) of 10 and 11, in the NSR and AT groups, respectively. In the NSR group, the predominant reason for PTaI instability was HRV, whereas among AT patients, it was largely due to PA that preceded the onset of AT. The proposed model showed better prediction of PTaI with minimum Mean Square Error (MSE) between the measured and predicted PTa Intervals (PTaIs). The factor that led to PTaI instability in AT patients was found to be different from that of the NSR group. The frequency of PA (fPA) was found to contribute more in the AT than the NSR group. The developed ARMAX model was better in predicting instability of atrial ECG dynamics in both groups than other autoregressive models currently in use.
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Affiliation(s)
- Jyothsana Arumughan
- Bio-signals and Medical Instrumentation Laboratory, Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela, Odisha, India
| | - Arya Bhardwaj
- Bio-signals and Medical Instrumentation Laboratory, Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela, Odisha, India
| | - J Sivaraman
- Bio-signals and Medical Instrumentation Laboratory, Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela, Odisha, India.
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Duque M, Aristizábal-Colorado D, Weir D, Gaviria MC, Uribe W. La repolarización auricular y sus implicaciones clínicas. REVISTA COLOMBIANA DE CARDIOLOGÍA 2020. [DOI: 10.1016/j.rccar.2019.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Sivaraman J, Uma G, Langley P, Umapathy M, Venkatesan S, Palanikumar G. A study on stability analysis of atrial repolarization variability using ARX model in sinus rhythm and atrial tachycardia ECGs. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2016; 137:341-351. [PMID: 28110737 DOI: 10.1016/j.cmpb.2016.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 09/26/2016] [Accepted: 10/07/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND The interaction between the PTa and PP interval dynamics from the surface ECG is seldom explained. Mathematical modeling of these intervals is of interest in finding the relationship between the heart rate and repolarization variability. OBJECTIVE The goal of this paper is to assess the bounded input bounded output (BIBO) stability in PTa interval (PTaI) dynamics using autoregressive exogenous (ARX) model and to investigate the reason for causing instability in the atrial repolarization process. METHODS Twenty-five male subjects in normal sinus rhythm (NSR) and ten male subjects experiencing atrial tachycardia (AT) were included in this study. Five minute long, modified limb lead (MLL) ECGs were recorded with an EDAN SE-1010 PC ECG system. The number of minute ECGs with unstable segments (Nus) and the frequency of premature activation (PA) (i.e. atrial activation) were counted for each ECG recording and compared between AT and NSR subjects. RESULTS The instability in PTaI dynamics was quantified by measuring the numbers of unstable segments in ECG data for each subject. The unstable segments in the PTaI dynamics were associated with the frequency of PA. The presence of PA is not the only factor causing the instability in PTaI dynamics in NSR subjects, and it is found that the cause of instability is mainly due to the heart rate variability (HRV). CONCLUSION The ARX model showed better prediction of PTa interval dynamics in both groups. The frequency of PA is significantly higher in AT patients than NSR subjects. A more complex model is needed to better identify and characterize healthy heart dynamics.
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Affiliation(s)
- J Sivaraman
- Department of Biomedical Engineering, Vel Tech MultiTech, Chennai, India.
