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Sample records for 12-lead electrocardiography ecg

  1. A cloud computing based 12-lead ECG telemedicine service

    PubMed Central

    2012-01-01

    Background Due to the great variability of 12-lead ECG instruments and medical specialists’ interpretation skills, it remains a challenge to deliver rapid and accurate 12-lead ECG reports with senior cardiologists’ decision making support in emergency telecardiology. Methods We create a new cloud and pervasive computing based 12-lead Electrocardiography (ECG) service to realize ubiquitous 12-lead ECG tele-diagnosis. Results This developed service enables ECG to be transmitted and interpreted via mobile phones. That is, tele-consultation can take place while the patient is on the ambulance, between the onsite clinicians and the off-site senior cardiologists, or among hospitals. Most importantly, this developed service is convenient, efficient, and inexpensive. Conclusions This cloud computing based ECG tele-consultation service expands the traditional 12-lead ECG applications onto the collaboration of clinicians at different locations or among hospitals. In short, this service can greatly improve medical service quality and efficiency, especially for patients in rural areas. This service has been evaluated and proved to be useful by cardiologists in Taiwan. PMID:22838382

  2. Ambulance 12-lead electrocardiography transmission via cell phone technology to cardiologists.

    PubMed

    Hsieh, Jui-Chien; Lin, Bo-Xuan; Wu, Feng-Ren; Chang, Pei-Chann; Tsuei, Yi-Wei; Yang, Chung-Chi

    2010-10-01

    This study demonstrates transmission of 12-lead electrocardiography (ECG) in an ambulance to the cell phone of the attendant emergency medical technician and then to the hospital and to cell phones of off-site cardiologists. The emergency medical technician cell phone receives Extensible Markup Language files generated by a Phillips Extensible Markup Language ECG instrument via Wi-Fi-based wireless network and then sends them to an ECG-processing server at the hospital over the mobile telephone network. After reducing ECG noises and artifacts, the server converts files to Digital Imaging and Communications in Medicine-based ECG reports stored in Picture Archiving and Communication System. These reports are sent to the cell phones of off-site cardiologists. Consequently, on-site Emergency Department physicians and off-site cardiologists can discuss ECG reports via Picture Archiving and Communication System on their computers or cell phones to prepare for the most appropriate treatment while the patient is on the way to the hospital. In conclusion, this 12-lead ECG transmission e-technology expands the functions of a 12-lead ECG instrument and facilitates more efficient prehospital cardiac care.

  3. Computational Electrocardiography: Revisiting Holter ECG Monitoring.

    PubMed

    Deserno, Thomas M; Marx, Nikolaus

    2016-08-05

    Since 1942, when Goldberger introduced the 12-lead electrocardiography (ECG), this diagnostic method has not been changed. After 70 years of technologic developments, we revisit Holter ECG from recording to understanding. A fundamental change is fore-seen towards "computational ECG" (CECG), where continuous monitoring is producing big data volumes that are impossible to be inspected conventionally but require efficient computational methods. We draw parallels between CECG and computational biology, in particular with respect to computed tomography, computed radiology, and computed photography. From that, we identify technology and methodology needed for CECG. Real-time transfer of raw data into meaningful parameters that are tracked over time will allow prediction of serious events, such as sudden cardiac death. Evolved from Holter's technology, portable smartphones with Bluetooth-connected textile-embedded sensors will capture noisy raw data (recording), process meaningful parameters over time (analysis), and transfer them to cloud services for sharing (handling), predicting serious events, and alarming (understanding). To make this happen, the following fields need more research: i) signal processing, ii) cycle decomposition; iii) cycle normalization, iv) cycle modeling, v) clinical parameter computation, vi) physiological modeling, and vii) event prediction. We shall start immediately developing methodology for CECG analysis and understanding.

  4. Development and clinical study of mobile 12-lead electrocardiography based on cloud computing for cardiac emergency.

    PubMed

    Fujita, Hideo; Uchimura, Yuji; Waki, Kayo; Omae, Koji; Takeuchi, Ichiro; Ohe, Kazuhiko

    2013-01-01

    To improve emergency services for accurate diagnosis of cardiac emergency, we developed a low-cost new mobile electrocardiography system "Cloud Cardiology®" based upon cloud computing for prehospital diagnosis. This comprises a compact 12-lead ECG unit equipped with Bluetooth and Android Smartphone with an application for transmission. Cloud server enables us to share ECG simultaneously inside and outside the hospital. We evaluated the clinical effectiveness by conducting a clinical trial with historical comparison to evaluate this system in a rapid response car in the real emergency service settings. We found that this system has an ability to shorten the onset to balloon time of patients with acute myocardial infarction, resulting in better clinical outcome. Here we propose that cloud-computing based simultaneous data sharing could be powerful solution for emergency service for cardiology, along with its significant clinical outcome.

  5. 12-lead Holter electrocardiography. Review of the literature and clinical application update.

    PubMed

    Su, Li; Borov, Stefan; Zrenner, Bernhard

    2013-06-01

    This brief review is focused on 12-lead Holter electrocardiogram (ECG) recording including a review of the literature and the description of the advantages of its application. The standard 12-lead ECG provides a bedside snapshot of the electrical activity of the heart including vector information, but a snapshot of a few beats for some seconds might miss the whole story. Traditional Holter ECG displaying two or three leads may record all heart beats during a prolonged period, but the limited vector information might be a cause of shortcomings in the ECG diagnosis. The 12-lead Holter ECG overcomes these disadvantages and should be preferred for detecting episodes of arrhythmias, localize their origin or the localization of myocardial ischemia. The 12-lead Holter ECG monitoring is efficient in the evaluation of the effect of drugs or interventional therapeutic procedures, i.e., efficiency of biventricular pacing in patients with heart failure and permanent atrial fibrillation (AF). The automatic analysis of parameters in 12-lead Holter ECG is also providing information for risk stratification. In order to obtain a precise diagnosis based on the criteria established on standard ECG, the "real" 12-lead ECG with ten electrodes is advocated.

  6. The clinical application of a PACS-dependent 12-lead ECG and image information system in E-medicine and telemedicine.

    PubMed

    Hsieh, Jui-Chien; Lo, Hsiu-Chiung

    2010-08-01

    This study presents a software technology to transform paper-based 12-lead electrocardiography (ECG) examination into (1) 12-lead ECG electronic diagnoses (e-diagnoses) and (2) mobile diagnoses (m-diagnoses) in emergency telemedicine. While Digital Imaging and Communications in Medicine (DICOM)-based images are commonly used in hospitals, the development of computerized 12-lead ECG is impeded by heterogeneous data formats of clinically used 12-lead ECG instrumentations, such as Standard Communications Protocol (SCP) ECG and Extensible Markup Language (XML) ECG. Additionally, there is no data link between clinically used 12-lead ECG instrumentations and mobile devices. To realize computerized 12-lead ECG examination procedures and ECG telemedicine, this study develops a DICOM-based 12-lead ECG information system capable of providing clinicians with medical images and waveform-based ECG diagnoses via Picture Archiving and Communication System (PACS). First, a waveform-based DICOM-ECG converter transforming clinically used SCP-ECG and XML-ECG to DICOM is applied to PACS for image- and waveform-based DICOM file manipulation. Second, a mobile Structured Query Language database communicating with PACS is installed in physicians' mobile phones so that they can retrieve images and waveform-based ECG ubiquitously. Clinical evaluations of this system indicated the following. First, this developed PACS-dependent 12-lead ECG information system improves 12-lead ECG management and interoperability. Second, this system enables the remote physicians to perform ubiquitous 12-lead ECG and image diagnoses, which enhances the efficiency of emergency telemedicine. These findings prove the effectiveness and usefulness of the PACS-dependent 12-lead ECG information system, which can be easily adopted in telemedicine.

  7. Discussion of "Computational Electrocardiography: Revisiting Holter ECG Monitoring".

    PubMed

    Baumgartner, Christian; Caiani, Enrico G; Dickhaus, Hartmut; Kulikowski, Casimir A; Schiecke, Karin; van Bemmel, Jan H; Witte, Herbert

    2016-08-05

    This article is part of a For-Discussion-Section of Methods of Information in Medicine about the paper "Computational Electrocardiography: Revisiting Holter ECG Monitoring" written by Thomas M. Deserno and Nikolaus Marx. It is introduced by an editorial. This article contains the combined commentaries invited to independently comment on the paper of Deserno and Marx. In subsequent issues the discussion can continue through letters to the editor.

  8. Findings From 12-lead Electrocardiography That Predict Circulatory Shock From Pulmonary Embolism: Systematic Review and Meta-Analysis

    PubMed Central

    Shopp, Jacob D.; Stewart, Lauren K.; Emmett, Thomas W.; Kline, Jeffrey A.

    2015-01-01

    Objectives Treatment guidelines for acute pulmonary embolism (PE) recommend risk-stratifying patients to assess PE severity, as those at higher risk should be considered for therapy in addition to standard anticoagulation to prevent right ventricular (RV) failure, which can cause hemodynamic collapse. The hypothesis was that 12-lead electrocardiography (ECG) can aid in this determination. The objective of this study was to measure the prognostic value of specific ECG findings (the Daniel score, which includes heart rate over 100 beats/min, presence of the S1Q3T3 pattern, incomplete and complete right bundle branch block [RBBB], and T wave inversion in leads V1–V4; plus ST elevation in lead aVR, and atrial fibrillation suggestive of RV strain from acute pulmonary hypertension), in patients with acute PE. Methods Studies were identified by a structured search of MEDLINE, PubMed, EMBASE, the Cochrane library, Google Scholar, Scopus, and bibliographies in October 2014. Case reports, non-English papers, and those that lacked either patient outcomes or ECG findings were excluded. Papers with evidence of a predefined reference standard for PE and the results of 12-lead ECG, stratified by outcome (hemodynamic collapse, defined as circulatory shock requiring vasopressors or mechanical ventilation, or in-hospital or death within 30 days) were included. Papers were assessed for selection and publication bias. The authors also assessed heterogeneity (I2) and calculated the odds ratios (OR) for each ECG sign from the random effects model if I2 > 24% and fixed effects if I2 < 25%. Funnel plots were used to examine for publication bias. Results Forty-five full-length studies of 8,209 patients were analyzed. The most frequent ECG signs found in patients with acute PE were tachycardia (38%), T wave inversion in lead V1 (38%), and ST elevation in lead aVR (36%). Ten studies with 3,007 patients were included for full analysis. Six ECG findings (heart rate > 100 beats/min, S1Q3T3

  9. Findings From 12-lead Electrocardiography That Predict Circulatory Shock From Pulmonary Embolism: Systematic Review and Meta-analysis.

    PubMed

    Shopp, Jacob D; Stewart, Lauren K; Emmett, Thomas W; Kline, Jeffrey A

    2015-10-01

    Treatment guidelines for acute pulmonary embolism (PE) recommend risk stratifying patients to assess PE severity, as those at higher risk should be considered for therapy in addition to standard anticoagulation to prevent right ventricular (RV) failure, which can cause hemodynamic collapse. The hypothesis was that 12-lead electrocardiography (ECG) can aid in this determination. The objective of this study was to measure the prognostic value of specific ECG findings (the Daniel score, which includes heart rate > 100 beats/min, presence of the S1Q3T3 pattern, incomplete and complete right bundle branch block [RBBB], and T-wave inversion in leads V1-V4, plus ST elevation in lead aVR and atrial fibrillation suggestive of RV strain from acute pulmonary hypertension), in patients with acute PE. Studies were identified by a structured search of MEDLINE, PubMed, EMBASE, the Cochrane library, Google Scholar, Scopus, and bibliographies in October 2014. Case reports, non-English papers, and those that lacked either patient outcomes or ECG findings were excluded. Papers with evidence of a predefined reference standard for PE and the results of 12-lead ECG, stratified by outcome (hemodynamic collapse, defined as circulatory shock requiring vasopressors or mechanical ventilation, or in hospital or death within 30 days) were included. Papers were assessed for selection and publication bias. The authors also assessed heterogeneity (I(2) ) and calculated the odds ratios (OR) for each ECG sign from the random effects model if I(2) > 24% and fixed effects if I(2) < 25%. Funnel plots were used to examine for publication bias. Forty-five full-length studies of 8,209 patients were analyzed. The most frequent ECG signs found in patients with acute PE were tachycardia (38%), T-wave inversion in lead V1 (38%), and ST elevation in lead aVR (36%). Ten studies with 3,007 patients were included for full analysis. Six ECG findings (heart rate > 100 beats/min, S1Q3T3, complete RBBB, inverted T

  10. Accurate Interpretation of the 12-Lead ECG Electrode Placement: A Systematic Review

    ERIC Educational Resources Information Center

    Khunti, Kirti

    2014-01-01

    Background: Coronary heart disease (CHD) patients require monitoring through ECGs; the 12-lead electrocardiogram (ECG) is considered to be the non-invasive gold standard. Examples of incorrect treatment because of inaccurate or poor ECG monitoring techniques have been reported in the literature. The findings that only 50% of nurses and less than…

  11. Accurate Interpretation of the 12-Lead ECG Electrode Placement: A Systematic Review

    ERIC Educational Resources Information Center

    Khunti, Kirti

    2014-01-01

    Background: Coronary heart disease (CHD) patients require monitoring through ECGs; the 12-lead electrocardiogram (ECG) is considered to be the non-invasive gold standard. Examples of incorrect treatment because of inaccurate or poor ECG monitoring techniques have been reported in the literature. The findings that only 50% of nurses and less than…

  12. Dobutamine stress magnetocardiography for the detection of significant coronary artery stenoses - a prospective study in comparison with simultaneous 12-lead electrocardiography.

    PubMed

    Park, J-W; Leithäuser, B; Vrsansky, M; Jung, F

    2008-01-01

    Exercise electrocardiography is an imperfect test for the detection of coronary artery disease (CAD). Magnetocardiography detects cardiac electrical disturbances associated with myocardial ischemia. We prospectively investigated the accuracy of high-dose dobutamine stress magnetocardiography (DS-MCG) and simultaneous electrocardiography (DS-ECG) for the detection of significant CAD. 100 patients with an intermediate pre-test probability for CAD underwent DS-MCG using a multichannel magnetometer prior to invasive coronary angiography. Patients were examined at rest and during a standard dobutamine-atropine scheme. Significant reduction of epicardial current strength/density during stress, reconstructed from the magnetic field map and superposed on a virtual heart model indicates myocardial ischemia. A 12-lead DS-ECG was recorded simultaneously. Significant coronary artery stenosis was defined as > or = 70% of lumen reduction. Without beta-blocker all 100 patients reached the targeted heart rate. The image quality of DS-MCG and DS-ECG was sufficient for analysis in all patients. In 19 patients CAD was ruled out angiographically. Thirty two or seven patients revealed coronary artery stenoses of 30-49% or of 50-69%, respectively. In 42 patients we found significant stenoses of > or = 70%. In 41 of these patients DS-MCG revealed myocardial ischemia. The sensitivity of DS-MCG and DS-ECG for the detection of significant coronary artery stenosis was 97.6% and 26.2%, the specificity of DS-MCG and DS-ECG 82.8% and 82.8%, respectively. DS-MCG can be performed with a standard dobutamine/atropine stress protocol. DS-MCG yields a significantly higher accuracy for the detection of significant coronary artery stenosis than DS-ECG.

  13. PDF-ECG in clinical practice: A model for long-term preservation of digital 12-lead ECG data.

    PubMed

    Sassi, Roberto; Bond, Raymond R; Cairns, Andrew; Finlay, Dewar D; Guldenring, Daniel; Libretti, Guido; Isola, Lamberto; Vaglio, Martino; Poeta, Roberto; Campana, Marco; Cuccia, Claudio; Badilini, Fabio

    2017-08-12

    In clinical practice, data archiving of resting 12-lead electrocardiograms (ECGs) is mainly achieved by storing a PDF report in the hospital electronic health record (EHR). When available, digital ECG source data (raw samples) are only retained within the ECG management system. The widespread availability of the ECG source data would undoubtedly permit successive analysis and facilitate longitudinal studies, with both scientific and diagnostic benefits. PDF-ECG is a hybrid archival format which allows to store in the same file both the standard graphical report of an ECG together with its source ECG data (waveforms). Using PDF-ECG as a model to address the challenge of ECG data portability, long-term archiving and documentation, a real-world proof-of-concept test was conducted in a northern Italy hospital. A set of volunteers undertook a basic ECG using routine hospital equipment and the source data captured. Using dedicated web services, PDF-ECG documents were then generated and seamlessly uploaded in the hospital EHR, replacing the standard PDF reports automatically generated at the time of acquisition. Finally, the PDF-ECG files could be successfully retrieved and re-analyzed. Adding PDF-ECG to an existing EHR had a minimal impact on the hospital's workflow, while preserving the ECG digital data. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Evaluation of a none compressed 12-lead ECG transmission via internet using IPSec.

    PubMed

    Wei, Anne; Nait-Ali, Amine

    2007-06-01

    Electrocardiogram (ECG) transmission in real time could involve some problems with the quality of services and security. This paper aims to evaluate a none compressed 12-lead ECG transmission using the Secure Internet Protocol (IPSec), compared with the popular Internet Protocol (IP). Using an analytical model, the transmission performance is estimated in terms of end-to-end delay and loss rate. Our results show that ECG transmission could be assured both security and quality of services.

  15. Electrocardiographic systems with reduced numbers of leads-synthesis of the 12-lead ECG.

    PubMed

    Tomašić, Ivan; Trobec, Roman

    2014-01-01

    Systems with reduced numbers of leads that can synthesize the 12-lead electrocardiogram (ECG) with an insignificant or a small loss of diagnostic information have been proposed. The advantage over standard 12-lead ECG systems is the smaller number of measurement sites (i.e., electrodes) and, consequently, fewer wires. In this paper, we review all the important systems with reduced numbers of leads together with the methodology for synthesizing the leads. The fundamental theoretical background necessary to understand the most important concepts related to the synthesis is included. The presented theoretical and experimental justifications for the synthesis show that it is not necessary to measure a large number of leads directly, because the standard 12-lead ECG and arbitrary additional leads can be synthesized. Various approaches to evaluating the synthesized 12-lead ECG are defined and explained, and a number of systems that synthesize 12-lead ECG are presented as they were introduced in the literature. We cover the developments and improvements from the 1940s to the present day. The systems are classified on the basis of the synthesis method used, the approach to the evaluation of the synthesized ECG (depending on the measurement sites used), and on the number and types of leads employed. Based on a detailed assessment of state-of-the-art systems, open problems and challenges are highlighted, while further developments of electrocardiographic systems are envisaged.

  16. Usefulness of multichannel Holter ECG recording in the third intercostal space for detecting type 1 Brugada ECG: comparison with repeated 12-lead ECGs.

    PubMed

    Shimeno, Kenji; Takagi, Masahiko; Maeda, Keiko; Tatsumi, Hiroaki; Doi, Atsushi; Yoshiyama, Minoru

    2009-09-01

    Type 1 Brugada ECG is essential for the diagnosis of Brugada syndrome. We aimed to evaluate the usefulness of multichannel Holter ECG recording in the third intercostal space for detecting type 1 Brugada ECG. We enrolled 60 consecutive individuals with type 1 Brugada ECG and 31 individuals with type 2 or 3 Brugada ECG, in the presence or absence of Na+ channel blockers. All individuals underwent 12-lead ECGs recorded in the standard position and the third intercostal space at least 5 times every 3 months (4L-ECGs, 3L-ECGs, respectively) and multichannel Holter ECG. On multichannel Holter ECG, the precordial electrodes were attached at standard positions (4L-Holter) and the third intercostal space (3L-Holter) for leads V1 and V2. Among the 60 individuals, type 1 Brugada ECG in 4L-ECGs, 3L-ECGs, 4L-Holter, and 3L-Holter was detected in 15 (25%), 26 (43.3%), 23 (38.3%), and 33 individuals (55%), respectively, whereas detected in none of the 31 individuals. The documented duration of type 1 Brugada ECG on 3L-Holter was significantly longer than that on 4L-Holter (700 +/- 467 vs 372 +/- 422 min; P = 0.01, 3L-Holter vs 4L-Holter, respectively), and type 1 Brugada ECG was most frequently observed between 6 pm and 12 pm. Neither the presence nor the duration of the appearance of type 1 Brugada ECG differed significantly between symptomatic and asymptomatic individuals. Multichannel Holter ECG recording in the third intercostal space is more sensitive and useful for the diagnosis of type 1 Brugada ECG than repeated 12-lead ECGs or multichannel Holter ECG in the standard position.

  17. The 24-lead ECG display for enhanced recognition of STEMI-equivalent patterns in the 12-lead ECG.

    PubMed

    Pahlm, Ulrika; Pahlm, Olle; Wagner, Galen S

    2014-01-01

    In a patient with chest pain and suspected acute coronary syndrome, the electrocardiogram (ECG) is the only readily available diagnostic tool. It is important to maximize its usefulness to detect acute myocardial ischemia that may evolve to myocardial infarction unless the patient is treated expediently with reperfusion therapy. Since diagnostic guidelines have usually included only ST-elevation myocardial infarction (STEMI) as the entity that should be diagnosed and treated urgently, a patient with coronary occlusion represented on ECG as ST depression is likely not to be considered a candidate for receiving immediate coronary angiography and coronary intervention. ECG criteria for STEMI detection require that ST elevation meet predetermined millivolt thresholds and appear in at least two spatially contiguous ECG leads. The typical ECG reader recognizes only three contiguous pairs: aVL and I; II and aVF; aVF and III. However, viewing the "orderly sequenced" 12-lead ECG display, two more contiguous pairs become obvious in the frontal plane: +I and -aVR; -aVR and +II. The 24-lead ECG is a display of the standard 12-lead ECG as both the classical positive leads and their negative (inverted) counterparts. Leads +V1, +V2, +V3, +V4, +V5, and +V6 and their inverted counterparts are used to generate a "clock-face display" for the transverse plane. Similarly, +aVL, +I, -aVR, +II, +aVF, +III in the frontal plane and their inverted counterparts are used to generate a clock-face display for the frontal plane. Optimum results, 78% sensitivity and 93% specificity, were obtained using the following 19 ECG leads: frontal plane: +aVR, -III, +aVL, +I, -aVR, +II, +aVF, +III, -aVL; transverse plane: +V1, +V2, +V3, +V4, +V5, +V6, -V1, -V2, -V3. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Real-Time 12-Lead High-Frequency QRS Electrocardiography for Enhanced Detection of Myocardial Ischemia and Coronary Artery Disease

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Kulecz, Walter B.; DePalma, Jude L.; Feiveson, Alan H.; Wilson, John S.; Rahman, M. Atiar; Bungo, Michael W.

    2004-01-01

    Several studies have shown that diminution of the high-frequency (HF; 150-250 Hz) components present within the central portion of the QRS complex of an electrocardiogram (ECG) is a more sensitive indicator for the presence of myocardial ischemia than are changes in the ST segments of the conventional low-frequency ECG. However, until now, no device has been capable of displaying, in real time on a beat-to-beat basis, changes in these HF QRS ECG components in a continuously monitored patient. Although several software programs have been designed to acquire the HF components over the entire QRS interval, such programs have involved laborious off-line calculations and postprocessing, limiting their clinical utility. We describe a personal computer-based ECG software program developed recently at the National Aeronautics and Space Administration (NASA) that acquires, analyzes, and displays HF QRS components in each of the 12 conventional ECG leads in real time. The system also updates these signals and their related derived parameters in real time on a beat-to-beat basis for any chosen monitoring period and simultaneously displays the diagnostic information from the conventional (low-frequency) 12-lead ECG. The real-time NASA HF QRS ECG software is being evaluated currently in multiple clinical settings in North America. We describe its potential usefulness in the diagnosis of myocardial ischemia and coronary artery disease.

  19. Real-Time 12-Lead High-Frequency QRS Electrocardiography for Enhanced Detection of Myocardial Ischemia and Coronary Artery Disease

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Kulecz, Walter B.; DePalma, Jude L.; Feiveson, Alan H.; Wilson, John S.; Rahman, M. Atiar; Bungo, Michael W.

    2004-01-01

    Several studies have shown that diminution of the high-frequency (HF; 150-250 Hz) components present within the central portion of the QRS complex of an electrocardiogram (ECG) is a more sensitive indicator for the presence of myocardial ischemia than are changes in the ST segments of the conventional low-frequency ECG. However, until now, no device has been capable of displaying, in real time on a beat-to-beat basis, changes in these HF QRS ECG components in a continuously monitored patient. Although several software programs have been designed to acquire the HF components over the entire QRS interval, such programs have involved laborious off-line calculations and postprocessing, limiting their clinical utility. We describe a personal computer-based ECG software program developed recently at the National Aeronautics and Space Administration (NASA) that acquires, analyzes, and displays HF QRS components in each of the 12 conventional ECG leads in real time. The system also updates these signals and their related derived parameters in real time on a beat-to-beat basis for any chosen monitoring period and simultaneously displays the diagnostic information from the conventional (low-frequency) 12-lead ECG. The real-time NASA HF QRS ECG software is being evaluated currently in multiple clinical settings in North America. We describe its potential usefulness in the diagnosis of myocardial ischemia and coronary artery disease.

  20. Automated detection of ventricular pre-excitation in pediatric 12-lead ECG.

    PubMed

    Gregg, Richard E; Zhou, Sophia H; Dubin, Anne M

    2016-01-01

    With increased interest in screening of young people for potential causes of sudden death, accurate automated detection of ventricular pre-excitation (VPE) or Wolff-Parkinson-White syndrome (WPW) in the pediatric resting ECG is important. Several recent studies have shown interobserver variability when reading screening ECGs and thus an accurate automated reading for this potential cause of sudden death is critical. We designed and tested an automated algorithm to detect pediatric VPE optimized for low prevalence. Digital ECGs with 12 leads or 15 leads (12-lead plus V3R, V4R and V7) were selected from multiple hospitals and separated into a testing and training database. Inclusion criterion was age less than 16 years. The reference for algorithm detection of VPE was cardiologist annotation of VPE for each ECG. The training database (n=772) consisted of VPE ECGs (n=37), normal ECGs (n=492) and a high concentration of conduction defects, RBBB (n=232) and LBBB (n=11). The testing database was a random sample (n=763). All ECGs were analyzed with the Philips DXL ECG Analysis algorithm for basic waveform measurements. Additional ECG features specific to VPE, mainly delta wave scoring, were calculated from the basic measurements and the average beat. A classifier based on decision tree bootstrap aggregation (tree bagger) was trained in multiple steps to select the number of decision trees and the 10 best features. The classifier accuracy was measured on the test database. The new algorithm detected pediatric VPE with a sensitivity of 78%, a specificity of 99.9%, a positive predictive value of 88% and negative predictive value of 99.7%. This new algorithm for detection of pediatric VPE performs well with a reasonable positive and negative predictive value despite the low prevalence in the general population. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Self-organized neural network for the quality control of 12-lead ECG signals.

    PubMed

    Chen, Yun; Yang, Hui

    2012-09-01

    Telemedicine is very important for the timely delivery of health care to cardiovascular patients, especially those who live in the rural areas of developing countries. However, there are a number of uncertainty factors inherent to the mobile-phone-based recording of electrocardiogram (ECG) signals such as personnel with minimal training and other extraneous noises. PhysioNet organized a challenge in 2011 to develop efficient algorithms that can assess the ECG signal quality in telemedicine settings. This paper presents our efforts in this challenge to integrate multiscale recurrence analysis with a self-organizing map for controlling the ECG signal quality. As opposed to directly evaluating the 12-lead ECG, we utilize an information-preserving transform, i.e. Dower transform, to derive the 3-lead vectorcardiogram (VCG) from the 12-lead ECG in the first place. Secondly, we delineate the nonlinear and nonstationary characteristics underlying the 3-lead VCG signals into multiple time-frequency scales. Furthermore, a self-organizing map is trained, in both supervised and unsupervised ways, to identify the correlations between signal quality and multiscale recurrence features. The efficacy and robustness of this approach are validated using real-world ECG recordings available from PhysioNet. The average performance was demonstrated to be 95.25% for the training dataset and 90.0% for the independent test dataset with unknown labels.

  2. New System for Digital to Analog Transformation and Reconstruction of 12-Lead ECGs

    PubMed Central

    Kothadia, Roshni; Kulecz, Walter B.; Kofman, Igor S.; Black, Adam J.; Grier, James W.; Schlegel, Todd T.

    2013-01-01

    Introduction We describe initial validation of a new system for digital to analog conversion (DAC) and reconstruction of 12-lead ECGs. The system utilizes an open and optimized software format with a commensurately optimized DAC hardware configuration to accurately reproduce, from digital files, the original analog electrocardiographic signals of previously instrumented patients. By doing so, the system also ultimately allows for transmission of data collected on one manufacturer's 12-lead ECG hardware/software into that of any other. Materials and Methods To initially validate the system, we compared original and post-DAC re-digitized 12-lead ECG data files (∼5-minutes long) in two types of validation studies in 10 patients. The first type quantitatively compared the total waveform voltage differences between the original and re-digitized data while the second type qualitatively compared the automated electrocardiographic diagnostic statements generated by the original versus re-digitized data. Results The grand-averaged difference in root mean squared voltage between the original and re-digitized data was 20.8 µV per channel when re-digitization involved the same manufacturer's analog to digital converter (ADC) as the original digitization, and 28.4 µV per channel when it involved a different manufacturer's ADC. Automated diagnostic statements generated by the original versus reconstructed data did not differ when using the diagnostic algorithm from the same manufacturer on whose device the original data were collected, and differed only slightly for just 1 of 10 patients when using a third-party diagnostic algorithm throughout. Conclusion Original analog 12-lead ECG signals can be reconstructed from digital data files with accuracy sufficient for clinical use. Such reconstructions can readily enable automated second opinions for difficult-to-interpret 12-lead ECGs, either locally or remotely through the use of dedicated or cloud-based servers. PMID:23613787

  3. The Application of Root Mean Square Electrocardiography (RMS ECG) for the Detection of Acquired and Congenital Long QT Syndrome

    PubMed Central

    Lux, Robert L.; Sower, Christopher Todd; Allen, Nancy; Etheridge, Susan P.; Tristani-Firouzi, Martin; Saarel, Elizabeth V.

    2014-01-01

    Background Precise measurement of the QT interval is often hampered by difficulty determining the end of the low amplitude T wave. Root mean square electrocardiography (RMS ECG) provides a novel alternative measure of ventricular repolarization. Experimental data have shown that the interval between the RMS ECG QRS and T wave peaks (RTPK) closely reflects the mean ventricular action potential duration while the RMS T wave width (TW) tracks the dispersion of repolarization timing. Here, we tested the precision of RMS ECG to assess ventricular repolarization in humans in the setting of drug-induced and congenital Long QT Syndrome (LQTS). Methods RMS ECG signals were derived from high-resolution 24 hour Holter monitor recordings from 68 subjects after receiving placebo and moxifloxacin and from standard 12 lead ECGs obtained in 97 subjects with LQTS and 97 age- and sex-matched controls. RTPK, QTRMS and RMS TW intervals were automatically measured using custom software and compared to traditional QT measures using lead II. Results All measures of repolarization were prolonged during moxifloxacin administration and in LQTS subjects, but the variance of RMS intervals was significantly smaller than traditional lead II measurements. TW was prolonged during moxifloxacin and in subjects with LQT-2, but not LQT-1 or LQT-3. Conclusion These data validate the application of RMS ECG for the detection of drug-induced and congenital LQTS. RMS ECG measurements are more precise than the current standard of care lead II measurements. PMID:24454918

  4. The application of root mean square electrocardiography (RMS ECG) for the detection of acquired and congenital long QT syndrome.

    PubMed

    Lux, Robert L; Sower, Christopher Todd; Allen, Nancy; Etheridge, Susan P; Tristani-Firouzi, Martin; Saarel, Elizabeth V

    2014-01-01

    Precise measurement of the QT interval is often hampered by difficulty determining the end of the low amplitude T wave. Root mean square electrocardiography (RMS ECG) provides a novel alternative measure of ventricular repolarization. Experimental data have shown that the interval between the RMS ECG QRS and T wave peaks (RTPK) closely reflects the mean ventricular action potential duration while the RMS T wave width (TW) tracks the dispersion of repolarization timing. Here, we tested the precision of RMS ECG to assess ventricular repolarization in humans in the setting of drug-induced and congenital Long QT Syndrome (LQTS). RMS ECG signals were derived from high-resolution 24 hour Holter monitor recordings from 68 subjects after receiving placebo and moxifloxacin and from standard 12 lead ECGs obtained in 97 subjects with LQTS and 97 age- and sex-matched controls. RTPK, QTRMS and RMS TW intervals were automatically measured using custom software and compared to traditional QT measures using lead II. All measures of repolarization were prolonged during moxifloxacin administration and in LQTS subjects, but the variance of RMS intervals was significantly smaller than traditional lead II measurements. TW was prolonged during moxifloxacin and in subjects with LQT-2, but not LQT-1 or LQT-3. These data validate the application of RMS ECG for the detection of drug-induced and congenital LQTS. RMS ECG measurements are more precise than the current standard of care lead II measurements.

  5. Real-time ECG emulation: a multiple dipole model for electrocardiography simulation.

    PubMed

    Abkai, Ciamak; Hesser, Jürgen

    2009-01-01

    A new model for describing electrocardiography (ECG) is presented, which is based on multiple dipoles compared to standard single dipole approaches in vector electrocardiography. The multiple dipole parameters are derived from real data (e.g. four dipoles from 12-channel ECG) by solving the backward problem of ECG numerically. Results are transformed to a waveform description based on Gaussian mixture for every dimension of each dipole. These compact parameterized descriptors are used for a very realistic real-time simulation applying the forward solution of the proposed model.

  6. Wireless Self-Acquistion of 12-Lead ECG via Android Smart Phone

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.

    2012-01-01

    Researchers at NASA s Johnson Space Center and at Orbital Research, Inc. (a NASA SBIR grant recipient) have recently developed a dry-electrode harness that allows for self-acquisition of resting 12-lead ECGs by minimally trained laypersons. When used in conjunction with commercial wireless (e.g., Bluetooth(TM) or 802.11-enabled) 12-lead ECG devices and custom smart phone-based software, the collected 12-lead ECG data can also immediately be forwarded from any geographic location within cellular range to the user s physician(s) of choice. The system can also be used to immediately forward to central receiving stations 12-lead ECG data collected during space flight or during activities in any remote terrestrial location supported by an internet or cellular phone infrastructure. The main novel aspects of the system are first, the dry-electrode 12-lead ECG harness itself, and second, an accompanying Android(TM) smart phone-based wireless 12-lead ECG capability. The ECG harness nominally employs dry electrodes manufactured by Orbital Research, Inc, recently cleared through the Food and Drug Administration (FDA). However, other dry electrodes that are not yet FDA cleared, for example those recently developed by Nanosonic, Inc as part of another NASA SBIR grant, can also be used. The various advantageous features of the harness include: 1) laypersons can be quickly instructed on its correct use, remotely if necessary; 2) all tangled "leadwire spaghetti" is eliminated, as is the common clinical problem of "leadwire reversal"; 3) all adhesives and disposables are also eliminated, the harness being fully reusable; if multiple individuals intend to use use the same harness, then standard antimicrobial wipes can be employed to sterilize the dry electrodes (and harness surface if needed) between users; 5) padded cushions at the lateral sides of the torso function to press the left arm (LA) and right arm (RA) dry electrodes mounted on the cushions against sideward or downward

  7. Comparison of Digital 12-Lead ECG and Digital 12-Lead Holter ECG Recordings in Healthy Male Subjects: Results from a Randomized, Double-Blinded, Placebo-Controlled Clinical Trial.

    PubMed

    Wang, Duolao; Bakhai, Ameet; Arezina, Radivoj; Täubel, Jörg

    2016-11-01

    Electrocardiogram (ECG) variability is greatly affected by the ECG recording method. This study aims to compare Holter and standard ECG recording methods in terms of central locations and variations of ECG data. We used the ECG data from a double-blinded, placebo-controlled, randomized clinical trial and used a mixed model approach to assess the agreement between two methods in central locations and variations of eight ECG parameters (Heart Rate, PR, QRS, QT, RR, QTcB, QTcF, and QTcI intervals). A total of 34 heathy male subjects with mean age of 25.7 ± 4.78 years were randomized to receive either active drug or placebo. Digital 12-lead ECG and digital 12-lead Holter ECG recordings were performed to assess ECG variability. There are no significant differences in least square mean between the Holter and the standard method for all ECG parameters. The total variance is consistently higher for the Holter method than the standard method for all ECG parameters except for QRS. The intraclass correlation coefficient (ICC) values for the Holter method are consistently lower than those for the standard method for all ECG parameters except for QRS, in particular, the ICC for QTcF is reduced from 0.86 for the standard method to 0.67 for the Holter method. This study suggests that Holter ECGs recorded in a controlled environment are not significantly different but more variable than those from the standard method. © 2016 Wiley Periodicals, Inc.

  8. New Padded Harness for Self-Acquisition of Resting 12-Lead ECGs

    NASA Technical Reports Server (NTRS)

    Schlegel, T. T.; Rood, A. T.

    2011-01-01

    We have developed a dry-electrode harness that permits easy, rapid, and unsupervised self-acquisition of resting 12-lead ECGs without the use of any disposables. Various other advantageous features of the harness include: 1) padded or inflatable cushions at the lateral sides of the torso that function to press the left arm (LA) and right arm (RA) dry electrodes mounted on cushions against sideward (as shown in the Figure below) or downward-rested arms of the subject; 2) sufficient distal placement of the arm electrodes with good abutment and without the need for adhesives, straps, bands, bracelets, or gloves on the arms; 3) padding over the sternum to avoid "tenting" in the V1 through V3 (and V3R, when present) electrode positions; 4) easy-to-don, one-piece design with an adjustable single point of connection and an adjustable shoulder strap; and 5) Lund or "modified Lund" placement of the dry electrodes, the results of which more effectively reproduce results from "standard" 12-lead ECG placements than do results from Mason-Likar lead placements.

  9. Utility of Electrocardiography (ECG)-Gated Computed Tomography (CT) for Preoperative Evaluations of Thymic Epithelial Tumors.

    PubMed

    Ozawa, Yoshiyuki; Hara, Masaki; Nakagawa, Motoo; Shibamoto, Yuta

    2016-01-01

    Preoperative evaluation of invasion to the adjacent organs is important for the thymic epithelial tumors on CT. The purpose of our study was to evaluate the utility of electrocardiography (ECG)-gated CT for assessing thymic epithelial tumors with regard to the motion artifacts produced and the preoperative diagnostic accuracy of the technique. Forty thymic epithelial tumors (36 thymomas and 4 thymic carcinomas) were examined with ECG-gated contrast-enhanced CT using a dual source scanner. The scan delay after the contrast media injection was 30 s for the non-ECG-gated CT and 100 s for the ECG-gated CT. Two radiologists blindly evaluated both the non-ECG-gated and ECG-gated CT images for motion artifacts and determined whether the tumors had invaded adjacent structures (mediastinal fat, superior vena cava, brachiocephalic veins, aorta, pulmonary artery, pericardium, or lungs) on each image. Motion artifacts were evaluated using a 3-grade scale. Surgical and pathological findings were used as a reference standard for tumor invasion. Motion artifacts were significantly reduced for all structures by ECG gating (p=0.0089 for the lungs and p<0.0001 for the other structures). Non-ECG-gated CT and ECG-gated CT demonstrated 79% and 95% accuracy, respectively, during assessments of pericardial invasion (p=0.03). ECG-gated CT reduced the severity of motion artifacts and might be useful for preoperative assessment whether thymic epithelial tumors have invaded adjacent structures.

  10. Automatic extraction of ECG strips from continuous 12-lead holter recordings for QT analysis at prescheduled versus optimized time points.

    PubMed

    Badilini, Fabio; Vaglio, Martino; Sarapa, Nenad

    2009-01-01

    Continuous 12-lead ECG monitoring (Holter) in early-phase pharmaceutical studies is today widely used as an ideal platform to extract discrete ECGs for analysis. The extraction process is typically performed manually by trained readers using commercial Holter processing systems. Antares, a novel method for automatic 12-lead extraction from continuous Holter recordings applying minimal noise criteria and heart-rate stability conditions is presented. A set of 12-lead Holter recordings from healthy subjects administered with sotalol is used to compare ECG extractions at fixed time points with ECG extractions generated by Antares optimizing noise and heart rate inside 5 minute windows centered around each expected time point of interest. Global, low- and high-frequency noise content of extracted ECGs was significantly reduced via optimized approach by Antares. Heart rate was also slightly reduced (from 69 +/- 13 to 64 +/- 13 bpm, P < 0.05). Similarly, the corrected QT interval from optimized extractions was significantly reduced (QTcB from 414 +/- 32 to 402 +/- 30 ms, P < 0.05). Using only baseline data, and after adjusting for intersubject variability, the standard deviation (SD) of QT intervals was highly reduced with optimized extraction (SD of QTcF from 11 +/- 8 to 7 +/- 2 ms, P < 0.05). Extraction of discrete 12-lead ECG strips from continuous Holter generates less noisy and more stable ECGs leading to more robust QTc data, thereby potentially facilitating the assessment of ECG effects on clinical trials.

  11. 1.5 Tesla MRI-Conditional 12-lead ECG for MR Imaging and Intra-MR Intervention

    PubMed Central

    Tse, Zion Tsz Ho; Dumoulin, Charles L.; Clifford, Gari D.; Schweitzer, Jeff; Qin, Lei; Oster, Julien; Jerosch-Herold, Michael; Kwong, Raymond Y.; Michaud, Gregory; Stevenson, William G.; Schmidt, Ehud J.

    2013-01-01

    Propose High-fidelity 12-lead Electrocardiogram (ECG) is important for physiological monitoring of patients during MR-guided intervention and cardiac MR imaging. Issues in obtaining non-corrupted ECGs inside MRI include a superimposed Magneto-Hydro-Dynamic (MHD) voltage, gradient-switching induced-voltages, and radiofrequency (RF) heating. These problems increase with magnetic field. We intended to develop and clinically validate a 1.5T MRI-conditional 12-lead ECG system. Methods The system was constructed, including transmission-lines to reduce radio-frequency induction, and switching-circuits to remove induced voltages. Adaptive filters, trained by 12-lead measurements outside MRI and in two orientations inside MRI, were used to remove MHD. The system was tested on ten (one exercising) volunteers and four arrhythmia patients. Results Switching circuits removed most imaging-induced voltages (residual noise <3% of the R-wave). MHD removal provided intra-MRI ECGs that varied by <3.8% from those outside the MRI, preserving the true ST segment. In premature-ventricular-contraction (PVC) patients, clean ECGs separated PVC and sinus-rhythm beats. Measured heating was <1.5 C0. The system reliably acquired multiphase (SSFP) wall-motion-cine and phase-contrast-cine scans, including in subjects where 4-lead gating failed. The system required a minimum TR of 4ms to allow robust ECG processing. Conclusion High-fidelity intra-MRI 12-lead ECG is possible. PMID:23580148

  12. Effects of electrocardiography contamination and comparison of ECG removal methods on upper trapezius electromyography recordings.