| | - G Uma
- Department of Instrumentation and Control Engineering, National Institute of Technology, Tiruchirappalli, India
| | - P Langley
- School of Engineering, University of Hull, Hull, United Kingdom
| | - M Umapathy
- Department of Instrumentation and Control Engineering, National Institute of Technology, Tiruchirappalli, India
| | - S Venkatesan
- Department of Cardiology, Madras Medical College, Rajiv Gandhi Government General Hospital, Chennai, India
| | - G Palanikumar
- Department of Instrumentation and Control Engineering, National Institute of Technology, Tiruchirappalli, India
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Kanzaki Y, Inden Y, Ando M, Kamikubo Y, Ito T, Mizutani Y, Kato H, Fujii A, Yanagisawa S, Hirai M, Murohara T. An ECG Index of P-Wave Force Predicts the Recurrence of Atrial Fibrillation after Pulmonary Vein Isolation. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2016; 39:1191-1197. [PMID: 27723112 DOI: 10.1111/pace.12956] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 08/26/2016] [Accepted: 09/20/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Although several prognostic factors of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) have been investigated, the accurate prediction of AF recurrence remains difficult. We propose an electrocardiogram (ECG) index, the P-wave force (PWF), which is the product of the amplitude of the negative terminal phase of the P wave in the V1 electrode and the filtered P-wave duration, obtained by a signal-averaged P-wave analysis. This study was conducted to evaluate the impact of the PWF on the recurrence of AF after PVI. METHODS We retrospectively evaluated 79 paroxysmal AF patients (64 ± 9 years, 56 males) who underwent PVI by cryoballoon ablation. Standard 12-lead ECG and a P-wave signal-averaged electrocardiogram (SAECG) were recorded the day before and 1 month after the PVI procedure. RESULTS During the mean follow-up of 10.2 months, AF recurred in 11 (14%) patients. The PWF 1 month after ablation was significantly higher in the recurrence group compared to that in the nonrecurrence group (8.8 ± 3.1 mVms vs 6.5 ± 2.9 mVms, P = 0.017). The patients with a PWF value ≥9.3 mVms had a significantly greater risk of recurrence after the ablation compared to the patients with a PWF value <9.3 mVms (log-rank test, P < 0.001). CONCLUSION Higher PWF after cryoballoon ablation was associated with poor prognosis during follow-up. The PWF may be a useful and noninvasive marker to predict the recurrence of AF.
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Affiliation(s)
- Yasunori Kanzaki
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yasuya Inden
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Monami Ando
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yosuke Kamikubo
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tadahiro Ito
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshiaki Mizutani
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroyuki Kato
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Aya Fujii
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Satoshi Yanagisawa
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Makoto Hirai
- Department of Cardiology, Nagoya University Graduate School of Health Science, Nagoya, Japan
| | - Toyoaki Murohara
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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PROPOSED SIMPLE METHOD FOR ELECTROCARDIOGRAM RECORDING IN FREE-RANGING ASIAN ELEPHANTS (ELEPHAS MAXIMUS). J Zoo Wildl Med 2016; 47:6-11. [PMID: 27010258 DOI: 10.1638/2015-0162.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Electrocardiography represents a relevant diagnostic tool for detecting cardiac disease in animals. Elephants can present various congenital and acquired cardiovascular diseases. However, few electrophysiologic studies have been reported in captive elephants, mainly due to challenging technical difficulties in obtaining good-quality electrocardiogram (ECG) tracings, and no data are currently available for free-ranging Asian elephants (Elephas maximus). The purpose of this pilot prospective study was to evaluate the feasibility of using a simple method for recording ECG tracings in wild, apparently healthy, unsedated Asian elephants (n = 7) in the standing position. Successful six-lead recordings (I, II, III, aVR, aVL, and aVF) were obtained, with the aVL lead providing the best-quality tracings in most animals. Variables measured in the aVL lead included heart rate, amplitudes and duration of the P waves, QRS complexes, T and U waves, and duration of the PR, QT, and QU intervals. A negative deflection following positive P waves, representative of an atrial repolarization wave (Ta wave), was observed for five out of the seven elephants.
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Jayaraman S, Gandhi U, Sangareddi V, Mangalanathan U, Shanmugam RM. Unmasking of atrial repolarization waves using a simple modified limb lead system. Anatol J Cardiol 2015; 15:605-10. [PMID: 25550180 PMCID: PMC5336858 DOI: 10.5152/akd.2014.5695] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2014] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE In the present study, a modified limb lead (MLL) system was used to record the Ta wave in sinus rhythm and with AV block in male patients. METHODS Eighty male subjects (mean age 36 ± 7 years) in sinus rhythm and 20 male patients with AV block (mean age 72 ± 5 years) were included in this study. Standard limb lead (SLL) ECGs and MLL ECGs were recorded for 60 seconds each with an EDAN SE-1010 PC ECG system. RESULTS In sinus rhythm subjects, the observable Ta wave duration was 109 ± 4.7 ms, the P-Ta duration was 196 ± 5.1 ms, and the corrected P-Ta duration was 238 ± 7.2 ms. The Ta wave peak amplitude was -42 ± 8 µV. In AV block patients, the Ta wave duration was 314 ± 28 ms the P-Ta duration was 418 ± 29 ms and the corrected P-Ta duration was 46 ± 31 ms, while the Ta wave peak amplitude was -37 ± 9 µV. A correlation was found between the P and Ta wave amplitude, and no correlation was found between the P and Ta wave duration or the Ta amplitude and Ta duration in sinus rhythm and AV block subjects. CONCLUSION The end of the Ta wave is not observable in sinus rhythm subjects, as it extends into the QRS complex and ST segment. In AV block patients, the Ta wave duration was generally three times longer than the observable Ta duration in sinus rhythm subjects.