    PubMed

    Marker, Ryan J; Maluf, Katrina S

    2014-12-01

    Electromyography (EMG) recordings from the trapezius are often contaminated by the electrocardiography (ECG) signal, making it difficult to distinguish low-level muscle activity from muscular rest. This study investigates the influence of ECG contamination on EMG amplitude and frequency estimations in the upper trapezius during muscular rest and low-level contractions. A new method of ECG contamination removal, filtered template subtraction (FTS), is described and compared to 30 Hz high-pass filter (HPF) and averaged template subtraction (ATS) methods. FTS creates a unique template of each ECG artifact using a low-pass filtered copy of the contaminated signal, which is subtracted from contaminated periods in the original signal. ECG contamination results in an over-estimation of EMG amplitude during rest in the upper trapezius, with negligible effects on amplitude and frequency estimations during low-intensity isometric contractions. FTS and HPF successfully removed ECG contamination from periods of muscular rest, yet introduced errors during muscle contraction. Conversely, ATS failed to fully remove ECG contamination during muscular rest, yet did not introduce errors during muscle contraction. The relative advantages and disadvantages of different ECG contamination removal methods should be considered in the context of the specific motor tasks that require analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Interoperability in digital electrocardiography: harmonization of ISO/IEEE x73-PHD and SCP-ECG.

    PubMed

    Trigo, Jesús D; Chiarugi, Franco; Alesanco, Alvaro; Martínez-Espronceda, Miguel; Serrano, Luis; Chronaki, Catherine E; Escayola, Javier; Martínez, Ignacio; García, José

    2010-11-01

    The ISO/IEEE 11073 (x73) family of standards is a reference frame for medical device interoperability. A draft for an ECG device specialization (ISO/IEEE 11073-10406-d02) has already been presented to the Personal Health Device (PHD) Working Group, and the Standard Communications Protocol for Computer-Assisted ElectroCardioGraphy (SCP-ECG) Standard for short-term diagnostic ECGs (EN1064:2005+A1:2007) has recently been approved as part of the x73 family (ISO 11073-91064:2009). These factors suggest the coordinated use of these two standards in foreseeable telecardiology environments, and hence the need to harmonize them. Such harmonization is the subject of this paper. Thus, a mapping of the mandatory attributes defined in the second draft of the ISO/IEEE 11073-10406-d02 and the minimum SCP-ECG fields is presented, and various other capabilities of the SCP-ECG Standard (such as the messaging part) are also analyzed from an x73-PHD point of view. As a result, this paper addresses and analyzes the implications of some inconsistencies in the coordinated use of these two standards. Finally, a proof-of-concept implementation of the draft x73-PHD ECG device specialization is presented, along with the conversion from x73-PHD to SCP-ECG. This paper, therefore, provides recommendations for future implementations of telecardiology systems that are compliant with both x73-PHD and SCP-ECG.

  14. Automated detection of heart ailments from 12-lead ECG using complex wavelet sub-band bi-spectrum features.

    PubMed

    Tripathy, Rajesh Kumar; Dandapat, Samarendra

    2017-04-01

    The complex wavelet sub-band bi-spectrum (CWSB) features are proposed for detection and classification of myocardial infarction (MI), heart muscle disease (HMD) and bundle branch block (BBB) from 12-lead ECG. The dual tree CW transform of 12-lead ECG produces CW coefficients at different sub-bands. The higher-order CW analysis is used for evaluation of CWSB. The mean of the absolute value of CWSB, and the number of negative phase angle and the number of positive phase angle features from the phase of CWSB of 12-lead ECG are evaluated. Extreme learning machine and support vector machine (SVM) classifiers are used to evaluate the performance of CWSB features. Experimental results show that the proposed CWSB features of 12-lead ECG and the SVM classifier are successful for classification of various heart pathologies. The individual accuracy values for MI, HMD and BBB classes are obtained as 98.37, 97.39 and 96.40%, respectively, using SVM classifier and radial basis function kernel function. A comparison has also been made with existing 12-lead ECG-based cardiac disease detection techniques.

  15. Utility of Electrocardiography (ECG)-Gated Computed Tomography (CT) for Preoperative Evaluations of Thymic Epithelial Tumors

    PubMed Central

    Ozawa, Yoshiyuki; Hara, Masaki; Nakagawa, Motoo; Shibamoto, Yuta

    2016-01-01

    Summary Background Preoperative evaluation of invasion to the adjacent organs is important for the thymic epithelial tumors on CT. The purpose of our study was to evaluate the utility of electrocardiography (ECG)-gated CT for assessing thymic epithelial tumors with regard to the motion artifacts produced and the preoperative diagnostic accuracy of the technique. Material/Methods Forty thymic epithelial tumors (36 thymomas and 4 thymic carcinomas) were examined with ECG-gated contrast-enhanced CT using a dual source scanner. The scan delay after the contrast media injection was 30 s for the non-ECG-gated CT and 100 s for the ECG-gated CT. Two radiologists blindly evaluated both the non-ECG-gated and ECG-gated CT images for motion artifacts and determined whether the tumors had invaded adjacent structures (mediastinal fat, superior vena cava, brachiocephalic veins, aorta, pulmonary artery, pericardium, or lungs) on each image. Motion artifacts were evaluated using a 3-grade scale. Surgical and pathological findings were used as a reference standard for tumor invasion. Results Motion artifacts were significantly reduced for all structures by ECG gating (p=0.0089 for the lungs and p<0.0001 for the other structures). Non-ECG-gated CT and ECG-gated CT demonstrated 79% and 95% accuracy, respectively, during assessments of pericardial invasion (p=0.03). Conclusions ECG-gated CT reduced the severity of motion artifacts and might be useful for preoperative assessment whether thymic epithelial tumors have invaded adjacent structures. PMID:27920842

  16. Construction and Use of Resting 12-Lead High Fidelity ECG "SuperScores" in Screening for Heart Disease

    NASA Technical Reports Server (NTRS)

    Schlegel, T. T.; Arenare, B.; Greco, E. C.; DePalma, J. L.; Starc, V.; Nunez, T.; Medina, R.; Jugo, D.; Rahman, M.A.; Delgado, R.

    2007-01-01

    We investigated the accuracy of several conventional and advanced resting ECG parameters for identifying obstructive coronary artery disease (CAD) and cardiomyopathy (CM). Advanced high-fidelity 12-lead ECG tests (approx. 5-min supine) were first performed on a "training set" of 99 individuals: 33 with ischemic or dilated CM and low ejection fraction (EF less than 40%); 33 with catheterization-proven obstructive CAD but normal EF; and 33 age-/gender-matched healthy controls. Multiple conventional and advanced ECG parameters were studied for their individual and combined retrospective accuracies in detecting underlying disease, the advanced parameters falling within the following categories: 1) Signal averaged ECG, including 12-lead high frequency QRS (150-250 Hz) plus multiple filtered and unfiltered parameters from the derived Frank leads; 2) 12-lead P, QRS and T-wave morphology via singular value decomposition (SVD) plus signal averaging; 3) Multichannel (12-lead, derived Frank lead, SVD lead) beat-to-beat QT interval variability; 4) Spatial ventricular gradient (and gradient component) variability; and 5) Heart rate variability. Several multiparameter ECG SuperScores were derivable, using stepwise and then generalized additive logistic modeling, that each had 100% retrospective accuracy in detecting underlying CM or CAD. The performance of these same SuperScores was then prospectively evaluated using a test set of another 120 individuals (40 new individuals in each of the CM, CAD and control groups, respectively). All 12-lead ECG SuperScores retrospectively generated for CM continued to perform well in prospectively identifying CM (i.e., areas under the ROC curve greater than 0.95), with one such score (containing just 4 components) maintaining 100% prospective accuracy. SuperScores retrospectively generated for CAD performed somewhat less accurately, with prospective areas under the ROC curve typically in the 0.90-0.95 range. We conclude that resting 12-lead

  17. Construction and Use of Resting 12-Lead High Fidelity ECG "SuperScores" in Screening for Heart Disease

    NASA Technical Reports Server (NTRS)

    Schlegel, T. T.; Arenare, B.; Greco, E. C.; DePalma, J. L.; Starc, V.; Nunez, T.; Medina, R.; Jugo, D.; Rahman, M.A.; Delgado, R.

    2007-01-01

    We investigated the accuracy of several conventional and advanced resting ECG parameters for identifying obstructive coronary artery disease (CAD) and cardiomyopathy (CM). Advanced high-fidelity 12-lead ECG tests (approx. 5-min supine) were first performed on a "training set" of 99 individuals: 33 with ischemic or dilated CM and low ejection fraction (EF less than 40%); 33 with catheterization-proven obstructive CAD but normal EF; and 33 age-/gender-matched healthy controls. Multiple conventional and advanced ECG parameters were studied for their individual and combined retrospective accuracies in detecting underlying disease, the advanced parameters falling within the following categories: 1) Signal averaged ECG, including 12-lead high frequency QRS (150-250 Hz) plus multiple filtered and unfiltered parameters from the derived Frank leads; 2) 12-lead P, QRS and T-wave morphology via singular value decomposition (SVD) plus signal averaging; 3) Multichannel (12-lead, derived Frank lead, SVD lead) beat-to-beat QT interval variability; 4) Spatial ventricular gradient (and gradient component) variability; and 5) Heart rate variability. Several multiparameter ECG SuperScores were derivable, using stepwise and then generalized additive logistic modeling, that each had 100% retrospective accuracy in detecting underlying CM or CAD. The performance of these same SuperScores was then prospectively evaluated using a test set of another 120 individuals (40 new individuals in each of the CM, CAD and control groups, respectively). All 12-lead ECG SuperScores retrospectively generated for CM continued to perform well in prospectively identifying CM (i.e., areas under the ROC curve greater than 0.95), with one such score (containing just 4 components) maintaining 100% prospective accuracy. SuperScores retrospectively generated for CAD performed somewhat less accurately, with prospective areas under the ROC curve typically in the 0.90-0.95 range. We conclude that resting 12-lead

  18. Diffuse ST-Segment Depression with ST-Segment Elevation in Lead aVR in 12-Lead Electrocardiography May Indicate Ischemic Change of Severe Aortic Stenosis

    PubMed Central

    Huang, Tien-Chi; Lee, Meng-Kuang; Lin, Shin-Jing; Lu, Ye-Hsu; Lee, Kun-Tai

    2015-01-01

    Diffuse ST-segment depression with ST-segment elevation in the lead augmented vector right (aVR) in 12-lead electrocardiography may indicate the possibility of coronary artery disease involving the left main coronary artery or proximal left anterior descending artery, pulmonary embolism or takotsubo cardiomyopathy. We report a 69-year-old female with severe aortic stenosis, who had similar electrocardiographic findings which indicated ischemic change and led to cardiogenic shock and ventricular tachycardia. Intubation and insertion of an intra- aortic balloon pump (IABP) were performed and the result of coronary angiography showed only less than 40% stenosis. Her blood pressure gradually stabilized, and diffuse ST-segment depression or ST-segment elevation in lead aVR was not noted in the 12-lead electrocardiography. However, we removed the IABP and after 6 hours, sudden profound shock refractory to combined vasopressors occurred. Electrocardiography again showed ST- segment elevation in aVR with and diffuse ST-segment depression. After several episodes of ventricular tachycardia, cardiopulmonary resuscitation was not successful and the patient expired in our hospital. PMID:27122905

  19. Diffuse ST-Segment Depression with ST-Segment Elevation in Lead aVR in 12-Lead Electrocardiography May Indicate Ischemic Change of Severe Aortic Stenosis.

    PubMed

    Huang, Tien-Chi; Lee, Meng-Kuang; Lin, Shin-Jing; Lu, Ye-Hsu; Lee, Kun-Tai

    2015-09-01

    Diffuse ST-segment depression with ST-segment elevation in the lead augmented vector right (aVR) in 12-lead electrocardiography may indicate the possibility of coronary artery disease involving the left main coronary artery or proximal left anterior descending artery, pulmonary embolism or takotsubo cardiomyopathy. We report a 69-year-old female with severe aortic stenosis, who had similar electrocardiographic findings which indicated ischemic change and led to cardiogenic shock and ventricular tachycardia. Intubation and insertion of an intra- aortic balloon pump (IABP) were performed and the result of coronary angiography showed only less than 40% stenosis. Her blood pressure gradually stabilized, and diffuse ST-segment depression or ST-segment elevation in lead aVR was not noted in the 12-lead electrocardiography. However, we removed the IABP and after 6 hours, sudden profound shock refractory to combined vasopressors occurred. Electrocardiography again showed ST- segment elevation in aVR with and diffuse ST-segment depression. After several episodes of ventricular tachycardia, cardiopulmonary resuscitation was not successful and the patient expired in our hospital. Diffuse ST depression; Severe aortic stenosis; ST elevation in aVR.

  20. Are 12-lead ECG findings associated with the risk of cardiovascular events after ischemic stroke in young adults?

    PubMed

    Pirinen, Jani; Putaala, Jukka; Aarnio, Karoliina; Aro, Aapo L; Sinisalo, Juha; Kaste, Markku; Haapaniemi, Elena; Tatlisumak, Turgut; Lehto, Mika

    2016-11-01

    Ischemic stroke (IS) in a young patient is a disaster and recurrent cardiovascular events could add further impairment. Identifying patients with high risk of such events is therefore important. The prognostic relevance of ECG for this population is unknown. A total of 690 IS patients aged 15-49 years were included. A 12-lead ECG was obtained 1-14 d after the onset of stroke. We adjusted for demographic factors, comorbidities, and stroke characteristics, Cox regression models were used to identify independent ECG parameters associated with long-term risks of (1) any cardiovascular event, (2) cardiac events, and (3) recurrent stroke. Median follow-up time was 8.8 years. About 26.4% of patients experienced a cardiovascular event, 14.5% had cardiac events, and 14.6% recurrent strokes. ECG parameters associated with recurrent cardiovascular events were bundle branch blocks, P-terminal force, left ventricular hypertrophy, and a broader QRS complex. Furthermore, more leftward P-wave axis, prolonged QTc, and P-wave duration >120 ms were associated with increased risks of cardiac events. No ECG parameters were independently associated with recurrent stroke. A 12-lead ECG can be used for risk prediction of cardiovascular events but not for recurrent stroke in young IS patients. KEY MESSAGES ECG is an easy, inexpensive, and useful tool for identifying young ischemic stroke patients with a high risk for recurrent cardiovascular events and it has a statistically significant association with these events even after adjusting for confounding factors. Bundle branch blocks, P-terminal force, broader QRS complex, LVH according to Cornell voltage duration criteria, more leftward P-wave axis, prolonged QTc, and P-wave duration >120 ms are predictors for future cardiovascular or cardiac events in these patients. No ECG parameters were independently associated with recurrent stroke.

  1. Endocardial or epicardial ventricular tachycardia in nonischemic cardiomyopathy? The role of 12-lead ECG criteria in clinical practice.

    PubMed

    Piers, Sebastiaan R D; Silva, Marta de Riva; Kapel, Gijsbert F L; Trines, Serge A; Schalij, Martin J; Zeppenfeld, Katja

    2014-06-01

    Specific 12-lead ECG criteria have been reported to predict an epicardial site of origin (SoO) of induced ventricular tachycardias (VTs) in left ventricular nonischemic cardiomyopathy. The purpose of this study was to (1) determine the value of ECG criteria to predict an epicardial SoO of clinically documented VTs, (2) analyze the effect of VT cycle length (CL) and antiarrhythmic drugs on the accuracy of ECG criteria, and (3) assess interobserver variability. In 36 consecutive patients with nonischemic left ventricular cardiomyopathy (age 58 ± 16 years, 75% male) who underwent combined endocardial/epicardial VT ablation, all clinically documented and induced right bundle branch block VTs were analyzed for previously reported ECG criteria to determine the SoO, as defined by ≥11/12 pace-map, concealed entrainment, and/or VT termination during ablation. In 21 patients with clinically documented (25 mm/s) right bundle branch block VT, none of the ECG criteria differentiated between patients with and those without an epicardial SoO. In induced VTs (100 mm/s), 2 of 4 interval criteria differentiated between an endocardial and epicardial SoO for slow VTs (CL >350 ms) and 2 of 4 criteria in patients on amiodarone, but none for fast VTs (CL ≤350 ms) or patients off amiodarone. The Q wave in lead I was the most accurate criterion for an epicardial SoO (sensitivity 88%, specificity 80%). In both clinically documented and induced VTs, interobserver agreement was poor for pseudodelta wave and moderate for other criteria. When applied to clinically documented VTs, no ECG criterion could differentiate between patients with and those without an epicardial SoO. Published interval-based ECG criteria do not apply to fast VTs and patients off amiodarone. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  2. Accuracy of advanced versus strictly conventional 12-lead ECG for detection and screening of coronary artery disease, left ventricular hypertrophy and left ventricular systolic dysfunction

    PubMed Central

    2010-01-01

    Background Resting conventional 12-lead ECG has low sensitivity for detection of coronary artery disease (CAD) and left ventricular hypertrophy (LVH) and low positive predictive value (PPV) for prediction of left ventricular systolic dysfunction (LVSD). We hypothesized that a ~5-min resting 12-lead advanced ECG test ("A-ECG") that combined results from both the advanced and conventional ECG could more accurately screen for these conditions than strictly conventional ECG. Methods Results from nearly every conventional and advanced resting ECG parameter known from the literature to have diagnostic or predictive value were first retrospectively evaluated in 418 healthy controls and 290 patients with imaging-proven CAD, LVH and/or LVSD. Each ECG parameter was examined for potential inclusion within multi-parameter A-ECG scores derived from multivariate regression models that were designed to optimally screen for disease in general or LVSD in particular. The performance of the best retrospectively-validated A-ECG scores was then compared against that of optimized pooled criteria from the strictly conventional ECG in a test set of 315 additional individuals. Results Compared to optimized pooled criteria from the strictly conventional ECG, a 7-parameter A-ECG score validated in the training set increased the sensitivity of resting ECG for identifying disease in the test set from 78% (72-84%) to 92% (88-96%) (P < 0.0001) while also increasing specificity from 85% (77-91%) to 94% (88-98%) (P < 0.05). In diseased patients, another 5-parameter A-ECG score increased the PPV of ECG for LVSD from 53% (41-65%) to 92% (78-98%) (P < 0.0001) without compromising related negative predictive value. Conclusion Resting 12-lead A-ECG scoring is more accurate than strictly conventional ECG in screening for CAD, LVH and LVSD. PMID:20565702

  3. T-wave loop area from a pre-implant 12-lead ECG is associated with appropriate ICD shocks

    PubMed Central

    Hnatkova, Katerina; Friede, Tim; Malik, Marek; Zabel, Markus

    2017-01-01

    Aims In implantable cardioverter-defibrillator (ICD) patients, predictors of ICD shocks and mortality are needed to improve patient selection. Electrocardiographic (ECG) markers are simple to obtain and have been demonstrated to predict mortality. We aimed to assess the association of T-wave loop area and circularity with ICD shocks. Methods The study investigated patients with ICDs implanted between 1998 and 2010 for whom digital 12-lead ECGs (Schiller CS200 ECG-Network) of sufficient quality were obtained within 1 month prior to the implantation. T-wave loop area and circularity were calculated. Follow-up data of appropriate shocks were obtained during ICD clinic visits that included reviews of device stored electrograms. Results A total of 605 patients (82% males) were included; 68% had ischemic cardiomyopathy and 72% were treated for primary prevention. Over 3.8±1.4 years of follow-up, 114 patients (19%) experienced appropriate shock(s). Those with smaller T-wave loop area received fewer shocks (TLA, hazard ratio, HR, per increase of 1 technical unit, 0.71; [95% confidence interval, 0.53–0.94]; P = 0.02) and those with larger T-wave loop circularity (TLC) representing rounder T wave loop received more shocks (HR per 1% TLC increase 2.96; [0.85–10.36]; P = 0.09). When the quartile containing the largest TLA and TLC values, respectively, were compared to the remaining cases, TLA remained significantly associated with fewer and TLC with more frequent shocks also after multivariate adjustment for clinical variables (HR, 0.59 [0.35–0.99], P = 0.044; and 1.64 [1.08–2.49], P = 0.021, respectively). Conclusions The size and shape of the T-wave loop calculated from pre-implantation 12-lead ECGs are associated with appropriate ICD shocks. PMID:28291831

  4. The presence of fragmented QRS on 12-lead ECG in patients with coronary slow flow.

    PubMed

    Yilmaz, Hale; Gungor, Baris; Kemaloglu, Tugba; Sayar, Nurten; Erer, Betul; Yilmaz, Mehmet; Cakmak, Nazmiye; Gurkan, Ufuk; Oz, Dilaver; Bolca, Osman

    2014-01-01

    Coronary slow flow (CSF) is characterised by delayed opacification of coronary arteries in the absence of epicardial occlusive disease. It has been reported that CSF may cause angina, myocardial ischaemia, and infarction. Fragmentation of QRS complex (fQRS) is an easily evaluated non-invasive electrocardiographic parameter. It has been associated with alternation of myocardial activation due to myocardial scar and/or ischaemia. Whether CSF is associated with fQRS is unknown. The presence of fQRS on ECG may be an indicator of myocardial damage in patients with CSF. To investigate the presence of fQRS in patients with CSF. Sixty patients (mean age 55.5 ± 10.5 years) with CSF and 44 patients with normal coronary arteries without associated CSF (mean age 53 ± 8.4 years) were included in this study. The fQRS was defined as the presence of an additional R wave or notching of R or S wave or the presence of fragmentation in two contiguous leads corresponding to a major coronary artery territory. The presence of fQRS was higher in the CSF group than in the controls (p = 0.005). Hypertension was significantly more common in the CSF group (p < 0.001). There was no significant association between the presence of fQRS and an increasing number of vessel involvements. Logistic regression analysis demonstrated that the presence of CSF was the independent determinant of fQRS (OR = 10.848; 95% CI 2.385-49.347; p = 0.002). Fragmented QRS, indicating increased risk for arrhythmias and cardiovascular mortality, was found to be significantly higher in patients with CSF. We have not found an association between the presence of fragmented QRS and the degree of CSF. Further prospective studies are needed to establish the significance as a possible new risk factor in patients with CSF.

  5. Ability of a 5-minute electrocardiography (ECG) for predicting arrhythmias in Doberman Pinschers with cardiomyopathy in comparison with a 24-hour ambulatory ECG.

    PubMed

    Wess, G; Schulze, A; Geraghty, N; Hartmann, K

    2010-01-01

    Ventricular premature contractions (VPCs) are common in the occult stage of cardiomyopathy in Doberman Pinschers. Although the gold standard for detecting arrhythmia is the 24-hour ambulatory electrocardiography (ECG) (Holter), this method is more expensive, time-consuming and often not as readily available as common ECG. Comparison of 5-minute ECGs with Holter examinations. Eight hundred and seventy-five 5-minute ECGs and Holter examinations of 431 Doberman Pinschers. Each examination included a 5-minute ECG and Holter examination. A cut-off value of > 100 VPCs/24 hours using Holter was considered diagnostic for the presence of cardiomyopathy. Statistical evaluation included calculation of sensitivity, specificity, positive predictive value, and negative predictive value. Holter examinations revealed > 100 VPCs/24 hours in 204/875 examinations. At least 1 VPC during a 5-minute ECG was detected in 131 (64.2%) of these 204 examinations. No VPCs were found in the 5-minute ECG in 73 (35.8%) examinations of affected Doberman Pinschers. A 5-minute ECG with at least 1 VPC as cut-off had a sensitivity of 64.2%, a specificity of 96.7%, a positive predictive value of 85.6% and a negative predictive value of 89.9% for the presence of > 100 VPCs/24 hours. A 5-minute ECG is a rather insensitive method for detecting arrhythmias in Doberman Pinschers. However, the occurrence of at least 1 VPC in 5 minutes strongly warrants further examination of the dog, because specificity (96.7%) and positive predictive value (85.6%) are high and could suggest occult cardiomyopathy.

  6. Study design and rationale for biomedical shirt-based electrocardiography monitoring in relevant clinical situations: ECG-shirt study.

    PubMed

    Balsam, Paweł; Lodziński, Piotr; Tymińska, Agata; Ozierański, Krzysztof; Januszkiewicz, Łukasz; Główczyńska, Renata; Wesołowska, Katarzyna; Peller, Michał; Pietrzak, Radosław; Książczyk, Tomasz; Borodzicz, Sonia; Kołtowski, Łukasz; Borkowski, Mariusz; Werner, Bożena; Opolski, Grzegorz; Grabowski, Marcin

    2017-08-25

    Today, the main challenge for researchers is to develop new technologies which may help to improve the diagnoses of cardiovascular disease (CVD), thereby reducing healthcare costs and improving the quality of life for patients. This study aims to show the utility of biomedical shirt-based electrocardiography (ECG) monitoring of patients with CVD in different clinical situations using the Nuubo® ECG (nECG) system. An investigator-initiated, multicentre, prospective observational study was carried out in a cardiology (adult and paediatric) and cardiac rehabilitation wards . ECG monitoring was used with the biomedical shirt in the following four independent groups of patients: 1) 30 patients after pulmonary vein isolation (PVI), 2) 30 cardiac resynchronization therapy (CRT) recipients, 3) 120 patients during cardiac rehabilitation after myocardial infarction, and 4) 40 pediatric patients with supraventricular tachycardia (SVT) before electrophysiology study. Approval for all study groups was obtained from the institutional review board. The biomedical shirt captures the electrocardiographic signal via textile electrodes integrated into a garment.The software allows the visualization and analysis of data such as ECG, heart rate, arrhythmia detecting algorithm and relative position of the body is captured by an electronic device. The major advantages of the nECG system are continuous ECG monitoring during daily activities, high quality of ECG recordings, as well as assurance of a proper adherence due to adequate comfort while wearing the shirt. There are only a few studies that have examined wearable systems, especially in pediatric populations. This study is registered in ClinicalTrials.gov: Identifier NCT03068169.

  7. A real-time data-logger system using an optical disk WORM for archiving continuous 12-lead ECG data during exercise testing.

    PubMed

    Froning, J N; Froelicher, V F; Olson, M D

    1988-01-01

    An exercise ECG analysis program was developed over 15 years on a number of mainframes, minicomputers and, most recently, microcomputer-based systems. It has been rehosted into both Motorola MC68000 and Intel 80286 microprocessor-based development systems and is currently used with a removable 200 Mbyte optical disk (Write-Once-Read-Many, WORM) based data-logger system that can record and store all 12 leads simultaneously and continuously for an entire exercise test (up to 38 minutes). Data is acquired with 12-bit A/D resolution at 500 samples/sec. All ECG data and patient information are archived on the optical disk for later off-line recall and analysis on a PC or real-time replay through a D/A converter. Recorded ECG signals are at patient levels so they can be replayed through the patient cable box on any commercial system. Current development includes both simultaneous on-line processing and storage of 12-lead ECG data and off-line processing and development performed on the long-term, continuous ECG data being archived on optical disk. Patient medical histories and clinical information are separately entered into an applications database, where ECG measures and test results are later included. This new optical disk based exercise ECG database contains more than 600 complete exercise tests and is projected to increase to nearly 3,000 within 2 years.

  8. The Normal Electrocardiogram: Resting 12-Lead and Electrocardiogram Monitoring in the Hospital.

    PubMed

    Harris, Patricia R E

    2016-09-01

    The electrocardiogram (ECG) is a well-established diagnostic tool extensively used in clinical settings. Knowledge of cardiac rhythm and mastery of cardiac waveform interpretation are fundamental for intensive care nurses. Recognition of the normal findings for the 12-lead ECG and understanding the significance of changes from baseline in continuous cardiac monitoring are essential steps toward ensuring safe patient care. This article highlights historical developments in electrocardiography, describes the normal resting 12-lead ECG, and discusses the need for continuous cardiac monitoring. In addition, future directions for the ECG are explored briefly. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Tissue Doppler Imaging Combined with Advanced 12-Lead ECG Analysis Might Improve Early Diagnosis of Hypertrophic Cardiomyopathy in Childhood

    NASA Technical Reports Server (NTRS)

    Femlund, E.; Schlegel, T.; Liuba, P.

    2011-01-01

    Optimization of early diagnosis of childhood hypertrophic cardiomyopathy (HCM) is essential in lowering the risk of HCM complications. Standard echocardiography (ECHO) has shown to be less sensitive in this regard. In this study, we sought to assess whether spatial QRS-T angle deviation, which has shown to predict HCM in adults with high sensitivity, and myocardial Tissue Doppler Imaging (TDI) could be additional tools in early diagnosis of HCM in childhood. Methods: Children and adolescents with familial HCM (n=10, median age 16, range 5-27 years), and without obvious hypertrophy but with heredity for HCM (n=12, median age 16, range 4-25 years, HCM or sudden death with autopsy-verified HCM in greater than or equal to 1 first-degree relative, HCM-risk) were additionally investigated with TDI and advanced 12-lead ECG analysis using Cardiax(Registered trademark) (IMED Co Ltd, Budapest, Hungary and Houston). Spatial QRS-T angle (SA) was derived from Kors regression-related transformation. Healthy age-matched controls (n=21) were also studied. All participants underwent thorough clinical examination. Results: Spatial QRS-T angle (Figure/ Panel A) and septal E/Ea ratio (Figure/Panel B) were most increased in HCM group as compared to the HCM-risk and control groups (p less than 0.05). Of note, these 2 variables showed a trend toward higher levels in HCM-risk group than in control group (p=0.05 for E/Ea and 0.06 for QRS/T by ANOVA). In a logistic regression model, increased SA and septal E/Ea ratio appeared to significantly predict both the disease (Chi-square in HCM group: 9 and 5, respectively, p less than 0.05 for both) and the risk for HCM (Chi-square in HCM-risk group: 5 and 4 respectively, p less than 0.05 for both), with further increased predictability level when these 2 variables were combined (Chi-square 10 in HCM group, and 7 in HCM-risk group, p less than 0.01 for both). Conclusions: In this small material, Tissue Doppler Imaging and spatial mean QRS-T angle

  10. Development of new anatomy reconstruction software to localize cardiac isochrones to the cardiac surface from the 12 lead ECG.

    PubMed

    van Dam, Peter M; Gordon, Jeffrey P; Laks, Michael M; Boyle, Noel G

    2015-01-01

    medical image data (pixel size <1.5mm). For the lungs and torso the number of triangles in the mesh was reduced, thus decreasing the accuracy of the reconstructed mesh. A novel software tool has been introduced, which is able to reconstruct accurate cardiac anatomical models from MRI or CT within only a few hours. This new anatomical reconstruction tool might reduce the modeling errors within the cardiac isochrone positioning system and thus enable the clinical application of CIPS to localize the PVC/VT focus to the ventricular myocardium from only the standard 12 lead ECG.

  11. Discrimination of ST deviation caused by acute coronary occlusion from normal variants and other abnormal conditions, using computed electrocardiographic imaging based on 12-lead ECG.

    PubMed

    Akil, Shahnaz; Al-Mashat, Mariam; Hedén, Bo; Hedeer, Fredrik; Jögi, Jonas; Wang, John J; Wagner, Galen S; Warren, James W; Pahlm, Olle; Horáček, B Milan

    2013-01-01

    Many graphical methods for displaying ST-segment deviation in the ECG have been tried for enhancing decision-making in patients with suspected acute coronary syndromes. Computed electrocardiographic imaging (CEI), based on a mathematical inverse solution, has been recently applied to transform ST-J point measurements made in conventional 12-lead ECG into a display of epicardial potentials in bull's-eye format. The purpose of this study is to assess utility of CEI in the clinical setting. In 99 patients with stable coronary disease, 12-lead ECGs were recorded during elective percutaneous coronary intervention (PCI), first before balloon-catheter insertion and then when an intracoronary balloon blocked blood supply to a region of myocardium for more than 4minutes (typically 5minutes). Four groups of patients were additionally studied, namely those with preexcitation, pericarditis, early repolarization syndrome (ERS), and left ventricular hypertrophy (LVH) with strain. Comparisons between performances of published criteria for ST-elevation myocardial infarction (STEMI) and quantitative as well as visual assessment of CEI images were based on sensitivities and specificities. Visual assessment of CEI outperformed STEMI criteria. This was especially evident for the capability of detecting LCx occlusion with sensitivities for STEMI criteria=35% and for visual assessment of CEI by 2 physicians=71%, i. e. twice as many patients were correctly identified by CEI. False positive rates for CEI were low in patients with LVH with strain as well as with preexcitation for both methods. For pericarditis and ERS, visual as well as quantitative assessment of CEI performed better than STEMI criteria. Visual assessment of CEI is a promising method for increasing the accuracy of ECG-based triage to PCI or conservative care. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Left-ventricular mechanical activation and aortic-arch orientation recovered from magneto-hydrodynamic voltages observed in 12-lead ECGs obtained inside MRIs: a feasibility study.

    PubMed

    Gregory, T Stan; Schmidt, Ehud J; Zhang, Shelley Hualei; Kwong, Raymond Y; Stevenson, William G; Murrow, Jonathan R; Tse, Zion Tsz Ho

    2014-12-01

    To explore use of the Magnetohydrodynamic Voltage (VMHD), observed in intra-MRI 12-lead electrocardiograms (ECG), to indicate the timing of the onset of left-ventricular mechanical activation (LVMA) and the orientation of the aortic-arch (AAO). Blood flow through the aortic arch during systole, in the presence of the MRI magnetic field (B 0), generates VMHD. Since the magnitude and direction of VMHD are determined by the timing and directionality of blood flow relative to B 0, we hypothesized that clinically useful measures, LVMA and AAO, could be extracted from temporal and vectorial VMHD characteristics. VMHD signals were extracted from 12-lead ECG traces by comparing traces obtained inside and outside the MRI scanner. VMHD was converted into the Vectorcardiogram frame of reference. LVMA was quantified in 1 subject at 1.5T and 3 subjects at 3T, and the result compared to CINE MRI. AAO was inferred for 4 subjects at 3T and compared to anatomical imaging of the aortic arch orientation in the transverse plane. A < 10% error was observed in LVMA measurements, while a < 3° error was observed in aortic arch orientation measurements. The temporal and vectorial nature of VMHD is useful in estimating these clinically relevant parameters.

  13. Left-ventricular mechanical activation and aortic-arch orientation recovered from Magneto-hydrodynamic Voltages observed in 12-lead ECGs obtained inside MRIs: A Feasibility Study

    PubMed Central

    Gregory, T. Stan; Schmidt, Ehud J.; Zhang, Shelley Hualei; Kwong, Raymond Y.; Stevenson, William G.; Murrow, Jonathan R.; Ho Tse, Zion Tsz

    2014-01-01

    Purpose To explore use of the Magnetohydrodynamic Voltage (VMHD), observed in intra-MRI 12-lead Electrocardiograms (ECG), to indicate the timing of the onset of left-ventricular mechanical activation (LVMA) and the orientation of the aortic-arch (AAO). Theory Blood flow through the aortic arch during systole, in the presence of the MRI magnetic field (B0), generates VMHD. Since the magnitude and direction of VMHD are determined by the timing and directionality of blood flow relative to B0, we hypothesized that clinically useful measures, LVMA and AAO, could be extracted from temporal and vectorial VMHD characteristics. Methods VMHD signals were extracted from 12-lead ECG traces by comparing traces obtained inside and outside the MRI scanner. VMHD was converted into the Vectorcardiogram frame of reference. LVMA was quantified in 1 subject at 1.5T and 3 subjects at 3T, and the result compared to CINE MRI. AAO was inferred for 4 subjects at 3T and compared to anatomical imaging of the aortic arch orientation in the transverse plane. Results and Conclusions A <10% error was observed in LVMA measurements, while a <3° error was observed in aortic arch orientation measurements. The temporal and vectorial nature of VMHD is useful in estimating these clinically relevant parameters. PMID:25224074

  14. Screening for Cardiac Magnetic Resonance Scar Features by 12-lead ECG, in Patients with Preserved Ejection Fraction

    PubMed Central

    Mewton, Nathan; Strauss, David G.; Rizzi, Patricia; Verrier, Richard L.; Liu, Chia Ying; Tereshchenko, Larisa G.; Nearing, Bruce; Volpe, Gustavo J.; Marchlinski, Francis E.; Moxley, John; Killian, Tony; Wu, Katherine C.; Spooner, Peter; Lima, João A.C.

    2015-01-01

    Background Increased QRS score and wide spatial QRS-T angle are independent predictors of cardiovascular mortality in the general population. Our main objective was to assess whether a QRS score ≥5 and/or QRS-T angle ≥105° enable screening of patients for myocardial scar features. Methods 77 patients age ≤70 years with QRS score ≥5 AND/OR spatial QRS-T angle ≥105° as well as left ventricular ejection fraction (LVEF) >35% were enrolled in the study. All participants underwent complete clinical examination, signal averaged ECG (SAECG), 30-minute ambulatory ECG recording for T wave alternans (TWA), and late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Relationship between QRS score, QRS-T angle with scar presence and pattern, as well as gray zone, core, and total scar size by LGE-CMR were assessed. Results Myocardial scar was present in 41 (53%) patients, of whom 19 (46%) exhibited a typical ischemic pattern. QRS score but not QRS-T angle was related to total scar size and gray zone size (R2=0.12, P=0.002; R2=0.17; P ≤0.0001 respectively). Patients with QRS scores ≥6 had significantly greater myocardial scar and gray zone size, increased QRS duration and QRS-T angle, a higher prevalence of late potentials (LP) presence, increased LV end-diastolic volume and decreased LVEF. There was a significant independent and positive association between TWA value and total scar (P=0.001) and gray zone size (P=0.01). Conclusion Patients with preserved LVEF and myocardial scar by CMR also have electrocardiographic features that could be involved in ventricular arrhythmogenesis. PMID:26806840

  15. Screening for Cardiac Magnetic Resonance Scar Features by 12-Lead ECG, in Patients with Preserved Ejection Fraction.

    PubMed

    Mewton, Nathan; Strauss, David G; Rizzi, Patricia; Verrier, Richard L; Liu, Chia Ying; Tereshchenko, Larisa G; Nearing, Bruce; Volpe, Gustavo J; Marchlinski, Francis E; Moxley, John; Killian, Tony; Wu, Katherine C; Spooner, Peter; Lima, João A C

    2016-01-01

    Increased QRS score and wide spatial QRS-T angle are independent predictors of cardiovascular mortality in the general population. Our main objective was to assess whether a QRS score ≥ 5 and/or QRS-T angle ≥ 105° enable screening of patients for myocardial scar features. Seventy-seven patients of age ≤ 70 years with QRS score ≥ 5 and/or spatial QRS-T angle ≥ 105° as well as left ventricular ejection fraction (LVEF) >35% were enrolled in the study. All participants underwent complete clinical examination, signal-averaged ECG (SAECG), 30-minute ambulatory ECG recording for T-wave alternans (TWA), and late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Relationship between QRS score, QRS-T angle with scar presence and pattern, as well as gray zone, core, and total scar size by LGE-CMR were assessed. Myocardial scar was present in 41 (53%) patients, of whom 19 (46%) exhibited a typical ischemic pattern. QRS score but not QRS-T angle was related to total scar size and gray zone size (R(2) = 0.12, P = 0.002; R(2) = 0.17; P ≤ 0.0001, respectively). Patients with QRS scores ≥ 6 had significantly greater myocardial scar and gray zone size, increased QRS duration and QRS-T angle, a higher prevalence of late potentials (LPs) presence, increased LV end-diastolic volume and decreased LVEF. There was a significant independent and positive association between TWA value and total scar (P = 0.001) and gray zone size (P = 0.01). Patients with preserved LVEF and myocardial scar by CMR also have electrocardiographic features that could be involved in ventricular arrhythmogenesis. © 2016 Wiley Periodicals, Inc.

  16. Vectorcardiographic diagnostic & prognostic information derived from the 12-lead electrocardiogram: Historical review and clinical perspective.

    PubMed

    Man, Sumche; Maan, Arie C; Schalij, Martin J; Swenne, Cees A

    2015-01-01

    In the course of time, electrocardiography has assumed several modalities with varying electrode numbers, electrode positions and lead systems. 12-lead electrocardiography and 3-lead vectorcardiography have become particularly popular. These modalities developed in parallel through the mid-twentieth century. In the same time interval, the physical concepts underlying electrocardiography were defined and worked out. In particular, the vector concept (heart vector, lead vector, volume conductor) appeared to be essential to understanding the manifestations of electrical heart activity, both in the 12-lead electrocardiogram (ECG) and in the 3-lead vectorcardiogram (VCG). Not universally appreciated in the clinic, the vectorcardiogram, and with it the vector concept, went out of use. A revival of vectorcardiography started in the 90's, when VCGs were mathematically synthesized from standard 12-lead ECGs. This facilitated combined electrocardiography and vectorcardiography without the need for a special recording system. This paper gives an overview of these historical developments, elaborates on the vector concept and seeks to define where VCG analysis/interpretation can add diagnostic/prognostic value to conventional 12-lead ECG analysis.

  17. A Unique Digital Electrocardiographic Repository for the Development of Quantitative Electrocardiography and Cardiac Safety: The Telemetric and Holter ECG Warehouse (THEW)

    PubMed Central

    Couderc, Jean-Philippe

    2010-01-01

    The sharing of scientific data reinforces open scientific inquiry; it encourages diversity of analysis and opinion while promoting new research and facilitating the education of next generations of scientists. In this article, we present an initiative for the development of a repository containing continuous electrocardiographic information and their associated clinical information. This information is shared with the worldwide scientific community in order to improve quantitative electrocardiology and cardiac safety. First, we present the objectives of the initiative and its mission. Then, we describe the resources available in this initiative following three components: data, expertise and tools. The Data available in the Telemetric and Holter ECG Warehouse (THEW) includes continuous ECG signals and associated clinical information. The initiative attracted various academic and private partners whom expertise covers a large list of research arenas related to quantitative electrocardiography; their contribution to the THEW promotes cross-fertilization of scientific knowledge, resources, and ideas that will advance the field of quantitative electrocardiography. Finally, the tools of the THEW include software and servers to access and review the data available in the repository. To conclude, the THEW is an initiative developed to benefit the scientific community and to advance the field of quantitative electrocardiography and cardiac safety. It is a new repository designed to complement the existing ones such as Physionet, the AHA-BIH Arrhythmia Database, and the CSE database. The THEW hosts unique datasets from clinical trials and drug safety studies that, so far, were not available to the worldwide scientific community. PMID:20863512

  18. Implementation and verification of an enhanced algorithm for the automatic computation of RR-interval series derived from 24 h 12-lead ECGs.

    PubMed

    Hagmair, Stefan; Braunisch, Matthias C; Bachler, Martin; Schmaderer, Christoph; Hasenau, Anna-Lena; Bauer, Axel; Rizas, Kostantinos D; Wassertheurer, Siegfried; Mayer, Christopher C

    2017-01-01

    An important tool in early diagnosis of cardiac dysfunctions is the analysis of electrocardiograms (ECGs) obtained from ambulatory long-term recordings. Heart rate variability (HRV) analysis became a significant tool for assessing the cardiac health. The usefulness of HRV assessment for the prediction of cardiovascular events in end-stage renal disease patients was previously reported. The aim of this work is to verify an enhanced algorithm to obtain an RR-interval time series in a fully automated manner. The multi-lead corrected R-peaks of each ECG lead are used for RR-series computation and the algorithm is verified by a comparison with manually reviewed reference RR-time series. Twenty-four hour 12-lead ECG recordings of 339 end-stage renal disease patients from the ISAR (rISk strAtification in end-stage Renal disease) study were used. Seven universal indicators were calculated to allow for a generalization of the comparison results. The median score of the indicator of synchronization, i.e. intraclass correlation coefficient, was 96.4% and the median of the root mean square error of the difference time series was 7.5 ms. The negligible error and high synchronization rate indicate high similarity and verified the agreement between the fully automated RR-interval series calculated with the AIT Multi-Lead ECGsolver and the reference time series. As a future perspective, HRV parameters calculated on this RR-time series can be evaluated in longitudinal studies to ensure clinical benefit.

  19. A unique digital electrocardiographic repository for the development of quantitative electrocardiography and cardiac safety: the Telemetric and Holter ECG Warehouse (THEW).