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Affiliation(s)
- Sivaraman Jayaraman
- Department of Instrumentation and Control Engineering, National Institute of Technology; Tiruchirappalli-India.
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Perego M, Skert S, Santilli RA. Analysis of the atrial repolarization wave in dogs with third-degree atrioventricular block. Am J Vet Res 2013; 75:54-8. [PMID: 24370246 DOI: 10.2460/ajvr.75.1.54] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To characterize the electrocardiographic features of the atrial repolarization (Ta) wave in dogs with third-degree atrioventricular (AV) block. SAMPLE ECGs of 36 dogs with third-degree AV block and no identifiable structural heart diseases. PROCEDURES Standard 12-lead ECGs were acquired with a digital system, and measurements were manually edited. RESULTS A Ta wave was detectable in all dogs for at least 1 ECG lead. The Ta wave had negative polarity in leads I, II, III, and aVF and positive polarity in leads aVL and aVR, with a mean electrical axis of -114.26°. Mean duration and mean amplitude of the Ta wave in lead II were 140.2 milliseconds and -0.09 mV, respectively, with the ratio for the Ta-to-P wave duration of 2.3 and the ratio of Ta-to-P wave amplitude of -0.35. Significant correlations were found between the Ta wave duration and duration of the P-Ta interval, Ta wave amplitude and the ECG lead, Ta wave duration and body weight, and duration of the P-Ta interval and atrial rate. Measurements of the Ta wave were repeatable. CONCLUSIONS AND CLINICAL RELEVANCE Measurements of the Ta wave in dogs with third-degree AV block were repeatable. The values for the Ta wave reported here can be used as reference values for dogs with AV conduction disturbances and an echocardiographically normal atrial size. Further studies are needed to validate these results in dogs with structural heart diseases.
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Affiliation(s)
- Manuela Perego
- Cardiology Division, Clinica Veterinaria Malpensa, Viale Marconi 27, Samarate (VA) Italy
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In-silico modeling of atrial repolarization in normal and atrial fibrillation remodeled state. Med Biol Eng Comput 2013; 51:1105-19. [PMID: 23864549 DOI: 10.1007/s11517-013-1090-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 05/21/2013] [Indexed: 10/26/2022]
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia, and the total number of AF patients is constantly increasing. The mechanisms leading to and sustaining AF are not completely understood yet. Heterogeneities in atrial electrophysiology seem to play an important role in this context. Although some heterogeneities have been used in in-silico human atrial modeling studies, they have not been thoroughly investigated. In this study, the original electrophysiological (EP) models of Courtemanche et al., Nygren et al. and Maleckar et al. were adjusted to reproduce action potentials in 13 atrial regions. The parameter sets were validated against experimental action potential duration data and ECG data from patients with AV block. The use of the heterogeneous EP model led to a more synchronized repolarization sequence in a variety of 3D atrial anatomical models. Combination of the heterogeneous EP model with a model of persistent AF-remodeled electrophysiology led to a drastic change in cell electrophysiology. Simulated Ta-waves were significantly shorter under the remodeling. The heterogeneities in cell electrophysiology explain the previously observed Ta-wave effects. The results mark an important step toward the reliable simulation of the atrial repolarization sequence, give a deeper understanding of the mechanism of atrial repolarization and enable further clinical investigations.
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Krueger MW, Seemann G, Rhode K, Keller DUJ, Schilling C, Arujuna A, Gill J, O'Neill MD, Razavi R, Dössel O. Personalization of atrial anatomy and electrophysiology as a basis for clinical modeling of radio-frequency ablation of atrial fibrillation. IEEE TRANSACTIONS ON MEDICAL IMAGING 2013; 32:73-84. [PMID: 22665507 DOI: 10.1109/tmi.2012.2201948] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Multiscale cardiac modeling has made great advances over the last decade. Highly detailed atrial models were created and used for the investigation of initiation and perpetuation of atrial fibrillation. The next challenge is the use of personalized atrial models in clinical practice. In this study, a framework of simple and robust tools is presented, which enables the generation and validation of patient-specific anatomical and electrophysiological atrial models. Introduction of rule-based atrial fiber orientation produced a realistic excitation sequence and a better correlation to the measured electrocardiograms. Personalization of the global conduction velocity lead to a precise match of the measured P-wave duration. The use of a virtual cohort of nine patient and volunteer models averaged out possible model-specific errors. Intra-atrial excitation conduction was personalized manually from left atrial local activation time maps. Inclusion of LE-MRI data into the simulations revealed possible gaps in ablation lesions. A fast marching level set approach to compute atrial depolarization was extended to incorporate anisotropy and conduction velocity heterogeneities and reproduced the monodomain solution. The presented chain of tools is an important step towards the use of atrial models for the patient-specific AF diagnosis and ablation therapy planing.
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Affiliation(s)
- Martin W Krueger
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany.
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Abstract
Increasing awareness of atrial fibrillation (AF) and its impact on public health revives interest in identification of noninvasive markers of predisposition to AF and ECG-based risk stratification. P-wave duration is generally accepted as the most reliable noninvasive marker of atrial conduction, and its prolongation has been associated with history of AF. However, patients with paroxysmal AF without structural heart disease may not have any impressive P-wave prolongation, thus suggesting that global conduction slowing is not an obligatory requirement for development of AF. P-wave morphology is therefore drawing increasing attention as it reflects the three-dimensional course of atrial depolarization propagation and detects local conduction disturbances. The factors that determine P-wave appearance include (1) the origin of the sinus rhythm that defines right atrial depolarization vector, (2) localization of left atrial breakthrough that defines left atrial depolarization vector, and (3) the shape and size of atrial chambers. However, it is often difficult to distinguish whether P-wave abnormalities are caused by atrial enlargement or interatrial conduction delay. Recent advances in endocardial mapping technologies have linked certain P-wave morphologies with interatrial conduction patterns and the function of major interatrial conduction routes. The value of P-wave morphology extends beyond cardiac arrhythmias associated with atrial conduction delay and can be used for prediction of clinical outcome of a wide range of cardiovascular disorders, including ischemic heart disease and congestive heart failure.
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Affiliation(s)
- Pyotr G Platonov
- Center for Integrative Electrocardiology at Lund University (CIEL) and Arrhythmia Clinic, Skåne University Hospital, Lund, Sweden.
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Holmqvist F, Carlson J, Waktare JEP, Platonov PG. Noninvasive evidence of shortened atrial refractoriness during sinus rhythm in patients with paroxysmal atrial fibrillation. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2009; 32:302-7. [PMID: 19272058 DOI: 10.1111/j.1540-8159.2008.02236.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Shortening of the atrial refractory period is the key feature of atrial electrical remodeling during atrial fibrillation (AF). During sinus rhythm (SR), assessment of the atrial refractoriness is hampered by the fact that the atrial repolarization wave (Ta wave) is largely obscured by the following QRST complex. The purpose of this study was to study the Ta wave in subjects with paroxysmal AF during SR with third-degree atrioventricular (AV) block, and in matched controls. METHODS Fifteen patients (mean age 70 +/- 10 years, five males) with paroxysmal AF undergoing AV-nodal ablation were studied. Fifteen age- and gender-matched subjects (mean age 71 +/- 9 years, five males) with third-degree AV block, without a history of heart disease, were used as controls. Standard 12-lead electrocardiograms (ECGs) were recorded and transformed to orthogonal leads and studied using P-wave signal averaging technique. RESULTS The P to Ta interval was shorter (408 +/- 47 ms vs 451 +/- 53 ms, P = 0.017) and in Lead Y the Ta peak location was earlier (156 +/- 31 ms vs 187 +/- 34 ms, P = 0.002) in subjects with paroxysmal AF than in the controls. The P-wave duration (126 +/- 15 ms vs 129 +/- 17 ms, P = 0.59) and morphology was similar in AF patients and controls. CONCLUSIONS In this study, the ECG signs of shorter atrial refractoriness associated with a history of AF are visualized for the first time during SR. The finding of the earlier location of the PTa peak in AF subjects implies that a possible indicator of increased arrhythmia susceptibility may be visible already in the unprocessed ECG.