    PubMed

    Couderc, Jean-Philippe

    2010-01-01

    The sharing of scientific data reinforces open scientific inquiry; it encourages diversity of analysis and opinion while promoting new research and facilitating the education of next generations of scientists. In this article, we present an initiative for the development of a repository containing continuous electrocardiographic information and their associated clinical information. This information is shared with the worldwide scientific community to improve quantitative electrocardiology and cardiac safety. First, we present the objectives of the initiative and its mission. Then, we describe the resources available in this initiative following 3 components: data, expertise, and tools. The data available in the Telemetric and Holter ECG Warehouse (THEW) includes continuous electrocardiogram signals and associated clinical information. The initiative attracted various academic and private partners whom expertise covers a large list of research arenas related to quantitative electrocardiography; their contribution to the THEW promotes cross-fertilization of scientific knowledge, resources, and ideas that will advance the field of quantitative electrocardiography. Finally, the tools of the THEW include software and servers to access and review the data available in the repository. To conclude, the THEW is an initiative developed to benefit the scientific community and to advance the field of quantitative electrocardiography and cardiac safety. It is a new repository designed to complement the existing ones such as Physionet, the American Heart Association - Beth Israel Hospital (AHA-BIH) arrhythmia database, and the Common Standard for Electrocardiography (CSE) database. The THEW hosts unique datasets from clinical trials and drug safety studies that, so far, were not available. Copyright © 2010 Elsevier Inc. All rights reserved.

  20. Nationwide improvement of door-to-balloon times in patients with acute ST-segment elevation myocardial infarction requiring primary percutaneous coronary intervention with out-of-hospital 12-lead ECG recording and transmission.

    PubMed

    Ong, Marcus Eng Hock; Wong, Aaron Sung Lung; Seet, Chong Meng; Teo, Swee Guan; Lim, Beng Leong; Ong, Paul Jau Lueng; Lai, Shieh Mei; Ong, Sea Hing; Lee, Francis Chun Yue; Chan, Kim Poh; Anantharaman, Venkataraman; Chua, Terrance Siang Jin; Pek, Pin Pin; Li, Huihua

    2013-03-01

    Reducing door-to-balloon times for acute ST-segment elevation myocardial infarction (STEMI) patients has been shown to improve long-term survival. We aim to reduce door-to-balloon time for STEMI patients requiring primary percutaneous coronary intervention by adoption of out-of-hospital 12-lead ECG transmission by Singapore's national ambulance service. This was a nationwide, before-after study of STEMI patients who presented to the emergency departments (ED) and required percutaneous coronary intervention. In the before phase, chest pain patients received 12-lead ECGs in the ED. In the after phase, 12-lead ECGs were performed by ambulance crews and transmitted from the field to the ED. Patients whose ECG showed greater than or equal to 2 mm ST-segment elevation in anterior or greater than or equal to 1 mm ST-segment elevation in inferior leads for 2 or more contiguous leads and symptom onset of less than 12 hours' duration were eligible for percutaneous coronary intervention activation before arrival. ECGs (2,653) were transmitted by the ambulance service; 180 (7%) were suspected STEMI. One hundred twenty-seven patients from the before and 156 from the after phase met inclusion criteria for analysis. Median door-to-balloon time was 75 minutes in the before and 51 minutes in the after phase (median difference=23 minutes; 95% confidence interval 18 to 27 minutes). Median door-to-balloon times were significantly reduced regardless of presentation hours. Overall, there was significant reduction in door-to-activation, door-to-ECG, and door-to-cardiovascular laboratory times. No significant difference was found pertaining to adverse events. This study describes a nationwide implementation of out-of-hospital ECG transmission resulting in reduced door-to-balloon times, regardless of presentation hours. Out-of-hospital ECG transmission should be adopted as best practice for management of chest pain. Copyright © 2012. Published by Mosby, Inc.

  1. Evaluation of reperfused myocardial infarction by low-dose multidetector computed tomography using prospective electrocardiography (ECG)-triggering: comparison with magnetic resonance imaging.

    PubMed

    Gweon, Hye Mi; Kim, Sang Jin; Kim, Tae Hoon; Lee, Sang Min; Hong, Yoo Jin; Rim, Se-Joong; Hong, Bum Ki; Min, Phil Ki; Yoon, Young Won; Kwon, Hyuck Moon

    2010-09-01

    To evaluate the potential of prospective electrocardiography (ECG)- gated 64-slice multidetector computed tomography (MDCT) for evaluation of myocardial enhancement, infarct size, and stent patency after percutaneous coronary intervention (PCI) with stenting in patients with myocardial infarction. Seventeen patients who were admitted with acute myocardial infarction were examined with prospective ECG-gated 64-slice cardiac MDCT and magnetic resonance (MR) imaging after reperfusion using PCI with stenting. Cardiac MDCT was performed with two different phases: arterial and delayed phases. We evaluated the stent patency on the arterial phase, and nonviable myocardium on the delayed phase of computed tomography (CT) image, and they were compared with the results from the delayed MR images. Total mean radiation dose was 7.7 +/- 0.5 mSv on the two phases of CT images. All patients except one showed good patency of the stent at the culprit lesion on the arterial phase CT images. All patients had hyperenhanced area on the delayed phase CT images, which correlated well with those on the delayed phase MR images, with a mean difference of 1.6% (20 +/- 10% vs. 22 +/- 10%, r = 0.935, p = 0.10). Delayed MR images had a better contrast-to-noise ratio (CNR) than delayed CT images (27.1 +/- 17.8% vs. 4.3 +/- 2.1%, p < 0.001). Prospective ECG-gated 64-slice MDCT provides the potential to evaluate myocardial viability on delayed phase as well as for stent patency on arterial phase with an acceptable radiation dose after PCI with stenting in patients with myocardial infarction.

  2. Evaluation of an algorithm based on single-condition decision rules for binary classification of 12-lead ambulatory ECG recording quality.

    PubMed

    Di Marco, Luigi Yuri; Duan, Wenfeng; Bojarnejad, Marjan; Zheng, Dingchang; King, Susan; Murray, Alan; Langley, Philip

    2012-09-01

    A new algorithm for classifying ECG recording quality based on the detection of commonly observed ECG contaminants which often render the ECG unusable for diagnostic purposes was evaluated. Contaminants (baseline drift, flat line, QRS-artefact, spurious spikes, amplitude stepwise changes, noise) were detected on individual leads from joint time-frequency analysis and QRS amplitude. Classification was based on cascaded single-condition decision rules (SCDR) that tested levels of contaminants against classification thresholds. A supervised learning classifier (SLC) was implemented for comparison. The SCDR and SLC algorithms were trained on an annotated database (Set A, PhysioNet Challenge 2011) of 'acceptable' versus 'unacceptable' quality recordings using the 'leave M out' approach with repeated random partitioning and cross-validation. Two training approaches were considered: (i) balanced, in which training records had equal numbers of 'acceptable' and 'unacceptable' recordings, (ii) unbalanced, in which the ratio of 'acceptable' to 'unacceptable' recordings from Set A was preserved. For each training approach, thresholds were calculated, and classification accuracy of the algorithm compared to other rule based algorithms and the SLC using a database for which classifications were unknown (Set B PhysioNet Challenge 2011). The SCDR algorithm achieved the highest accuracy (91.40%) compared to the SLC (90.40%) in spite of its simple logic. It also offers the advantage that it facilitates reporting of meaningful causes of poor signal quality to users.

  3. Eyewitness to history: Landmarks in the development of computerized electrocardiography.

    PubMed

    Rautaharju, Pentti M

    2016-01-01

    The use of digital computers for ECG processing was pioneered in the early 1960s by two immigrants to the US, Hubert Pipberger, who initiated a collaborative VA project to collect an ECG-independent Frank lead data base, and Cesar Caceres at NIH who selected for his ECAN program standard 12-lead ECGs processed as single leads. Ray Bonner in the early 1970s placed his IBM 5880 program in a cart to print ECGs with interpretation, and computer-ECG programs were developed by Telemed, Marquette, HP-Philips and Mortara. The "Common Standards for quantitative Electrocardiography (CSE)" directed by Jos Willems evaluated nine ECG programs and eight cardiologists in clinically-defined categories. The total accuracy by a representative "average" cardiologist (75.5%) was 5.8% higher than that of the average program (69.7, p<0.001). Future comparisons of computer-based and expert reader performance are likely to show evolving results with continuing improvement of computer-ECG algorithms and changing expertise of ECG interpreters. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. When Deriving the Spatial QRS-T Angle from the 12-lead ECG, which Transform is More Frank: Regression or Inverse Dower?

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Cortez, Daniel

    2010-01-01

    Our primary objective was to ascertain which commonly used 12-to-Frank-lead transformation yields spatial QRS-T angle values closest to those obtained from simultaneously collected true Frank-lead recordings. Simultaneous 12-lead and Frank XYZ-lead recordings were analyzed for 100 post-myocardial infarction patients and 50 controls. Relative agreement, with true Frank-lead results, of 12-to-Frank-lead transformed results for the spatial QRS-T angle using Kors regression versus inverse Dower was assessed via ANOVA, Lin s concordance and Bland-Altman plots. Spatial QRS-T angles from the true Frank leads were not significantly different than those derived from the Kors regression-related transformation but were significantly smaller than those derived from the inverse Dower-related transformation (P less than 0.001). Independent of method, spatial mean QRS-T angles were also always significantly larger than spatial maximum (peaks) QRS-T angles. Spatial QRS-T angles are best approximated by regression-related transforms. Spatial mean and spatial peaks QRS-T angles should also not be used interchangeably.

  5. When Deriving the Spatial QRS-T Angle from the 12-lead ECG, which Transform is More Frank: Regression or Inverse Dower?

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Cortez, Daniel

    2010-01-01

    Our primary objective was to ascertain which commonly used 12-to-Frank-lead transformation yields spatial QRS-T angle values closest to those obtained from simultaneously collected true Frank-lead recordings. Simultaneous 12-lead and Frank XYZ-lead recordings were analyzed for 100 post-myocardial infarction patients and 50 controls. Relative agreement, with true Frank-lead results, of 12-to-Frank-lead transformed results for the spatial QRS-T angle using Kors regression versus inverse Dower was assessed via ANOVA, Lin s concordance and Bland-Altman plots. Spatial QRS-T angles from the true Frank leads were not significantly different than those derived from the Kors regression-related transformation but were significantly smaller than those derived from the inverse Dower-related transformation (P less than 0.001). Independent of method, spatial mean QRS-T angles were also always significantly larger than spatial maximum (peaks) QRS-T angles. Spatial QRS-T angles are best approximated by regression-related transforms. Spatial mean and spatial peaks QRS-T angles should also not be used interchangeably.

  6. Cardiovascular evaluation, including resting and exercise electrocardiography, before participation in competitive sports: cross sectional study

    PubMed Central

    Capalbo, Andrea; Pucci, Nicola; Giuliattini, Jacopo; Condino, Francesca; Alessandri, Flavio; Abbate, Rosanna; Gensini, Gian Franco; Califano, Sergio

    2008-01-01

    Objective To evaluate the clinical usefulness of complete preparticipation cardiovascular screening in a large cohort of sports participants. Design Cross sectional study of data over a five year period. Setting Institute of Sports Medicine in Florence, Italy. Participants 30 065 (23 570 men) people seeking to obtain clinical eligibility for competitive sports. Main outcome measures Results of resting and exercise 12 lead electrocardiography. Results Resting 12 lead ECG patterns showed abnormalities in 1812 (6%) participants, with the most common abnormalities (>80%) concerning innocent ECG changes. Exercise ECG showed an abnormal pattern in 1459 (4.9%) participants. Exercise ECG showed cardiac anomalies in 1227 athletes with normal findings on resting ECG. At the end of screening, 196 (0.6%) participants were considered ineligible for competitive sports. Among the 159 participants who were disqualified at the end of the screening for cardiac reasons, a consistent proportion (n=126, 79.2%) had shown innocent or negative findings on resting 12 lead ECG but clear pathological alterations during the exercise test. After adjustment for possible confounders, logistic regression analysis showed that age >30 years was significantly associated with an increased risk of being disqualified for cardiac findings during exercise testing. Conclusions Among people seeking to take part in competitive sports, exercise ECG can identify those with cardiac abnormalities. Follow-up studies would show if disqualification of such people would reduce the incidence of CV events among athletes. PMID:18599474

  7. Feasibility and accuracy of a new mobile electrocardiography device, ER-2000®, in the diagnosis of arrhythmia

    PubMed Central

    Park, Yae Min; Lee, Dae In; Park, Hwan Cheol; Shim, Jaemin; Choi, Jong-Il; Lim, Hong Euy; Park, Sang Weon; Kim, Young-Hoon

    2015-01-01

    Background We performed this study to evaluate the feasibility and accuracy of a new mobile electrocardiography (ECG) device, ER-2000®, in detecting cardiac arrhythmia, by comparing it to a 12-lead ECG used as the gold standard. Methods Mode 1 of ER-2000® was recorded using three electrodes with cables attached to the anterior chest wall, and mode 2 was recorded using the side chest channel and finger channel. Standard 12-lead ECG was used to record with a speed of 25 mm/s, simultaneously. Results Seventeen patients with complaints of palpitation were enrolled. Twelve-lead ECG revealed normal sinus rhythm in three patients, sinus tachycardia in one, atrial fibrillation (AF) in two, atrial tachycardia (AT) in one, first degree atrioventricular block in one, pacing rhythm in two patients who underwent permanent pacemaker implantation, AF with intermittent ventricular pacing in one, complete right bundle branch block in one, J-wave elevation in one, narrow QRS tachycardia in one, atrial premature beat (APB) in one, ventricular premature beat (VPB) in one, and narrow QRS tachycardia with intermittent aberrant conduction in one. Rhythm diagnosis obtained by the two different modes of ER-2000® was correlated with that obtained by the 12-lead ECG in all patients except in one in whom ER-2000® showed one APB while 12-lead ECG showed sinus rhythm. R-R interval was accurately recorded despite the detailed morphology of QRS, and T-wave was somewhat modified with the use of ER-2000®. A pacing blip detected by 12-lead ECG was not detected by ER-2000® despite a similar wide QRS duration in the paced QRS. Conclusions A rhythm strip obtained using ER-2000® is accurate in diagnosing arrhythmia, despite some differences in the detailed morphology of the QRS and T-wave, and the pacing spike compared to those obtained by the 12-lead ECG. PMID:26336560

  8. Smartphone ECG for evaluation of STEMI: results of the ST LEUIS Pilot Study.

    PubMed

    Muhlestein, Joseph Boone; Le, Viet; Albert, David; Moreno, Fidela Ll; Anderson, Jeffrey L; Yanowitz, Frank; Vranian, Robert B; Barsness, Gregory W; Bethea, Charles F; Severance, Harry W; Ramo, Barry; Pierce, John; Barbagelata, Alejandro; Muhlestein, Joseph Brent

    2015-01-01

    12-lead ECG is a critical component of initial evaluation of cardiac ischemia, but has traditionally been limited to large, dedicated equipment in medical care environments. Smartphones provide a potential alternative platform for the extension of ECG to new care settings and to improve timeliness of care. To gain experience with smartphone electrocardiography prior to designing a larger multicenter study evaluating standard 12-lead ECG compared to smartphone ECG. 6 patients for whom the hospital STEMI protocol was activated were evaluated with traditional 12-lead ECG followed immediately by a smartphone ECG using right (VnR) and left (VnL) limb leads for precordial grounding. The AliveCor™ Heart Monitor was utilized for this study. All tracings were taken prior to catheterization or immediately after revascularization while still in the catheterization laboratory. The smartphone ECG had excellent correlation with the gold standard 12-lead ECG in all patients. Four out of six tracings were judged to meet STEMI criteria on both modalities as determined by three experienced cardiologists, and in the remaining two, consensus indicated a non-STEMI ECG diagnosis. No significant difference was noted between VnR and VnL. Smartphone based electrocardiography is a promising, developing technology intended to increase availability and speed of electrocardiographic evaluation. This study confirmed the potential of a smartphone ECG for evaluation of acute ischemia and the feasibility of studying this technology further to define the diagnostic accuracy, limitations and appropriate use of this new technology. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Is an Abnormal ECG Just the Tip of the ICE-berg? Examining the Utility of Electrocardiography in Detecting Methamphetamine-Induced Cardiac Pathology.

    PubMed

    Paratz, Elizabeth D; Zhao, Jessie; Sherwen, Amanda K; Scarlato, Rose-Marie; MacIsaac, Andrew I

    2017-07-01

    Methamphetamine use is escalating in Australia and New Zealand, with increasing emergency department attendance and mortality. Cardiac complications play a large role in methamphetamine-related mortality, and it would be informative to assess the frequency of abnormal electrocardiograms (ECGs) amongst methamphetamine users. To determine the frequency and severity of ECG abnormalities amongst methamphetamine users compared to a control group. We conducted a retrospective cohort analysis on 212 patients admitted to a tertiary hospital (106 patients with methamphetamine use, 106 age and gender-matched control patients). Electrocardiograms were analysed according to American College of Cardiology guidelines. Mean age was 33.4 years, with 73.6% male gender, with no significant differences between groups in smoking status, ECG indication, or coronary angiography rates. Methamphetamine users were more likely to have psychiatric admissions (22.6% vs 1.9%, p<0.0001). Overall, ECG abnormalities were significantly more common (71.7% vs 32.1%, p<0.0001) in methamphetamine users, particularly tachyarrhythmias (38.7% vs 26.4%, p<0.0001), right axis deviation (7.5% vs 0.0%, p=0.004), left ventricular hypertrophy (26.4% vs 4.7%, p<0.0001), P pulmonale pattern (7.5% vs 0.9%, p=0.017), inferior Q waves (10.4% vs 0.0%, p=0.001), lateral T wave inversion (3.8% vs 0.0%, p=0.043), and longer QTc interval (436.41±31.61ms vs 407.28±24.38ms, p<0.0001). Transthoracic echocardiogram (n=24) demonstrated left ventricular dysfunction (38%), thrombus (8%), valvular lesions (17%), infective endocarditis (17%), and pulmonary hypertension (13%). Electrocardiograms were only moderately sensitive at predicting abnormal TTE. Electrocardiographic abnormalities are more common in methamphetamine users than age and gender-matched controls. Due to the high frequency of abnormalities, ECGs should be performed in all methamphetamine users who present to hospital. Methamphetamine users with abnormal ECGs

  10. Surface 12 lead electrocardiogram recordings using smart phone technology.

    PubMed

    Baquero, Giselle A; Banchs, Javier E; Ahmed, Shameer; Naccarelli, Gerald V; Luck, Jerry C

    2015-01-01

    AliveCor ECG is an FDA approved ambulatory cardiac rhythm monitor that records a single channel (lead I) ECG rhythm strip using an iPhone. In the past few years, the use of smartphones and tablets with health related applications has significantly proliferated. In this initial feasibility trial, we attempted to reproduce the 12 lead ECG using the bipolar arrangement of the AliveCor monitor coupled to smart phone technology. We used the AliveCor heart monitor coupled with an iPhone cellular phone and the AliveECG application (APP) in 5 individuals. In our 5 individuals, recordings from both a standard 12 lead ECG and the AliveCor generated 12 lead ECG had the same interpretation. This study demonstrates the feasibility of creating a 12 lead ECG with a smart phone. The validity of the recordings would seem to suggest that this technology could become an important useful tool for clinical use. This new hand held smart phone 12 lead ECG recorder needs further development and validation. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. History of precordial leads in electrocardiography.

    PubMed

    Burch, G E

    1978-09-01

    Precordial leads were first used by Waller, whose capillary electroscope was too insensitive to detect the electric forces emanating from the human heart unless the electrode was placed over the precordium as near to the heart as possible. When Einthoven developed the elegant, reliable and sensitive string galvanometer, he could record the electric forces of the heart from the hands and feet of the subject without even undressing him. When Einthoven's great galvanometer became available, only the three standard limb leads were used. Thomas Lewis and others experimented with precordial direct leads and made many important discoveries in electrocardiography and cardiology. Wolferth and Wood, in 1932, introduced the first precordial lead in clinical, diagnostic cardiology. The recordings were 'upside-down', i.e. positive deflections were down and negative ones up. They called this the 4th lead (lead IV). The precordial electrode was placed on the chest over the apex of the heart, regardless of where the apex was located. This immediately opened new avenues of study in infarction, ventricular hypertrophy, bundle branch block, and all other cardiac states. Then CL, CR, CF, CB and V leads were introduced. The points considered best for placing the 'exploring' or precordial electrode became an issue, and much confusion prevailed until Wilson and his associates developed the central or isopotential terminal and until the American Heart Association and the Heart Society of Britain and Ireland met in London and published the standards for recording precordial leads in 1938. There followed, for obvious reasons, a slow settling of the confusion until the V1 through V6 precordial leads became standard procedure all over the world, as exists today. Goldberger introduced the augmented unipolar limb leads (aVR, aVL and aVF) which have resulted in the standard 12-lead electrocardiogram of routine use today. No one would consider an electrocardiographic evaluation adequate in a

  12. Single Doses up to 800 mg of E-52862 Do Not Prolong the QTc Interval--A Retrospective Validation by Pharmacokinetic-Pharmacodynamic Modelling of Electrocardiography Data Utilising the Effects of a Meal on QTc to Demonstrate ECG Assay Sensitivity.

    PubMed

    Täubel, Jörg; Ferber, Georg; Lorch, Ulrike; Wang, Duolao; Sust, Mariano; Camm, A John

    2015-01-01

    E-52862 is a Sigma-1 receptor antagonist (S1RA) currently under investigation as a potential analgesic medicine. We successfully applied a concentration-effect model retrospectively to a four-way crossover Phase I single ascending dose study and utilized the QTc shortening effects of a meal to demonstrate assay sensitivity by establishing the time course effects from baseline in all four periods, independently from any potential drug effects. Thirty two healthy male and female subjects were included in four treatment periods to receive single ascending doses of 500 mg, 600 mg or 800 mg of E-52862 or placebo. PK was linear over the dose range investigated and doses up to 600 mg were well tolerated. The baseline electrocardiography (ECG) measurements on Day-1 were time-matched with ECG and pharmacokinetic (PK) samples on Day 1 (dosing day). In this conventional mean change to time-matched placebo analysis, the largest time-matched difference to placebo QTcI was 1.44 ms (90% CI: -4.04, 6.93 ms) for 500 mg; -0.39 ms (90% CI: -3.91, 3.13 ms) for 600 mg and 1.32 ms (90% CI: -1.89, 4.53 ms) for 800 mg of E-52862, thereby showing the absence of any QTc prolonging effect at the doses tested. In addition concentration-effect models, one based on the placebo corrected change from baseline and one for the change of QTcI from average baseline with time as fixed effect were fitted to the data confirming the results of the time course analysis. The sensitivity of this study to detect small changes in the QTc interval was confirmed by demonstrating a shortening of QTcF of -8.1 (90% CI: -10.4, -5.9) one hour and -7.2 (90% CI: -9.4, -5.0) three hours after a standardised meal. EU Clinical Trials Register EudraCT 2010 020343 13.

  13. Telemetric Electrocardiography

    PubMed Central

    Cerkez, Constantine T.; Steward, Gordon C.; Manning, George W.

    1965-01-01

    By means of a satellite transmitter nearby the subject an electrocardiogram can be obtained by telemetry in a hospital electrocardiographic (ECG) laboratory from an area of approximately 20 miles in diameter within the city of London, Ontario. The technique employed in this preliminary trial produced excellent tracings, quite comparable to tracings obtained using the same leads with direct recording. Ninety-four trials were performed on 63 subjects, 37 of whom were patients with a suspected or known myocardial abnormality. A normal group of 26 healthy subjects, 16 of whom were strenuously exercised on a bicycle ergometer to the point of physical exhaustion, were also studied. Monitoring patients during ordinary daily activities has proved extremely useful in the detection and diagnosis of cardiac arrhythmias, intermittent conduction disturbances, latent coronary artery disease, and asymptomatic heart disease. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7Fig. 8Fig. 9Fig. 10Fig. 11Fig. 12Fig. 13Fig. 14Fig. 15 PMID:5842592

  14. Comparing twelve-lead electrocardiography with close-to-heart patch based electrocardiography.

    PubMed

    Hansen, Ingeborg H; Hoppe, Karsten; Gjerde, Anna; Kanters, Joergen K; Sorensen, Helge B D

    2015-01-01

    Electrocardiographic (ECG) recording using adhesive patch-type ECG monitors (PEMs) has several advantages over conventional ECG recorders. However, due to the unconventional electrode locations used in PEM systems, the morphology of the acquired ECG signals may differ from conventional ECG leads used in the clinic impeding clinical interpretation. In this study, recordings from an ePatch® lead system involving three torso sites are compared with concurrently recorded standard 12-lead ECG. Pearson's correlation coefficients (CC) of -0.90 and 0.91 is found between two of the PEM signals and the standard 12-lead ECG signals aVR and V2, respectively. Deriving the 12-lead ECG from the PEM leads through linear transforms on a subject-specific basis yield CC values ranging from 0.78 to 0.96 between measured and derived leads. The corresponding CC values for the PEM ECG leads range from 0.88 to 0.95. It is found that the PEM lead system captures "residual" information not contained in the standard 12-lead ECG and i.a. a negative deflection after the T-wave is discovered in the PEM signals.

  15. [Singularity spectra analysis of the ST segments of 12-lead electrocardiogram].

    PubMed

    Wang, Jun; Ning, Xinbao; Xu, Yinlin; Ma, Qianli; Chen, Ying; Li, Dehua

    2007-12-01

    By analysing the f(a) singularity spectra of the ST segments of the synchronous 12-lead ECG, we have found that the singularity spectrum is close to monofractality and its area is only half the area of the synchronous 12-lead ECG f(alpha) singularity spectrum. The ST segments of the synchronous 12-lead ECG signal also has f(alpha) singularity spectra distribution and it also has a reasonable varying scope. We have also found that the lead number of the ST segment f (alpha) singularity spectra for adults having coronary heart disease overstep the reasonable scope tends to increase over that of the ECG f(alpha) singularity spectra. These findings show that using the ST segments f(alpha) singularity spectra distribution of the synchronous 12-lead ECG is more effective than using the synchronous 12-lead ECG on the clinical analysis.

  16. Artefactual spikes in electrocardiography: a worthwhile introspection.

    PubMed

    Moni, Monika; Rajda, Jay; Lakshmanadoss, Umashankar

    2013-02-01

    Electrical devices, which have become an integral part of our daily life, may influence the electrical recording of the heart. These disturbances from external sources outside of the heart's own activity produce changes in the electrocardiography (ECG) of the patient, simulating rhythmic disturbances of the heart. Understanding these disturbances is essential in order to better interprete the ECG. Common sources of electrical interferences include external devices, such as alternating current and improper earthing, and surgical procedures like diathermy. We report a case of electrical interference in a patient's ECG due to an inserted bladder stimulator. This case report highlights the importance of precise identification of artefacts in the interpretation of ECG, as well as prompt localisation and elimination of the source of interference.

  17. Clinical Application of Electrocardiography.

    ERIC Educational Resources Information Center

    Brammell, H. L.; Orr, William

    The scalar electrocardiogram (ECG) is one of the most important and commonly used clinical tools in medicine. A detailed description of the recordings of cardiac electrical activity made by the ECG is presented, and the vast numbers of uses made with the data provided by this diagnostic tool are cited. Clinical applications of the ECG are listed.…

  18. Non-contact ECG monitoring

    NASA Astrophysics Data System (ADS)

    Smirnov, Alexey S.; Erlikh, Vadim V.; Kodkin, Vladimir L.; Keller, Andrei V.; Epishev, Vitaly V.

    2016-03-01

    The research is dedicated to non-contact methods of electrocardiography. The authors describe the routine of experimental procedure and suggest the approach to solving the problems which arise at indirect signal recording. The paper presents the results of experiments conducted by the authors, covers the flow charts of ECG recorders and reviews the drawbacks of filtering methods used in foreign equivalents.

  19. Comparative study of thallium-201 single-photon emission computed tomography and electrocardiography in Duchenne and other types of muscular dystrophy

    SciTech Connect

    Yamamoto, S.; Matsushima, H.; Suzuki, A.; Sotobata, I.; Indo, T.; Matsuoka, Y.

    1988-04-01

    Single-photon emission computed tomography (SPECT) using thallium-201 was compared with 12-lead electrocardiography (ECG) in patients with Duchenne (29), facioscapulohumeral (7), limb-girdle (6) and myotonic (5) dystrophies, by dividing the left ventricular (LV) wall into 5 segments. SPECT showed thallium defects (37 patients, mostly in the posteroapical wall), malrotation (23), apical aneurysm (5) and dilatation (7). ECG showed abnormal QRS (36 patients), particularly as a posterolateral pattern (13). Both methods of assessment were normal in only 7 patients. The Duchenne type frequently showed both a thallium defect (particularly in the posteroapical wall) and an abnormal QRS (predominantly in the posterolateral wall); the 3 other types showed abnormalities over the 5 LV wall segments in both tests. The percent of agreement between the 2 tests was 64, 66, 70, 72 and 72 for the lateral, apical, anteroseptal, posterior and inferior walls, respectively. The 2 tests were discordant in 31% of the LV wall, with SPECT (+) but ECG (-) in 21% (mostly in the apicoinferior wall) and SPECT (-) but ECG (+) in 10% (mostly in the lateral wall). Some patients showed large SPECT hypoperfusion despite minimal electrocardiographic changes. ECG thus appeared to underestimate LV fibrosis and to reflect posteroapical rather than posterolateral dystrophy in its posterolateral QRS pattern. In this disease, extensive SPECT hypoperfusion was also shown, irrespective of clinical subtype and skeletal involvement.

  20. A new microcomputer-based ECG analysis system.

    PubMed

    Kyle, M C; Klingeman, J D; Conrad, J D; Freis, E D; Pipberger, H V

    1983-09-01

    A new automated ECG system using advances in microprocessor technology and computerized electrocardiography is described. This microcomputer-based system is self-contained and mobile. It acquires both the 12-lead and orthogonal lead (Frank) electrocardiograms and analyzes the latter within minutes. Software includes the program developed in the Veterans Administration which uses advanced statistical classification techniques and a large well-documented patient data base. Diagnostic probabilities are computed using a Bayesian approach. Diagnostic performance has been tested using independent clinical criteria and found to be quite accurate. This system enables the clinician to immediately review the computer's identifications, measurements, and diagnostic classifications and quickly use these results in clinical decision making. Serial comparisons are readily made since all previous recordings are stored on floppy diskettes. The use of microprocessors in this system makes it economically feasible for practicing physicians.

  1. Heart Rate and Electrocardiography Monitoring in Mice

    PubMed Central

    Ho, David; Zhao, Xin; Gao, Shumin; Hong, Chull; Vatner, Dorothy E.; Vatner, Stephen F.

    2011-01-01

    The majority of current cardiovascular research involves studies in genetically engineered mouse models. The measurement of heart rate is central to understanding cardiovascular control under normal conditions, with altered autonomic tone, superimposed stress or disease states, both in wild type mice as well as those with altered genes. Electrocardiography (ECG) is the “gold standard” using either hard wire or telemetry transmission. In addition, heart rate is measured or monitored from the frequency of the arterial pressure pulse or cardiac contraction, or by pulse oximetry. For each of these techniques, discussions of materials and methods, as well as advantages and limitations are covered. However, only the direct ECG monitoring will determine not only the precise heart rates but also whether the cardiac rhythm is normal or not. PMID:21743842

  2. Novel Tool for Complete Digitization of Paper Electrocardiography Data

    PubMed Central

    Harless, Chris; Shah, Amit J.; Wick, Carson A.; Mcclellan, James H.

    2013-01-01

    Objective: We present a Matlab-based tool to convert electrocardiography (ECG) information from paper charts into digital ECG signals. The tool can be used for long-term retrospective studies of cardiac patients to study the evolving features with prognostic value. Methods and procedures: To perform the conversion, we: 1) detect the graphical grid on ECG charts using grayscale thresholding; 2) digitize the ECG signal based on its contour using a column-wise pixel scan; and 3) use template-based optical character recognition to extract patient demographic information from the paper ECG in order to interface the data with the patients' medical record. To validate the digitization technique: 1) correlation between the digital signals and signals digitized from paper ECG are performed and 2) clinically significant ECG parameters are measured and compared from both the paper-based ECG signals and the digitized ECG. Results: The validation demonstrates a correlation value of 0.85–0.9 between the digital ECG signal and the signal digitized from the paper ECG. There is a high correlation in the clinical parameters between the ECG information from the paper charts and digitized signal, with intra-observer and inter-observer correlations of 0.8–0.9 \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$({\\rm p}<{0.05})$\\end{document}, and kappa statistics ranging from 0.85 (inter-observer) to 1.00 (intra-observer). Conclusion: The important features of the ECG signal, especially the QRST complex and the associated intervals, are preserved by obtaining the contour from the paper ECG. The differences between the measures of clinically important features extracted from the original signal and the reconstructed signal are insignificant, thus highlighting the accuracy of this technique

  3. Advanced Electrocardiography Can Identify Occult Cardiomyopathy in Doberman Pinschers

    NASA Technical Reports Server (NTRS)

    Spiljak, M.; Petric, A. Domanjko; Wilberg, M.; Olsen, L. H.; Stepancic, A.; Schlegel, T. T.; Starc, V.

    2011-01-01

    Recently, multiple advanced resting electrocardiographic (A-ECG) techniques have improved the diagnostic value of short-duration ECG in detection of dilated cardiomyopathy (DCM) in humans. This study investigated whether 12-lead A-ECG recordings could accurately identify the occult phase of DCM in dogs. Short-duration (3-5 min) high-fidelity 12-lead ECG recordings were obtained from 31 privately-owned, clinically healthy Doberman Pinschers (5.4 +/- 1.7 years, 11/20 males/females). Dogs were divided into 2 groups: 1) 19 healthy dogs with normal echocardiographic M-mode measurements: left ventricular internal diameter in diastole (LVIDd . 47mm) and in systole (LVIDs . 38mm) and normal 24-hour ECG recordings (<50 ventricular premature complexes, VPCs); and 2) 12 dogs with occult DCM: 11/12 dogs had increased M-mode measurements (LVIDd . 49mm and/or LVIDs . 40mm) and 5/11 dogs had also >100 VPCs/24h; 1/12 dogs had only abnormal 24-hour ECG recordings (>100 VPCs/24h). ECG recordings were evaluated via custom software programs to calculate multiple parameters of high-frequency (HF) QRS ECG, heart rate variability, QT variability, waveform complexity and 3-D ECG. Student's t-tests determined 19 ECG parameters that were significantly different (P < 0.05) between groups. Principal component factor analysis identified a 5-factor model with 81.4% explained variance. QRS dipolar and non-dipolar voltages, Cornell voltage criteria and QRS waveform residuum were increased significantly (P < 0.05), whereas mean HF QRS amplitude was decreased significantly (P < 0.05) in dogs with occult DCM. For the 5 selected parameters the prediction of occult DCM was performed using a binary logistic regression model with Chi-square tested significance (P < 0.01). ROC analyses showed that the five selected ECG parameters could identify occult ECG with sensitivity 89% and specificity 83%. Results suggest that 12-lead A-ECG might improve diagnostic value of short-duration ECG in earlier detection

  4. Time-voltage QRS area of the 12-lead electrocardiogram: detection of left ventricular hypertrophy.

    PubMed

    Okin, P M; Roman, M J; Devereux, R B; Pickering, T G; Borer, J S; Kligfield, P

    1998-04-01

    Identification of left ventricular hypertrophy (LVH) using 12-lead ECG criteria based primarily on QRS amplitudes has been limited by poor sensitivity at acceptable levels of specificity. Because the product of QRS voltage and duration, as an approximation of the time-voltage area of the QRS complex, can improve accuracy of the 12-lead ECG for LVH, we examined the diagnostic value of true time-voltage area measurements of QRS complexes from the standard 12-lead ECG. Standard 12-lead ECGs and echocardiograms were obtained in 175 control subjects without LVH and in 74 patients with regurgitant valvular heart disease and LVH defined by echocardiographic criteria (indexed LV mass >110 g/m2 in women and >125 g/m2 in men). Standard voltage criteria, voltage-duration products (voltage multiplied by QRS duration), and true time-voltage areas of the QRS were calculated for Sokolow-Lyon criteria (SV1 +RV(5/6)) and the 12-lead sum of voltage criteria. Test sensitivities were compared using gender-specific partitions with matched specificity of 98% in the 175 subjects without LVH. Measurement of the time-voltage area significantly improved sensitivity for both criteria. The 76% sensitivity of the 12-lead sum area and 65% sensitivity of Sokolow-Lyon area were significantly greater than the 54% sensitivity of the approximation of QRS area provided by each voltage-duration product (P<.001 and P=.021) and than the 46% and 43% sensitivities of the respective simple voltage criteria (each P<.001). Comparison of receiver operating characteristic curves confirmed the superior overall performance of time-voltage area criteria compared with both voltage-duration products and simple voltage criteria. These results suggest that use of time-voltage areas can dramatically improve identification of LVH by 12-lead ECG. Further study of this approach is needed to identify optimal criteria for LVH based on the time-voltage area measurements from the 12-lead ECG.

  5. Cleanliness of disposable vs nondisposable electrocardiography lead wires in children.

    PubMed

    Addison, Nancy; Quatrara, Beth; Letzkus, Lisa; Strider, David; Rovnyak, Virginia; Syptak, Virginia; Fuzy, Lisa

    2014-09-01

    Mediastinitis costs hospitals thousands of dollars a year and increases the incidence of patient morbidity and mortality. No studies have been done to evaluate adenosine triphosphate (ATP) counts on disposable and nondisposable electrocardiography (ECG) lead wires in pediatric patients. To compare the cleanliness of disposable and nondisposable ECG lead wires in postoperative pediatric cardiac surgery patients by measuring the quantity of ATP (in relative luminescence units [RLUs]). ATP levels correlate with microbial cell counts and are used by institutions to assess hospital equipment and cleanliness. A prospective, randomized trial was initiated with approval from the institutional review board. Verbal consent was obtained from the parents/guardians for each patient. Trained nurses performed ATP swabs on the right and left upper ECG cables on postoperative days 1, 2, and 3. This study enrolled 51 patients. The disposable ECG lead wire ATP count on postoperative day 1 (median, 157 RLUs) was significantly lower (P < .001) than the count for nondisposable ATP lead wires (median, 610 RLUs). On postoperative day 2, the ATP count for the disposable ECG lead wires (median, 200 RLUs) was also lower (P = .06) than the count for the nondisposable ECG lead wires (median, 453 RLUs). Results of this study support the use of disposable ECG lead wires in postoperative pediatric cardiac surgery patients for at least the first 48 hours as a direct strategy to reduce the ATP counts on ECG lead wires. ©2014 American Association of Critical-Care Nurses.

  6. Methods for Improving the Diagnosis of a Brugada ECG Pattern.

    PubMed

    Gottschalk, Byron H; Garcia-Niebla, Javier; Anselm, Daniel D; Glover, Benedict; Baranchuk, Adrian

    2016-03-01

    Brugada syndrome (BrS) is an inherited channelopathy that predisposes individuals to malignant arrhythmias and can lead to sudden cardiac death. The condition is characterized by two electrocardiography (ECG) patterns: the type-1 or "coved" ECG and the type-2 or "saddleback" ECG. Although the type-1 Brugada ECG pattern is diagnostic for the condition, the type-2 Brugada ECG pattern requires differential diagnosis from conditions that produce a similar morphology. In this article, we present a case that is suspicious but not diagnostic for BrS and discuss the application of ECG methodologies for increasing or decreasing suspicion for a diagnosis of BrS. © 2015 Wiley Periodicals, Inc.

  7. 12-lead Holter monitoring in diving and water sports: a preliminary investigation.

    PubMed

    Bosco, Gerardo; De Marzi, Elena; Michieli, Pierantonio; Omar, Hesham R; Camporesi, Enrico M; Padulo, Johnny; Paoli, Antonio; Mangar, Devanand; Schiavon, Maurizio

    2014-12-01

    To demonstrate the utility of 12-lead Holter monitoring underwater. A Holter monitor, recording a 12-lead electrocardiogram (ECG) underwater, was applied to 16 pre-trained volunteer scuba divers (13 males and three females). Dive computers were synchronized with the Holter recorder to correlate the ECG tracings with diving events. Our main objective was to demonstrate the utility of recording over a period of time a good quality 12-lead ECG underwater. The ECGs were analyzed for heart rate (HR), arrhythmias, conduction abnormalities and ischaemic events in relation to various stages of diving as follows: baseline, pre diving, diving, and post diving. The ECG tracings were of good quality with minimal artefacts. Analysis of variance (ANOVA) demonstrated a significant difference in HR during the various diving stages (P < 0.0001). Other recorded ECG abnormalities included supraventricular ectopic beats (four cases), ventricular ectopic beats (eight cases) and ventricular couplets (two cases). Conduction abnormalities included rate-dependent right and left bundle branch block; however, these findings were previously known in these divers. No evidence of ischaemia was seen. Continuous 12-lead Holter monitoring underwater can produce good quality tracings. Further studies are necessary to assess its usefulness in divers at risk for or with known coronary artery disease, and its comparison with other forms of cardiac stress tests.

  8. 12-lead electrocardiogram features of arrhythmic risk: A focus on early repolarization

    PubMed Central

    Rizzo, Caterina; Monitillo, Francesco; Iacoviello, Massimo

    2016-01-01

    The 12-lead electrocardiogram (ECG) is still the most used tool in cardiology clinical practice. Considering its easy accessibility, low cost and the information that it provides, it remains the starting point for diagnosis and prognosis. More specifically, its ability to detect prognostic markers for sudden cardiac death due to arrhythmias by identifying specific patterns that express electrical disturbances of the heart muscle, which may predispose to malignant arrhythmias, is universally recognized. Alterations in the ventricular repolarization process, identifiable on a 12-lead ECG, play a role in the genesis of ventricular arrhythmias in different cardiac diseases. The aim of this paper is to focus the attention on a new marker of arrhythmic risk, the early repolarization pattern in order to highlight the prognostic role of the 12-lead ECG. PMID:27621772

  9. Pre-hospital 12-Lead ST-Segment Monitoring Improves the Early Diagnosis of Acute Coronary Syndrome

    PubMed Central

    Hemsey, Jessica Zègre; Dracup, Kathleen; Fleischmann, Kirsten; Sommargren, Claire E.; Drew, Barbara J.