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Holmqvist F, Carlson J, Platonov PG. Detailed ECG analysis of atrial repolarization in humans. Ann Noninvasive Electrocardiol 2009; 14:13-8. [PMID: 19149788 DOI: 10.1111/j.1542-474x.2008.00268.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
INTRODUCTION Data on human atrial repolarization are scarce since the QRS complex normally obscures its ECG trace. In the present study, consecutive patients with third-degree AV block were studied to better describe the human Ta wave. METHODS AND RESULTS Forty patients (mean age 75 years, 17 men) were included. All anti-arrhythmic drugs were discontinued before ECG recording. Standard 12-lead ECGs were recorded, transformed to orthogonal leads and studied using signal-averaged P wave analysis. The average P wave duration was 124 +/- 16 ms. The PTa duration was 449 +/- 55 ms (corrected PTa 512 +/- 60 ms) and the Ta duration (P wave end to Ta wave end) was 323 +/- 56 ms. The polarity of the Ta wave was opposite to that of the P wave in all leads. The Ta peaks were located at 196 +/- 55 ms in Lead Y, 216 +/- 50 ms in Lead X, and 335 +/- 92 in Lead Z. No correlation was found between P wave duration and Ta duration, or between Ta peak amplitude and Ta duration. The morphology of the Ta wave was similar regardless of the interatrial conduction. CONCLUSIONS The Ta wave has the opposite polarity, and the duration is generally two to three times that, of the P wave. Although the Ta peak may occasionally be located in the PQ interval during normal AV conduction, it is unlikely that enough information can be obtained from analysis of this segment to differentiate normal from abnormal atrial repolarization. Hence, an algorithm for QRST cancellation during sinus rhythm is needed to further improve analysis.
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Hull J, Arvandi A, Nugent K. PQ segment depression in a patient with a benign atrial tumor. Int J Cardiol 2008; 130:e22-4. [DOI: 10.1016/j.ijcard.2007.07.045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2007] [Accepted: 07/01/2007] [Indexed: 11/29/2022]
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Häggmark S, Haney MF, Johansson G, Biber B, Näslund U. Vectorcardiographic ST deviations related to increased heart rate in the absence of ischemia in an experimental pig model. J Electrocardiol 2006; 39:169-76. [PMID: 16580414 DOI: 10.1016/j.jelectrocard.2005.08.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Indexed: 10/24/2022]
Abstract
The electrocardiographic ST segment may change when heart rate (HR) increases. We aimed to analyze vectorcardiographic ST relation and myocardial conditions during controlled HR increases in anesthetized pigs. The relative parameters ST change vector magnitude and ST change vector angle were calculated at paced HRs ranging from 85 to 175 beats per minute. ST change vector magnitude increased from baseline 6.3 +/- 1.3 to 26.0 +/- 3.1 microV (P < .01; range, 4-50 microV) at HR 175 beats per minute with similar changes in ST change vector angle, whereas the absolute parameter ST vector magnitude demonstrated a heterogeneous pattern without any systematic relation to HR changes. Microdialysis results from left ventricular wall, with analysis of glucose, lactate, and pyruvate, showed no sign of ischemia during pacing. Potassium concentrations did not change during pacing. We conclude that significant HR-related ST vector changes can occur in the absence of myocardial ischemia.
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Affiliation(s)
- Sören Häggmark
- Cardiothoracic Surgery, Heart Centre, University Hospital, Umeå, SE-901 85 Umeå, Sweden.