    2011-01-01

    Aims/Methods We studied 620 patients who activated ‘911’ for chest pain symptoms to determine the sensitivity and specificity of 12-lead ECG ST-segment monitoring in the pre-hospital period (PH ECG) for diagnosing acute coronary syndrome (ACS), and to assess whether the addition of PH ECG signs of ischemia/injury to the initial hospital 12-lead ECG obtained in the emergency department (ED) would improve the diagnosis of ACS. Results The sensitivity and specificity of the PH ECG were 65.4% and 66.4%. There was a significant increase in sensitivity (79.9%) and decrease in specificity (61.2%) when considered in conjunction with the initial hospital ECG (p<0.001). Those with PH ECG ischemia/injury were more than 2.5 times likely to have an ACS diagnosis than those who had no PH ECG ischemia/injury (p<0.001). Conclusions PH ECG data obtained with 12-lead ST-segment monitoring provides diagnostic information about ACS above and beyond the initial hospital ECG. PMID:22115367

  10. Polyphonic sonification of electrocardiography signals for diagnosis of cardiac pathologies

    PubMed Central

    Kather, Jakob Nikolas; Hermann, Thomas; Bukschat, Yannick; Kramer, Tilmann; Schad, Lothar R.; Zöllner, Frank Gerrit

    2017-01-01

    Electrocardiography (ECG) data are multidimensional temporal data with ubiquitous applications in the clinic. Conventionally, these data are presented visually. It is presently unclear to what degree data sonification (auditory display), can enable the detection of clinically relevant cardiac pathologies in ECG data. In this study, we introduce a method for polyphonic sonification of ECG data, whereby different ECG channels are simultaneously represented by sound of different pitch. We retrospectively applied this method to 12 samples from a publicly available ECG database. We and colleagues from our professional environment then analyzed these data in a blinded way. Based on these analyses, we found that the sonification technique can be intuitively understood after a short training session. On average, the correct classification rate for observers trained in cardiology was 78%, compared to 68% and 50% for observers not trained in cardiology or not trained in medicine at all, respectively. These values compare to an expected random guessing performance of 25%. Strikingly, 27% of all observers had a classification accuracy over 90%, indicating that sonification can be very successfully used by talented individuals. These findings can serve as a baseline for potential clinical applications of ECG sonification. PMID:28317848

  11. Polyphonic sonification of electrocardiography signals for diagnosis of cardiac pathologies

    NASA Astrophysics Data System (ADS)

    Kather, Jakob Nikolas; Hermann, Thomas; Bukschat, Yannick; Kramer, Tilmann; Schad, Lothar R.; Zöllner, Frank Gerrit

    2017-03-01

    Electrocardiography (ECG) data are multidimensional temporal data with ubiquitous applications in the clinic. Conventionally, these data are presented visually. It is presently unclear to what degree data sonification (auditory display), can enable the detection of clinically relevant cardiac pathologies in ECG data. In this study, we introduce a method for polyphonic sonification of ECG data, whereby different ECG channels are simultaneously represented by sound of different pitch. We retrospectively applied this method to 12 samples from a publicly available ECG database. We and colleagues from our professional environment then analyzed these data in a blinded way. Based on these analyses, we found that the sonification technique can be intuitively understood after a short training session. On average, the correct classification rate for observers trained in cardiology was 78%, compared to 68% and 50% for observers not trained in cardiology or not trained in medicine at all, respectively. These values compare to an expected random guessing performance of 25%. Strikingly, 27% of all observers had a classification accuracy over 90%, indicating that sonification can be very successfully used by talented individuals. These findings can serve as a baseline for potential clinical applications of ECG sonification.

  12. Comparison of the patient-activated event recording system vs. traditional 24 h Holter electrocardiography in individuals with paroxysmal palpitations or dizziness.

    PubMed

    de Asmundis, Carlo; Conte, Giulio; Sieira, Juan; Chierchia, Gian-Battista; Rodriguez-Manero, Moises; Di Giovanni, Giacomo; Ciconte, Giuseppe; Levinstein, Moises; Baltogiannis, Giannis; Saitoh, Yukio; Casado-Arroyo, Rubén; Brugada, Pedro

    2014-08-01

    Electrocardiographic documentation of symptomatic episodes of palpitations by means of traditional methods such as 24 h Holter monitoring (HM) or loop recorders is challenging. Patient-activated electrocardiography (ECG) recorders have been proved to be a useful tool in the diagnosis of arrhythmias in these patients. However, no comparison studies between the two techniques have been conducted. The aim of this study was to compare the diagnostic value of Holter ECG and a patient-activated event recorder (OMRON portable HeartScan ECG Monitor(®)) (HeartScan) in the detection of arrhythmias in patients with paroxysmal palpitations or dizziness suggestive of cardiac arrhythmias. Patients with paroxysmal palpitations or dizziness were eligible for this study. All patients underwent an HM for 24 h and a 15-day HeartScan after the HM. Six hundred and twenty-five patients (48% male, mean age: 37 ± 11 years) were included in the study. All patients present with normal heart structure, normal baseline 12-lead ECG, and normal echocardiogram. Indications for ECG monitoring were palpitations in 577 patients (92.3%) and dizziness in 48 (7.7%). Holter monitoring offered a clinical diagnosis in 11 patients (1.8%). Conversely, HeartScan diagnosed the clinical arrhythmia in 558 individuals (89%). Detection of symptoms-related arrhythmias by means of HeartScan was significantly higher when compared with HM (P < 0.01). The studied system proved to be an efficient event recorder providing the diagnosis of the clinical arrhythmia in 89% of patients with paroxysmal palpitations or dizziness. Further studies are needed to confirm our results. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  13. Comparison of magnetocardiography and electrocardiography

    NASA Astrophysics Data System (ADS)

    Ho, S. C.; Ho, F. P.; Tien, C. C.; Wilkin, J. H.; Miller, J. W.

    1986-02-01

    The paper compares the MCG and ECG of two abnormal subjects. For the case of complete left bundle branch block, the MCG and ECG have similar morphology, but different signal strengths. For the case of dilated cardiomyopathy, the magnetic QRS complex divides into peaks R and R', not found in ECG.

  14. Electrocardiographic (ECG) criteria for determining left ventricular mass in young healthy men; data from the LARGE Heart study

    PubMed Central

    Sohaib, Syed M Afzal; Payne, John R; Shukla, Rajeev; World, Michael; Pennell, Dudley J; Montgomery, Hugh E

    2009-01-01

    Background Doubts remain over the use of the ECG in identifying those with increased left ventricular (LV) mass. This is especially so in young individuals, despite their high prevalence of ECG criteria for LV hypertrophy. We performed a study using cardiovascular magnetic resonance (CMR), which provides an in vivo non-invasive gold standard method of measuring LV mass, allowing accurate assessment of electrocardiography as a tool for defining LV hypertrophy in the young. Methods and results Standard 12-lead ECGs were obtained from 101 Caucasian male army recruits aged (mean ± SEM) 19.7 ± 0.2 years. LV mass was measured using CMR. LV mass indexed to body surface area demonstrated no significant correlation with the Cornell Amplitude criteria or Cornell Product for LV hypertrophy. Moderate correlations were seen with the Sokolow-Lyon Amplitude (0.28) and Sokolow-Lyon Product (0.284). Defining LV hypertrophy as a body surface area indexed left ventricular mass of 93 g/m2, calculated sensitivities [and specificities] were as follows; 38.7% [74.3%] for the Sokolow-Lyon criteria, 43.4% [61.4%] for the Sokolow-Lyon Product, 19.4% [91.4%] for Cornell Amplitude, and 22.6% [85.7%] for Cornell Product. These values are substantially less than those reported for older age groups. Conclusion ECG criteria for LV hypertrophy may have little value in determining LV mass or the presence of LV hypertrophy in young fit males. PMID:19149884

  15. History of research in Japan on electrocardiography in the racehorse

    PubMed Central

    HIRAGA, Atsushi; SUGANO, Shigeru

    2015-01-01

    ABSTRACT Since the first recording of electrocardiograms (ECGs) of a horse in Japan was carried out in 1944, studies on ECGs have been performed intensively. During the early stages of research from the 1950s to 1960s, leads to use for ECG recording were evaluated using several different approaches including unipolar leads, bipolar limb leads, and bipolar chest leads. Based on these studies, the AB lead, which is oriented along the long axis of the heart, became the standard reference method in Japan. Electrodes of the AB lead are placed on the upper 1/4th point along a straight line between the withers and the left shoulder blade (base: B), and 10 cm posterior to the left olecranon (apex: A). The incidence of equine arrhythmias among racehorses has been surveyed, and details of the electrocardiographic characteristics of several arrhythmias have been investigated. In particular, atrial fibrillation (AF) has been extensively studied, and papers have reported findings such as that paroxysmal AF occurs during racing and described electrocardiographic changes that occur at the onset of AF during exercise. Development of a radiotelemetry system for ECG recording enabled the first recording of equine ECGs during galloping in 1964, the detection of arrhythmias, and calculation of heart rate during exercise. Studies on comparative and developmental changes of ECGs have described characteristics of the equine ECGs. Future research on changes in cardiac function, including autonomic function, that occur with aging may lead to new developments in equine electrocardiography and contribute to improving the health and welfare of the horse. PMID:25829865

  16. Assessment of atrial fibrillation ablation outcomes with clinic ECG, monthly 24-h Holter ECG, and twice-daily telemonitoring ECG.

    PubMed

    Kimura, Takehiro; Aizawa, Yoshiyasu; Kurata, Naomi; Nakajima, Kazuaki; Kashimura, Shin; Kunitomi, Akira; Nishiyama, Takahiko; Katsumata, Yoshinori; Nishiyama, Nobuhiro; Fukumoto, Kotaro; Tanimoto, Yoko; Fukuda, Keiichi; Takatsuki, Seiji

    2017-03-01

    Differences in the methodologies for evaluating atrial fibrillation (AF) ablation outcomes should be evaluated. In the present study, we compared the AF ablation outcomes among periodic clinic electrocardiography (ECG), 24-h Holter ECG, and telemonitoring ECG to evaluate the differences among these methods. In addition, we evaluated the AF-free survival rate for each method with different durations of the blanking period. A total of 30 AF patients were followed up for 6 months after initial catheter ablation, with clinic ECG on every clinic visit, monthly 24-h Holter ECG, and telemonitoring ECG twice daily and upon symptoms. AF relapse was defined as AF or atrial tachycardia detected with any of the methods. Two patients dropped out of the study, and 28 patients were followed up for 8.8 ± 2.7 months. Patients underwent 3.6 ± 0.8 clinic ECG, 5.1 ± 0.8 Holter ECG, and 273 ± 68 telemonitoring ECG examinations. During the first, second, third, fourth, fifth, and sixth months of follow-up, Holter ECG detected relapses in 11.1, 8.3, 11.5, 15.4, 4.2, and 4.8 % of patients and telemonitoring ECG detected relapses in 32.1, 25.0, 25.0, 17.9, 28.6, and 17.9 % of patients, respectively. When no duration was set for the blanking period, the AF-free survival rate was significantly lower with telemonitoring ECG (46.4 %) than with Holter ECG (78.6 %, P = 0.013) or clinic ECG (85.7 %, P = 0.002). In addition, when the duration of the blanking period was set to 3 months, the AF-free survival rate was significantly lower with telemonitoring ECG than with clinic ECG (92.9 vs. 71.4 %, P = 0.041). The AF ablation outcomes with twice-daily telemonitoring ECG might differ from those with clinic ECG when the duration of the blanking period is 0-3 months. A follow-up based solely on clinic ECG might underestimate AF recurrence.

  17. [Multimedia instruction: its efficacy in nurse electrocardiography learning].

    PubMed

    Chang, Mei-Hua; Hsu, Li-Ling

    2010-08-01

    Rapid enhancements in information technology have focused increasing attention on the potentials of multimedia-assisted instruction in nursing education. Multimedia-assisted instruction not only goes beyond constraints on time and space, it further provides learners with a more active and dynamic environments for learning. In this context, learning becomes easier and more convenient. Most importantly, such instruction has been shown to enhance the effectiveness of student learning. The purpose of this research was to develop multimedia-assisted teaching materials focused on the subject of electrocardiography and to discuss the resulting efficacy of electrocardiography education relative to the overall in-service nursing education curriculum. This study employed a pretest-posttest quasi-experimental design method and purposive sampling. Seventy-seven nurses were enrolled as participants from intensive care units of a Taipei hospital. An EKG knowledge questionnaire was employed to collect data once prior to the start of the course and once following course completion. Data were analyzed using the SPSS 15.0 for Windows software package. RESULTS showed the experimental group scored significantly higher on ECG knowledge after the intervention than the control group. The experimental group further showed significant differences in ECG knowledge in terms of pre- and post-intervention measurements. In the future, the strategy of multimedia-assisted instruction should be applied extensively in the nursing staff continuing education curriculum in order to increase learner interest and motivation.

  18. The ISCE ECG genome pilot challenge: a 2004 progress report.

    PubMed

    Kligfield, Paul; Badilini, Fabio; Brown, Barry; Helfenbein, Erich; Kohls, Mark

    2004-01-01

    The International Society for Computerized Electrocardiography (ISCE) "genome project" began in 2000 as an open-ended discussion of ECG database needs and opportunities. Cooperation within ISCE led to a "pilot challenge" of the database concept, which called for establishment of methodology for transmission, storage, and integrated re-analysis of digitized waveforms of three different ECG manufacturers. The present report documents the early implementation of that goal.

  19. Interactive Videoconference Supported Teaching in Undergraduate Nursing: A Case Study for ECG

    ERIC Educational Resources Information Center

    Celikkan, Ufuk; Senuzun, Fisun; Sari, Dilek; Sahin, Yasar Guneri

    2013-01-01

    This paper describes how interactive videoconference can benefit the Electrocardiography (ECG) skills of undergraduate nursing students. We have implemented a learning system that interactively transfers the visual and practical aspects of ECG from a nursing skills lab into a classroom where the theoretical part of the course is taught. The…

  20. Interactive Videoconference Supported Teaching in Undergraduate Nursing: A Case Study for ECG

    ERIC Educational Resources Information Center

    Celikkan, Ufuk; Senuzun, Fisun; Sari, Dilek; Sahin, Yasar Guneri

    2013-01-01

    This paper describes how interactive videoconference can benefit the Electrocardiography (ECG) skills of undergraduate nursing students. We have implemented a learning system that interactively transfers the visual and practical aspects of ECG from a nursing skills lab into a classroom where the theoretical part of the course is taught. The…

  1. High-frequency ECG

    NASA Technical Reports Server (NTRS)

    Tragardh, Elin; Schlegel, Todd T.

    2006-01-01

    The standard ECG is by convention limited to 0.05-150 Hz, but higher frequencies are also present in the ECG signal. With high-resolution technology, it is possible to record and analyze these higher frequencies. The highest amplitudes of the high-frequency components are found within the QRS complex. In past years, the term "high frequency", "high fidelity", and "wideband electrocardiography" have been used by several investigators to refer to the process of recording ECGs with an extended bandwidth of up to 1000 Hz. Several investigators have tried to analyze HF-QRS with the hope that additional features seen in the QRS complex would provide information enhancing the diagnostic value of the ECG. The development of computerized ECG-recording devices that made it possible to record ECG signals with high resolution in both time and amplitude, as well as better possibilities to store and process the signals digitally, offered new methods for analysis. Different techniques to extract the HF-QRS have been described. Several bandwidths and filter types have been applied for the extraction as well as different signal-averaging techniques for noise reduction. There is no standard method for acquiring and quantifying HF-QRS. The physiological mechanisms underlying HF-QRS are still not fully understood. One theory is that HF-QRS are related to the conduction velocity and the fragmentation of the depolarization wave in the myocardium. In a three-dimensional model of the ventricles with a fractal conduction system it was shown that high numbers of splitting branches are associated with HF-QRS. In this experiment, it was also shown that the changes seen in HF-QRS in patients with myocardial ischemia might be due to the slowing of the conduction velocity in the region of ischemia. This mechanism has been tested by Watanabe et al by infusing sodium channel blockers into the left anterior descending artery in dogs. In their study, 60 unipolar ECGs were recorded from the entire

  2. ECG (image)

    MedlinePlus

    ... electrocardiogram (ECG, EKG) is used extensively in the diagnosis of heart disease, ranging from congenital heart disease in infants to myocardial infarction and myocarditis in adults. Several different types of ...

  3. Debatable issues in automated ECG reporting.

    PubMed

    Macfarlane, Peter W; Mason, Jay W; Kligfield, Paul; Sommargren, Claire E; Drew, Barbara; van Dam, Peter; Abächerli, Roger; Albert, David E; Hodges, Morrison

    2017-09-01

    Although automated ECG analysis has been available for many years, there are some aspects which require to be re-assessed with respect to their value while newer techniques which are worthy of review are beginning to find their way into routine use. At the annual International Society of Computerized Electrocardiology conference held in April 2017, four areas in particular were debated. These were a) automated 12 lead resting ECG analysis; b) real time out of hospital ECG monitoring; c) ECG imaging; and d) single channel ECG rhythm interpretation. One speaker presented the positive aspects of each technique and another outlined the more negative aspects. Debate ensued. There were many positives set out for each technique but equally, more negative features were not in short supply, particularly for out of hospital ECG monitoring. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Coordinator Traffic Diffusion for Data-Intensive Zigbee Transmission in Real-time Electrocardiography Monitoring.

    PubMed

    Tseng, Chinyang Henry

    2013-12-01

    Zigbee is expected to have an explosive growth in wireless medical monitoring systems because it possesses the advantages of low cost, safe power strength, and easy deployment. However, limited work focuses on solving the bottleneck issue at the Zigbee coordinator in a data-intensive system to guarantee transmission reliability of life-critical data. This paper proposes coordinator traffic diffusion (CTD) method to redirect excessive traffic from coordinator to the sink in electrocardiography (ECG) medical application. CTD router, which implements CTD design, automatically redirects ECG data traffic to the sink node without involving the coordinator, and thus reliable real-time ECG monitoring service can be delivered precisely. CTD design is tested in both TI CC2530 Zigbee platform and NS2 simulation. Experimental result demonstrates that a CTD design can assist routers in successfully delivering real-time ECG data samples reliably with the best transmission rate, 24 kb/s. This performance cannot be achieved by the original Zigbee design.

  5. Secure chaotic transmission of electrocardiography signals with acousto-optic modulation under profiled beam propagation.

    PubMed

    Almehmadi, Fares S; Chatterjee, Monish R

    2015-01-10

    Electrocardiography (ECG) signals are used for both medical purposes and identifying individuals. It is often necessary to encrypt this highly sensitive information before it is transmitted over any channel. A closed-loop acousto-optic hybrid device acting as a chaotic modulator is applied to ECG signals to achieve this encryption. Recently improved modeling of this approach using profiled optical beams has shown it to be very sensitive to key parameters that characterize the encryption and decryption process, exhibiting its potential for secure transmission of analog and digital signals. Here the encryption and decryption is demonstrated for ECG signals, both analog and digital versions, illustrating strong encryption without significant distortion. Performance analysis pertinent to both analog and digital transmission of the ECG waveform is also carried out using output signal-to-noise, signal-to-distortion, and bit-error-rate measures relative to the key parameters and presence of channel noise in the system.

  6. Carbon Tube Electrodes for Electrocardiography-Gated Cardiac Multimodality Imaging in Mice

    PubMed Central

    Choquet, Philippe; Goetz, Christian; Aubertin, Gaelle; Hubele, Fabrice; Sannié, Sébastien; Constantinesco, André

    2011-01-01

    This report describes a simple design of noninvasive carbon tube electrodes that facilitates electrocardiography (ECG) in mice during cardiac multimodality preclinical imaging. Both forepaws and the left hindpaw, covered by conductive gel, of mice were placed into the openings of small carbon tubes. Cardiac ECG-gated single-photon emission CT, X-ray CT, and MRI were tested (n = 60) in 20 mice. For all applications, electrodes were used in a warmed multimodality imaging cell. A heart rate of 563 ± 48 bpm was recorded from anesthetized mice regardless of the imaging technique used, with acquisition times ranging from 1 to 2 h. PMID:21333165

  7. Hybrid Thermoelectric-Photovoltaic Generators in Wireless Electroencephalography Diadem and Electrocardiography Shirt

    NASA Astrophysics Data System (ADS)

    Leonov, Vladimir; Torfs, Tom; Vullers, Ruud J. M.; van Hoof, Chris

    2010-09-01

    Hybrid wearable energy harvesters consisting of a thermoelectric generator (TEG) and photovoltaic (PV) cells are used in this work for powering two autonomous medical devices: an electroencephalography (EEG) system and an electrocardiography (ECG) system in a shirt. Two alternative solutions for powering the systems have been implemented. In the battery-free EEG diadem, PV cells cover the outer surface of radiators used in a TEG. In the ECG shirt, thermoelectric modules are the main power supply that constantly recharges a battery, while PV cells are used mainly to provide standby power, i.e., when the shirt is not worn. Both devices are maintenance free for their entire service life.

  8. Horizontal ECG in acute anterolateral myocardial infarction.

    PubMed

    Erdogan, Okan; Dalkilic, Bahar; Kepez, Alper

    2016-07-01

    The present study aims to compare the amount of ST segment changes recorded by horizontal electrocardiography (hECG) with standard ECG (sECG) in patients with acute anterior and/or lateral ST segment elevation myocardial infarction (STEMI). Consecutive eligible patients (n = 58) who were diagnosed with acute anterior and/or lateral STEMI were included in the study. After recording simultaneous sECG and hECG by placing precordial leads (V3-6) horizontally on the left 4th intercostal space, ST segment changes were compared. The mean ST segment changes (mV) on hECG were significantly higher than sECG in V4 (0.27 ± 0.2 vs. 0.21 ± 0.21, p = 0.001), V5 (0.21 ± 0.17 vs. 0.12 ± 0.16, p < 0.001) and V6 (0.09 ± 0.1 vs. 0.04 ± 0.12, p < 0.001), respectively. When hECG and sECG were compared in patients with BMI < 30 kg/m(2), mean ST segment changes (mV) on hECG were significantly higher than sECG in V4 (0.29 ± 0.21 vs. 0.21 ± 0.24, p = 0.004), V5 (0.22 ± 0.19 vs. 0.13 ± 0.17, p < 0.001) and V6 (0.11 ± 0.11 vs. 0.04 ± 0.11, p < 0.001), respectively. Mean ST segment changes in patients with anterior and/or lateral STEMI were significantly higher and easily detectable on hECG compared with sECG. We suggest that hECG be used in conjunction with sECG to diagnose anterior and lateral wall STEMI in cases of diagnostic doubt.

  9. Electrocardiography in people living at high altitude of Nepal

    PubMed Central

    Aryal, Nirmal; Weatherall, Mark; Bhatta, Yadav Kumar Deo; Mann, Stewart

    2017-01-01

    Objective The main objective of this study was to estimate the prevalence of coronary heart disease (CHD) of high-altitude populations in Nepal determined by an ECG recordings and a medical history. Methods We carried out a cross-sectional survey of cardiovascular disease and risk factors among people living at four different altitude levels, all above 2800 m, in the Mustang and Humla districts of Nepal. 12-lead ECGs were recorded on 485 participants. ECG recordings were categorised as definitely abnormal, borderline or normal. Results No participant had Q waves to suggest past Q-wave infarction. Overall, 5.6% (95% CI 3.7 to 8.0) of participants gave a self-report of CHD. The prevalence of abnormal (or borderline abnormal) ECG was 19.6% (95% CI 16.1 to 23.4). The main abnormalities were: right axis deviation in 5.4% (95% CI 3.5 to 7.7) and left ventricular hypertrophy by voltage criteria in 3.5% (95% CI 2.0 to 5.5). ECG abnormalities were mainly on the left side of the heart for Mustang participants (Tibetan origin) and on the right side for Humla participants (Indo-Aryans). There was a moderate association between the probability of abnormal (or borderline abnormal) ECG and altitude when adjusted for potential confounding variables in a multivariate logistic model; with an OR for association per 1000 m elevation of altitude of 2.83 (95% CI 1.07 to 7.45), p=0.03. Conclusions Electrocardiographic evidence suggests that although high-altitude populations do not have a high prevalence of CHD, abnormal ECG findings increase by altitude and risk pattern varies by ethnicity. PMID:28243317

  10. A combination of P wave electrocardiography and plasma brain natriuretic peptide level for predicting the progression to persistent atrial fibrillation: comparisons of sympathetic activity and left atrial size.

    PubMed

    Akutsu, Yasushi; Kaneko, Kyouichi; Kodama, Yusuke; Miyoshi, Fumito; Li, Hui-Ling; Watanabe, Norikazu; Asano, Taku; Tanno, Kaoru; Suyama, Jumpei; Namiki, Atsuo; Gokan, Takehiko; Kobayashi, Youichi

    2013-11-01

    Development of atrial fibrillation (AF) is complexly associated with electrical and structural remodeling and other factors every stage of AF development. We hypothesized that P wave electrocardiography with an elevated brain natriuretic peptide (BNP) level would be associated with the progression to persistence from paroxysmal AF. P wave electrocardiography such as a maximum P wave duration (MPWD) and dispersion by 12-leads ECG, heart/mediastinum (H/M) ratio by delayed iodine-123 metaiodobenzylguanidine scintigraphic imaging, left ventricular ejection fraction (LVEF), and left atrial dimension (LAD) by echocardiography, and plasma BNP level were measured to evaluate the electrical and structural properties and sympathetic activity in 71 patients (mean ± standard deviation, age: 67 ± 13 years, 63.4 % males) with idiopathic paroxysmal AF. Over a 12.9-year follow-up period, AF developed into persistent AF in 30 patients. A wider MPWD (>129 ms) (p = 0.001), wider P wave dispersion (>60 ms) (p = 0.001), LAD enlargement (>40 mm) (p = 0.001), higher BNP level (>72 pg/mL) (p = 0.002), lower H/M ratio (≤2.7) (p = 0.025), and lower LVEF (≤60 %) (p = 0.035) were associated with the progression to persistent AF, and the wide MPWD was an independently powerful predictor of the progression to persistent AF with a hazard ratio (HR) of 5.49 [95 % confidence interval (CI) 2.38-12.7, p < 0.0001] after adjusting for potential confounding variables, such as age and sex. The combination of wide MPWD and elevated BNP level was additive and incremental prognostic power with 13.3 [2.16-13, p < 0.0001]. The wide MPWD with elevated BNP level was associated with the progression to persistent AF.

  11. Improved recording of atrial activity by modified bipolar leads derived from the 12-lead electrocardiogram.

    PubMed

    Kennedy, Alan; Finlay, Dewar D; Guldenring, Daniel; Bond, Raymond R; McEneaney, David J; Peace, Aaron; McLaughlin, James

    2015-01-01

    This study investigates the use of multivariate linear regression to estimate three bipolar ECG leads from the 12-lead ECG in order to improve P-wave signal strength. The study population consisted of body surface potential maps recorded from 229 healthy subjects. P-waves were then isolated and population based transformation weights developed. A derived P-lead (measured between the right sternoclavicular joint and midway along the costal margin in line with the seventh intercostal space) demonstrated significant improvement in median P-wave root mean square (RMS) signal strength when compared to lead II (94μV vs. 76μV, p<0.001). A derived ES lead (from the EASI lead system) also showed small but significant improvement in median P-wave RMS (79μV vs. 76μV, p=0.0054). Finally, a derived modified Lewis lead did not improve median P-wave RMS when compared to lead II. However, this derived lead improved atrioventricular RMS ratio. P-wave leads derived from the 12-lead ECG can improve signal-to-noise ratio of the P-wave; this may improve the performance of detection algorithms that rely on P-wave analysis. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  12. Screening for coronary heart disease with electrocardiography: U.S. Preventive Services Task Force recommendation statement.

    PubMed

    Moyer, Virginia A

    2012-10-02

    Update of the 2004 U.S. Preventive Services Task Force (USPSTF) recommendation statement on screening for coronary heart disease (CHD). The USPSTF reviewed new evidence on the benefits of screening with electrocardiography (ECG) in asymptomatic adults to reduce the risk for CHD events versus not screening, the effect of identifying high-risk persons on treatment to reduce risk, the accuracy of stratifying individuals into risk categories, and the harms of screening. The USPSTF recommends against screening with resting or exercise ECG for the prediction of CHD events in asymptomatic adults at low risk for CHD events (D recommendation). The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening with resting or exercise ECG for the prediction of CHD events in asymptomatic adults at intermediate or high risk for CHD events (I statement).

  13. Combination of the LSQR method and a genetic algorithm for solving the electrocardiography inverse problem.

    PubMed

    Jiang, Mingfeng; Xia, Ling; Shou, Guofa; Tang, Min

    2007-03-07

    Computing epicardial potentials from body surface potentials constitutes one form of ill-posed inverse problem of electrocardiography (ECG). To solve this ECG inverse problem, the Tikhonov regularization and truncated singular-value decomposition (TSVD) methods have been commonly used to overcome the ill-posed property by imposing constraints on the magnitudes or derivatives of the computed epicardial potentials. Such direct regularization methods, however, are impractical when the transfer matrix is large. The least-squares QR (LSQR) method, one of the iterative regularization methods based on Lanczos bidiagonalization and QR factorization, has been shown to be numerically more reliable in various circumstances than the other methods considered. This LSQR method, however, to our knowledge, has not been introduced and investigated for the ECG inverse problem. In this paper, the regularization properties of the Krylov subspace iterative method of LSQR for solving the ECG inverse problem were investigated. Due to the 'semi-convergence' property of the LSQR method, the L-curve method was used to determine the stopping iteration number. The performance of the LSQR method for solving the ECG inverse problem was also evaluated based on a realistic heart-torso model simulation protocol. The results show that the inverse solutions recovered by the LSQR method were more accurate than those recovered by the Tikhonov and TSVD methods. In addition, by combing the LSQR with genetic algorithms (GA), the performance can be improved further. It suggests that their combination may provide a good scheme for solving the ECG inverse problem.

  14. High Resolution 12-lead Electrocardiograms of On-Duty Professional Firefighters: A Pilot Feasibility Study

    PubMed Central

    Carey, Mary G.; Thevenin, Bernard J.-M.

    2010-01-01

    Background Cardiovascular deaths among on-duty firefighters are high; double that of police officers and quadruple that of first responders. The aim of this pilot study was to establish the feasibility of obtaining high resolutions ECGs of on-duty firefighters useful for detecting ECG predictors for cardiac events. Methods Twenty-eight professional firefighters (age, 46 ± 6 years) wore a 12-lead ECG Holter for 24 hours (16 hours while on-duty and 8 hours post-duty). All activities including fire and medical calls were monitored. Results On average the recordings were 92% analyzable. All were in sinus with a heart rate of 80 ±11bpm (35–188 range). The average rr50 over the 24-hour Holter study was 6.2 ±6% (range: 1–23%) and rms-SD was 81 ± 55 (range: 24–209). Using the QRS/Tsimple formula, the average spatial QRS-T angle was 104 ±17 degrees (range 78–132 degrees). Nonsustained ventricular tachycardia occurred irrespectively of activity or time of day in three (11%) firefighters, which was significantly higher than in comparable normal populations (p<0.05). Conclusions This preliminary work demonstrates that it is feasible to obtain high resolution ECGs during firefighting activities and further points to the high prevalence of arrhythmias among firefighters. The strategy of continuous field monitoring of firefighters could provide new insight into the association between their specific professional lifestyle and high cardiac risks. PMID:21206348

  15. The 12-lead electrocardiogram and risk of sudden death: current utility and future prospects

    PubMed Central

    Narayanan, Kumar; Chugh, Sumeet S.

    2015-01-01

    More than 100 years after it was first invented, the 12-lead electrocardiogram (ECG) continues to occupy an important place in the diagnostic armamentarium of the practicing clinician. With the recognition of relatively rare but important clinical entities such as Wolff–Parkinson–White and the long QT syndrome, this clinical tool was firmly established as a test for assessing risk of sudden cardiac death (SCD). However, over the past two decades the role of the ECG in risk prediction for common forms of SCD, for example in patients with coronary artery disease, has been the focus of considerable investigation. Especially in light of the limitations of current risk stratification approaches, there is a renewed focus on this broadly available and relatively inexpensive test. Various abnormalities of depolarization and repolarization on the ECG have been linked to SCD risk; however, more focused work is needed before they can be deployed in the clinical arena. The present review summarizes the current knowledge on various ECG risk markers for prediction of SCD and discusses some future directions in this field. PMID:26842119

  16. The 12-lead electrocardiogram and risk of sudden death: current utility and future prospects.

    PubMed

    Narayanan, Kumar; Chugh, Sumeet S

    2015-10-01

    More than 100 years after it was first invented, the 12-lead electrocardiogram (ECG) continues to occupy an important place in the diagnostic armamentarium of the practicing clinician. With the recognition of relatively rare but important clinical entities such as Wolff-Parkinson-White and the long QT syndrome, this clinical tool was firmly established as a test for assessing risk of sudden cardiac death (SCD). However, over the past two decades the role of the ECG in risk prediction for common forms of SCD, for example in patients with coronary artery disease, has been the focus of considerable investigation. Especially in light of the limitations of current risk stratification approaches, there is a renewed focus on this broadly available and relatively inexpensive test. Various abnormalities of depolarization and repolarization on the ECG have been linked to SCD risk; however, more focused work is needed before they can be deployed in the clinical arena. The present review summarizes the current knowledge on various ECG risk markers for prediction of SCD and discusses some future directions in this field.

  17. Effects of web-based electrocardiography simulation on strategies and learning styles.

    PubMed

    Granero-Molina, José; Fernández-Sola, Cayetano; López-Domene, Esperanza; Hernández-Padilla, José Manuel; Preto, Leonel São Romão; Castro-Sánchez, Adelaida María

    2015-08-01

    To identify the association between the use of web simulation electrocardiography and the learning approaches, strategies and styles of nursing degree students. A descriptive and correlational design with a one-group pretest-posttest measurement was used. The study sample included 246 students in a Basic and Advanced Cardiac Life Support nursing class of nursing degree. No significant differences between genders were found in any dimension of learning styles and approaches to learning. After the introduction of web simulation electrocardiography, significant differences were found in some item scores of learning styles: theorist (p < 0.040), pragmatic (p < 0.010) and approaches to learning. The use of a web electrocardiogram (ECG) simulation is associated with the development of active and reflexive learning styles, improving motivation and a deep approach in nursing students.

  18. Automated J wave detection from digital 12-lead electrocardiogram.

    PubMed

    Wang, Yi Grace; Wu, Hau-Tieng; Daubechies, Ingrid; Li, Yabing; Estes, E Harvey; Soliman, Elsayed Z

    2015-01-01

    In this report we provide a method for automated detection of J wave, defined as a notch or slur in the descending slope of the terminal positive wave of the QRS complex, using signal processing and functional data analysis techniques. Two different sets of ECG tracings were selected from the EPICARE ECG core laboratory, Wake Forest School of Medicine, Winston Salem, NC. The first set was a training set comprised of 100 ECGs of which 50 ECGs had J-wave and the other 50 did not. The second set was a test set (n=116 ECGs) in which the J-wave status (present/absent) was only known by the ECG Center staff. All ECGs were recorded using GE MAC 1200 (GE Marquette, Milwaukee, Wisconsin) at 10mm/mV calibration, speed of 25mm/s and 500HZ sampling rate. All ECGs were initially inspected visually for technical errors and inadequate quality, and then automatically processed with the GE Marquette 12-SL program 2001 version (GE Marquette, Milwaukee, WI). We excluded ECG tracings with major abnormalities or rhythm disorder. Confirmation of the presence or absence of a J wave was done visually by the ECG Center staff and verified once again by three of the coauthors. There was no disagreement in the identification of the J wave state. The signal processing and functional data analysis techniques applied to the ECGs were conducted at Duke University and the University of Toronto. In the training set, the automated detection had sensitivity of 100% and specificity of 94%. For the test set, sensitivity was 89% and specificity was 86%. In conclusion, test results of the automated method we developed show a good J wave detection accuracy, suggesting possible utility of this approach for defining and detection of other complex ECG waveforms.

  19. Detection of myocardial ischemia by vessel-specific leads derived from the 12-lead electrocardiogram and its subsets.

    PubMed

    Horácek, B Milan; Mirmoghisi, Maryam; Warren, James W; Wagner, Galen S; Wang, John J

    2008-01-01

    Currently used electrocardiographic criteria for identifying patients with ST-elevation myocardial infarction (STEMI) perform with high specificity but low sensitivity. Our aim was to enhance ischemia-detection ability of conventional STEMI criteria based on 12-lead electrocardiogram (ECG) by adding new criteria using 3 vessel-specific leads (VSLs) derived from 12-lead ECG. Study data consisted of 12-lead ECGs acquired during 99 ischemic episodes caused by balloon inflation in, respectively, left anterior descending coronary artery (LAD; n = 35), right coronary artery (RCA; n = 47), and left circumflex coronary artery (LCx; n = 17). ST deviation was measured at J point in 12 standard leads, and for 3 VSLs, its value was derived from 12-lead ECG by using 8 independent predictor leads or just a pair of precordial leads combined with a pair of limb leads. Mean values of sensitivity (SE) and specificity (SP) of ischemia detection achieved with conventional STEMI vs VSL criteria were then obtained from bootstrap trials. We found that the detection of ischemic state by conventional criteria achieved the mean SE/SP of 60%/96% in the total set of ischemic episodes, 74%/97% in the LAD subgroup, 60%/94% in the RCA subgroup, and 36%/100% in the LCx subgroup. In comparison, the mean SE/SP values of VSLs derived from 8 independent leads of 12-lead ECG were, at 125-microV threshold, 76%(*)/96% in the total set, 91%(*)/97% in the LAD subgroup, 70%/94% in the RCA subgroup, and 71%(*)/100% in the LCx subgroup (with asterisk denoting a statistically significant increase). The mean SE/SP of VSLs derived from some of the 4-predictor lead sets (namely, those including lead V(3)) matched or exceeded values achieved by VSLs derived from 8 predictors; for instance, with predictor leads I, II, V(3), V(6) derived VSLs attained at 125-microV threshold the mean SE/SP of 80%(*)/95% in the total set, 91%(*)/97% in the LAD subgroup, 74%/92% in the RCA subgroup, and 71%(*)/100% in the LCx

  20. Accurate detection of coronary artery disease by integrated analysis of the ST-segment depression/heart rate patterns during the exercise and recovery phases of the exercise electrocardiography test.

    PubMed

    Lehtinen, R; Sievänen, H; Viik, J; Turjanmaa, V; Niemelä, K; Malmivuo, J

    1996-11-01

    In this comparative cross-sectional study, we evaluated whether a novel computerized diagnostic variable, ST-segment depression/heart rate ST/HR analysis during both the exercise and postexercise recovery phases of the exercise electrocardiography (ECG) test, can detect coronary artery disease more accurately than methods using either exercise or recovery phase alone. The study population comprised 347 clinical patients referred for a routine bicycle exercise ECG test at Tampere University Hospital, Finland. Of these, 127 had angiographically proven coronary artery disease, whereas 13 had no coronary artery disease according to angiography, 18 had no perfusion defect according to technetium-99m sestamibi single-photon emission computed tomography, and 189 were clinically normal with respect to cardiac diseases. For each patient, the maximum values of the ST/HR hysteresis, ST/HR index, end-exercise ST depression, and recovery ST depression were determined from the Mason-Likar modification of the standard 12-lead exercise electrocardiogram [aVL, aVR, and V1 excluded]. The diagnostic performance of these continuous diagnostic variables was compared by means of receiver-operating characteristic analysis. The area under the receiver-operating characteristic curve of the ST/HR hysteresis was 89%, which was significantly larger than that of the end-exercise ST depression (76%, p < or = 0.0001), recovery ST depression (84%, p = 0.0063), or ST/HR index (83%, p = 0.0023), indicating superior diagnostic performance of the ST/HR hysteresis independent of the partition value selection. In conclusion, computerized analysis of the HR-adjusted ST depression pattern during the exercise phase, integrated with the HR-adjusted ST depression pattern during the recovery phase after exercise, can significantly improve the diagnostic performance and clinical utility of the exercise ECG test for the detection of coronary artery disease.

  1. A decision support system and rule-based algorithm to augment the human interpretation of the 12-lead electrocardiogram.

    PubMed

    Cairns, Andrew W; Bond, Raymond R; Finlay, Dewar D; Guldenring, Daniel; Badilini, Fabio; Libretti, Guido; Peace, Aaron J; Leslie, Stephen J

    2017-08-09

    The 12-lead Electrocardiogram (ECG) has been used to detect cardiac abnormalities in the same format for more than 70years. However, due to the complex nature of 12-lead ECG interpretation, there is a significant cognitive workload required from the interpreter. This complexity in ECG interpretation often leads to errors in diagnosis and subsequent treatment. We have previously reported on the development of an ECG interpretation support system designed to augment the human interpretation process. This computerised decision support system has been named 'Interactive Progressive based Interpretation' (IPI). In this study, a decision support algorithm was built into the IPI system to suggest potential diagnoses based on the interpreter's annotations of the 12-lead ECG. We hypothesise semi-automatic interpretation using a digital assistant can be an optimal man-machine model for ECG interpretation. To improve interpretation accuracy and reduce missed co-abnormalities. The Differential Diagnoses Algorithm (DDA) was developed using web technologies where diagnostic ECG criteria are defined in an open storage format, Javascript Object Notation (JSON), which is queried using a rule-based reasoning algorithm to suggest diagnoses. To test our hypothesis, a counterbalanced trial was designed where subjects interpreted ECGs using the conventional approach and using the IPI+DDA approach. A total of 375 interpretations were collected. The IPI+DDA approach was shown to improve diagnostic accuracy by 8.7% (although not statistically significant, p-value=0.1852), the IPI+DDA suggested the correct interpretation more often than the human interpreter in 7/10 cases (varying statistical significance). Human interpretation accuracy increased to 70% when seven suggestions were generated. Although results were not found to be statistically significant, we found; 1) our decision support tool increased the number of correct interpretations, 2) the DDA algorithm suggested the correct

  2. Assessing computerized eye tracking technology for gaining insight into expert interpretation of the 12-lead electrocardiogram: an objective quantitative approach.

    PubMed

    Bond, R R; Zhu, T; Finlay, D D; Drew, B; Kligfield, P D; Guldenring, D; Breen, C; Gallagher, A G; Daly, M J; Clifford, G D

    2014-01-01

    It is well known that accurate interpretation of the 12-lead electrocardiogram (ECG) requires a high degree of skill. There is also a moderate degree of variability among those who interpret the ECG. While this is the case, there are no best practice guidelines for the actual ECG interpretation process. Hence, this study adopts computerized eye tracking technology to investigate whether eye-gaze can be used to gain a deeper insight into how expert annotators interpret the ECG. Annotators were recruited in San Jose, California at the 2013 International Society of Computerised Electrocardiology (ISCE). Each annotator was recruited to interpret a number of 12-lead ECGs (N=12) while their eye gaze was recorded using a Tobii X60 eye tracker. The device is based on corneal reflection and is non-intrusive. With a sampling rate of 60Hz, eye gaze coordinates were acquired every 16.7ms. Fixations were determined using a predefined computerized classification algorithm, which was then used to generate heat maps of where the annotators looked. The ECGs used in this study form four groups (3=ST elevation myocardial infarction [STEMI], 3=hypertrophy, 3=arrhythmias and 3=exhibiting unique artefacts). There was also an equal distribution of difficulty levels (3=easy to interpret, 3=average and 3=difficult). ECGs were displayed using the 4x3+1 display format and computerized annotations were concealed. Precisely 252 expert ECG interpretations (21 annotators×12 ECGs) were recorded. Average duration for ECG interpretation was 58s (SD=23). Fleiss' generalized kappa coefficient (Pa=0.56) indicated a moderate inter-rater reliability among the annotators. There was a 79% inter-rater agreement for STEMI cases, 71% agreement for arrhythmia cases, 65% for the lead misplacement and dextrocardia cases and only 37% agreement for the hypertrophy cases. In analyzing the total fixation duration, it was found that on average annotators study lead V1 the most (4.29s), followed by leads V2 (3.83s

  3. e-SCP-ECG+ Protocol: An Expansion on SCP-ECG Protocol for Health Telemonitoring—Pilot Implementation

    PubMed Central

    Mandellos, George J.; Koukias, Michael N.; Styliadis, Ioannis St.; Lymberopoulos, Dimitrios K.

    2010-01-01

    Standard Communication Protocol for Computer-assisted Electrocardiography (SCP-ECG) provides standardized communication among different ECG devices and medical information systems. This paper extends the use of this protocol in order to be included in health monitoring systems. It introduces new sections into SCP-ECG structure for transferring data for positioning, allergies, and five additional biosignals: noninvasive blood pressure (NiBP), body temperature (Temp), Carbon dioxide (CO2), blood oxygen saturation (SPO2), and pulse rate. It also introduces new tags in existing sections for transferring comprehensive demographic data. The proposed enhanced version is referred to as e-SCP-ECG+ protocol. This paper also considers the pilot implementation of the new protocol as a software component in a Health Telemonitoring System. PMID:20628537

  4. Empirical mode decomposition of the ECG signal for noise removal

    NASA Astrophysics Data System (ADS)

    Khan, Jesmin; Bhuiyan, Sharif; Murphy, Gregory; Alam, Mohammad

    2011-04-01

    Electrocardiography is a diagnostic procedure for the detection and diagnosis of heart abnormalities. The electrocardiogram (ECG) signal contains important information that is utilized by physicians for the diagnosis and analysis of heart diseases. So good quality ECG signal plays a vital role for the interpretation and identification of pathological, anatomical and physiological aspects of the whole cardiac muscle. However, the ECG signals are corrupted by noise which severely limit the utility of the recorded ECG signal for medical evaluation. The most common noise presents in the ECG signal is the high frequency noise caused by the forces acting on the electrodes. In this paper, we propose a new ECG denoising method based on the empirical mode decomposition (EMD). The proposed method is able to enhance the ECG signal upon removing the noise with minimum signal distortion. Simulation is done on the MIT-BIH database to verify the efficacy of the proposed algorithm. Experiments show that the presented method offers very good results to remove noise from the ECG signal.

  5. Role of a 12-lead electrocardiogram in the diagnosis of cardiac tamponade as diagnosed by transthoracic echocardiography in patients with malignant pericardial effusion.

    PubMed

    Argula, Rahul G; Negi, Smita I; Banchs, Jose; Yusuf, Syed Wamique

    2015-03-01

    Few studies have looked at the utility of the 12-lead electrocardiogram (ECG) in diagnosing cardiac tamponade in malignant pericardial effusion (PE). The aim of this study was to determine the sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of 12-lead ECG in diagnosing cardiac tamponade in PE. Abnormalities on a 12 lead ECG can be used to diagnose or exclude cardiac tamponade in patients with malignant PE. Using echocardiography as the gold standard for diagnosis of cardiac tamponade, we determined the Se, Sp, PPV, and NPV for individual and combinations of the 3 ECG abnormalities (low-voltage complexes, electrical alternans, and sinus tachycardia). For PEs of all sizes, the Se, Sp, PPV, and NPV for detecting cardiac tamponade were: low-voltage complexes (56%, 74%, 81%, 46%), electrical alternans (23%, 98%, 95%, 39%), and sinus tachycardia (76%, 60%, 79%, 56%), respectively. Presence of all 3 and any of the 3 ECG abnormalities had a Se, Sp, PPV, and NPV of 8%, 100%, 100%, 36% and 89%, 47%, 77%, 69%, respectively, for cardiac tamponade. The odds ratios for cardiac tamponade in PE were 3.7 (95% confidence interval [CI]: 1.65-8.30) for low-voltage complexes, 12.3 (95% CI: 1.58-95.17) for electrical alternans, and 4.9 (95% CI: 2.22-10.80) for sinus tachycardia. Presence of any of 3 ECG abnormalities had an odds ratio of 7.3 (95% CI: 2.9-18.1) for cardiac tamponade. In malignant PE, combination of ECG abnormalities can supplement clinical examination in the diagnosis of echocardiographic cardiac tamponade. Due to its low NPV, 12-lead ECG cannot be used as a screening tool to exclude cardiac tamponade with malignant PE. © 2015 Wiley Periodicals, Inc.

  6. High Frequency QRS ECG Accurately Detects Cardiomyopathy

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Arenare, Brian; Poulin, Gregory; Moser, Daniel R.; Delgado, Reynolds

    2005-01-01

    High frequency (HF, 150-250 Hz) analysis over the entire QRS interval of the ECG is more sensitive than conventional ECG for detecting myocardial ischemia. However, the accuracy of HF QRS ECG for detecting cardiomyopathy is unknown. We obtained simultaneous resting conventional and HF QRS 12-lead ECGs in 66 patients with cardiomyopathy (EF = 23.2 plus or minus 6.l%, mean plus or minus SD) and in 66 age- and gender-matched healthy controls using PC-based ECG software recently developed at NASA. The single most accurate ECG parameter for detecting cardiomyopathy was an HF QRS morphological score that takes into consideration the total number and severity of reduced amplitude zones (RAZs) present plus the clustering of RAZs together in contiguous leads. This RAZ score had an area under the receiver operator curve (ROC) of 0.91, and was 88% sensitive, 82% specific and 85% accurate for identifying cardiomyopathy at optimum score cut-off of 140 points. Although conventional ECG parameters such as the QRS and QTc intervals were also significantly longer in patients than controls (P less than 0.001, BBBs excluded), these conventional parameters were less accurate (area under the ROC = 0.77 and 0.77, respectively) than HF QRS morphological parameters for identifying underlying cardiomyopathy. The total amplitude of the HF QRS complexes, as measured by summed root mean square voltages (RMSVs), also differed between patients and controls (33.8 plus or minus 11.5 vs. 41.5 plus or minus 13.6 mV, respectively, P less than 0.003), but this parameter was even less accurate in distinguishing the two groups (area under ROC = 0.67) than the HF QRS morphologic and conventional ECG parameters. Diagnostic accuracy was optimal (86%) when the RAZ score from the HF QRS ECG and the QTc interval from the conventional ECG were used simultaneously with cut-offs of greater than or equal to 40 points and greater than or equal to 445 ms, respectively. In conclusion 12-lead HF QRS ECG employing

  7. High Frequency QRS ECG Accurately Detects Cardiomyopathy

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Arenare, Brian; Poulin, Gregory; Moser, Daniel R.; Delgado, Reynolds

    2005-01-01

    High frequency (HF, 150-250 Hz) analysis over the entire QRS interval of the ECG is more sensitive than conventional ECG for detecting myocardial ischemia. However, the accuracy of HF QRS ECG for detecting cardiomyopathy is unknown. We obtained simultaneous resting conventional and HF QRS 12-lead ECGs in 66 patients with cardiomyopathy (EF = 23.2 plus or minus 6.l%, mean plus or minus SD) and in 66 age- and gender-matched healthy controls using PC-based ECG software recently developed at NASA. The single most accurate ECG parameter for detecting cardiomyopathy was an HF QRS morphological score that takes into consideration the total number and severity of reduced amplitude zones (RAZs) present plus the clustering of RAZs together in contiguous leads. This RAZ score had an area under the receiver operator curve (ROC) of 0.91, and was 88% sensitive, 82% specific and 85% accurate for identifying cardiomyopathy at optimum score cut-off of 140 points. Although conventional ECG parameters such as the QRS and QTc intervals were also significantly longer in patients than controls (P less than 0.001, BBBs excluded), these conventional parameters were less accurate (area under the ROC = 0.77 and 0.77, respectively) than HF QRS morphological parameters for identifying underlying cardiomyopathy. The total amplitude of the HF QRS complexes, as measured by summed root mean square voltages (RMSVs), also differed between patients and controls (33.8 plus or minus 11.5 vs. 41.5 plus or minus 13.6 mV, respectively, P less than 0.003), but this parameter was even less accurate in distinguishing the two groups (area under ROC = 0.67) than the HF QRS morphologic and conventional ECG parameters. Diagnostic accuracy was optimal (86%) when the RAZ score from the HF QRS ECG and the QTc interval from the conventional ECG were used simultaneously with cut-offs of greater than or equal to 40 points and greater than or equal to 445 ms, respectively. In conclusion 12-lead HF QRS ECG employing

  8. Effects of a Web-based teaching method on undergraduate nursing students' learning of electrocardiography.

    PubMed

    Jang, Keum S; Hwang, Seon Y; Park, Soon J; Kim, Yoon M; Kim, Mi J

    2005-01-01

    This study examined the effects of a Web-based teaching method (versus a traditional lecture method) on undergraduate nursing students' learning of electrocardiography (ECG). The Web-based learning program was developed by the authors and implemented for 4 weeks. The study used a pretest-posttest experimental design. A total of 105 senior nursing students were recruited at a university in Korea. Fifty-four students were assigned to an experimental group in 2002, and 51 were assigned to a control group in 2003. Knowledge about ECG among students in the Web-based group was significantly lower than that of students in the control group (p < .01). Conversely, the ability to interpret ECG recordings was significantly higher among students in the Web-based group (p < .05). No significant differences were found between the two groups in level of motivation or satisfaction with learning. The self-directed, Web-based ECG learning program appears to be effective in helping nursing students to interpret ECG recordings.

  9. Agreement Between a Smartphone Pulse Sensor Application and Electrocardiography for Determining lnRMSSD.

    PubMed

    Esco, Michael R; Flatt, Andrew A; Nakamura, Fábio Y

    2017-02-01

    Esco, MR, Flatt, AA, and Nakamura, FY. Agreement between a smartphone pulse sensor application and electrocardiography for determining lnRMSSD. J Strength Cond Res 31(2): 380-385, 2017-The purpose of this study was to determine the agreement between a smartphone pulse finger sensor (SPFS) and electrocardiography (ECG) for determining ultra-short-term heart rate variability in 3 different positions. Thirty college-aged men (n = 15) and women (n = 15) volunteered to participate in this study. Sixty-second heart rate measures were simultaneously taken with the SPFS and ECG in supine, seated, and standing positions. The log transformed root mean square of successive R-R interval differences (lnRMSSD) was calculated from the SPFS and ECG. The lnRMSSD values were 81.5 ± 11.7 using ECG and 81.6 ± 11.3 using SPFS (p = 0.63, Cohen's d = 0.01) in the supine position, 76.5 ± 8.2 using ECG and 77.5 ± 8.2 using SPFS (p = 0.007, Cohen's d = 0.11) in the seated position, and 66.5 ± 9.2 using ECG and 67.8 ± 9.1 using SPFS (p < 0.001, Cohen's d = 0.15) in the standing position. The SPFS showed a possibly strong correlation to the ECG in all 3 positions (r values from 0.98 to 0.99). In addition, the limits of agreement (constant error ± 1.98 SD) were -0.13 ± 2.83 for the supine values, -0.94 ± 3.47 for the seated values, and -1.37 ± 3.56 for the standing values. The results of the study suggest good agreement between the SPFS and ECG for measuring lnRMSSD in supine, seated, and standing positions. Although significant differences were noted between the 2 methods in the seated and standing positions, the effect sizes were trivial.

  10. The utilization of twelve-lead electrocardiography for predicting sudden cardiac death after heart transplantation.

    PubMed

    Chang, Hung-Yu; Yin, Wei-Hsian; Lo, Li-Wei; Lin, Yenn-Jiang; Chang, Shih-Lin; Hu, Yu-Feng; Feng, An-Ning; Chiang, Meng-Cheng; Young, Mason-Shing; Chang, Chong-Yi; Chuang, Yi-Cheng; Chong, Eric; Chen, Shih-Ann; Wei, Jeng

    2013-10-03

    Sudden cardiac death (SCD) occurs commonly after heart transplantation (HTX). The utilization of surface electrocardiography (ECG) to assess post-HTX SCD has not been investigated thoroughly. This study aimed to investigate the specific changes in surface ECG in HTX patients with SCD. A total of 227 HTX patients (age 48 ± 14 y/o, mean donor age 34 ± 14 y/o, 173 males) were followed up regularly at the outpatient clinic. Twelve-lead ECG's were recorded during 1-2 monthly visits. Serial ECG parameters and relevant clinical data were collected and analyzed. During the follow-up period of 96 ± 51 months, SCD occurred in 28 (12.3%) patients. The baseline ECG parameters were comparable between patients with and without SCD. Important ECG trends of rising rest heart rates and prolongation of corrected QT (QTc) and JT (JTc) intervals were observed prior to development of SCD. After adjustment for other clinical variables, the independent predictors for SCD were older donor age (p = 0.014, OR 1.05, 95% CI 1.01-1.09), faster heart rate (p = 0.006, OR 1.06, 95% CI 1.02-1.1) and longer JTc interval (p = 0.015, OR 1.03, 95% CI 1.01-1.06). SCD occurred in 71.4% patients presenting with all three risk predictors. Besides older donor age, important ECG signs, including prolongation of the JTc interval and increased heart rate during post HTX follow up, could predict SCD. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  11. Assessment of Microvolt T Wave Alternans in Children with Repaired Tetralogy of Fallot during 24-Hour Holter Electrocardiography.

    PubMed

    Doksöz, Önder; Meşe, Timur; Karaarslan, Utku; Ceylan, Gökhan; Demirpençe, Savaş; Tavlı, Vedide; Ünal, Nurettin

    2016-07-01

    We aimed to examine microvolt T wave alternans (MTWA) in 24-hour Holter electrocardiography (ECG) of children with repaired tetralogy of Fallot (TOF) to assess associations of MTWA with ventricular arrhythmias, ECG parameters, and echocardiographic findings. Holter ECG records and archive files of 56 repaired TOF patients (62.5% male) who were analyzed retrospectively. Subjects' ECG parameters and MTWA values were compared with age-sex-matched control group. T wave changes were analyzed by time-domain-modified moving average method from the three channels of 24-hour Holter ECG. Mean age was 123.4 ± 48.3 months. Median MTWA value was 55.5 μV in the control group, whereas 95.5 μV in patients group (P < 0.001). A significant weak positive correlation was found between the presence of ventricular extrasystoles and tricuspid regurgitation. There was no correlation between ECG parameters, echocardiographic findings, and MTWA. MTWA was increased in children with repaired TOF as reported before. To our knowledge, this is the first study analyzing MTWA with 24-hour Holter ECG in repaired TOF patients. © 2015 Wiley Periodicals, Inc.

  12. Recommendations for the standardization and interpretation of the electrocardiogram: part II: Electrocardiography diagnostic statement list: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology.

    PubMed

    Mason, Jay W; Hancock, E William; Gettes, Leonard S; Bailey, James J; Childers, Rory; Deal, Barbara J; Josephson, Mark; Kligfield, Paul; Kors, Jan A; Macfarlane, Peter; Pahlm, Olle; Mirvis, David M; Okin, Peter; Rautaharju, Pentti; Surawicz, Borys; van Herpen, Gerard; Wagner, Galen S; Wellens, Hein

    2007-03-13

    This statement provides a concise list of diagnostic terms for ECG interpretation that can be shared by students, teachers, and readers of electrocardiography. This effort was motivated by the existence of multiple automated diagnostic code sets containing imprecise and overlapping terms. An intended outcome of this statement list is greater uniformity of ECG diagnosis and a resultant improvement in patient care. The lexicon includes primary diagnostic statements, secondary diagnostic statements, modifiers, and statements for the comparison of ECGs. This diagnostic lexicon should be reviewed and updated periodically.

  13. Recommendations for the standardization and interpretation of the electrocardiogram. Part II: Electrocardiography diagnostic statement list. A scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society.

    PubMed

    Mason, Jay W; Hancock, E William; Gettes, Leonard S

    2007-03-01

    This statement provides a concise list of diagnostic terms for ECG interpretation that can be shared by students, teachers, and readers of electrocardiography. This effort was motivated by the existence of multiple automated diagnostic code sets containing imprecise and overlapping terms. An intended outcome of this statement list is greater uniformity of ECG diagnosis and a resultant improvement in patient care. The lexicon includes primary diagnostic statements, secondary diagnostic statements, modifiers, and statements for the comparison of ECGs. This diagnostic lexicon should be reviewed and updated periodically.

  14. Recommendations for the standardization and interpretation of the electrocardiogram: part II: electrocardiography diagnostic statement list a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society Endorsed by the International Society for Computerized Electrocardiology.

    PubMed

    Mason, Jay W; Hancock, E William; Gettes, Leonard S; Bailey, James J; Childers, Rory; Deal, Barbara J; Josephson, Mark; Kligfield, Paul; Kors, Jan A; Macfarlane, Peter; Pahlm, Olle; Mirvis, David M; Okin, Peter; Rautaharju, Pentti; Surawicz, Borys; van Herpen, Gerard; Wagner, Galen S; Wellens, Hein

    2007-03-13

    This statement provides a concise list of diagnostic terms for ECG interpretation that can be shared by students, teachers, and readers of electrocardiography. This effort was motivated by the existence of multiple automated diagnostic code sets containing imprecise and overlapping terms. An intended outcome of this statement list is greater uniformity of ECG diagnosis and a resultant improvement in patient care. The lexicon includes primary diagnostic statements, secondary diagnostic statements, modifiers, and statements for the comparison of ECGs. This diagnostic lexicon should be reviewed and updated periodically.

  15. Flexible Graphene Electrodes for Prolonged Dynamic ECG Monitoring

    PubMed Central

    Lou, Cunguang; Li, Ruikai; Li, Zhaopeng; Liang, Tie; Wei, Zihui; Run, Mingtao; Yan, Xiaobing; Liu, Xiuling

    2016-01-01

    This paper describes the development of a graphene-based dry flexible electrocardiography (ECG) electrode and a portable wireless ECG measurement system. First, graphene films on polyethylene terephthalate (PET) substrates and graphene paper were used to construct the ECG electrode. Then, a graphene textile was synthesized for the fabrication of a wearable ECG monitoring system. The structure and the electrical properties of the graphene electrodes were evaluated using Raman spectroscopy, scanning electron microscopy (SEM), and alternating current impedance spectroscopy. ECG signals were then collected from healthy subjects using the developed graphene electrode and portable measurement system. The results show that the graphene electrode was able to acquire the typical characteristics and features of human ECG signals with a high signal-to-noise (SNR) ratio in different states of motion. A week-long continuous wearability test showed no degradation in the ECG signal quality over time. The graphene-based flexible electrode demonstrates comfortability, good biocompatibility, and high electrophysiological detection sensitivity. The graphene electrode also combines the potential for use in long-term wearable dynamic cardiac activity monitoring systems with convenience and comfort for use in home health care of elderly and high-risk adults. PMID:27809270

  16. [Diagnostic accuracy of NT-proBNP compared with electrocardiography in detecting left ventricular hypertrophy of hypertensive origin].

    PubMed

    Andrade, Helder; Morillas, Pedro; Castillo, Jesús; Roldán, Julián; Mateo, Irene; Agudo, Pilar; Quiles, Juan; Bertomeu-Martínez, Vicente

    2011-10-01

    Electrocardiography (ECG) is the most widely used method for diagnosing left ventricular hypertrophy (LVH) in hypertensive patients. We assessed the value of N-terminal pro-brain natriuretic peptide (NT-proBNP) determination compared with ECG for detecting LVH in 336 consecutive hypertensive patients with preserved systolic function. We found a significant correlation between NT-proBNP levels and left ventricular mass adjusted for body surface area (r=.41; P<.001). The area under the receiver operating characteristic curve was 0.75 (95% CI, 0.7-0.8). A cut-off of 74.2 pg/mL had a greater sensitivity than ECG (76.6% vs 25.5%; P<.001) and a higher negative predictive value (87.8% vs 76.6%; P<.001) in the identification of LVH. NT-proBNP determination may be a useful tool for LVH screening in hypertensive patients.

  17. Design intelligent wheelchair with ECG measurement and wireless transmission function.

    PubMed

    Chou, Hsi-Chiang; Wang, Yi-Ming; Chang, Huai-Yuan

    2015-01-01

    The phenomenon of aging populations has produced widespread health awareness and magnified the need for improved medical quality and technologies. Statistics show that ischemic heart disease is the leading cause of death for older people and people with reduced mobility; therefore, wheelchairs have become their primary means of transport. Hence, an arrhythmia-detecting smart wheelchair was proposed in this study to provide real-time electrocardiography (ECG)-monitoring to patients with heart disease and reduced mobility. A self-developed, handheld ECG-sensing instrument was integrated with a wheelchair and a lab-written, arrhythmia-detecting program. The measured ECG data were transmitted through a Wi-Fi module and analyzed and diagnosed using the human-machine interface.

  18. Wireless Smartphone ECG Enables Large-Scale Screening in Diverse Populations.

    PubMed

    Haberman, Zachary C; Jahn, Ryan T; Bose, Rupan; Tun, Han; Shinbane, Jerold S; Doshi, Rahul N; Chang, Philip M; Saxon, Leslie A

    2015-05-01

    The ubiquitous presence of internet-connected phones and tablets presents a new opportunity for cost-effective and efficient electrocardiogram (ECG) screening and on-demand diagnosis. Wireless, single-lead real-time ECG monitoring supported by iOS and android devices can be obtained quickly and on-demand. ECGs can be immediately downloaded and reviewed using any internet browser. We compared the standard 12-lead ECG to the smartphone ECG in healthy young adults, elite athletes, and cardiology clinic patients. Accuracy for determining baseline ECG intervals and rate and rhythm was assessed. In 381 participants, 30-second lead I ECG waveforms were obtained using an iPhone case or iPad. Standard 12-lead ECGs were acquired immediately after the smartphone tracing was obtained. De-identified ECGs were interpreted by automated algorithms and adjudicated by two board-certified electrophysiologists. Both smartphone and standard ECGs detected atrial rate and rhythm, AV block, and QRS delay with equal accuracy. Sensitivities ranged from 72% (QRS delay) to 94% (atrial fibrillation). Specificities were all above 94% for both modalities. Smartphone ECG accurately detects baseline intervals, atrial rate, and rhythm and enables screening in diverse populations. Efficient ECG analysis using automated discrimination and an enhanced smartphone application with notification capabilities are features that can be easily incorporated into the acquisition process. © 2015 Wiley Periodicals, Inc.

  19. Electrocardiography versus photoplethysmography in assessment of maternal heart rate variability during labor.

    PubMed

    Gonçalves, Hernâni; Pinto, Paula; Silva, Manuela; Ayres-de-Campos, Diogo; Bernardes, João

    2016-01-01

    Evaluation of maternal heart rate (MHR) variability provides useful information on the maternal-fetal clinical state. Electrocardiography (ECG) is the most accurate method to monitor MHR but it may not always be available, and pulse oximetry using photoplethysmography (PPG) can be an alternative. In this study we compared ECG and PPG signals, obtained with conventional fetal monitors, to evaluate signal loss, MHR variability indices, and the ability of the latter to predict fetal acidemia and operative delivery. Both signals were simultaneously acquired in 51 term pregnancies during the last 2 h of labor (H1 and H2). Linear time- and frequency-domain, and nonlinear MHR variability indices were estimated, and the dataset was divided into normal and acidemic cases, as well as into normal and operative deliveries. Differences between ECG and PPG signals were assessed using non-parametric confidence intervals, hypothesis testing, correlation coefficient and a measure of disagreement. Prediction of fetal acidemia and operative delivery was assessed using areas under the receiver operating characteristic curve (auROC). Signal loss was higher with ECG during the first segments of H1, and higher with PPG in the last segment of H2, and it increased in both signals with labour progression. MHR variability indices were significantly different when acquired with ECG and PPG signals, with low correlation coefficients and high disagreement for entropy and fast oscillation-based indices, and low disagreement for the mean MHR and slow oscillation-based indices. However, both acquisition modes evidenced significant differences between H1 and H2 and comparable auROC values were obtained in the detection of fetal acidemia and operative vaginal delivery. Although PPG captures the faster oscillations of the MHR signal less well than ECG and is prone to have higher signal loss in the last 10-min preceding delivery, it can be considered an alternative for MHR monitoring during labor

  20. Heart rate variability and arrhythmic patterns of 24-hour Holter electrocardiography among Nigerians with cardiovascular diseases.

    PubMed

    Adebayo, Rasaaq Ayodele; Ikwu, Amanze Nkemjika; Balogun, Michael Olabode; Akintomide, Anthony Olubunmi; Ajayi, Olufemi Eyitayo; Adeyeye, Victor Oladeji; Mene-Afejuku, Tuoyo Omasan; Bamikole, Olaniyi James; Ogunyemi, Suraj Adefabi; Ajibare, Adeola Olubunmi; Oketona, Omolola Abiodun

    2015-01-01

    Facilities for Holter electrocardiography (ECG) monitoring in many Nigerian hospitals are limited. There are few published works in Nigeria on the use of 24-hour Holter ECG in cardiac arrhythmic evaluation of patients with cardiovascular diseases. To study the clinical indications, arrhythmic pattern, and heart rate variability (HRV) among subjects referred for 24-hour Holter ECG at our Cardiac Care Unit. Three-hundred and ten patients (134 males and 176 females) were studied consecutively over a 48-month period using Schiller type (MT-101) Holter ECG machine. Out of the 310 patients reviewed, 134 were males (43.2%) and 176 were females (56.8%). The commonest indication for Holter ECG was palpitation followed by syncope in 71 (23%) and 49 (15.8%) of subjects, respectively. Premature ventricular complex and premature atrial complex were the commonest types of arrhythmia in 51.5% and 15% subjects, respectively. Ventricular arrhythmia was more prevalent in dilated cardiomyopathy patients (85.7%). The HRV of subjects with palpitation, stroke, and diabetes mellitus with autonomic neuropathy, using standard deviation of normal to normal intervals average (milliseconds), were 107.32±49.61, 79.15±49.15, and 66.50±15.54, respectively. The HRV, using standard deviation of averages of normal to normal intervals average (milliseconds), of patients with palpitation, stroke, and diabetes mellitus with autonomic neuropathy were 77.39±62.34, 57.82±37.05, and 55.50±12.71, respectively. Palpitation and syncope were the commonest indications for Holter ECG among our subjects. The commonest arrhythmic patterns were premature ventricular complex and premature atrial complex, with ventricular arrhythmia being more prevalent in dilated cardiomyopathy. There was a reduction in HRV in patients with stroke and diabetic autonomic neuropathy.

  1. A brief review: history to understand fundamentals of electrocardiography

    PubMed Central

    AlGhatrif, Majd; Lindsay, Joseph

    2012-01-01

    The last decade of the 19th century witnessed the rise of a new era in which physicians used technology along with classical history taking and physical examination for the diagnosis of heart disease. The introduction of chest x-rays and the electrocardiograph (electrocardiogram) provided objective information about the structure and function of the heart. In the first half of the 20th century, a number of innovative individuals set in motion a fascinating sequence of discoveries and inventions that led to the 12-lead electrocardiogram, as we know it now. Electrocardiography, nowadays, is an essential part of the initial evaluation for patients presenting with cardiac complaints. As a first line diagnostic tool, health care providers at different levels of training and expertise frequently find it imperative to interpret electrocardiograms. It is likely that an understanding of the electrical basis of electrocardiograms would reduce the likelihood of error. An understanding of the disorders behind electrocardiographic phenomena could reduce the need for memorizing what may seem to be an endless list of patterns. In this article, we will review the important steps in the evolution of electrocardiogram. As is the case in most human endeavors, an understanding of history enables one to deal effectively with the present. PMID:23882360

  2. A Review of Fetal ECG Signal Processing; Issues and Promising Directions

    PubMed Central

    Sameni, Reza; Clifford, Gari D.

    2010-01-01

    The field of electrocardiography has been in existence for over a century, yet despite significant advances in adult clinical electrocardiography, signal processing techniques and fast digital processors, the analysis of fetal ECGs is still in its infancy. This is, partly due to a lack of availability of gold standard databases, partly due to the relatively low signal-to-noise ratio of the fetal ECG compared to the maternal ECG (caused by the various media between the fetal heart and the measuring electrodes, and the fact that the fetal heart is simply smaller), and in part, due to the less complete clinical knowledge concerning fetal cardiac function and development. In this paper we review a range of promising recording and signal processing techniques for fetal ECG analysis that have been developed over the last forty years, and discuss both their shortcomings and advantages. Before doing so, however, we review fetal cardiac development, and the etiology of the fetal ECG. A selection of relevant models for the fetal/maternal ECG mixture is also discussed. In light of current understanding of the fetal ECG, we then attempt to justify recommendations for promising future directions in signal processing, and database creation. PMID:21614148

  3. The origins of electrocardiography in Poland.

    PubMed

    Gryglewski, Ryszard W

    2015-06-01

    The progress of science and technology in the 19(th) century enabled better understanding of the electrical activity that occurs during a heartbeat. However, it was only the construction and introduction of the galvanometer that cleared the way for appropriate experimental and clinical studies. Marey, Waller, Wenckebach, Einthoven, and Pardee are just examples of the world's pioneers of electrocardiography. Polish researchers, including Cybulski, Eiger, Rzętkowski, Surzycki, and Latkowski, also contributed to the development of this area of study. The following article is a review aiming to reconstruct the origins of electrocardiography in Poland, both as a measurement method used in experiments and as a diagnostic tool in clinical studies conducted in the years preceding the outbreak of World War I.

  4. The origins of electrocardiography in Poland

    PubMed Central

    2015-01-01

    The progress of science and technology in the 19th century enabled better understanding of the electrical activity that occurs during a heartbeat. However, it was only the construction and introduction of the galvanometer that cleared the way for appropriate experimental and clinical studies. Marey, Waller, Wenckebach, Einthoven, and Pardee are just examples of the world's pioneers of electrocardiography. Polish researchers, including Cybulski, Eiger, Rzętkowski, Surzycki, and Latkowski, also contributed to the development of this area of study. The following article is a review aiming to reconstruct the origins of electrocardiography in Poland, both as a measurement method used in experiments and as a diagnostic tool in clinical studies conducted in the years preceding the outbreak of World War I. PMID:26336508

  5. Smartphone home monitoring of ECG

    NASA Astrophysics Data System (ADS)

    Szu, Harold; Hsu, Charles; Moon, Gyu; Landa, Joseph; Nakajima, Hiroshi; Hata, Yutaka

    2012-06-01

    A system of ambulatory, halter, electrocardiography (ECG) monitoring system has already been commercially available for recording and transmitting heartbeats data by the Internet. However, it enjoys the confidence with a reservation and thus a limited market penetration, our system was targeting at aging global villagers having an increasingly biomedical wellness (BMW) homecare needs, not hospital related BMI (biomedical illness). It was designed within SWaP-C (Size, Weight, and Power, Cost) using 3 innovative modules: (i) Smart Electrode (lowpower mixed signal embedded with modern compressive sensing and nanotechnology to improve the electrodes' contact impedance); (ii) Learnable Database (in terms of adaptive wavelets transform QRST feature extraction, Sequential Query Relational database allowing home care monitoring retrievable Aided Target Recognition); (iii) Smartphone (touch screen interface, powerful computation capability, caretaker reporting with GPI, ID, and patient panic button for programmable emergence procedure). It can provide a supplementary home screening system for the post or the pre-diagnosis care at home with a build-in database searchable with the time, the place, and the degree of urgency happened, using in-situ screening.

  6. Continuous stroke unit electrocardiographic monitoring versus 24-hour Holter electrocardiography for detection of paroxysmal atrial fibrillation after stroke.

    PubMed

    Rizos, Timolaos; Güntner, Janina; Jenetzky, Ekkehart; Marquardt, Lars; Reichardt, Christine; Becker, Rüdiger; Reinhardt, Roland; Hepp, Thomas; Kirchhof, Paulus; Aleynichenko, Elena; Ringleb, Peter; Hacke, Werner; Veltkamp, Roland

    2012-10-01

    Cardioembolism in paroxysmal atrial fibrillation (pxAF) is a frequent cause of ischemic stroke. Sensitive detection of pxAF after stroke is crucial for adequate secondary stroke prevention; the optimal diagnostic modality to detect pxAF on stroke units is unknown. We compared 24-hour Holter electrocardiography (ECG) with continuous stroke unit ECG monitoring (CEM) for pxAF detection. Patients with acute ischemic stroke or transient ischemic attack were prospectively enrolled. After a 12-channel ECG on admission, all patients received 24-hour Holter ECG and CEM. Additionally, ECG monitoring data underwent automated analysis using dedicated software to identify pxAF. Patients with a history of atrial fibrillation or with atrial fibrillation on the admission ECG were excluded. Four hundred ninety-six patients (median age, 69 years; 61.5% male) fulfilled all inclusion criteria (ischemic stroke: 80.4%; transient ischemic attack: 19.6%). Median stroke unit stay lasted 88.8 hours (interquartile range, 65.0-122.0). ECG data for automated CEM analysis were available for a median time of 64.0 hours (43.0-89.8). Paroxysmal AF was documented in 41 of 496 patients (8.3%). Of these, Holter detected pxAF in 34.1%; CEM in 65.9%; and automated CEM in 92.7%. CEM and automated CEM detected significantly more patients with pxAF than Holter (P<0.001), and automated CEM detected more patients than CEM (P<0.001). Automated analysis of CEM improves pxAF detection in patients with stroke on stroke units compared with 24-hour Holter ECG. The comparative usefulness of prolonged or repetitive Holter ECG recordings requires further evaluation.

  7. Willem Einthoven and the birth of clinical electrocardiography a hundred years ago.

    PubMed

    Barold, S Serge

    2003-01-01

    The first electrocardiogram (ECG) from the intact human heart was recorded with a mercury capillary electrometer by Augustus Waller in May 1887 at St. Mary's Hospital, London. The tracings were poor and exhibited only 2 distorted deflections. Willem Einthoven (1860-1927) who was professor of physiology at the University of Leiden, The Netherlands, began his studies of the ECG with the mercury capillary electrometer, and improved its distortion mathematically so that he was finally able to register a good representation of the ECG before the beginning of the twentieth century. He later further improved ECG recordings with the introduction of a string galvanometer of his design. Einthoven published his first article about the string galvanometer in 1901, followed by a more detailed description in 1903 which included a report of ECGs taken with the new instrument. The year 2002 marks the centennial of Willem Einthoven's first recording of the ECG in a clinically applicable fashion with the string galvanometer. The clinical use of Einthoven's immobile equipment required transtelephonic transmission of the ECG from the physiology laboratory to the clinic at the Academic Hospital about a mile away as documented in the 1906 paper on the "télécardiogramme". This report contained a wealth of ECG patterns and arrhythmias. Einthoven developed a system of electrocardiographic standardization that continues to be used all over the world and introduced the triaxial bipolar system with 3 limb leads and thus established uniformity of the recording process. Einthoven also conceived the famous equilateral triangle with leads I, II, and III at its sides and the calculation of the electrical axis (in the frontal plane) depicted as a single vector with an arrow at the center of the triangle. Einthoven recognized the great potential importance of the ECG as a diagnostic and investigative tool and his achievements made him the founder of modern electrocardiography. He was awarded the

  8. Electrical Changes in Resting, Exercise, and Holter Electrocardiography in Fabry Cardiomyopathy.

    PubMed

    Krämer, Johannes; Nordbeck, Peter; Störk, Stefan; Ritter, Christian; Ertl, Georg; Wanner, Christoph; Weidemann, Frank

    2015-10-27

    In Fabry cardiomyopathy, little is known about the interaction between its key feature of myocardial replacement fibrosis and changes in resting, Holter, and exercise electrocardiography (-ECG). Resting ECG, 24-h Holter ECG, and exercise ECG were performed in 95 patients (50 women) with Fabry disease, staged using cardiac magnetic resonance imaging to measure left ventricular fibrosis. With resting ECG, T alterations were seen in patients with cardiac fibrosis, while time intervals and rhythm were unchanged (except for a longer QRS duration in patients with severe fibrosis). All patients with severe fibrosis showed T inversion, ST alteration, or both. With Holter ECG, maximum and minimum heart rate did not differ with fibrosis severity. Patients without fibrotic tissue showed less ventricular premature beats (VPB) (median 5/24 h) compared to those with mild (median 11/24 h) or severe fibrosis (median 115/24 h; P < 0.05, respectively). Fibrosis was a strong predictor of VPB burden (r (2) = 0.5; P < 0.001). During exercise, patients with severe fibrosis had the least increase in systolic blood pressure (sBP) (47 ± 22 mmHg vs. 62 ± 25 mmHg, P < 0.05) and the lowest maximum heart rate (113 ± 18/min; P < 0.05). Patients with mild fibrosis had a high sBP during exercise (198 ± 37 mmHg; P < 0.05). Decreased diastolic blood pressure (>10 mmHg) occurred in some patients with no (3/41) or mild fibrosis (3/34) but not in patients with severe fibrosis (0/20; P < 0.01). Our data suggest that cardiac replacement fibrosis is responsible for repolarization abnormalities on resting ECG and increased VPB with Holter ECG. During exercise ECG, advanced cardiomyopathy is characterized by chronotropic incompetence with limitations on blood pressure and heart rate increase.

  9. Electrodes for long-term esophageal electrocardiography.

    PubMed

    Niederhauser, Thomas; Haeberlin, Andreas; Marisa, Thanks; Jungo, Michael; Goette, Josef; Jacomet, Marcel; Abacherli, Roger; Vogel, Rolf

    2013-09-01

    The emerging application of long-term and high-quality ECG recording requires alternative electrodes to improve the signal quality and recording capability of surface skin electrodes. The esophageal ECG has the potential to overcome these limitations but necessitates novel recorder and lead designs. The electrode material is of particular interest, since the material has to ensure conflicting requirements like excellent biopotential recording properties and inertness. To this end, novel electrode materials like PEDOT and silver-PDMS as well as established electrode materials such as stainless steel, platinum, gold, iridium oxide, titanium nitride, and glassy carbon were investigated by long-term electrochemical impedance spectroscopy and model-based signal analysis using the derived in vitro interfacial properties in conjunction with a dedicated ECG amplifier. The results of this novel approach show that titanium nitride and iridium oxide featuring microstructured surfaces did not degrade when exposed to artificial acidic saliva. These materials provide low electrode potential drifts and insignificant signal distortion superior to surface skin electrodes making them compatible with accepted standards for ambulatory ECG. They are superior to the noble and polarizable metals such as platinum, silver, and gold that induced more signal distortions and are superior to esophageal stainless steel electrodes that corrode in artificial saliva. The study provides rigorous criteria for the selection of electrode materials for prolonged ECG recording by combining long-term in vitro electrode material properties with ECG signal quality assessment.

  10. Prognostic value of computed tomographic coronary angiography and exercise electrocardiography for cardiovascular events

    PubMed Central

    Kim, Kye-Hwan; Jeon, Kyung Nyeo; Kang, Min Gyu; Ahn, Jong Hwa; Koh, Jin-Sin; Park, Yongwhi; Hwang, Seok-Jae; Jeong, Young-Hoon; Kwak, Choong Hwan; Hwang, Jin-Yong; Park, Jeong Rang

    2016-01-01

    Background/Aims: This study is a head-to-head comparison of predictive values for long-term cardiovascular outcomes between exercise electrocardiography (ex-ECG) and computed tomography coronary angiography (CTCA) in patients with chest pain. Methods: Four hundred and forty-two patients (mean age, 56.1 years; men, 61.3%) who underwent both ex-ECG and CTCA for evaluation of chest pain were included. For ex-ECG parameters, the patients were classified according to negative or positive results, and Duke treadmill score (DTS). Coronary artery calcium score (CACS), presence of plaque, and coronary artery stenosis were evaluated as CTCA parameters. Cardiovascular events for prognostic evaluation were defined as unstable angina, acute myocardial infarction, revascularization, heart failure, and cardiac death. Results: The mean follow-up duration was 2.8 ± 1.1 years. Fifteen patients experienced cardiovascular events. Based on pretest probability, the low- and intermediate-risks of coronary artery disease were 94.6%. Odds ratio of CACS > 40, presence of plaque, coronary stenosis ≥ 50% and DTS ≤ 4 were significant (3.79, p = 0.012; 9.54, p = 0.030; 6.99, p < 0.001; and 4.58, p = 0.008, respectively). In the Cox regression model, coronary stenosis ≥ 50% (hazard ratio, 7.426; 95% confidence interval, 2.685 to 20.525) was only significant. After adding DTS ≤ 4 to coronary stenosis ≥ 50%, the integrated discrimination improvement and net reclassification improvement analyses did not show significant. Conclusions: CTCA was better than ex-ECG in terms of predicting long-term outcomes in low- to intermediate-risk populations. The predictive value of the combination of CTCA and ex-ECG was not superior to that of CTCA alone. PMID:27017387

  11. Probabilistic Source Separation for Robust Fetal Electrocardiography

    PubMed Central

    2013-01-01

    Blind source separation (BSS) techniques are widely used to extract signals of interest from a mixture with other signals, such as extracting fetal electrocardiogram (ECG) signals from noninvasive recordings on the maternal abdomen. These BSS techniques, however, typically lack possibilities to incorporate any prior knowledge on the mixing of the source signals. Particularly for fetal ECG signals, knowledge on the mixing is available based on the origin and propagation properties of these signals. In this paper, a novel source separation method is developed that combines the strengths and accuracy of BSS techniques with the robustness of an underlying physiological model of the fetal ECG. The method is developed within a probabilistic framework and yields an iterative convergence of the separation matrix towards a maximum a posteriori estimation, where in each iteration the latest estimate of the separation matrix is corrected towards a tradeoff between the BSS technique and the physiological model. The method is evaluated by comparing its performance with that of FastICA on both simulated and real multichannel fetal ECG recordings, demonstrating that the developed method outperforms FastICA in extracting the fetal ECG source signals. PMID:24363776

  12. Routine Electrocardiography Request in Adenoidectomy: Is it necessary?

    PubMed

    Fasunla, A J; Onakoya, P A; Ogunkunle, O O; Mbam, T T; Nwaorgu, O G B

    2011-10-01

    To evaluate the relevance of routine electrocardiographic request in pre-operative work-up of children undergoing adenoidectomy. This is a two year prospective study of children with obstructive adenoid that had adenoidectomy. This is a tertiary hospital based study at the Otorhinolaryngology Department of University College Hospital, Ibadan. Children (≤12 years) with clinical and radiological evidence of an obstructive adenoid were investigated. Information obtained with an interviewer assisted questionnaire included the biodata, clinical presentation of the patients, ECG findings, echocardiographic findings, cardiothoracic ratio, palatal airway and ratio of adenoid diameter to the nasopharyngeal diameter. The adenoid volume was measured after adenoidectomy. The results were analyzed using SPSS version 14 and level of statistical significance was P < 0.05. There were seventy four patients; 45 (60.8%) males and 29 (39.2%) females with a mean age of 38.35 months, S.D ± 30.32 (range 5-144 months). All the patients presented with mouth breathing and recurrent mucopurulent rhinorrhea. Mild snoring was detected in 18 (25%) patients, moderate snoring in 39 (54.17%) patients and severe snoring in 15 (20.83%) patients. Mild apnea was observed in 55 (74.32%) patients and moderate in 19 (25.68%) patients. Only seven (9.46%) patients had abnormal electrocardiographic findings but their ejection fraction on echocardiography ranged from 63 to 72% with a mean value of 68.17%, S.D ± 3.22. Cardiac complications of enlarged obstructive adenoid appear not to be common. Routine preoperative electrocardiography should therefore be restricted to only the high risk patients.

  13. Novel approach to documenting expert ECG interpretation using eye tracking technology: a historical and biographical representation of the late Dr Rory Childers in action.

    PubMed

    Bond, R R; Kligfield, P D; Zhu, T; Finlay, D D; Drew, B; Guldenring, D; Breen, C; Clifford, G D; Wagner, G S

    2015-01-01

    The 12-lead electrocardiogram (ECG) is a complex set of cardiac signals that require a high degree of skill and clinical knowledge to interpret. Therefore, it is imperative to record and understand how expert readers interpret the 12-lead ECG. This short paper showcases how eye tracking technology and audio data can be fused together and visualised to gain insight into the interpretation techniques employed by an eminent ECG champion, namely Dr Rory Childers. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. The ECG as decision support in STEMI.