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Abstract
A 12-lead electrocardiogram (ECG) graphically displays the heart's electrical activity. It is the most common clinical tool for detection and diagnosis of heart disease, and is especially useful for detecting conditions related to abnormalities of cardiac rhythm. ECG should be considered in patients who have known cardiovascular disease or an increased risk for it. The responsibility for correctly interpreting an ECG lies with the physician, who should be able to recognize patient-dependent errors, operator-dependent errors, and artifact. Current ECG tracings should always be compared with previous tracings. Following a specific routine and methodical analysis of the data will ensure an accurate interpretation result. In the worst-case scenario, they can always be faxed or transmitted for inter-consultation with a more experienced reader.
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Häggmark S, Haney MF, Jensen SM, Johansson G, Näslund U. ST-segment deviations during pacing-induced increased heart rate in patients without coronary artery disease. Clin Physiol Funct Imaging 2005; 25:246-52. [PMID: 15972028 DOI: 10.1111/j.1475-097x.2005.00613.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION In order to interpret ST-segment changes as an indicator of ischemia in patients with higher heart rates (HRs), the relation between ST-segment levels and HR needs to be well defined in subjects without coronary artery disease. METHODS Eighteen patients with normal ECGs in the catheterization laboratory, after radiofrequency ablation of AV nodal re-entry tachycardia or an accessory pathway were included. Computerized online vectorcardiography (VCG) was performed during step-wise atrial pacing-induced increases in HR up to 150 beats min(-1) (bpm). The ST-vector magnitude (ST-VM) and the relative ST change vector magnitude (STC-VM) were analysed at the J point, J + 20 and J + 60 ms. RESULTS There was no divergence in the course of ST-VM or STC-VM based on J point + 0, 20, or 60 ms during increasing HR. The STC-VM mean values increased progressively during increases in HR above 100 bpm, with an average increase in STC-VM of 15-20 microV per 10 bpm increases in HR. The ST-VM response during HR increases showed a heterogeneous and unpredictable pattern. CONCLUSION The STC-VM increases linearly with rising HRs above 100 bpm. The STC-VM can exceed widely recognized ischemic thresholds during higher HRs in the absence of ischemia. The choice of J point time to ST-VM measurements as tested here is not important for the STC-VM relation to HR at these HR levels. Further clinical testing is needed to improve the diagnostic specificity of STC-VM measurements during increased HRs.
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Affiliation(s)
- Sören Häggmark
- Cardiothoracic Surgery, Heart Centre, University Hospital, Umeå, Sweden.
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Herweg B, Chang F, Chandra P, Danilo P, Rosen MR. Cardiac memory in canine atrium : identification and implications. Circulation 2001; 103:455-61. [PMID: 11157700 DOI: 10.1161/01.cir.103.3.455] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Memory is a diverse biological phenomenon whose importance in the ventricle has been demonstrated. We hypothesized its occurrence in the atrium, contributing to the modulation of cardiac rhythm. METHODS AND RESULTS We analyzed P and Ta waves in conscious chronically instrumented dogs with complete heart block. Animals were atrioventricularly sequentially paced at 5% greater than the sinus rate from the lateral right atrium (RA) during control, followed by 2 periods of 1-hour test pacing at 50% greater than the sinus rate, or by equivalent test pacing from the left atrial appendage (LAA) at 5% or 50% greater than the sinus rate. Recovery RA pacing periods of 20- and 30-minute duration, respectively, succeeded each test pacing period. RA test pacing at either rate did not affect the variables measured, but changing the pacing site from RA to LAA altered the P and Ta waves. Displacement of the spatial atrial gradient vector occurred during recovery from LAA pacing, was more marked at rapid pacing rates, and manifested accumulation and resolution consistent with cardiac memory. Concurrently, the right effective refractory period decreased. CONCLUSIONS Memory is demonstrable in canine atrium, showing rapid onset, accumulation during successive pacing periods, and resolution on cessation of pacing. Given its association with a reduced effective refractory period, it may contribute to the substrate for atrial arrhythmias.
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Affiliation(s)
- B Herweg
- Department of Pharmacology, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
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