    PubMed

    Ripa, Maria Sejersten

    2012-03-01

    The electrocardiogram (ECG) can be used for determining the presence, location and extent of jeopardized myocardium during acute coronary occlusion. Accordingly, the ECG has become essential in the treatment of patients with acute coronary syndrome (ACS). This thesis aims at optimizing the decision support, provided by the ECG, for choosing the best treatment strategy in the individual patient with ST-segment elevation acute myocardial infarction (STEMI). ECG recorded in the prehospital setting has become the standard of care in many communities, but to achieve the full advantage of this early approach it is important that the ECG is recorded from accurately placed electrodes to produce an ECG that resembles the standard 12-lead ECG. Accurate electrode placement is difficult especially in the acute setting, and we investigated an alternative lead system with fewer electrodes in easily identified positions. We showed that the system produced waveforms similar to the standard 12-lead ECG. However, occasional diagnostic errors were seen, compromising general acceptance of the system. Once the ECG has been recorded a decision regarding triage must be made on the basis of a correct ECG diagnosis. We found that trained paramedics can diagnose STEMI correctly in patients without ECG confounding factors, while the presence of ECG confounding factors decreased their ability substantially. Consequently, since many patients do present with ECG confounding factors, transmission to an on-call cardiologist for an early correct diagnosis is needed. We showed that time to pPCI was reduced by more than 1 hour by transmitting prehospital ECG to a cardiologist's handheld device for diagnosis, triage, and activation of the catheterization laboratory when needed. The optimal treatment strategy is dependent on the duration of ischemia however patient information is often inaccurate. Accordingly, it would be advantageous if the first available ECG can help identify patients who will

  15. Variation in the Use of 12‐Lead Electrocardiography for Patients With Chest Pain by Emergency Medical Services in North Carolina

    PubMed Central

    Bush, Montika; Glickman, Lawrence T.; Fernandez, Antonio R.; Garvey, J. L.; Glickman, Seth W.

    2013-01-01

    Background Prehospital 12‐lead electrocardiography (ECG) is critical to timely STEMI care although its use remains inconsistent. Previous studies to identify reasons for failure to obtain a prehospital ECG have generally only focused on individual emergency medical service (EMS) systems in urban areas. Our study objective was to identify patient, geographic, and EMS agency‐related factors associated with failure to perform a prehospital ECG across a statewide geography. Methods and Results We analyzed data from the Prehospital Medical Information System (PreMIS) in North Carolina from January 2008 to November 2010 for patients >30 years of age who used EMS and had a prehospital chief complaint of chest pain. Among 3.1 million EMS encounters, 134 350 patients met study criteria. From 2008–2010, 82 311 (61%) persons with chest pain received a prehospital ECG; utilization increased from 55% in 2008 to 65% in 2010 (trend P<0.001). Utilization by health referral region ranged from 22.9% to 74.2% and was lowest in rural areas. Men were more likely than women to have an ECG performed (63.0% vs 61.3%, adjusted RR 1.02, 95% CI 1.01 to 1.04). The certification‐level of the EMS provider (paramedic vsbasic/intermediate) and system‐level ECG equipment availability were the strongest predictors of ECG utilization. Persons in an ambulance with a certified paramedic were significantly more likely to receive a prehospital ECG than nonparamedics (RR 2.15, 95% CI 1.55, 2.99). Conclusions Across a large geographic area prehospital ECG use increased significantly, although important quality improvement opportunities remain. Increasing ECG availability and improving EMS certification and training levels are needed to improve overall care and reduce rural‐urban treatment differences. PMID:23920232

  16. The Use of Fetal Noninvasive Electrocardiography.

    PubMed

    Lakhno, Igor

    2016-01-01

    Preeclampsia (PE) is one of the severe complications of pregnancy that leads to fetal deterioration. The aim was to survey the validity of fetal distress diagnostics in case of Doppler ultrasonic umbilical vein and arteries blood flow velocity investigation and ECG parameters analysis obtained from maternal abdominal signal before labor in preeclamptic patients. Fetal noninvasive ECG and umbilical arterial and venous Doppler investigation were performed in 120 patients at 34-40 weeks of gestation. And 30 of them had physiological gestation and were involved in Group I. In Group II 52 pregnant women with mild-moderate PE were observed. 38 patients with severe PE were monitored in Group III. The most considerable negative correlation was determined in pair Apgar score 1 versus T/QRS (R = -0.50; p < 0.05). So the increased T/QRS ratio was the most evident marker of fetal distress. Fetal noninvasive ECG showed sensitivity of 96.6% and specificity of 98.4% and, therefore, was determined as more accurate method for fetal monitoring.

  17. The Use of Fetal Noninvasive Electrocardiography

    PubMed Central

    2016-01-01

    Preeclampsia (PE) is one of the severe complications of pregnancy that leads to fetal deterioration. The aim was to survey the validity of fetal distress diagnostics in case of Doppler ultrasonic umbilical vein and arteries blood flow velocity investigation and ECG parameters analysis obtained from maternal abdominal signal before labor in preeclamptic patients. Fetal noninvasive ECG and umbilical arterial and venous Doppler investigation were performed in 120 patients at 34–40 weeks of gestation. And 30 of them had physiological gestation and were involved in Group I. In Group II 52 pregnant women with mild-moderate PE were observed. 38 patients with severe PE were monitored in Group III. The most considerable negative correlation was determined in pair Apgar score 1 versus T/QRS (R = −0.50; p < 0.05). So the increased T/QRS ratio was the most evident marker of fetal distress. Fetal noninvasive ECG showed sensitivity of 96.6% and specificity of 98.4% and, therefore, was determined as more accurate method for fetal monitoring. PMID:27006859

  18. Evaluation of a Rapid Anisotropic Model for ECG Simulation.

    PubMed

    Pezzuto, Simone; Kal'avský, Peter; Potse, Mark; Prinzen, Frits W; Auricchio, Angelo; Krause, Rolf

    2017-01-01

    State-of-the-art cardiac electrophysiology models that are able to deliver physiologically motivated activation maps and electrocardiograms (ECGs) can only be solved on high-performance computing architectures. This makes it nearly impossible to adopt such models in clinical practice. ECG imaging tools typically rely on simplified models, but these neglect the anisotropic electric conductivity of the tissue in the forward problem. Moreover, their results are often confined to the heart-torso interface. We propose a forward model that fully accounts for the anisotropic tissue conductivity and produces the standard 12-lead ECG in a few seconds. The activation sequence is approximated with an eikonal model in the 3d myocardium, while the ECG is computed with the lead-field approach. Both solvers were implemented on graphics processing units and massively parallelized. We studied the numerical convergence and scalability of the approach. We also compared the method to the bidomain model in terms of ECGs and activation maps, using a simplified but physiologically motivated geometry and 6 patient-specific anatomies. The proposed methods provided a good approximation of activation maps and ECGs computed with a bidomain model, in only a few seconds. Both solvers scaled very well to high-end hardware. These methods are suitable for use in ECG imaging methods, and may soon become fast enough for use in interactive simulation tools.

  19. Evaluation of a Rapid Anisotropic Model for ECG Simulation

    PubMed Central

    Pezzuto, Simone; Kal'avský, Peter; Potse, Mark; Prinzen, Frits W.; Auricchio, Angelo; Krause, Rolf

    2017-01-01

    State-of-the-art cardiac electrophysiology models that are able to deliver physiologically motivated activation maps and electrocardiograms (ECGs) can only be solved on high-performance computing architectures. This makes it nearly impossible to adopt such models in clinical practice. ECG imaging tools typically rely on simplified models, but these neglect the anisotropic electric conductivity of the tissue in the forward problem. Moreover, their results are often confined to the heart-torso interface. We propose a forward model that fully accounts for the anisotropic tissue conductivity and produces the standard 12-lead ECG in a few seconds. The activation sequence is approximated with an eikonal model in the 3d myocardium, while the ECG is computed with the lead-field approach. Both solvers were implemented on graphics processing units and massively parallelized. We studied the numerical convergence and scalability of the approach. We also compared the method to the bidomain model in terms of ECGs and activation maps, using a simplified but physiologically motivated geometry and 6 patient-specific anatomies. The proposed methods provided a good approximation of activation maps and ECGs computed with a bidomain model, in only a few seconds. Both solvers scaled very well to high-end hardware. These methods are suitable for use in ECG imaging methods, and may soon become fast enough for use in interactive simulation tools. PMID:28512434

  20. Noninvasive Diagnosis of Coronary Artery Disease Using 12-Lead High-Frequency Electrocardiograms

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Arenare, Brian

    2006-01-01

    method is the presence versus the absence of reduced-amplitude zones (RAZs). In terms that must be simplified for the sake of brevity, an RAZ comprises several cycles of a high-frequency QRS signal during which the amplitude of the high-frequency oscillation in a portion of the signal is abnormally low (see figure). A given signal sample exhibiting an interval of reduced amplitude may or may not be classified as an RAZ, depending on quantitative criteria regarding peaks and troughs within the reduced-amplitude portion of the high-frequency QRS signal. This analysis is performed in all 12 leads in real time.

  1. Electrocardiographic and chronobiological features of paroxysmal AV block recorded by ambulatory electrocardiography.

    PubMed

    Saito, Ken; Takeda, Shiho; Saito, Yuko; Kawamura, Mami; Yoshikawa, Yoko; Yano, Hayato; Sata, Masataka

    2014-01-01

    The goal of this study was to investigate the electrocardiographic and chronobio-logical features of paroxysmal atrioventricular (AV) block (PAVB) using data from ambulatory electrocardiography (AECG). The study population consisted of five men and six women aged from 47 to 82 years of age. Main presenting symptoms were pre-syncope in five patients (45.5%) and syncope in three patients (27.3%). Organic cardiovascular diseases were seen in eight patients (72.7%), and AV conduction disturbances were seen in six patients (54.5%), such as right bundle branch block, first to second degree AV block on standard 12-lead electrocardiography. Incidence of PAVB events were 1-329 (37.9 ± 98.0) episodes/patient/day, and the maximum pause during Holter recordings was 3.3-12.4 (6.39 ± 3.09) seconds. This maximum pause caused by intrinsic AV block was longer than that of vagally mediated AV block (8.4 ± 3.2 sec vs 4.7 ± 1.0 sec, p<0.05). In chronobiological analysis, episodes of PAVB exhibited a circadian rhythm characterized by a peak between 2:00 am and 4:00 am and a trough between 0:00 pm and 2:00 pm. AECG is a useful tool to detect the maximum pause occurring during sleep and provides critical data necessary to prevent the sudden cardiac death caused by PAVB.

  2. The non-contact measure of the heart rate variability by laser Doppler vibrometry: comparison with electrocardiography

    NASA Astrophysics Data System (ADS)

    Cosoli, G.; Casacanditella, L.; Tomasini, E. P.; Scalise, L.

    2016-06-01

    The assessment of the heart rate variability (HRV) is of utmost importance, being one of the most promising markers of the activity of the autonomic nervous system and associated to cardiovascular mortality. Different signals can be used to perform HRV, primarily electrocardiography (ECG), photoplethysmography (PPG), phonocardiography (PCG) or vibrocardiography (VCG), since the fundamental aspect is the individuation of a periodic feature strictly correlated with cardiac activity (i.e. R-peak in ECG or the first sound in PCG). In this work, the authors demonstrate that the VCG performances in HRV analysis are sufficiently accurate if compared to the ones measured by ECG (i.e. standard methodology); moreover, the authors want to prove the feasibility of such measurement in correspondence of different measurement points (i.e. carotid artery—which is the typical VCG measurement point—and the radial artery on the wrist)1. Results show that VCG has a mean deviation of  <1 bpm with respect to ECG in heart rate (HR) measurement; carotid artery is the most accurate site for the assessment, but also the radial artery is a valid site, even if with a reduced SNR. With regards to HRV parameters, the mean percentage deviation is  <10% in correspondence of carotid artery, and  ≈16% for the radial artery. So, VCG allows for non-contact monitoring of the cardiac activity.

  3. High-risk angina patient: identification by clinical features, hospital course, electrocardiography, and technetium-99m stannous pyrophosphate scintigraphy

    SciTech Connect

    Olson, H.G.; Lyons, K.P.; Aronow, W.S.; Stinson, P.J.; Kuperus, J.; Waters, H.J.

    1981-10-01

    We evaluated 193 consecutive unstable angina patients by clinical features, hospital course and electrocardiography. All patients were managed medically. Of the 193 patients, 150 (78%) had a technetium-99m pyrophosphate (Tc-PYP) myocardial scintigram after hospitalization. Of these, 49 (33%) had positive scintigrams. At a follow-up of 24.9 +- 10.8 months after hospitalization, 16 of 49 patients (33%) with positive scintigrams died from cardiac causes, compared with six of 101 patients (6%) with negative scintigrams (p < 0.001). Of 49 patients with positive scintigrams, 11 (22%) had had nonfatal myocardial infarction at follow-up, compared with seven of 101 patients (7%) with negative scintigrams (p < 0.01). Age, duration of clinical coronary artery disease, continuing angina during hospitalization, ischemic ECG, cardiomegaly and a history of heart failure also correlated with cardiac death at follow-up. Ischemic ECG and a history of angina with a crescendo pattern also correlated with nonfatal infarction at follow-up. Patients with continuing angina, an ischemic ECG and a positive scintigram constituted a high-risk unstable angina subgroup, with a survival rate of 58% at 6 months, 47% at 12 months and 42% at 24 and 36 months. We conclude that the assessment of clinical features, hospital course, ECG and Tc-PYP scintigraphy may be useful in identifying high-risk unstable angina patients.

  4. High-risk angina patient. Identification by clinical features, hospital course, electrocardiography and technetium-99m stannous pyrophosphate scintigraphy

    SciTech Connect

    Olson, H.G.; Lyons, K.P.; Aronow, W.S.; Stinson, P.J.; Kuperus, J.; Waters, H.J.

    1981-10-01

    We evaluated 193 consecutive unstable angina patients by clinical features, hospital course and electrocardiography. All patients were managed medically. Of the 193 patients, 150 (78%) had a technetium-99m pyrophosphate (Tc-PYP) myocardial scintigram after hospitalization. Of these, 49 (33%) had positive scintigrams. At a follow-up of 24.9 +/- 10.8 months after hospitalization, 16 of 49 patients (33%) with positive scintigrams died from cardiac causes, compared with six of 101 patients (6%) with negative scintigrams (p less than 0.001). Of 49 patients with positive scintigrams, 11 (22%) had had nonfatal myocardial infarction at follow-up, compared with seven of 101 patients (7%) with negative scintigrams (p less than 0.01). Age, duration of clinical coronary artery disease, continuing angina during hospitalization, ischemic ECG, cardiomegaly and a history of heart failure also correlated with cardiac death at follow-up. Ischemic ECG and a history of angina with a crescendo pattern also correlated with nonfatal infarction at follow-up. Patients with continuing angina, an ischemic ECG and a positive scintigram constituted a high-risk unstable angina subgroup with a survival rate of 58% at 6 months, 47% at 12 months and 42% at 24 and 36 months. We conclude that the assessment of clinical features, hospital course, ECG and Tc-PYP scintigraphy may be useful in identifying high-risk unstable angina patients.

  5. Myocardial infarction size and location: a comparative study of epicardial isopotential mapping, thallium-201 scintigraphy, electrocardiography and vectorcardiography

    SciTech Connect

    Toyama, S.; Suzuki, K.; Takahashi, T.; Yamashita, Y.

    1987-07-01

    Based on epicardial isopotential mapping (the Ep Map), which was calculated from body surface isopotential mapping (the Body Map) with Yamashita's method, using the finite element technique, we predicted the location and size of the abnormal depolarized area (the infarcted area) in 19 clinical cases of anterior and 18 cases of inferoposterior infarction. The prediction was done using Toyama's diagnostic method, previously reported. The accuracy of the prediction by the Ep Map was assessed by comparing it with findings from thallium-201 scintigraphy (SCG), electrocardiography (ECG) and vectorcardiography (VCG). In all cases of anterior infarction, the location of the abnormal depolarized areas determined on the Ep Map, which was localized at the anterior wall along the anterior intraventricular septum, agreed with the location of the abnormal findings obtained by SCG, ECG and VCG. For all inferoposterior infarction cases, the abnormal depolarized areas were localized at the posterior wall and the location also coincided with that of the abnormal findings obtained by SCG, ECG and VCG. Furthermore, we ranked and ordered the size of the abnormal depolarized areas, which were predicted by the Ep Map for both anterior and inferoposterior infarction cases. In the cases of anterior infarction, the order of the size of the abnormal depolarized area by the Ep Map was correlated to the size of the abnormal findings by SCG, as well as to the results from Selvester's QRS scoring system in ECG and to the angle of the maximum QRS vector in the horizontal plane in VCG.

  6. Implementation of integrated heterogeneous electronic electrocardiography data into Maharaj Nakorn Chiang Mai Hospital Information System.

    PubMed

    Khumrin, Piyapong; Chumpoo, Pitupoom

    2016-03-01

    Electrocardiography is one of the most important non-invasive diagnostic tools for diagnosing coronary heart disease. The electrocardiography information system in Maharaj Nakorn Chiang Mai Hospital required a massive manual labor effort. In this article, we propose an approach toward the integration of heterogeneous electrocardiography data and the implementation of an integrated electrocardiography information system into the existing Hospital Information System. The system integrates different electrocardiography formats into a consistent electrocardiography rendering by using Java software. The interface acts as middleware to seamlessly integrate different electrocardiography formats. Instead of using a common electrocardiography protocol, we applied a central format based on Java classes for mapping different electrocardiography formats which contains a specific parser for each electrocardiography format to acquire the same information. Our observations showed that the new system improved the effectiveness of data management, work flow, and data quality; increased the availability of information; and finally improved quality of care. © The Author(s) 2014.

  7. Utility of 12-lead electrocardiogram for differentiating paroxysmal supraventricular tachycardias in dogs.

    PubMed

    Santilli, R A; Perego, M; Crosara, S; Gardini, F; Bellino, C; Moretti, P; Spadacini, G

    2008-01-01

    The 12-lead surface ECG is validated for differentiating supraventricular tachycardias (SVT) in humans. Despite the description of SVT in veterinary medicine, no studies have analyzed the electrocardiographic features of this type of arrhythmias in dogs. To describe the specific electrocardiographic criteria used to differentiate the most common SVT in dogs. Twenty-three dogs examined at Clinica Veterinaria Malpensa for SVT with the mechanism documented by electrophysiologic studies (EPS). Twelve-lead electrocardiographic variables obtained from 14 dogs with orthodromic atrioventricular reciprocating tachycardia (OAVRT) and 9 dogs with focal atrial tachycardia (FAT) were compared. Dogs with FAT had faster heart rates (278 +/- 62 versus 229 +/- 42 bpm; P= .049) and less QRS alternans (33 versus 86%; P= .022). P waves appeared during tachycardia in 22 dogs, with a superior axis in 100% of OAVRT and 22% of FAT (P < .001). OAVRT was characterized by a shorter RP interval (85.0 +/- 16.8 versus 157.1 +/- 37.3 ms; P < .001) and smaller RP/PR ratio (0.60 +/- 0.18 versus 1.45 +/- 0.52; P < .001). Repolarization anomalies were present in 64% of OAVRT and no FAT (P < .001). Multivariate analysis identified QRS alternans and a positive P wave in aVR during tachycardia as independent predictors of arrhythmia type. Electrocardiographic criteria used in people for differentiating SVT can also be applied in dogs.

  8. Computational Analysis of ECGs

    NASA Astrophysics Data System (ADS)

    Waters, Kevin

    2013-03-01

    Electrocardiogram is among the most powerful methods at present to diagnose heart conditions. Here we employed Fourier transform to analyze Electrocardiograms. The goal of the project is to find a way to isolate different wave signals in ways that today's technology is not capable of. Our focus was on building on a code that is capable of filtering out P, QRS, T waves and noise from the ECG, so we created frequency filters that omitted selected amount of data. We first deconstructed and then constructed the ECG this way to find an optimal code assembly for each ECG wave (P-wave, QRS-wave, T-wave). By focusing on one patient, we succeeded to disentangle the complicated ECG signal. We plan to extend this method to more patients.

  9. Assessment of autonomic neurodevelopment in the mouse fetuses by using fetal electrocardiography.

    PubMed

    Khandoker, Ahsan H; Al Khoori, Thuraia; Ito, Takuya; Sugibayashi, Rika; Kimura, Yoshitaka

    2016-08-01

    Fetal Electrocardiography (FECG) offers unique capabilities for assessment of beat-to-beat fetal heart rate (FHR) and fetal heart rate variability (FHRV), which are indirect markers of autonomic nervous system, its development. In this study the fetal ECG signals, FHR and FHRV are successfully recorded to assess the neurodevelopment in fetal mice in the second and third trimester from days 12.5 to 18.5 by using direct insertion of fetal ECG electrodes in the uterine. FHR increases from day 12.5 till 15.5 reaching a plateau and then shows a sudden increase on the day 18.5. Development of fetal increasing heart rate variability (FHRV) is clearly evident from the results. Short term FHRV (RMSSD) corresponding to parasympathetic nervous system activity and long term FHRV (SDNN) corresponding to sympathetic and parasympathetic nervous system activities increases till day 16.5 and then decreases from day 17.5. The increases in large fluctuations were noticed on days 17.5 and 18.5, which were thought to have caused by uterine contractions before delivery. The ability to assess FHR and FHRV in fetal mice makes a valuable tool for neurodevelopment research in perinatal medicine.

  10. A novel method of fabricating carbon nanotubes-polydimethylsiloxane composite electrodes for electrocardiography.

    PubMed

    Liu, Benyan; Chen, Yingmin; Luo, Zhangyuan; Zhang, Wenzan; Tu, Quan; Jin, Xun

    2015-01-01

    Polymer-based flexible electrodes are receiving much attention in medical applications due to their good wearing comfort. The current fabrication methods of such electrodes are not widely applied. In this study, polydimethylsiloxane (PDMS) and conductive additives of carbon nanotubes (CNTs) were employed to fabricate composite electrodes for electrocardiography (ECG). A three-step dispersion process consisting of ultrasonication, stirring, and in situ polymerization was developed to yield homogenous CNTs-PDMS mixtures. The CNTs-PDMS mixtures were used to fabricate CNTs-PDMS composite electrodes by replica technology. The influence of ultrasonication time and CNT concentration on polymer electrode performance was evaluated by impedance and ECG measurements. The signal amplitude of the electrodes prepared using an ultrasonication time of 12 h and CNT content of 5 wt% was comparable to that of commercial Ag/AgCl electrodes. The polymer electrodes were easily fabricated by conventional manufacturing techniques, indicating a potential advantage of reduced cost for mass production.

  11. Smartphone applications (apps) for heart rate measurement in children: comparison with electrocardiography monitor.

    PubMed

    Ho, Chi-Lin; Fu, Yun-Ching; Lin, Ming-Chih; Chan, Sheng-Ching; Hwang, Betau; Jan, Sheng-Ling

    2014-04-01

    Heart rate (HR) measurement is essential for children with abnormal heart beats. The purpose of this study was to determine whether HR measurement by smartphone applications (apps) could be a feasible alternative to an electrocardiography (ECG) monitor. A total of 40 children, median age of 4.3 years, were studied. Using four free smartphone apps, pulse rates were measured at the finger (or toe) and earlobe, and compared with baseline HRs measured by ECG monitors. Significant correlations between measured pulse rates and baseline HRs were found. Both correlation and accuracy rate were higher in the earlobe group than the finger/toe group. When HR was <120 beats per min (bpm), the accuracy rates were not different between the two different measuring sites for each app (median of 65 vs 76%). The accuracy rates in the finger/toe group were significantly lower than those in the earlobe group for all apps when HR was ≥ 120 bpm (27 vs 65%). There were differences among apps in their abilities to measure pulse rates. Taking children's pulse rate from the earlobe would be more accurate, especially for tachycardia. However, we do not recommend that smartphone apps should not be used for routine medical use or used as the sole form of HR measurement because the results of their accuracy are not good enough.

  12. Identification of weakly coupled multiphysics problems. Application to the inverse problem of electrocardiography

    NASA Astrophysics Data System (ADS)

    Corrado, Cesare; Gerbeau, Jean-Frédéric; Moireau, Philippe

    2015-02-01

    This work addresses the inverse problem of electrocardiography from a new perspective, by combining electrical and mechanical measurements. Our strategy relies on the definition of a model of the electromechanical contraction which is registered on ECG data but also on measured mechanical displacements of the heart tissue typically extracted from medical images. In this respect, we establish in this work the convergence of a sequential estimator which combines for such coupled problems various state of the art sequential data assimilation methods in a unified consistent and efficient framework. Indeed, we aggregate a Luenberger observer for the mechanical state and a Reduced-Order Unscented Kalman Filter applied on the parameters to be identified and a POD projection of the electrical state. Then using synthetic data we show the benefits of our approach for the estimation of the electrical state of the ventricles along the heart beat compared with more classical strategies which only consider an electrophysiological model with ECG measurements. Our numerical results actually show that the mechanical measurements improve the identifiability of the electrical problem allowing to reconstruct the electrical state of the coupled system more precisely. Therefore, this work is intended to be a first proof of concept, with theoretical justifications and numerical investigations, of the advantage of using available multi-modal observations for the estimation and identification of an electromechanical model of the heart.

  13. Combined Electrocardiography- and Respiratory-Triggered CT of the Lung to Reduce Respiratory Misregistration Artifacts between Imaging Slabs in Free-Breathing Children: Initial Experience

    PubMed Central

    Allmendinger, Thomas

    2017-01-01

    Objective Cardiac and respiratory motion artifacts degrade the image quality of lung CT in free-breathing children. The aim of this study was to evaluate the effect of combined electrocardiography (ECG) and respiratory triggering on respiratory misregistration artifacts on lung CT in free-breathing children. Materials and Methods In total, 15 children (median age 19 months, range 6 months–8 years; 7 boys), who underwent free-breathing ECG-triggered lung CT with and without respiratory-triggering were included. A pressure-sensing belt of a respiratory gating system was used to obtain the respiratory signal. The degree of respiratory misregistration artifacts between imaging slabs was graded on a 4-point scale (1, excellent image quality) on coronal and sagittal images and compared between ECG-triggered lung CT studies with and without respiratory triggering. A p value < 0.05 was considered significant. Results Lung CT with combined ECG and respiratory triggering showed significantly less respiratory misregistration artifacts than lung CT with ECG triggering only (1.1 ± 0.4 vs. 2.2 ± 1.0, p = 0.003). Conclusion Additional respiratory-triggering reduces respiratory misregistration artifacts on ECG-triggered lung CT in free-breathing children. PMID:28860904

  14. Combined Electrocardiography- and Respiratory-Triggered CT of the Lung to Reduce Respiratory Misregistration Artifacts between Imaging Slabs in Free-Breathing Children: Initial Experience.

    PubMed

    Goo, Hyun Woo; Allmendinger, Thomas

    2017-01-01

    Cardiac and respiratory motion artifacts degrade the image quality of lung CT in free-breathing children. The aim of this study was to evaluate the effect of combined electrocardiography (ECG) and respiratory triggering on respiratory misregistration artifacts on lung CT in free-breathing children. In total, 15 children (median age 19 months, range 6 months-8 years; 7 boys), who underwent free-breathing ECG-triggered lung CT with and without respiratory-triggering were included. A pressure-sensing belt of a respiratory gating system was used to obtain the respiratory signal. The degree of respiratory misregistration artifacts between imaging slabs was graded on a 4-point scale (1, excellent image quality) on coronal and sagittal images and compared between ECG-triggered lung CT studies with and without respiratory triggering. A p value < 0.05 was considered significant. Lung CT with combined ECG and respiratory triggering showed significantly less respiratory misregistration artifacts than lung CT with ECG triggering only (1.1 ± 0.4 vs. 2.2 ± 1.0, p = 0.003). Additional respiratory-triggering reduces respiratory misregistration artifacts on ECG-triggered lung CT in free-breathing children.

  15. Diagnostic value of prehospital ECG in acute stroke patients.

    PubMed

    Bobinger, Tobias; Kallmünzer, Bernd; Kopp, Markus; Kurka, Natalia; Arnold, Martin; Heider, Stefan; Schwab, Stefan; Köhrmann, Martin

    2017-05-16

    To investigate the diagnostic yield of prehospital ECG monitoring provided by emergency medical services in the case of suspected stroke. Consecutive patients with acute stroke admitted to our tertiary stroke center via emergency medical services and with available prehospital ECG were prospectively included during a 12-month study period. We assessed prehospital ECG recordings and compared the results to regular 12-lead ECG on admission and after continuous ECG monitoring at the stroke unit. Overall, 259 patients with prehospital ECG recording were included in the study (90.3% ischemic stroke, 9.7% intracerebral hemorrhage). Atrial fibrillation (AF) was detected in 25.1% of patients, second-degree or greater atrioventricular block in 5.4%, significant ST-segment elevation in 5.0%, and ventricular ectopy in 9.7%. In 18 patients, a diagnosis of new-onset AF with direct clinical consequences for the evaluation and secondary prevention of stroke was established by the prehospital recordings. In 2 patients, the AF episodes were limited to the prehospital period and were not detected by ECG on admission or during subsequent monitoring at the stroke unit. Of 126 patients (48.6%) with relevant abnormalities in the prehospital ECG, 16.7% received medical antiarrhythmic therapy during transport to the hospital, and 6.4% were transferred to a cardiology unit within the first 24 hours in the hospital. In a selected cohort of patients with stroke, the in-field recordings of the ECG detected a relevant rate of cardiac arrhythmia. The results can add to the in-hospital evaluation and should be considered in prehospital care of acute stroke. © 2017 American Academy of Neurology.

  16. The Impact of prehospital 12-lead electrocardiograms on door-to-balloon time in patients with ST-elevation myocardial infarction.

    PubMed

    Meadows-Pitt, Mary; Fields, Willa

    2014-05-01

    Multiple strategies have been implemented to reduce door-to-balloon times. The purpose of this study was to compare door-to-balloon times between ST-elevation myocardial infarction (STEMI) patients who arrived at the emergency department by ambulance with a pre-hospital electrocardiogram (ECG), to those who self-transported and had an ECG on ED arrival. This retrospective, comparative study evaluated differences in door-to-balloon times from October 2006 to December 2009 between STEMI patients that had a 12-lead ECG done in the ambulance prior to ED arrival and patients who self-transported and had an ECG on ED arrival. Of the 367 patients, 62% (n = 228) arrived by ambulance and 38% (n = 139) self-transported to the emergency department. Door-to-balloon times were 30 minutes less (P < .001) than patients who were self-transported. Door-to-balloon times can be reduced when chest pain patients are transported to the emergency department by ambulance. The paramedics are equipped to perform an ECG, thereby making a preliminary diagnosis of STEMI. The emergency department can them prepare for potential angioplasty or percutaneous coronary intervention. An opportunity exists for emergency nurses to educate the public about the importance of calling 911 for chest pain. Copyright © 2014 Emergency Nurses Association. Published by Mosby, Inc. All rights reserved.

  17. A computer-human interaction model to improve the diagnostic accuracy and clinical decision-making during 12-lead electrocardiogram interpretation.

    PubMed

    Cairns, Andrew W; Bond, Raymond R; Finlay, Dewar D; Breen, Cathal; Guldenring, Daniel; Gaffney, Robert; Gallagher, Anthony G; Peace, Aaron J; Henn, Pat

    2016-12-01

    The 12-lead Electrocardiogram (ECG) presents a plethora of information and demands extensive knowledge and a high cognitive workload to interpret. Whilst the ECG is an important clinical tool, it is frequently incorrectly interpreted. Even expert clinicians are known to impulsively provide a diagnosis based on their first impression and often miss co-abnormalities. Given it is widely reported that there is a lack of competency in ECG interpretation, it is imperative to optimise the interpretation process. Predominantly the ECG interpretation process remains a paper based approach and whilst computer algorithms are used to assist interpreters by providing printed computerised diagnoses, there are a lack of interactive human-computer interfaces to guide and assist the interpreter. An interactive computing system was developed to guide the decision making process of a clinician when interpreting the ECG. The system decomposes the interpretation process into a series of interactive sub-tasks and encourages the clinician to systematically interpret the ECG. We have named this model 'Interactive Progressive based Interpretation' (IPI) as the user cannot 'progress' unless they complete each sub-task. Using this model, the ECG is segmented into five parts and presented over five user interfaces (1: Rhythm interpretation, 2: Interpretation of the P-wave morphology, 3: Limb lead interpretation, 4: QRS morphology interpretation with chest lead and rhythm strip presentation and 5: Final review of 12-lead ECG). The IPI model was implemented using emerging web technologies (i.e. HTML5, CSS3, AJAX, PHP and MySQL). It was hypothesised that this system would reduce the number of interpretation errors and increase diagnostic accuracy in ECG interpreters. To test this, we compared the diagnostic accuracy of clinicians when they used the standard approach (control cohort) with clinicians who interpreted the same ECGs using the IPI approach (IPI cohort). For the control cohort, the

  18. A Hygroscopic Sensor Electrode for Fast Stabilized Non-Contact ECG Signal Acquisition.

    PubMed

    Fong, Ee-May; Chung, Wan-Young

    2015-08-05

    A capacitive electrocardiography (cECG) technique using a non-invasive ECG measuring technology that does not require direct contact between the sensor and the skin has attracted much interest. The system encounters several challenges when the sensor electrode and subject's skin are weakly coupled. Because there is no direct physical contact between the subject and any grounding point, there is no discharge path for the built-up electrostatic charge. Subsequently, the electrostatic charge build-up can temporarily contaminate the ECG signal from being clearly visible; a stabilization period (3-15 min) is required for the measurement of a clean, stable ECG signal at low humidity levels (below 55% relative humidity). Therefore, to obtain a clear ECG signal without noise and to reduce the ECG signal stabilization time to within 2 min in a dry ambient environment, we have developed a fabric electrode with embedded polymer (FEEP). The designed hygroscopic FEEP has an embedded superabsorbent polymer layer. The principle of FEEP as a conductive electrode is to provide humidity to the capacitive coupling to ensure strong coupling and to allow for the measurement of a stable, clear biomedical signal. The evaluation results show that hygroscopic FEEP is capable of rapidly measuring high-accuracy ECG signals with a higher SNR ratio.

  19. Classification of a Driver's cognitive workload levels using artificial neural network on ECG signals.

    PubMed

    Tjolleng, Amir; Jung, Kihyo; Hong, Wongi; Lee, Wonsup; Lee, Baekhee; You, Heecheon; Son, Joonwoo; Park, Seikwon

    2017-03-01

    An artificial neural network (ANN) model was developed in the present study to classify the level of a driver's cognitive workload based on electrocardiography (ECG). ECG signals were measured on 15 male participants while they performed a simulated driving task as a primary task with/without an N-back task as a secondary task. Three time-domain ECG measures (mean inter-beat interval (IBI), standard deviation of IBIs, and root mean squared difference of adjacent IBIs) and three frequencydomain ECG measures (power in low frequency, power in high frequency, and ratio of power in low and high frequencies) were calculated. To compensate for individual differences in heart response during the driving tasks, a three-step data processing procedure was performed to ECG signals of each participant: (1) selection of two most sensitive ECG measures, (2) definition of three (low, medium, and high) cognitive workload levels, and (3) normalization of the selected ECG measures. An ANN model was constructed using a feed-forward network and scaled conjugate gradient as a back-propagation learning rule. The accuracy of the ANN classification model was found satisfactory for learning data (95%) and testing data (82%).

  20. A Hygroscopic Sensor Electrode for Fast Stabilized Non-Contact ECG Signal Acquisition

    PubMed Central

    Fong, Ee-May; Chung, Wan-Young

    2015-01-01

    A capacitive electrocardiography (cECG) technique using a non-invasive ECG measuring technology that does not require direct contact between the sensor and the skin has attracted much interest. The system encounters several challenges when the sensor electrode and subject’s skin are weakly coupled. Because there is no direct physical contact between the subject and any grounding point, there is no discharge path for the built-up electrostatic charge. Subsequently, the electrostatic charge build-up can temporarily contaminate the ECG signal from being clearly visible; a stabilization period (3–15 min) is required for the measurement of a clean, stable ECG signal at low humidity levels (below 55% relative humidity). Therefore, to obtain a clear ECG signal without noise and to reduce the ECG signal stabilization time to within 2 min in a dry ambient environment, we have developed a fabric electrode with embedded polymer (FEEP). The designed hygroscopic FEEP has an embedded superabsorbent polymer layer. The principle of FEEP as a conductive electrode is to provide humidity to the capacitive coupling to ensure strong coupling and to allow for the measurement of a stable, clear biomedical signal. The evaluation results show that hygroscopic FEEP is capable of rapidly measuring high-accuracy ECG signals with a higher SNR ratio. PMID:26251913

  1. ECG artifact cancellation in surface EMG signals by fractional order calculus application.

    PubMed

    Miljković, Nadica; Popović, Nenad; Djordjević, Olivera; Konstantinović, Ljubica; Šekara, Tomislav B

    2017-03-01

    New aspects for automatic electrocardiography artifact removal from surface electromyography signals by application of fractional order calculus in combination with linear and nonlinear moving window filters are explored. Surface electromyography recordings of skeletal trunk muscles are commonly contaminated with spike shaped artifacts. This artifact originates from electrical heart activity, recorded by electrocardiography, commonly present in the surface electromyography signals recorded in heart proximity. For appropriate assessment of neuromuscular changes by means of surface electromyography, application of a proper filtering technique of electrocardiography artifact is crucial. A novel method for automatic artifact cancellation in surface electromyography signals by applying fractional order calculus and nonlinear median filter is introduced. The proposed method is compared with the linear moving average filter, with and without prior application of fractional order calculus. 3D graphs for assessment of window lengths of the filters, crest factors, root mean square differences, and fractional calculus orders (called WFC and WRC graphs) have been introduced. For an appropriate quantitative filtering evaluation, the synthetic electrocardiography signal and analogous semi-synthetic dataset have been generated. The examples of noise removal in 10 able-bodied subjects and in one patient with muscle dystrophy are presented for qualitative analysis. The crest factors, correlation coefficients, and root mean square differences of the recorded and semi-synthetic electromyography datasets showed that the most successful method was the median filter in combination with fractional order calculus of the order 0.9. Statistically more significant (p < 0.001) ECG peak reduction was obtained by the median filter application compared to the moving average filter in the cases of low level amplitude of muscle contraction compared to ECG spikes. The presented results suggest

  2. An integrated healthcare information system for end-to-end standardized exchange and homogeneous management of digital ECG formats.

    PubMed

    Trigo, Jesús Daniel; Martínez, Ignacio; Alesanco, Alvaro; Kollmann, Alexander; Escayola, Javier; Hayn, Dieter; Schreier, Günter; García, José

    2012-07-01

    This paper investigates the application of the enterprise information system (EIS) paradigm to standardized cardiovascular condition monitoring. There are many specifications in cardiology, particularly in the ECG standardization arena. The existence of ECG formats, however, does not guarantee the implementation of homogeneous, standardized solutions for ECG management. In fact, hospital management services need to cope with various ECG formats and, moreover, several different visualization applications. This heterogeneity hampers the normalization of integrated, standardized healthcare information systems, hence the need for finding an appropriate combination of ECG formats and a suitable EIS-based software architecture that enables standardized exchange and homogeneous management of ECG formats. Determining such a combination is one objective of this paper. The second aim is to design and develop the integrated healthcare information system that satisfies the requirements posed by the previous determination. The ECG formats selected include ISO/IEEE11073, Standard Communications Protocol for Computer-Assisted Electrocardiography, and an ECG ontology. The EIS-enabling techniques and technologies selected include web services, simple object access protocol, extensible markup language, or business process execution language. Such a selection ensures the standardized exchange of ECGs within, or across, healthcare information systems while providing modularity and accessibility.

  3. Towards the clinical use of concentric electrodes in ECG recordings: influence of ring dimensions and electrode position

    NASA Astrophysics Data System (ADS)

    Prats-Boluda, G.; Ye-Lin, Y.; Bueno-Barrachina, JM; Rodriguez de Sanabria, R.; Garcia-Casado, J.

    2016-02-01

    To overcome the limited spatial resolution of standard 12-lead ECG recordings, concentric ring electrodes (CRE) have been proposed to provide valuable data for the diagnosis of a wide range of cardiac abnormalities, including infarction and arrhythmia. Although theoretical studies indicate that the dimensions of the CRE regulate the depth of the electric dipoles sensed by these electrodes, this has not been experimentally confirmed. The aim of this work was to analyze the influence of CRE dimensions and position of a wireless multi-CRE sensor node on the cardiac signal recorded. For this, four wireless multichannel ECG recording nodes based on flexible multi-ring electrodes were placed at positions CMV1 (position comparable to V1), CMV2, CMV4R and CMV5; each node providing three bipolar concentric ECG signals (BC-ECG). Standard 12-lead ECG and 12 BC-ECG signals were recorded in 29 volunteers. The results revealed that a ring with an outer diameter of 33.5 mm achieves a balance between the ease-of-use and spatial resolution of smaller electrodes and improved detectability and higher amplitudes of signals from larger ring electrodes. Although a standard 12-lead ECG outperforms BC-ECC recordings in detectability of cardiac waves, if the relative amplitude of the wave is also considered, BC-ECG at CMV1 proved superior at picking up atrial activity. In fact, in most of the BC-ECG signals picked up at CMV1, P1 and P2 atrial activity waves were more clearly identified than in simultaneous 12-Lead ECG signals. Likewise, BC-ECG signals revealed higher spatial resolution in detecting anomalous electrical activity in local regions, such as impaired intraventricular driving, or atrioventricular blocks. Finally, the wireless multi-CRE sensor node provides enhanced comfort and handling to both patient and clinician over wired systems.

  4. A Study on the Optimal Positions of ECG Electrodes in a Garment for the Design of ECG-Monitoring Clothing for Male.

    PubMed

    Cho, Hakyung; Lee, Joo Hyeon

    2015-09-01

    Smart clothing is a sort of wearable device used for ubiquitous health monitoring. It provides comfort and efficiency in vital sign measurements and has been studied and developed in various types of monitoring platforms such as T-shirt and sports bra. However, despite these previous approaches, smart clothing for electrocardiography (ECG) monitoring has encountered a serious shortcoming relevant to motion artifacts caused by wearer movement. In effect, motion artifacts are one of the major problems in practical implementation of most wearable health-monitoring devices. In the ECG measurements collected by a garment, motion artifacts are usually caused by improper location of the electrode, leading to lack of contact between the electrode and skin with body motion. The aim of this study was to suggest a design for ECG-monitoring clothing contributing to reduction of motion artifacts. Based on the clothing science theory, it was assumed in this study that the stability of the electrode in a dynamic state differed depending on the electrode location in an ECG-monitoring garment. Founded on this assumption, effects of 56 electrode positions were determined by sectioning the surface of the garment into grids with 6 cm intervals in the front and back of the bodice. In order to determine the optimal locations of the ECG electrodes from the 56 positions, ECG measurements were collected from 10 participants at every electrode position in the garment while the wearer was in motion. The electrode locations indicating both an ECG measurement rate higher than 80.0 % and a large amplitude during motion were selected as the optimal electrode locations. The results of this analysis show four electrode locations with consistently higher ECG measurement rates and larger amplitudes amongst the 56 locations. These four locations were abstracted to be least affected by wearer movement in this research. Based on this result, a design of the garment-formed ECG monitoring platform

  5. Effect of ECG filter settings on J-waves.

    PubMed

    Nakagawa, Mikiko; Tsunemitsu, Chie; Katoh, Sayo; Kamiyama, Yukari; Sano, Nario; Ezaki, Kaori; Miyazaki, Hiroko; Teshima, Yasushi; Yufu, Kunio; Takahashi, Naohiko; Saikawa, Tetsunori

    2014-01-01

    While J-waves were observed in healthy populations, variations in their reported incidence may be partly explicable by the ECG filter setting. We obtained resting 12-lead ECG recordings in 665 consecutive patients and enrolled 112 (56 men, 56 women, mean age 59.3±16.1years) who manifested J-waves on ECGs acquired with a 150-Hz low-pass filter. We then studied the J-waves on individual ECGs to look for morphological changes when 25-, 35-, 75-, 100-, and 150Hz filters were used. The notching observed with the 150-Hz filter changed to slurring (42%) or was eliminated (28%) with the 25-Hz filter. Similarly, the slurring seen with the 150-Hz filter was eliminated on 71% of ECGs recorded with the 25-Hz filter. The amplitude of J-waves was significantly lower with 25- and 35-Hz than 75-, 100-, and 150-Hz filters (p<0.0001). The ECG filter setting significantly affects the J-wave morphology. © 2013.

  6. Tremor suppression in ECG

    PubMed Central

    Dotsinsky, Ivan A; Mihov, Georgy S

    2008-01-01

    Background Electrocardiogram recordings are very often contaminated by high-frequency noise usually power-line interference and EMG disturbances (tremor). Specific method for interference cancellation without affecting the proper ECG components, called subtraction procedure, was developed some two decades ago. Filtering out the tremor remains a priori partially successful since it has a relatively wide spectrum, which overlaps the useful ECG frequency band. Method The proposed method for tremor suppression implements the following three procedures. Contaminated ECG signals are subjected to moving averaging (comb filter with linear phase characteristic) with first zero set at 50 Hz to suppress tremor and PL interference simultaneously. The reduced peaks of QRS complexes and other relatively high and steep ECG waves are then restored by an introduced by us procedure called linearly-angular, so that the useful high frequency components are preserved in the range specified by the embedded in the ECG instrument filter, usually up to 125 Hz. Finally, a Savitzky-Golay smoothing filter is applied for supplementary tremor suppression outside the QRS complexes. Results The results obtained show a low level of the residual EMG disturbances together with negligible distortion of the wave shapes regardless of rhythm and morphology changes. PMID:19019218

  7. [Analysis of pacemaker ECGs].

    PubMed

    Israel, Carsten W; Ekosso-Ejangue, Lucy; Sheta, Mohamed-Karim

    2015-09-01

    The key to a successful analysis of a pacemaker electrocardiogram (ECG) is the application of the systematic approach used for any other ECG without a pacemaker: analysis of (1) basic rhythm and rate, (2) QRS axis, (3) PQ, QRS and QT intervals, (4) morphology of P waves, QRS, ST segments and T(U) waves and (5) the presence of arrhythmias. If only the most obvious abnormality of a pacemaker ECG is considered, wrong conclusions can easily be drawn. If a systematic approach is skipped it may be overlooked that e.g. atrial pacing is ineffective, the left ventricle is paced instead of the right ventricle, pacing competes with intrinsic conduction or that the atrioventricular (AV) conduction time is programmed too long. Apart from this analysis, a pacemaker ECG which is not clear should be checked for the presence of arrhythmias (e.g. atrial fibrillation, atrial flutter, junctional escape rhythm and endless loop tachycardia), pacemaker malfunction (e.g. atrial or ventricular undersensing or oversensing, atrial or ventricular loss of capture) and activity of specific pacing algorithms, such as automatic mode switching, rate adaptation, AV delay modifying algorithms, reaction to premature ventricular contractions (PVC), safety window pacing, hysteresis and noise mode. A systematic analysis of the pacemaker ECG almost always allows a probable diagnosis of arrhythmias and malfunctions to be made, which can be confirmed by pacemaker control and can often be corrected at the touch of the right button to the patient's benefit.

  8. High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

    NASA Technical Reports Server (NTRS)

    Rahman, Atiar

    2006-01-01

    Background: Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). Methods and Results: 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P<0.001). Conclusions: Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

  9. High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

    NASA Technical Reports Server (NTRS)

    Rahman, Atiar

    2006-01-01

    Background: Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). Methods and Results: 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P<0.001). Conclusions: Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

  10. High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P less than 0.00l). Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

  11. Wavelet-Based Watermarking and Compression for ECG Signals with Verification Evaluation

    PubMed Central

    Tseng, Kuo-Kun; He, Xialong; Kung, Woon-Man; Chen, Shuo-Tsung; Liao, Minghong; Huang, Huang-Nan

    2014-01-01

    In the current open society and with the growth of human rights, people are more and more concerned about the privacy of their information and other important data. This study makes use of electrocardiography (ECG) data in order to protect individual information. An ECG signal can not only be used to analyze disease, but also to provide crucial biometric information for identification and authentication. In this study, we propose a new idea of integrating electrocardiogram watermarking and compression approach, which has never been researched before. ECG watermarking can ensure the confidentiality and reliability of a user's data while reducing the amount of data. In the evaluation, we apply the embedding capacity, bit error rate (BER), signal-to-noise ratio (SNR), compression ratio (CR), and compressed-signal to noise ratio (CNR) methods to assess the proposed algorithm. After comprehensive evaluation the final results show that our algorithm is robust and feasible. PMID:24566636

  12. Intelligent Classification of Heartbeats for Automated Real-Time ECG Monitoring

    PubMed Central

    Park, Juyoung

    2014-01-01

    Abstract Background: The automatic interpretation of electrocardiography (ECG) data can provide continuous analysis of heart activity, allowing the effective use of wireless devices such as the Holter monitor. Materials and Methods: We propose an intelligent heartbeat monitoring system to detect the possibility of arrhythmia in real time. We detected heartbeats and extracted features such as the QRS complex and P wave from ECG signals using the Pan–Tompkins algorithm, and the heartbeats were then classified into 16 types using a decision tree. Results: We tested the sensitivity, specificity, and accuracy of our system against data from the MIT-BIH Arrhythmia Database. Our system achieved an average accuracy of 97% in heartbeat detection and an average heartbeat classification accuracy of above 96%, which is comparable with the best competing schemes. Conclusions: This work provides a guide to the systematic design of an intelligent classification system for decision support in Holter ECG monitoring. PMID:25010717

  13. High-pitch dual-source CT coronary angiography: analysis of the impact on image quality of altered electrocardiography waves during data acquisition.

    PubMed

    Wang, Xiaoling; Fang, Jiliang; Tong, Haibin; Zhao, Qing; Song, Qingqiao; Luo, Ping; Xue, Chao; Zhang, Min; Yang, Shuhua; Wang, Qun; Wang, Ping; Shi, Fengxiang; Xu, Lei; Rong, Peijing

    2012-06-01

    Electrocardiography (ECG) "altered waves" sometimes occur during data acquisition when computed tomography coronary angiography (CTCA) is performed with the prospectively ECG-triggered high-pitch (Flash spiral) mode using a second-generation dual-source CT. The aim of this study was to assess the effect of the ECG altered waves on image quality. Seventy-three consecutive patients with stable sinus rhythm ≤ 65 beats per minute were retrospectively enrolled in this study. CTCA was performed using the Flash spiral mode in which the data acquisition was prospectively triggered at 60 % of the R-R interval and completed within one cardiac cycle. The ECG waves before and during data acquisition were analyzed for grouping purposes. Image quality was evaluated using a four-point scale (1 = best, 4 = unevaluatable). Thirty patients (group 1) were found to have ECG altered waves during data acquisition, while 43 patients (group 2) had ECG "stable waves." The altered waves were seen as the baseline drifting; the broad, erected, or inverted P wave or QRS complexes; and a new wave. However, the length of the R-R interval did not change during the data acquisition. There were no significant differences in image quality scores between the two groups on the per-patient (2 ± 0.87 vs. 2.2 ± 0.74, P = 0.273) or per-segment (1.27 ± 0.54 vs. 1.32 ± 0.55, P = 0.577) basis. There were no significant differences in coronary evaluatability as well (per-patient; 93.3 vs. 95.3 %, P = 0.352; per-segment; 99.4 vs. 99.6 %, P = 1.0). CTCA image quality is not affected by ECG altered waves during data acquisition using the Flash spiral mode in low and stable heart rate patients. Thus, the ECG altered waves are considered artifacts.

  14. The usefulness of surface 12-lead electrocardiogram to predict intra-atrial conduction block after successful atrial flutter ablation.

    PubMed

    Mairesse, Georges H; Lacroix, Dominique; Klug, Didier; Le Franc, Pierre; Kouakam, Claude; Kacet, Salem

    2003-07-01

    Intraatrial conduction block at the inferior vena cava-tricuspid annulus isthmus was shown to predict successful atrial flutter ablation. However, its demonstration requires the use of several electrode catheters. Thus, a simple approach using surface 12-lead ECG to prove the conduction block would be valuable. Twenty-two patients were prospectively studied during low septal and low lateral atrial pacing before and after successful atrial flutter ablation. Creation of the conduction block was confirmed by comparing the sequence of atrial activation using 3 multipolar catheters during atrial pacing before and after ablation. During low septal pacing, there was no significant difference before and after ablation in P-wave width, axis, or morphology. During low lateral atrial pacing, there was a significant P-wave axis rotation towards the right (from -67 +/- 27 degrees to +13 +/- 35 degrees, P <.001), and P-wave polarity in limb lead II changed from predominantly negative to predominantly positive in 21 of 22 patients. There was also an increase in P-wave width (from 136 +/- 32 to 169 +/- 36 ms, P <.001) and stimulus-to-QRS interval (from 268 +/- 61 ms to 343 +/- 95 ms, P <.001) during low lateral pacing that was not observed during low septal pacing. We conclude that creation of a conduction block in the inferior vena cava-tricuspid annulus isthmus modifies surface 12-lead ECG during low lateral atrial pacing only. We also suggest that P-wave polarity in limb lead II during low lateral pacing could be used as a noninvasive marker of unidirectional counter-clockwise conduction block during atrial flutter ablation.

  15. Comparison of exercise electrocardiography and stress perfusion CMR for the detection of coronary artery disease in women

    PubMed Central

    2012-01-01

    Background Exercise electrocardiography (ECG) is frequently used in the work-up of patients with suspected coronary artery disease (CAD), however the accuracy is reduced in women. Cardiovascular magnetic resonance (CMR) stress testing can accurately diagnose CAD in women. To date, a direct comparison of CMR to ECG has not been performed. Methods and results We prospectively enrolled 88 consecutive women with chest pain or other symptoms suggestive of CAD. Patients underwent a comprehensive clinical evaluation, exercise ECG, a CMR stress test including perfusion and infarct imaging, and x-ray coronary angiography (CA) within 24 hours. CAD was defined as stenosis ≥70% on quantitative analysis of CA. Exercise ECG, CMR and CA was completed in 68 females (age 66.4 ± 8.8 years, number of CAD risk factors 3.5 ± 1.4). The prevalence of CAD on CA was 29%. The Duke treadmill score (DTS) in the entire group was −3.0 ± 5.4 and was similar in those with and without CAD (−4.5 ± 5.8 and −2.4 ± 5.1; P = 0.12). Sensitivity, specificity and accuracy for CAD diagnosis was higher for CMR compared with exercise ECG (sensitivities 85% and 50%, P = 0.02, specificities 94% and 73%, P = 0.01, and accuracies 91% and 66%, P = 0.0007, respectively). Even after applying the DTS the accuracy of CMR was higher compared to exercise ECG (area under ROC curve 0.94 ± 0.03 vs 0.56 ± 0.07; P = 0.0001). Conclusions In women with intermediate-to-high risk for CAD who are able to exercise and have interpretable resting ECG, CMR stress perfusion imaging has higher accuracy for the detection of relevant obstruction of the epicardial coronaries when directly compared to exercise ECG. PMID:22697372

  16. Electrocardiography-Gated Computed Tomography of the Bronchial Arteries With Iterative Image Reconstruction: Clinical Evaluation and Image Quality.

    PubMed

    Gang, Qiangqiang; Xu, Jun; Wang, Junling; Hao, Peng; Xu, Yikai

    2017-04-26

    The aim of this study was to apply electrocardiography (ECG)-gated prospective-triggered multidetector row computed tomography angiography with iterative model reconstruction (IMR) to optimize imaging of the bronchial arteries in patients with the chief complaint of hemoptysis. This was a prospective observational study. Between August 2015 and June 2016, we enrolled 31 consecutive patients with the chief complaint of hemoptysis who were scheduled to undergo computed tomography of the bronchial artery. Patients were randomly divided into 3 groups: group A, with filtered back-projection reconstruction; group B, with iDose reconstruction; and group C, with ECG-gated prospective-triggered multidetector row computed tomography angiography with IMR. Image quality, visibility, and traceability were compared. Image quality, including signal-to-noise and contrast-to-noise ratios, visibility, and traceability, was best in group C. With the help of IMR and ECG-synchronized prospective-triggered technology, the bronchial artery anatomy can be accurately depicted in patients with massive hemoptysis.

  17. Effect of cardiologist ECG review on emergency department practice.

    PubMed

    Todd, K H; Hoffman, J R; Morgan, M T

    1996-01-01

    To determine the effect of cardiology review of ECGs on emergency department practice. We carried out a prospective cohort study at an urban teaching ED. Our subjects were adult patients undergoing electrocardiography. We prospectively collected 1,000 consecutive ECGs and classified them by severity according to the following system: class 1, normal or minor abnormalities only; class 2, abnormalities with potential to alter case management; and class 3, potentially life-threatening abnormalities. Actual ECG readings by ED physicians (who had access to computerized interpretations at the time of treatment) were compared with those of staff cardiology quality-assurance reviewers; if they were not in agreement, an expert cardiology panel blindly chose the superior interpretation. Subsequently, an expert emergency physician panel reviewed discordant readings for discharged patients to determine the need for further action. Of 1,000 ECGs, the readings for 190 (19%) were significantly discordant. The expert cardiology panel preferred the ED reading in 72 cases (38%) and the staff cardiology reading in 118 (62%). In 30 other cases no ED reading was recorded in the medical record. Of the 148 cases in which the expert cardiology panel agreed with the cardiology reading or there was no ED reading, 102 patients were admitted and 46 discharged. Of the 46 discharges, 8 cardiology readings were categorized as class 1, leaving only 38 cases in which the staff cardiology reading might have affected the ED decision to discharge a patient. All of these readings were in class 2, with the exception of one unclassifiable diagnosis. There were no class 3 readings. On expert emergency physician panel review of these 38 ECGs and interpretations, only 8 (.8%, 95% confidence interval, .3% to 1.6%) were considered sufficiently important to warrant chart review. In actual practice, none of these cases was affected by the ECG quality-assurance (QA) process. Two of these patients died during

  18. Pacemaker stimulus amplitude alteration without loss of capture: an unusual ECG finding in cardiac tamponade from pacemaker lead perforation.

    PubMed

    Suksaranjit, P; Prasidthrathsint, K

    2014-01-01

    A variation in pacemaker stimulus amplitude can represent pacemaker system dysfunction from generator malfunction, lead insulation defect, lead fracture, or artefact of digital signal processing of the electrocardiography recorder. Pacemaker lead perforation into the pericardial space typically results in loss of capture which was not demonstrated in our patient. In summary, we report an unusual ECG finding of pacemaker stimulus amplitude alteration without loss of capture in the setting of cardiac tamponade from pacemaker lead perforation.

  19. Hybrid ECG signal conditioner

    NASA Technical Reports Server (NTRS)

    Rinard, G. A.; Steffen, D. A.; Sturm, R. E.

    1979-01-01

    Circuit with high common-mode rejection has ability to filter and amplify accepted analog electrocardiogram (ECG) signals of varying amplitude, shape, and polarity. In addition, low power circuit develops standardized pulses that can be counted and averaged by heart/breath rate processor.

  20. Pre-hospital ECG manifestations of acute myocardial ischemia are an independent predictor of adverse hospital outcomes

    PubMed Central

    Hemsey, Jessica Zègre; Dracup, Kathleen; Fleischmann, Kirsten; Sommargren, Claire E.; Paul, Steven M.; Drew, Barbara J.

    2013-01-01

    Background Prehospital electrocardiography (PH ECG) is becoming the standard of care for patients activating emergency medical services (EMS) for symptoms of acute coronary syndrome (ACS). Little is known about the prognostic value of ischemia found on PH ECG. Study Objectives The purpose of this study was to determine whether manifestations of acute myocardial ischemia on PH ECG are predictive of adverse hospital outcomes. Methods The study was a retrospective analysis of all PH ECGs recorded in 630 patients who called “911” for symptoms of ACS and were enrolled in a prospective clinical trial. ST-segment monitoring software was added to the PH ECG device with automatic storage and transmission of ECGs to the destination emergency department (ED). Patients’ medical records were reviewed for adverse hospital outcomes. Results In 630 patients who called “911” for ACS symptoms, 270 (42.9%) had PH ECG evidence of ischemia. Overall, 37% of patients with PH ECG ischemia had adverse hospital outcomes compared to 27% of patients without PH ECG ischemia (p< .05). Those with PH ECG ischemia were 1.55 times more likely to have adverse hospital outcomes than those without PH ECG ischemia (CI 1.09–2.21, p<0.05), after controlling for other predictors of adverse hospital outcomes (i.e., age, gender, medical history). Conclusions Evidence of ischemia on PH ECG is an independent predictor of adverse hospital outcomes. ST segment monitoring in the prehospital setting may identify high-risk patients with symptoms of ACS and provide important prognostic information at presentation to the ED. PMID:23357378

  1. Long-term Prognostic Value of Major and Minor ECG Abnormalities in Latent Keshan Disease With Suspect Chronic Keshan Disease

    PubMed Central

    Zhu, Yanhe; Lai, Bingqi; Niu, Xiaolin; Wei, Jin; Tan, Wuhong; Wang, Xinfeng

    2014-01-01

    Objective This study aims to determine whether baseline electrocardiography (ECG) abnormalities, the appearance of new ECG abnormalities, or other clinical characteristics are associated with increased rates of progression to chronic Keshan disease (KD) among patients with latent KD. Methods Four hundred and fourteen new latent KD patients from a monitored population in China were diagnosed and then followed for 10 years. Baseline and 10-year ECG abnormalities were classified according to the Minnesota Code as major and minor. Using Cox proportional hazards regression models, the addition of ECG abnormalities to traditional risk factors were examined to predict chronic KD events. Results In 414 latent KD patients with ECG abnormalities, 220 (53.1%) had minor and 194 (46.9%) had major ECG abnormalities. During the follow-up, 92 (22.2%) patients experienced chronic KD events; 32 (14.5%) and 60 (30.9%) of these chronic KD events occurred in the minor and major ECG abnormalities groups, respectively. After adjustment for baseline potential confounders, the hazard ratios and 95% confidence intervals (CIs) for progression to chronic KD in latent KD patients with major ECG abnormalities versus those with minor ECG abnormalities was 2.43 (95% CI 1.58–3.93). Conclusions Major ECG abnormalities and new ventricular premature complex abnormalities that occurred during the follow-up were both associated with an increased risk of progression to chronic KD. Atrial fibrillation and right bundle branch block with left anterior hemiblock are the most strongly predictive components of major ECG abnormalities. Depending on the model, adding ECG abnormalities to traditional risk factors was associated with improved risk prediction in latent KD. PMID:24975014

  2. Long-term prognostic value of major and minor ECG abnormalities in latent Keshan disease with suspect chronic Keshan disease.

    PubMed

    Zhu, Yanhe; Lai, Bingqi; Niu, Xiaolin; Wei, Jin; Tan, Wuhong; Wang, Xinfeng

    2014-01-01

    This study aims to determine whether baseline electrocardiography (ECG) abnormalities, the appearance of new ECG abnormalities, or other clinical characteristics are associated with increased rates of progression to chronic Keshan disease (KD) among patients with latent KD. Four hundred and fourteen new latent KD patients from a monitored population in China were diagnosed and then followed for 10 years. Baseline and 10-year ECG abnormalities were classified according to the Minnesota Code as major and minor. Using Cox proportional hazards regression models, the addition of ECG abnormalities to traditional risk factors were examined to predict chronic KD events. In 414 latent KD patients with ECG abnormalities, 220 (53.1%) had minor and 194 (46.9%) had major ECG abnormalities. During the follow-up, 92 (22.2%) patients experienced chronic KD events; 32 (14.5%) and 60 (30.9%) of these chronic KD events occurred in the minor and major ECG abnormalities groups, respectively. After adjustment for baseline potential confounders, the hazard ratios and 95% confidence intervals (CIs) for progression to chronic KD in latent KD patients with major ECG abnormalities versus those with minor ECG abnormalities was 2.43 (95% CI 1.58-3.93). Major ECG abnormalities and new ventricular premature complex abnormalities that occurred during the follow-up were both associated with an increased risk of progression to chronic KD. Atrial fibrillation and right bundle branch block with left anterior hemiblock are the most strongly predictive components of major ECG abnormalities. Depending on the model, adding ECG abnormalities to traditional risk factors was associated with improved risk prediction in latent KD.

  3. Electrocardiography and the preparticipation physical examination: is it time for routine screening?

    PubMed

    Donnelly, Diane K; Howard, Thomas M

    2006-04-01

    The preparticipation physical examination (PPE) is a screening tool endorsed by numerous organizations and used to evaluate young athletes prior to competition for both medical and musculoskeletal conditions that may predispose them to injury. The cardiac portion of the examination, as recommended by the American Heart Association, is detailed specifically to detect signs or symptoms consistent with certain congenital heart conditions that may increase a young athlete's risk of sudden cardiac death (SCD). Much controversy has erupted over the years as to whether this examination has the diagnostic sensitivity to detect these conditions and prevent SCD, and whether additional modalities, such as the 12-lead electrocardiograph (ECG), should be incorporated. Given the rarity of SCD events, the large population of young athletes that would qualify yearly for the examination, and the limitations that an ECG would present, it would not be efficient to add the ECG to the standard PPE on the symptomatic athlete. More efforts should be spent in standardizing the PPE on a national level to further improve its efficiency.

  4. [Adaptation of Einthoven's string galvanometer for electrocardiography in the Netherlands].

    PubMed

    Wyers, P J

    2001-12-22

    After the Dutch physiologist Willem Einthoven (1860-1927) published the construction of his string galvanometer in 1901, the development of electrocardiography in the Netherlands was slow. During the next twenty years only a few string galvanometers were in use in the Netherlands, mostly in physiology laboratories. Publications concerning electrocardiographic tests on patients were scarce. In 1924, Einthoven was awarded the Nobel Prize for Physiology and Medicine for discovering the mechanism of the electrocardiogram. From that moment onwards, electrocardiography developed rapidly in the Netherlands and during the following 30 years particular use was made of the French string galvanometer designed by Boulitte.

  5. An efficient unsupervised fetal QRS complex detection from abdominal maternal ECG.

    PubMed

    Varanini, M; Tartarisco, G; Billeci, L; Macerata, A; Pioggia, G; Balocchi, R

    2014-08-01

    Non-invasive fetal heart rate is of great relevance in clinical practice to monitor fetal health state during pregnancy. To date, however, despite significant advances in the field of electrocardiography, the analysis of abdominal fetal ECG is considered a challenging problem for biomedical and signal processing communities. This is mainly due to the low signal-to-noise ratio of fetal ECG and difficulties in cancellation of maternal QRS complexes, motion and electromyographic artefacts. In this paper we present an efficient unsupervised algorithm for fetal QRS complex detection from abdominal multichannel signal recordings combining ICA and maternal ECG cancelling, which outperforms each single method. The signal is first pre-processed to remove impulsive artefacts, baseline wandering and power line interference. The following steps are then applied: maternal ECG extraction through independent component analysis (ICA); maternal QRS detection; maternal ECG cancelling through weighted singular value decomposition; enhancing of fetal ECG through ICA and fetal QRS detection. We participated in the Physionet/Computing in Cardiology Challenge 2013, obtaining the top official scores of the challenge (among 53 teams of participants) of event 1 and event 2 concerning fetal heart rate and fetal interbeat intervals estimation section. The developed algorithms are released as open-source on the Physionet website.

  6. Investigations of sensitivity and resolution of ECG and MCG in a realistically shaped thorax model.

    PubMed

    Mäntynen, Ville; Konttila, Teijo; Stenroos, Matti

    2014-12-07

    Solving the inverse problem of electrocardiography (ECG) and magnetocardiography (MCG) is often referred to as cardiac source imaging. Spatial properties of ECG and MCG as imaging systems are, however, not well known. In this modelling study, we investigate the sensitivity and point-spread function (PSF) of ECG, MCG, and combined ECG+MCG as a function of source position and orientation, globally around the ventricles: signal topographies are modelled using a realistically-shaped volume conductor model, and the inverse problem is solved using a distributed source model and linear source estimation with minimal use of prior information. The results show that the sensitivity depends not only on the modality but also on the location and orientation of the source and that the sensitivity distribution is clearly reflected in the PSF. MCG can better characterize tangential anterior sources (with respect to the heart surface), while ECG excels with normally-oriented and posterior sources. Compared to either modality used alone, the sensitivity of combined ECG+MCG is less dependent on source orientation per source location, leading to better source estimates. Thus, for maximal sensitivity and optimal source estimation, the electric and magnetic measurements should be combined.

  7. MS-QI: A Modulation Spectrum-Based ECG Quality Index for Telehealth Applications.

    PubMed

    Tobon V, Diana P; Falk, Tiago H; Maier, Martin

    2016-08-01

    As telehealth applications emerge, the need for accurate and reliable biosignal quality indices has increased. One typical modality used in remote patient monitoring is the electrocardiogram (ECG), which is inherently susceptible to several different noise sources, including environmental (e.g., powerline interference), experimental (e.g., movement artifacts), and physiological (e.g., muscle and breathing artifacts). Accurate measurement of ECG quality can allow for automated decision support systems to make intelligent decisions about patient conditions. This is particularly true for in-home monitoring applications, where the patient is mobile and the ECG signal can be severely corrupted by movement artifacts. In this paper, we propose an innovative ECG quality index based on the so-called modulation spectral signal representation. The representation quantifies the rate of change of ECG spectral components, which are shown to be different from the rate of change of typical ECG noise sources. The proposed modulation spectral-based quality index, MS-QI, was tested on 1) synthetic ECG signals corrupted by varying levels of noise, 2) single-lead recorded data using the Hexoskin garment during three activity levels (sitting, walking, running), 3) 12-lead recorded data using conventional ECG machines (Computing in Cardiology 2011 dataset), and 4) two-lead ambulatory ECG recorded from arrhythmia patients (MIT-BIH Arrhythmia Database). Experimental results showed the proposed index outperforming two conventional benchmark quality measures, particularly in the scenarios involving recorded data in real-world environments.

  8. ECG by mobile technologies.

    PubMed

    Guzik, Przemyslaw; Malik, Marek

    Mobile electrocardiographs consist of three components: a mobile device (e.g. a smartphone), an electrocardiographic device or accessory, and a mobile application. Mobile platforms are small computers with sufficient computational power, good quality display, suitable data storage, and several possibilities of data transmission. Electrocardiographic electrodes and sensors for mobile use utilize unconventional materials, e.g. rubber, e-textile, and inkjet-printed nanoparticle electrodes. Mobile devices can be handheld, worn as vests or T-shirts, or attached to patient's skin as biopatches. Mobile electrocardiographic devices and accessories may additionally record other signals including respiratory rate, activity level, and geolocation. Large-scale clinical studies that utilize electrocardiography are easier to conduct using mobile technologies and the collected data are suitable for "big data" processing. This is expected to reveal phenomena so far inaccessible by standard electrocardiographic techniques.

  9. Shannon's Energy Based Algorithm in ECG Signal Processing.

    PubMed

    Beyramienanlou, Hamed; Lotfivand, Nasser

    2017-01-01

    Physikalisch-Technische Bundesanstalt (PTB) database is electrocardiograms (ECGs) set from healthy volunteers and patients with different heart diseases. PTB is provided for research and teaching purposes by National Metrology Institute of Germany. The analysis method of complex QRS in ECG signals for diagnosis of heart disease is extremely important. In this article, a method on Shannon energy (SE) in order to detect QRS complex in 12 leads of ECG signal is provided. At first, this algorithm computes the Shannon energy (SE) and then makes an envelope of Shannon energy (SE) by using the defined threshold. Then, the signal peaks are determined. The efficiency of the algorithm is tested on 70 cases. Of all 12 standard leads, ECG signals include 840 leads of the PTB Diagnostic ECG Database (PTBDB). The algorithm shows that the Shannon energy (SE) sensitivity is equal to 99.924%, the detection error rate (DER) is equal to 0.155%, Positive Predictivity (+P) is equal to 99.922%, and Classification Accuracy (Acc) is equal to 99.846%.

  10. Shannon's Energy Based Algorithm in ECG Signal Processing

    PubMed Central

    2017-01-01

    Physikalisch-Technische Bundesanstalt (PTB) database is electrocardiograms (ECGs) set from healthy volunteers and patients with different heart diseases. PTB is provided for research and teaching purposes by National Metrology Institute of Germany. The analysis method of complex QRS in ECG signals for diagnosis of heart disease is extremely important. In this article, a method on Shannon energy (SE) in order to detect QRS complex in 12 leads of ECG signal is provided. At first, this algorithm computes the Shannon energy (SE) and then makes an envelope of Shannon energy (SE) by using the defined threshold. Then, the signal peaks are determined. The efficiency of the algorithm is tested on 70 cases. Of all 12 standard leads, ECG signals include 840 leads of the PTB Diagnostic ECG Database (PTBDB). The algorithm shows that the Shannon energy (SE) sensitivity is equal to 99.924%, the detection error rate (DER) is equal to 0.155%, Positive Predictivity (+P) is equal to 99.922%, and Classification Accuracy (Acc) is equal to 99.846%. PMID:28197213

  11. Principal component analysis of atrial fibrillation: inclusion of posterior ECG leads does not improve correlation with left atrial activity.

    PubMed

    Raine, Daniel; Langley, Philip; Shepherd, Ewen; Lord, Stephen; Murray, Stephen; Murray, Alan; Bourke, John P

    2015-02-01

    Lead V1 is routinely analysed due to its large amplitude AF waveform. V1 correlates strongly with right atrial activity but only moderately with left atrial activity. Posterior lead V9 correlates strongest with left atrial activity. (1) To establish whether surface dominant AF frequency (DAF) calculated using principal component analysis (PCA) of a modified 12-lead ECG (including posterior leads) has a stronger correlation with left atrial activity compared to the standard ECG. (2) To assess the contribution of individual ECG leads to the AF principal component in both ECG configurations. Patients were assigned to modified or standard ECG groups. In the modified ECG, posterior leads V8 and V9 replaced V4 and V6. AF waveform was extracted from one-minute surface ECG recordings using PCA. Surface DAF was correlated with intracardiac DAF from the high right atrium (HRA), coronary sinus (CS) and pulmonary veins (PVs). 96 patients were studied. Surface DAF from the modified ECG did not have a stronger correlation with left atrial activity compared to the standard ECG. Both ECG configurations correlated strongly with HRA, CS and right PVs but only moderately with left PVs. V1 contributed most to the AF principal component in both ECG configurations. Copyright © 2015. Published by Elsevier Ltd.

  12. Principal component analysis of atrial fibrillation: Inclusion of posterior ECG leads does not improve correlation with left atrial activity

    PubMed Central

    Raine, Daniel; Langley, Philip; Shepherd, Ewen; Lord, Stephen; Murray, Stephen; Murray, Alan; Bourke, John P.

    2015-01-01

    Background Lead V1 is routinely analysed due to its large amplitude AF waveform. V1 correlates strongly with right atrial activity but only moderately with left atrial activity. Posterior lead V9 correlates strongest with left atrial activity. Aims (1) To establish whether surface dominant AF frequency (DAF) calculated using principal component analysis (PCA) of a modified 12-lead ECG (including posterior leads) has a stronger correlation with left atrial activity compared to the standard ECG. (2) To assess the contribution of individual ECG leads to the AF principal component in both ECG configurations. Methods Patients were assigned to modified or standard ECG groups. In the modified ECG, posterior leads V8 and V9 replaced V4 and V6. AF waveform was extracted from one-minute surface ECG recordings using PCA. Surface DAF was correlated with intracardiac DAF from the high right atrium (HRA), coronary sinus (CS) and pulmonary veins (PVs). Results 96 patients were studied. Surface DAF from the modified ECG did not have a stronger correlation with left atrial activity compared to the standard ECG. Both ECG configurations correlated strongly with HRA, CS and right PVs but only moderately with left PVs. V1 contributed most to the AF principal component in both ECG configurations. PMID:25619612

  13. Incremental value of clinical assessment, supine exercise electrocardiography, and biplane exercise radionuclide ventriculography in the prediction of coronary artery disease in men with chest pain

    SciTech Connect

    Currie, P.J.; Kelly, M.J.; Harper, R.W.; Federman, J.; Kalff, V.; Anderson, S.T.; Pitt, A.

    1983-11-01

    The incremental value of clinical assessment, exercise electrocardiography (ECG) and biplane radionuclide ventriculography (RVG) in the prediction of coronary artery disease (CAD) was assessed in 105 men without myocardial infarction who were undergoing coronary angiography for investigation of chest pain. Independent clinical assessment of chest pain was made prospectively by 2 physicians. Graded supine bicycle exercise testing was symptom-limited. Right anterior oblique ECG-gated first-pass RVG and left anterior oblique ECG-gated equilibrium RVG were performed at rest and exercise. Regional wall motion abnormalities were defined by agreement of 2 of 3 blinded observers. A combined strongly positive exercise ECG response was defined as greater than or equal to 2 mm ST depression or 1.0 to 1.9 mm ST depression with exercise-induced chest pain. A multivariate logistic regression model for the preexercise prediction of CAD was derived from the clinical data and selected 2 variables: chest pain class and cholesterol level. A second model assessed the incremental value of the exercise test in prediction of CAD and found 2 exercise variables that improved prediction: RVG wall motion abnormalities, and a combined strongly positive ECG response. Applying the derived predictive models, 37 of the 58 patients (64%) with preexercise probabilities of 10 to 90% crossed either below the 10% probability threshold or above the 90% threshold and 28 (48%) also moved across the 5 and 95% thresholds. Supine exercise testing with ECG and biplane RVG together, but neither test alone, effectively adds to clinical prediction of CAD. It is most useful in men with atypical chest pain and when the ECG and RVG results are concordant.

  14. The prevalence of abnormal ECG in trained sportsmen

    PubMed Central

    Malhotra, V.K.; Singh, Navreet; Bishnoi, R.S.; Chadha, D.S.; Bhardwaj, P.; Madan, H.; Dutta, R.; Ghosh, A.K.; Sengupta, S.; Perumal, P.

    2015-01-01

    Background Competitive sports training causes structural and conductive system changes manifesting by various electrocardiographic alterations. We undertook this study to assess the prevalence of abnormal ECG in trained Indian athletes and correlate it with the nature of sports training, that is endurance or strength training. Methods We evaluated a standard resting, lying 12 lead Electrocardiogram (ECG) in 66 actively training Indian athletes. Standard diagnostic criteria were used to define various morphological ECG abnormalities. Results 33/66 (50%) of the athletes were undertaking endurance training while the other 33 (50%) were involved in a strength-training regimen. Overall 54/66 (81%) sportsmen had significant ECG changes. 68% of these changes were considered as normal training related features, while the remaining 32% were considered abnormal. There were seven common training related ECG changes–Sinus Bradycardia (21%), Sinus Arrhythmia (16%), 1st degree Atrioventricular Heart Block (6%), Type 1 2nd-degree Atrioventicular Heart Block (3%), Incomplete Right bundle branch block (RBBB) (24%), Early Repolarization (42%), Left Ventricular Hypertrophy (LVH) (14%); while three abnormal ECG changes--T-wave inversion (13%), RBBB(4%), Right ventricular hypertrophy (RVH) with strain (29%) were noted. Early repolarization (commonest change), sinus bradycardia, and incomplete RBBB were the commoner features noticed, with a significantly higher presence in the endurance trained athletes. Conclusion A high proportion of athletes undergoing competitive level sports training are likely to have abnormal ECG recordings. Majority of these are benign, and related to the physiological adaptation to the extreme levels of exertion. These changes are commoner during endurance training (running) than strength training (weightlifting). PMID:26663958

  15. Use of Electrocardiography to Predict Future Development of Hypertension in the General Population

    PubMed Central

    Takase, Hiroyuki; Sugiura, Tomonori; Murai, Shunsuke; Yamashita, Sumiyo; Ohte, Nobuyuki; Dohi, Yasuaki

    2016-01-01

    Abstract Cardiac muscle responds to increased afterload by developing hypertrophy. During the early stages of hypertension, the heart can be transiently, but frequently, exposed to increased afterload. This study was designed to test the hypothesis that left ventricular hypertrophy (LVH) assessed by electrocardiography (ECG) can be used to predict future development of hypertension. Sokolow–Lyon voltage and Cornell product were calculated using ECG in 5770 normotensive participants who visited our hospital for a physical checkup (age 52.7 ± 11.3 years). LVH was defined as a Sokolow–Lyon voltage of >3.8 mV or a Cornell product of >2440 mm × ms. After baseline examination, participants were followed up with the endpoint being the development of hypertension. During the median follow-up period of 1089 days (15,789 person-years), hypertension developed in 1029 participants (65.2/1000 person-years). A Kaplan–Meier analysis demonstrated a significantly higher incidence of hypertension in participants with LVH than in those without LVH as assessed by Sokolow–Lyon voltage or Cornell product (P < 0.0001 for both). The hazard ratios for incident hypertension in participants with LVH defined by Sokolow–Lyon voltage and Cornell product were 1.49 (95% confidence interval [CI] 1.16–1.90, P < 0.01) and 1.34 (95% CI 1.09–1.65, P < 0.01), respectively, after adjustment for possible risk factors. Furthermore, in multivariable Cox hazard analysis, where Sokolow–Lyon voltage and Cornell product were taken as continuous variables, both indices were independent predictors of future hypertension (P < 0.0001). Both Sokolow–Lyon voltage and Cornell product are novel predictors of future development of hypertension in the general population. PMID:27124047

  16. Electrocardiography in conscious releasable Andean condors (Vultur gryphus): reference panel and unusual findings.

    PubMed

    Wiemeyer, Guillermo M; Lambertucci, Sergio A; Bianchini, Laura Torres; Belerenian, Guillermo

    2013-01-01

    Electrocardiography is a useful tool when included in healthcare protocols and is increasingly utilized for monitoring wild birds. However, the lack of reference data for many species is limiting the clinical value of this technique. In this study 26 Andean condors (Vultur gryphus) coming from rehabilitation and captive breeding programs were examined to determine electrocardiographic references prior to being released. Standard bipolar (I, II, and III) and augmented unipolar limb (aVR, aVL, and aVF) leads were recorded with birds under physical restraint. Five beats were analyzed on Lead II at 50 mm/sec and 1 cm = 1 mV to determine QRS complex morphology, cardiac rhythm, heart rate, P, PR, R, S, QRS, T, QT, and ST amplitude and/or duration. P and T wave configuration was determined for all leads, and Mean Electrical Axis (MEA) in the frontal plane was determined using leads I and III. Cardiac rhythm corresponded to regular sinus rhythm in 42% of the birds, with a relevant rate of sinus arrhythmia in 58%, and rS as the most common pattern (42%) for QRS complex in lead II. We found an influence of age and heart rate but not of sex on several ECG waves and intervals. Relevant ECG findings for studied Andean condors include a high rate of T(a), R', and U wave detection. Waves T(a) and R' were considered non-pathological, while the significance of U waves remains unclear. Our results provide a useful reference to improve clinical interpretation of full electrocardiographic examination in Andean condors. © 2013 Wiley Periodicals, Inc.

  17. Utility of 12-lead and signal-averaged Holter electrocardiograms after pilsicainide provocation for risk stratification in Brugada syndrome.

    PubMed

    Kakihara, Jun; Takagi, Masahiko; Hayashi, Yusuke; Tatsumi, Hiroaki; Doi, Atsushi; Yoshiyama, Minoru

    2017-03-31

    Non-invasive risk stratification for ventricular fibrillation (VF) in Brugada syndrome (BrS) has not been fully evaluated. The aim of this study was to assess the utility of signal-averaged Holter electrocardiogram (Holter SAECG) and 12-lead Holter electrocardiogram (Holter ECG) after a pilsicainide provocation test for non-invasive risk stratification in BrS. We enrolled 30 consecutive patients with BrS [divided into 2 groups: the VF group, those with a previous history of VF (n = 10); and the non-VF group, those without a history of VF (n = 20)] and 10 control subjects without type 1 ECG. We evaluated late potentials [LP: filtered QRS (f-QRS), RMS40, and LAS40] on the Holter SAECG for 4 h after the pilsicainide provocation and in the same patients on another day without performing the pilsicainide provocation. Furthermore, we measured QRS duration and QTc interval in leads V2 and V5, and J amplitude in lead V2 on the Holter ECG after the pilsicainide provocation. On the Holter SAECG, the f-QRS at 1 h and LAS40 at 3 h after the pilsicainide provocation were significantly larger in the VF group than in the non-VF group (f-QRS at 1 h: 113.9 ± 8.9 vs. 104.9 ± 8 ms; p = 0.01, LAS40 at 3 h: 45.4 ± 5.9 vs. 35.5 ± 7.4 ms; p < 0.001). The receiver-operating characteristic curve analysis for a single parameter of VF occurrence was determined [f-QRS at 1 h: area under the curve (AUC) 0.8, with sensitivity 80% and specificity 80%; and LAS40 at 3 h: AUC 0.87, with sensitivity 90% and specificity 75%]. On the Holter ECG, there were no significant differences in these parameters between the VF and non-VF groups. In conclusion, the LP after the pilsicainide provocation using Holter SAECG may be useful for risk stratification of VF episodes in patients with BrS.

  18. A Cardiac Early Warning System with Multi Channel SCG and ECG Monitoring for Mobile Health

    PubMed Central

    Sahoo, Prasan Kumar; Thakkar, Hiren Kumar; Lee, Ming-Yih

    2017-01-01

    Use of information and communication technology such as smart phone, smart watch, smart glass and portable health monitoring devices for healthcare services has made Mobile Health (mHealth) an emerging research area. Coronary Heart Disease (CHD) is considered as a leading cause of death world wide and an increasing number of people die prematurely due to CHD. Under such circumstances, there is a growing demand for a reliable cardiac monitoring system to catch the intermittent abnormalities and detect critical cardiac behaviors which lead to sudden death. Use of mobile devices to collect Electrocardiography (ECG), Seismocardiography (SCG) data and efficient analysis of those data can monitor a patient’s cardiac activities for early warning. This paper presents a novel cardiac data acquisition method and combined analysis of Electrocardiography (ECG) and multi channel Seismocardiography (SCG) data. An early warning system is implemented to monitor the cardiac activities of a person and accuracy assessment of the early warning system is conducted for the ECG data only. The assessment shows 88% accuracy and effectiveness of our proposed analysis, which implies the viability and applicability of the proposed early warning system. PMID:28353681

  19. A Cardiac Early Warning System with Multi Channel SCG and ECG Monitoring for Mobile Health.

    PubMed

    Sahoo, Prasan Kumar; Thakkar, Hiren Kumar; Lee, Ming-Yih

    2017-03-29

    Use of information and communication technology such as smart phone, smart watch, smart glass and portable health monitoring devices for healthcare services has made Mobile Health (mHealth) an emerging research area. Coronary Heart Disease (CHD) is considered as a leading cause of death world wide and an increasing number of people die prematurely due to CHD. Under such circumstances, there is a growing demand for a reliable cardiac monitoring system to catch the intermittent abnormalities and detect critical cardiac behaviors which lead to sudden death. Use of mobile devices to collect Electrocardiography (ECG), Seismocardiography (SCG) data and efficient analysis of those data can monitor a patient's cardiac activities for early warning. This paper presents a novel cardiac data acquisition method and combined analysis of Electrocardiography (ECG) and multi channel Seismocardiography (SCG) data. An early warning system is implemented to monitor the cardiac activities of a person and accuracy assessment of the early warning system is conducted for the ECG data only. The assessment shows 88% accuracy and effectiveness of our proposed analysis, which implies the viability and applicability of the proposed early warning system.

  20. Prevalence and prognostic significance of exercise-induced silent myocardial ischemia detected by thallium scintigraphy and electrocardiography in asymptomatic volunteers

    SciTech Connect

    Fleg, J.L.; Gerstenblith, G.; Zonderman, A.B.; Becker, L.C.; Weisfeldt, M.L.; Costa, P.T. Jr.; Lakatta, E.G. )

    1990-02-01

    Although a silent ischemic electrocardiographic response to treadmill exercise in clinically healthy populations is associated with an increased likelihood of future coronary events (i.e., angina pectoris, myocardial infarction, or cardiac death), such a response has a low predictive value for future events because of the low prevalence of disease in asymptomatic populations. To examine whether detection of reduced regional perfusion by thallium scintigraphy improved the predictive value of exercise-induced ST segment depression, we performed maximal treadmill exercise electrocardiography (ECG) and thallium scintigraphy (201Tl) in 407 asymptomatic volunteers 40-96 years of age (mean = 60) from the Baltimore Longitudinal Study on Aging. The prevalence of exercise-induced silent ischemia, defined by concordant ST segment depression and a thallium perfusion defect, increased more than sevenfold from 2% in the fifth and sixth decades to 15% in the ninth decade. Over a mean follow-up period of 4.6 years, cardiac events developed in 9.8% of subjects and consisted of 20 cases of new angina pectoris, 13 myocardial infarctions, and seven deaths. Events occurred in 7% of individuals with both negative 201Tl and ECG, 8% of those with either test positive, and 48% of those in whom both tests were positive (p less than 0.001). By proportional hazards analysis, age, hypertension, exercise duration, and a concordant positive ECG and 201Tl result were independent predictors of coronary events. Furthermore, those with positive ECG and 201Tl had a 3.6-fold relative risk for subsequent coronary events, independent of conventional risk factors.

  1. Normal Prehospital Electrocardiography is Linked to Long-term Survival in Patients Presenting to the Emergency Department with Symptoms of Acute Coronary Syndrome

    PubMed Central

    Zègre-Hemsey, Jessica K.; Sommargren, Claire E.; Asafu-Adjei, Josephine K.; Drew, Barbara J.

    2015-01-01

    Aims/Methods We studied 735 patients who activated “911” for chest pain and/or anginal equivalent symptoms and received 12-lead ECG monitoring with specialized ischemia monitoring software in the ambulance. Prehospital electrocardiograms (PH ECG) were analyzed to determine the proportion of patients who present with completely normal PH ECG findings (absence of ischemia/infarction, arrhythmia, or any other abnormality) and to compare outcomes amongst patients with and without any PH ECG abnormality. Results Of 735 patients (mean age 70.5, 52.4% male), 68 (9.3%) patients had completely normal PH ECG findings. They experienced significantly less adverse hospital outcomes (12% vs 37%), length of stay (1.19 vs 3.86 days), and long-term mortality (9% vs 28%) than those with any PH ECG abnormality (p<.05). Conclusion Normal PH ECG findings are associated with better short and long-term outcomes in ambulance patients with ischemic symptoms. These findings may enhance early triage and risk stratification in emergency cardiac care. PMID:25683824

  2. Normal prehospital electrocardiography is linked to long-term survival in patients presenting to the emergency department with symptoms of acute coronary syndrome.

    PubMed

    Zègre-Hemsey, Jessica K; Sommargren, Claire E; Asafu-Adjei, Josephine K; Drew, Barbara J

    2015-01-01

    We studied 735 patients who activated "911" for chest pain and/or anginal equivalent symptoms and received 12-lead ECG monitoring with specialized ischemia monitoring software in the ambulance. Prehospital electrocardiograms (PH ECG) were analyzed to determine the proportion of patients who present with completely normal PH ECG findings (absence of ischemia/infarction, arrhythmia, or any other abnormality) and to compare outcomes among patients with and without any PH ECG abnormality. Of 735 patients (mean age 70.5, 52.4% male), 68 (9.3%) patients had completely normal PH ECG findings. They experienced significantly less adverse hospital outcomes (12% vs 37%), length of stay (1.19 vs 3.86 days), and long-term mortality (9% vs 28%) than those with any PH ECG abnormality (p<.05). Normal PH ECG findings are associated with better short and long-term outcomes in ambulance patients with ischemic symptoms. These findings may enhance early triage and risk stratification in emergency cardiac care. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Agreement between a smart-phone pulse sensor application and ECG for determining lnRMSSD.

    PubMed

    Esco, Michael R; Flatt, Andrew A; Nakamura, Fabio Y

    2016-06-27

    The purpose of this study was to determine the agreement between a smartphone pulse finger sensor (SPFS) and electrocardiography (ECG) for determining ultra-short-term heart rate variability (HRV) in three different positions. Thirty college-aged men (n = 15) and women (n = 15) volunteered to participate in this study. Sixty second heart rate measures were simultaneously taken with the SPFS and ECG in supine, seated and standing positions. lnRMSSD was calculated from the SPFS and ECG. The lnRMSSD values were 81.5 ± 11.7 via ECG and 81.6 ± 11.3 via SPFS (p = 0.63, Cohen's d = 0.01) in the supine position, 76.5 ± 8.2 via ECG and 77.5 ± 8.2 via SPFS (p = 0.007, Cohen's d = 0.11) in the seated position, and 66.5 ± 9.2 via ECG and 67.8 ± 9.1 via SPFS (p < 0.001, Cohen's d = 0.15) in the standing positions. The SPFS showed a possibly strong correlation to the ECG in all three positions (r values from 0.98 to 0.99). In addition, the limits of agreement (CE ± 1.98 SD) were -0.13 ± 2.83 for the supine values, -0.94± 3.47 for the seated values, and -1.37 ± 3.56 for the standing values. The results of the study suggest good agreement between the SPFS and ECG for measuring lnRMSSD in supine, seated, and standing positions. Though significant differences were noted between the two methods in the seated and standing positions, the effect sizes were trivial.

  4. Continuous ECG Monitoring in Patients With Acute Coronary Syndrome or Heart Failure: EASI Versus Gold Standard.

    PubMed

    Lancia, Loreto; Toccaceli, Andrea; Petrucci, Cristina; Romano, Silvio; Penco, Maria

    2017-04-01

    The purpose of the study was to compare the EASI system with the standard 12-lead surface electrocardiogram (ECG) for the accuracy in detecting the main electrocardiographic parameters (J point, PR, QT, and QRS) commonly monitored in patients with acute coronary syndromes or heart failure. In this observational comparative study, 253 patients who were consecutively admitted to the coronary care unit with acute coronary syndrome or heart failure were evaluated. In all patients, two complete 12-lead ECGs were acquired simultaneously. A total of 6,072 electrocardiographic leads were compared (3,036 standard and 3,036 EASI). No significant differences were found between the investigate parameters of the two measurement methods, either in patients with acute coronary syndrome or in those with heart failure. This study confirmed the accuracy of the EASI system in monitoring the main ECG parameters in patients admitted to the coronary care unit with acute coronary syndrome or heart failure.

  5. Assessment of single vessel coronary artery disease: results of exercise electrocardiography, thallium-201 myocardial perfusion imaging and radionuclide angiography

    SciTech Connect

    Port, S.C.; Oshima, M.; Ray, G.; McNamee, P.; Schmidt, D.H.

    1985-07-01

    The sensitivity of the commonly used stress tests for the diagnosis of coronary artery disease was analyzed in 46 patients with significant occlusion (greater than or equal to 70% luminal diameter obstruction) of only one major coronary artery and no prior myocardial infarction. In all patients, thallium-201 perfusion imaging (both planar and seven-pinhole tomographic) and 12 lead electrocardiography were performed during the same graded treadmill exercise test and radionuclide angiography was performed during upright bicycle exercise. Exercise rate-pressure (double) product was 22,307 +/- 6,750 on the treadmill compared with 22,995 +/- 5,622 on the bicycle (p = NS). Exercise electrocardiograms were unequivocally abnormal in 24 patients (52%). Qualitative planar thallium images were abnormal in 42 patients (91%). Quantitative analysis of the tomographic thallium images were abnormal in 41 patients (89%). An exercise ejection fraction of less than 0.56 or a new wall motion abnormality was seen in 30 patients (65%). Results were similar for the right (n = 11) and left anterior descending (n = 28) coronary arteries while all tests but the planar thallium imaging showed a lower sensitivity for isolated circumflex artery disease (n = 7). The specificity of the tests was 72, 83, 89 and 72% for electrocardiography, planar thallium imaging, tomographic thallium imaging and radionuclide angiography, respectively. The results suggest that exercise thallium-201 perfusion imaging is the most sensitive noninvasive stress test for the diagnosis of single vessel coronary artery disease.

  6. New methodologies for measuring Brugada ECG patterns cannot differentiate the ECG pattern of Brugada syndrome from Brugada phenocopy.

    PubMed

    Gottschalk, Byron H; Garcia-Niebla, Javier; Anselm, Daniel D; Jaidka, Atul; De Luna, Antoni Bayés; Baranchuk, Adrian

    2016-01-01

    Brugada phenocopies (BrP) are clinical entities characterized by ECG patterns that are identical to true Brugada syndrome (BrS), but are elicited by various clinical circumstances. A recent study demonstrated that the patterns of BrP and BrS are indistinguishable under the naked eye, thereby validating the concept that the patterns are identical. The aim of our study was to determine whether recently developed ECG criteria would allow for discrimination between type-2 BrS ECG pattern and type-2 BrP ECG pattern. Ten ECGs from confirmed BrS (aborted sudden death, transformation into type 1 upon sodium channel blocking test and/or ventricular arrhythmias, positive genetics) cases and 9 ECGs from confirmed BrP were included in the study. Surface 12-lead ECGs were scanned, saved in JPEG format for blind measurement of two values: (i) β-angle; and (ii) the base of the triangle. Cut-off values of ≥58° for the β-angle and ≥4mm for the base of the triangle were used to determine the BrS ECG pattern. Mean values for the β-angle in leads V1 and V2 were 66.7±25.5 and 55.4±28.1 for BrS and 54.1±26.5 and 43.1±16.1 for BrP respectively (p=NS). Mean values for the base of the triangle in V1 and V2 were 7.5±3.9 and 5.7±3.9 for BrS and 5.6±3.2 and 4.7±2.7 for BrP respectively (p=NS). The β-angle had a sensitivity of 60%, specificity of 78% (LR+ 2.7, LR- 0.5). The base of the triangle had a sensitivity of 80%, specificity of 40% (LR+ 1.4, LR- 0.5). New ECG criteria presented relatively low sensitivity and specificity, positive and negative predictive values to discriminate between BrS and BrP ECG patterns, providing further evidence that the two patterns are identical. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Association between obesity and ECG variables in children and adolescents: A cross-sectional study

    PubMed Central

    SUN, GUO-ZHE; LI, YANG; ZHOU, XING-HU; GUO, XIAO-FAN; ZHANG, XIN-GANG; ZHENG, LI-QIANG; LI, YUAN; JIAO, YUN-DI; SUN, YING-XIAN

    2013-01-01

    Obesity exhibits a wide variety of electrocardiogram (ECG) abnormalities in adults, which often lead to cardiovascular events. However, there is currently no evidence of an association between obesity and ECG variables in children and adolescents. The present study aimed to explore the associations between obesity and ECG intervals and axes in children and adolescents. A cross-sectional observational study of 5,556 students aged 5–18 years was performed. Anthropometric data, blood pressure and standard 12-lead ECGs were collected for each participant. ECG variables were measured manually based on the temporal alignment of simultaneous 12 leads using a CV200 ECG Work Station. Overweight and obese groups demonstrated significantly longer PR intervals, wider QRS durations and leftward shifts of frontal P-wave, QRS and T-wave axes, while the obese group also demonstrated significantly higher heart rates, compared with normal weight groups within normotensive or hypertensive subjects (P<0.05). Abdominal obesity was also associated with longer PR intervals, wider QRS duration and a leftward shift of frontal ECG axes compared with normal waist circumference (WC) within normotensive or hypertensive subjects (P<0.05). Gender was a possible factor affecting the ECG variables. Furthermore, the ECG variables, including PR interval, QRS duration and frontal P-wave, QRS and T-wave axes, were significantly linearly correlated with body mass index, WC and waist-to-height ratio adjusted for age, gender, ethnicity and blood pressure. However, there was no significant association between obesity and the corrected QT interval (P>0.05). The results of the current study indicate that in children and adolescents, general and abdominal obesity is associated with longer PR intervals, wider QRS duration and a leftward shift of frontal P-wave, QRS and T-wave axes, independent of age, gender, ethnicity and blood pressure. PMID:24255675

  8. Multi-arrhythmias detection with an XML rule-based system from 12-Lead Electrocardiogram.

    PubMed

    Khelassi, Abdeldjalil; Yelles-Chaouche, Sarra-Nassira; Benais, Faiza

    2017-05-01

    The computer-aided detection of cardiac arrhythmias stills a crucial application in medical technologies. The rule based systems RBS ensure a high level of transparency and interpretability of the obtained results. To facilitate the diagnosis of the cardiologists and to reduce the uncertainty made in this diagnosis. In this research article, we have realized a classification and automatic recognition of cardiac arrhythmias, by using XML rules that represent the cardiologist knowledge. Thirteen experiments with different knowledge bases were realized for improving the performance of the used method in the detection of 13 cardiac arrhythmias. In the first 12 experiments, we have designed a specialized knowledge base for each cardiac arrhythmia, which contains just one arrhythmia detection rule. In the last experiment, we applied the knowledge base which contains rules of 12 arrhythmias. We used, for the experiments, an international data set with 279 features and 452 records characterizing 12 leads of ECG signal and social information of patients. The data sets were constructed and published at Bilkent University of Ankara, Turkey. In addition, the second version of the self-developed software "XMLRULE" was used; the software can infer more than one class and facilitate the interpretability of the obtained results. The 12 first experiments give 82.80% of correct detection as the mean of all experiments, the results were between 19% and 100% with a low rate in just one experiment. The last experiment in which all arrhythmias are considered, the results of correct detection was 38.33% with 90.55% of sensibility and 46.24% of specificity. It was clearly show that in these results the good choice of the classification model is very beneficial in terms of performance. The obtained results were better than the published results with other computational methods for the mono class detection, but it was less in multi-class detection. The RBS is the most transparent method for

  9. Comparison of standard and Lewis ECG in detection of atrioventricular dissociation in patients with wide QRS tachycardia.

    PubMed

    Aksu, Uğur; Kalkan, Kamuran; Gülcü, Oktay; Topcu, Selim; Sevimli, Serdar; Aksakal, Enbiya; Ipek, Emrah; Açıkel, Mahmut; Tanboğa, Ibrahim Halil

    2016-12-15

    The atrioventricular (AV) dissociation, which is frequently used in differential diagnosis of wide QRS complex tachycardia (WQCT), is the most specific finding of ventricular tachycardia (VT) with lower sensitivity. Herein, we aimed to show the importance of Lewis lead ECG records to detect 'visible p waves' during WQCT. A total of 21 consecutive patients who underwent electrophysiologic study (EPS) were included in the study. During EPS, by using a quadripolar diagnostic catheter directed to the right ventricular apex, a fixed stimulus was given and the ventriculoatrial (VA) Wenkebach point was found, and a VT was simulated by a RV apical stimulus at 300ms. The standard and Lewis lead ECG records were taken during this procedure. We detected 'visible p waves' in 7 (33.3%) and 14 (66.7%) patients in the standard and Lewis lead ECG groups, respectively. In terms of the 'visible p waves', there was a statistically significant difference between groups (p=0.022). The sensitivity of standard and Lewis lead ECG in determination of the visible p waves was 33.3% and 66.7%, respectively. The Lewis lead ECG can be more informative about AV dissociation than the standard 12 lead ECG. As a result, we could suggest the assessment of the Lewis lead ECG recording in addition to the standard 12 lead ECG in differential diagnosis of VT in patients with WQCT. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Predictors of Unusual ECG Characteristics in Cavotricuspid Isthmus-Dependent Atrial Flutter Ablation

    PubMed Central

    Hoffmayer, Kurt S.; Yang, Yanfei; Joseph, Stephen; McCabe, James M; Bhave, Prashant; Hsu, Jonathan; Ng, Ramford K.; Lee, Byron K; Badhwar, Nitish; Lee, Randall J; Tseng, Zian H; Olgin, Jeffrey E; Narayan, Sanjiv M.; Marcus, Gregory M; Scheinman, Melvin M.

    2012-01-01

    Background An unusual 12 lead electrocardiographic pattern may be present in patients with cavotricuspid isthmus-dependent flutter. Objective Using baseline patient characteristics and echocardiography we sought to study predictors of unusual ECG characteristics in patients with cavotricuspid isthmus-dependent atrial flutter. Methods This was a dual center, retrospective cohort study of 147 patients undergoing electrophysiology study and ablation for cavotricuspid isthmus dependent atrial flutter. Results Among this cohort, 23 patients (16%) had unusual 12-lead ECG characteristics. Using multivariate logistic regression, we found two clinical predictors for having an unusual ECG pattern. A clockwise pattern at time of EPS was the strongest predictor of an unusual ECG pattern (odds ratio [OR] 15.3 (95% confidence interval [CI] 4.0–59.4, p<0.005). In addition, patients with decreased systolic function had a 3.5 greater odds (95% CI 1.1–11.5, p=0.037) of having an unusual ECG pattern. Conclusions Our data demonstrate that among patients suffering from cavotricuspid isthmus dependent atrial flutter who are referred for ablation, 16% will have unusual ECG patterns. Patients with clockwise atrial activation and LV dysfunction have greater odds of manifesting unusual patterns by surface electrocardiogram. PMID:21605144

  11. Development of a portable Linux-based ECG measurement and monitoring system.

    PubMed

    Tan, Tan-Hsu; Chang, Ching-Su; Huang, Yung-Fa; Chen, Yung-Fu; Lee, Cheng

    2011-08-01

    This work presents a portable Linux-based electrocardiogram (ECG) signals measurement and monitoring system. The proposed system consists of an ECG front end and an embedded Linux platform (ELP). The ECG front end digitizes 12-lead ECG signals acquired from electrodes and then delivers them to the ELP via a universal serial bus (USB) interface for storage, signal processing, and graphic display. The proposed system can be installed anywhere (e.g., offices, homes, healthcare centers and ambulances) to allow people to self-monitor their health conditions at any time. The proposed system also enables remote diagnosis via Internet. Additionally, the system has a 7-in. interactive TFT-LCD touch screen that enables users to execute various functions, such as scaling a single-lead or multiple-lead ECG waveforms. The effectiveness of the proposed system was verified by using a commercial 12-lead ECG signal simulator and in vivo experiments. In addition to its portability, the proposed system is license-free as Linux, an open-source code, is utilized during software development. The cost-effectiveness of the system significantly enhances its practical application for personal healthcare.

  12. Optimisation of Embryonic and Larval ECG Measurement in Zebrafish for Quantifying the Effect of QT Prolonging Drugs

    PubMed Central

    Dhillon, Sundeep Singh; Dóró, Éva; Magyary, István; Egginton, Stuart; Sík, Attila; Müller, Ferenc

    2013-01-01

    Effective chemical compound toxicity screening is of paramount importance for safe cardiac drug development. Using mammals in preliminary screening for detection of cardiac dysfunction by electrocardiography (ECG) is costly and requires a large number of animals. Alternatively, zebrafish embryos can be used as the ECG waveform is similar to mammals, a minimal amount of chemical is necessary for drug testing, while embryos are abundant, inexpensive and represent replacement in animal research with reduced bioethical concerns. We demonstrate here the utility of pre-feeding stage zebrafish larvae in detection of cardiac dysfunction by electrocardiography. We have optimised an ECG recording system by addressing key parameters such as the form of immobilization, recording temperature, electrode positioning and developmental age. Furthermore, analysis of 3 days post fertilization (dpf) zebrafish embryos treated with known QT prolonging drugs such as terfenadine, verapamil and haloperidol led to reproducible detection of QT prolongation as previously shown for adult zebrafish. In addition, calculation of Z-factor scores revealed that the assay was sensitive and specific enough to detect large drug-induced changes in QTc intervals. Thus, the ECG recording system is a useful drug-screening tool to detect alteration to cardiac cycle components and secondary effects such as heart block and arrhythmias in zebrafish larvae before free feeding stage, and thus provides a suitable replacement for mammalian experimentation. PMID:23579446

  13. Digitalis toxicity: ECG vignette.

    PubMed

    Vyas, Aniruddha; Bachani, Neeta; Thakur, Hrishikesh; Lokhandwala, Yash

    2016-09-01

    "Digitalis toxicity, often candidly indexed as poisoning, has plagued the medical profession for over 200 years. The situation qualifies as a professional disgrace on the basis of three items: the situation persists, physicians are often slow to recognize it and, over the decades, writers have been harsh in their denunciation of fellow physicians when toxicity has occurred…." These are the opening remarks of an essay published in 1983 on the 2nd centenary of William Withering's 'magic potion from foxglove's extract for dropsy.' Even today, after many decades, these words appear relevant! We present and discuss an interesting ECG of digitalis toxicity.

  14. Advanced ECG in 2016: is there more than just a tracing?

    PubMed

    Reichlin, Tobias; Abächerli, Roger; Twerenbold, Raphael; Kühne, Michael; Schaer, Beat; Müller, Christian; Sticherling, Christian; Osswald, Stefan

    2016-01-01

    The 12-lead electrocardiogram (ECG) is the most frequently used technology in clinical cardiology. It is critical for evidence-based management of patients with most cardiovascular conditions, including patients with acute myocardial infarction, suspected chronic cardiac ischaemia, cardiac arrhythmias, heart failure and implantable cardiac devices. In contrast to many other techniques in cardiology, the ECG is simple, small, mobile, universally available and cheap, and therefore particularly attractive. Standard ECG interpretation mainly relies on direct visual assessment. The progress in biomedical computing and signal processing, and the available computational power offer fascinating new options for ECG analysis relevant to all fields of cardiology. Several digital ECG markers and advanced ECG technologies have shown promise in preliminary studies. This article reviews promising novel surface ECG technologies in three different fields. (1) For the detection of myocardial ischaemia and infarction, QRS morphology feature analysis, the analysis of high frequency QRS components (HF-QRS) and methods using vectorcardiography as well as ECG imaging are discussed. (2) For the identification and management of patients with cardiac arrhythmias, methods of advanced P-wave analysis are discussed and the concept of ECG imaging for noninvasive localisation of cardiac arrhythmias is presented. (3) For risk stratification of sudden cardiac death and the selection of patients for medical device therapy, several novel markers including an automated QRS-score for scar quantification, the QRS-T angle or the T-wave peak-to-end-interval are discussed. Despite the existing preliminary data, none of the advanced ECG markers and technologies has yet accomplished the transition into clinical practice. Further refinement of these technologies and broader validation in large unselected patient cohorts are the critical next step needed to facilitate translation of advanced ECG technologies

  15. A Pilot Study Assessing ECG versus ECHO Ventriculoventricular Optimization in Pediatric Resynchronization Patients.

    PubMed

    Punn, Rajesh; Hanisch, Debra; Motonaga, Kara S; Rosenthal, David N; Ceresnak, Scott R; Dubin, Anne M

    2016-02-01

    Cardiac resynchronization therapy indications and management are well described in adults. Echocardiography (ECHO) has been used to optimize mechanical synchrony in these patients; however, there are issues with reproducibility and time intensity. Pediatric patients add challenges, with diverse substrates and limited capacity for cooperation. Electrocardiographic (ECG) methods to assess electrical synchrony are expeditious but have not been extensively studied in children. We sought to compare ECHO and ECG CRT optimization in children. Prospective, pediatric, single-center cross-over trial comparing ECHO and ECG optimization with CRT. Patients were assigned to undergo either ECHO or ECG optimization, followed for 6 months, and crossed-over to the other assignment for another 6 months. ECHO pulsed-wave tissue Doppler and 12-lead ECG were obtained for 5 VV delays. ECG optimization was defined as the shortest QRSD and ECHO optimization as the lowest dyssynchrony index. ECHOs/ECGs were interpreted by readers blinded to optimization technique. After each 6 month period, these data were collected: ejection fraction, velocimetry-derived cardiac index, quality of life, ECHO-derived stroke distance, M-mode dyssynchrony, study cost, and time. Outcomes for each optimization method were compared. From June 2012 to December 2013, 19 patients enrolled. Mean age was 9.1 ± 4.3 years; 14 (74%) had structural heart disease. The mean time for optimization was shorter using ECG than ECHO (9 ± 1 min vs. 68 ± 13 min, P < 0.01). Mean cost for charges was $4,400 ± 700 less for ECG. No other outcome differed between groups. ECHO optimization of synchrony was not superior to ECG optimization in this pilot study. ECG optimization required less time and cost than ECHO optimization. © 2015 Wiley Periodicals, Inc.

  16. Noninvasive Fetal ECG analysis

    PubMed Central

    Clifford, Gari D.; Silva, Ikaro; Behar, Joachim; Moody, George B.

    2014-01-01

    Despite the important advances achieved in the field of adult electrocardiography signal processing, the analysis of the non-invasive fetal electrocardiogram (NI-FECG) remains a challenge. Currently no gold standard database exists which provides labelled FECG QRS complexes (and other morphological parameters), and publications rely either on proprietary databases or a very limited set of data recorded from few (or more often, just one) individuals. The PhysioNet/Computing in Cardiology Challenge 2013 enables to tackle some of these limitations by releasing a set of NI-FECG data publicly to the scientific community in order to evaluate signal processing techniques for NI-FECG extraction. The Challenge aim was to encourage development of accurate algorithms for locating QRS complexes and estimating the QT interval in noninvasive FECG signals. Using carefully reviewed reference QRS annotations and QT intervals as a gold standard, based on simultaneous direct FECG when possible, the Challenge was designed to measure and compare the performance of participants’ algorithms objectively. Multiple challenge events were designed to test basic FHR estimation accuracy, as well as accuracy in measurement of inter-beat (RR) and QT intervals needed as a basis for derivation of other FECG features. This editorial reviews the background issues, the design of the Challenge, the key achievements, and the follow-up research generated as a result of the Challenge, published in the concurrent special issue of Physiological Measurement. PMID:25071093

  17. Improving door-to-balloon time by decreasing door-to-ECG time for walk-in STEMI patients.

    PubMed

    Coyne, Christopher J; Testa, Nicholas; Desai, Shoma; Lagrone, Joy; Chang, Roger; Zheng, Ling; Kim, Hyung

    2015-01-01

    The American Heart Association/American College of Cardiology guidelines recommend rapid door-to-electrocardiography (ECG) times for patients with ST-segment elevation myocardial infarction (STEMI). Previous quality improvement research at our institution revealed that we were not meeting this benchmark for walk-in STEMI patients. The objective is to investigate whether simple, directed changes in the emergency department (ED) triage process for potential cardiac patients could decrease door-to-ECG times and secondarily door-to-balloon times. We conducted an interventional study at a large, urban, public teaching hospital from April 2010 to June 2012. All patients who walked into the ED with a confirmed STEMI were enrolled in the study. The primary intervention involved creating a chief complaint-based "cardiac triage" designation that streamlined the evaluation of potential cardiac patients. A secondary intervention involved moving our ECG technician and ECG station to our initial triage area. The primary outcome measure was door-to-ECG time and the secondary outcome measure was door-to-balloon time. We enrolled 91 walk-in STEMI patients prior to the intervention period and 141 patients after the invention. We observed statistically significant reductions in door-to-ECG time (43±93 to 30±72 minutes, median 23 to 14 minutes p<0.01), ECG-to-activation time (87±134 to 52±82 minutes, median 43 to 31 minutes p<0.01), and door-to-balloon time (134±146 to 84±40 minutes, median 85 -75 minutes p=0.03). By creating a chief complaint-based cardiac triage protocol and by streamlining ECG completion, walk-in STEMI patients are systematically processed through the ED. This is not only associated with a decrease in door-to-balloon time, but also a decrease in the variability of the time sensitive intervals of door-to-ECG and ECG-to-balloon time.

  18. Is the 12-lead electrocardiogram during antidromic circus movement tachycardia helpful in predicting the ablation site in atriofascicular pathways?

    PubMed

    Sternick, Eduardo Back; Lokhandwala, Yash; Bohora, Shomu; Timmermans, Carl; Martins, Priscila Reis; Dias, Liana Valadão; Correia, Frederico Soares; Wellens, Hein J J

    2014-11-01

    Unlike in the Wolff-Parkinson-White syndrome, there has been no systematic study on the role of the pre-excitation pattern in predicting the ablation site in patients with atriofascicular (AF) pathways. We assessed in a large cohort the value of the 12-lead electrocardiogram (ECG) during antidromic tachycardia (ADT) to predict the site of ablation. Forty-five patients were studied, 23 males (51%), mean age of 27 ± 12 years with 46 AF pathways and 48 ADT using the AF pathway for A-V conduction. Inclusion required induction of a sustained ADT and successful ablation. Ablation site was assessed during LAO 45° projection and clockwise classified as hours in posteroseptal, posterolateral, lateral, anterolateral, and anteroseptal tricuspid annulus as follows: 05:00-07:00, >07:00-08:00, >08:00-09:00, >09:00-11:00, and >11:00-13:00 o'clock. The QRS axis was assessed during ADT and classified as normal (>+15°), horizontal (+15° to -30°), and superior (<-30°). During ADT axis was superior (-57° ± 10°) in 15 (31%), horizontal (-11° ± 14°) in 22 (46%), and normal (+45° ± 16°) in 11 (23%) patients. The correct ablation site did not differ between the different groups of QRS axis. QRS width during ADT was narrower in patients with a normal when compared with a horizontal and leftward axis (127 ± 14 vs. 145 ± 12 ms, P < 0.0001), and the V-H interval was shorter (4 ± 3 ms vs. 19 ± 22 ms, P = 0.03). There was no correlation between the AF pathway ablation site and the QRS axis during ADT. The 12-lead ECG during maximal pre-excitation does not predict the proper site of tricuspid annulus ablation in patients with A-V conduction over an AF pathway. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  19. Screening ECGs for young competitive athletes: it is complicated.

    PubMed

    Dubin, Anne M

    2015-10-01

    The role of the ECG in preparticipation sports screening for adolescent athletes is a major area of controversy today. Sudden cardiac death, especially in a young seemingly healthy individual, is a tragic and highly publicized event, which is often surrounded by cries from the public and medical community to 'do something.' This emotional need to address these catastrophic events has led to over 4000 articles addressing the optimal way to screen the young athlete, as well as conflicting recommendations from the American Heart Association and the European Society of Cardiology, specifically in regards to inclusion of a screening ECG. This article will review the advances in the field over the last year, including the new guidelines on screening of the young athlete from the American Heart Association. This last year has seen several important additions to the controversy surrounding the use of the 12-lead ECG in the screening of the young athlete. Although improved ECG criteria have decreased the prevalence of false positives, the actual utility of this practice has not been tested in real clinical practice outside of a formal investigation.

  20. The development of wireless sensor network for ECG monitoring.

    PubMed

    Lin, Jun-Liang; Liu, Hsien-Chieh; Tai, Yu-Ting; Wu, Hsin-Hsien; Hsu, Shuo-Jen; Jaw, Fu-Shan; Chen, You-Yin

    2006-01-01

    The main problem we want to solve contains two subjects: The first one is the patient's pressure due to wired physiological signal estimation. With wireless sensor network technique, patients only need to carry a few small nodes, and then the physiological signal can be transmitted in the air. The other subject of the vital problem is that some protocols, like Bluetooth, provide a peer to peer wireless communication technique, but such peer to peer network may need a complex algorithm to find the best data transmission path. In this study, we use the hierarchy routing as network topology that three-layer architecture contains PAN coordinator, router and device. The study focuses on implementation of a prototype electrocardiography (ECG) system which replaces wired connections between sensor points and a central node with wireless links. Successful implementation of the final system would be of benefit to all involved in the use of ECG as access to and movement of the patient would not be impeded by the physical constraints imposed by the cables. Most aspects of the design would also be portable to other sensor applications, making the work relevant to a vast range of systems where movement of sensors is desirable and constrained by hard-wired links.

  1. Brugada ECG patterns in athletes.

    PubMed

    Chung, Eugene H

    2015-01-01

    Brugada syndrome is responsible for up to 4% of all sudden cardiac deaths worldwide and up to 20% of sudden cardiac deaths in patients with structurally normal hearts. Heterogeneity of repolarization and depolarization, particularly over the right ventricle and the outflow tract, is responsible for the arrhythmogenic substrate. The coved Type I ECG pattern is considered diagnostic of the syndrome but its prevalence is very low. Distinguishing between a saddle back Type 2 Brugada pattern and one of many "Brugada-like" patterns presents challenges especially in athletes. A number of criteria have been proposed to assess Brugada ECG patterns. Proper precordial ECG lead placement is paramount. This paper reviews Brugada syndrome, Brugada ECG patterns, and recently proposed criteria. Recommendations for evaluating a Brugada ECG pattern are provided.

  2. [Use of ECG-EC in the positioning of central venous catheters].

    PubMed

    Calabria, Maria; Zamboli, Pasquale; D'Amelio, Alessandro; Granata, Antonio; Di Lullo, Luca; Floccari, Fulvio; Logias, Franco; Fiorini, Fulvio

    2012-01-01

    Central venous catheters (CVC) are widely used in clinical practice for the administration of chemotherapy, parental nutrition, hemodynamic monitoring, and hemodialysis. International guidelines have defined the right internal jugular vein as the preferred site of CVC insertion and underline that accurate positioning of the catheter tip is essential to maximize the blood flow and reduce long-term complications. Endocavitary electrocardiography (EC-ECG) improves the accuracy of catheter tip positioning without increasing the placement time by the recognition of typical P wave patterns during catheter insertion:the normally shaped P wave identifies the mid to upper superior vena cava, the widest P wave may be used to place the CVC tip at the superior vena cava-right atrium junction, and biphasic P waves identify the location of the right atrium. Because of its simplicity and safety, EC-ECG should always be considered during CVC placement, especially if other means of verifying correct CVC insertion are not available.

  3. NOTE: Solving the ECG forward problem by means of a meshless finite element method

    NASA Astrophysics Data System (ADS)

    Li, Z. S.; Zhu, S. A.; He, Bin

    2007-07-01

    The conventional numerical computational techniques such as the finite element method (FEM) and the boundary element method (BEM) require laborious and time-consuming model meshing. The new meshless FEM only uses the boundary description and the node distribution and no meshing of the model is required. This paper presents the fundamentals and implementation of meshless FEM and the meshless FEM method is adapted to solve the electrocardiography (ECG) forward problem. The method is evaluated on a single-layer torso model, in which the analytical solution exists, and tested in a realistic geometry homogeneous torso model, with satisfactory results being obtained. The present results suggest that the meshless FEM may provide an alternative for ECG forward solutions.

  4. Solving the ECG forward problem by means of a meshless finite element method.

    PubMed

    Li, Z S; Zhu, S A; He, Bin

    2007-07-07

    The conventional numerical computational techniques such as the finite element method (FEM) and the boundary element method (BEM) require laborious and time-consuming model meshing. The new meshless FEM only uses the boundary description and the node distribution and no meshing of the model is required. This paper presents the fundamentals and implementation of meshless FEM and the meshless FEM method is adapted to solve the electrocardiography (ECG) forward problem. The method is evaluated on a single-layer torso model, in which the analytical solution exists, and tested in a realistic geometry homogeneous torso model, with satisfactory results being obtained. The present results suggest that the meshless FEM may provide an alternative for ECG forward solutions.

  5. [Monitor of ECG signal and heart rate using a mobile phone with Bluetooth communication protocol].

    PubMed

    Becerra-Luna, Brayans; Dávila-García, Rodrigo; Salgado-Rodríguez, Paola; Martínez-Memije, Raúl; Infante-Vázquez, Oscar

    2012-01-01

    To develop a portable signal monitoring equipment for electrocardiography (ECG) and heart rate (HR), communicated with a mobile phone using the Bluetooth (BT) communication protocol for display of the signal on screen. A monitoring system was designed in which the electronic section performs the ECG signal acquisition, as well as amplification, filtering, analog to digital conversion and transmission of the ECG and HR using BT. Two programs were developed for the system. The first one calculates HR through QRS identification and sends the ECG signals and HR to the mobile, and the second program is an application to acquire and display them on the mobile screen. We developed a portable electronic system powered by a 9 volt battery, with amplification and bandwidth meeting the international standards for ECG monitoring. The QRS complex identification was performed using the second derivative algorithm, while the programs allow sending and receiving information from the ECG and HR via BT, and viewing it on the mobile screen. The monitoring is feasible within distances of 15 m and it has been tested in various mobiles telephones of brands Nokia®, Sony Ericsson® and Samsung®. This system shows an alternative for mobile monitoring using BT and Java 2 Micro Edition (J2ME) programming. It allows the register of the ECG trace and HR, and it can be implemented in different phones. Copyright © 2011 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  6. The intracavitary ECG method for positioning the tip of central venous access devices in pediatric patients: results of an Italian multicenter study.

    PubMed

    Rossetti, Francesca; Pittiruti, Mauro; Lamperti, Massimo; Graziano, Ugo; Celentano, Davide; Capozzoli, Giuseppe

    2015-01-01

    The Italian Group for Venous Access Devices (GAVeCeLT) has carried out a multicenter study investigating the safety and accuracy of intracavitary electrocardiography (IC-ECG) in pediatric patients. We enrolled 309 patients (age 1 month-18 years) candidate to different central venous access devices (VAD) - 56 peripherally inserted central catheters (PICC), 178 short term centrally inserted central catheters (CICC), 65 long term VADs, 10 VADs for dialysis - in five Italian Hospitals. Three age groups were considered: A (<4 years, n = 157), B (4-11 years, n = 119), and C (12-18 years, n = 31). IC-ECG was applicable in 307 cases. The increase of the P wave on IC-ECG was detected in all cases but two. The tip of the catheter was positioned at the cavo-atrial junction (CAJ) (i.e., at the maximal height of the P wave on IC-ECG) and the position was checked during the procedure by fluoroscopy or chest x-ray, considering the CAJ at 1-2 cm (group A), 1.5-3 cm (group B), or 2-4 cm (group C) below the carina. There were no complications related to IC-ECG. The overall match between IC-ECG and x-ray was 95.8% (96.2% in group A, 95% in group B, and 96.8% in group C). In 95 cases, the IC-ECG was performed with a dedicated ECG monitor, specifically designed for IC-ECG (Nautilus, Romedex): in this group, the match between IC-ECG and x-ray was 98.8%. We conclude that the IC-ECG method is safe and accurate in the pediatric patients. The applicability of the method is 99.4% and its feasibility is 99.4%. The accuracy is 95.8% and even higher (98.8%) when using a dedicated ECG monitor.

  7. Detection of peripartum myocardial burden by vector-projected 187 channel electrocardiography and serum NT-proBNP.

    PubMed

    Terata, Miyuki; Nakai, Kenji; Fukushima, Akimune; Itoh, Manabu; Kikuchi, Akihiko; Sugiyama, Toru

    2013-01-01

    There 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.

  8. Relationship between echocardiographic LV mass and ECG based left ventricular voltages in an adolescent population: related or random?

    PubMed

    Czosek, Richard J; Cnota, James F; Knilans, Timothy K; Pratt, Jesse; Guerrier, Karine; Anderson, Jeffrey B

    2014-09-01

    In attempts to detect diseases that may place adolescents at risk for sudden death, some have advocated for population-based screening. Controversy exists over electrocardiography (ECG) screening due to the lack of specificity, cost, and detrimental effects of false positive or extraneous outcomes. Analyze the relationship between precordial lead voltage on ECG and left ventricle (LV) mass by echocardiogram in adolescent athletes. Retrospective cohort analysis of a prospectively obtained population of self-identified adolescent athletes during sports screening with ECG and echocardiogram. Correlation between ECG LV voltages (R wave in V6 [RV6] and S wave in lead V1 [SV1]) was compared to echocardiogram-based measurements of left ventricular mass. Potential effects on ECG voltages by body anthropometrics, including weight, body mass index (BMI), and body surface area were analyzed, and ECG voltages indexed to BMI were compared to LV mass indices to analyze for improved correlation. A total of 659 adolescents enrolled in this study (64% male). The mean age was 15.4 years (14-18). The correlations between LV mass and RV6, SV1, and RV6 + SV1 were all less than 0.20. The false positive rate for abnormal voltages was relatively high (5.5%) but improved if abnormal voltages in both RV6 and SV1 were mandated simultaneously (0%). Indexing ECG voltages to BMI significantly improved correlation to LV mass, though false positive findings were increased (12.9%). There is poor correlation between ECG precordial voltages and echocardiographic LV mass. This relationship is modified by BMI. This finding may contribute to the poor ECG screening characteristics. ©2014 Wiley Periodicals, Inc.

  9. Novel technical solutions for wireless ECG transmission & analysis in the age of the internet cloud.

    PubMed

    Al-Zaiti, Salah S; Shusterman, Vladimir; Carey, Mary G

    2013-01-01

    Current guidelines recommend early reperfusion therapy for ST-elevation myocardial infarction (STEMI) within 90 min of first medical encounter. Telecardiology entails the use of advanced communication technologies to transmit the prehospital 12-lead electrocardiogram (ECG) to offsite cardiologists for early triage to the cath lab; which has been shown to dramatically reduce door-to-balloon time and total mortality. However, hospitals often find adopting ECG transmission technologies very challenging. The current review identifies seven major technical challenges of prehospital ECG transmission, including: paramedics inconvenience and transport delay; signal noise and interpretation errors; equipment malfunction and transmission failure; reliability of mobile phone networks; lack of compliance with the standards of digital ECG formats; poor integration with electronic medical records; and costly hardware and software pre-requisite installation. Current and potential solutions to address each of these technical challenges are discussed in details and include: automated ECG transmission protocols; annotatable waveform-based ECGs; optimal routing solutions; and the use of cloud computing systems rather than vendor-specific processing stations. Nevertheless, strategies to monitor transmission effectiveness and patient outcomes are essential to sustain initial gains of implementing ECG transmission technologies. © 2013.

  10. Asymptomatic rhythm and conduction abnormalities in children with acute rheumatic fever: 24-hour electrocardiography study.

    PubMed

    Karacan, Mehmet; Işıkay, Sedat; Olgun, Haşim; Ceviz, Naci

    2010-12-01

    Some rhythm and conduction abnormalities can occur in children with acute rheumatic fever. These abnormalities have been defined based on standard electrocardiography; however, the real prevalence of these abnormalities has not been investigated previously by the evaluation of long-term electrocardiographic recordings. In this study, we evaluated the asymptomatic rhythm and conduction abnormalities in children with acute rheumatic fever by evaluating the 24-hour electrocardiography. We evaluated the standard electrocardiography and the 24-hour electrocardiography of 64 children with acute rheumatic fever. On standard electrocardiography, the frequency of the first-degree atrioventricular block was found to be 21.9%. Electrocardiography at 24 hours detected three additional and separate patients with a long PR interval. Mobitz type I block and atypical Wenckebach periodicity were determined in one patient (1.56%) on 24-hour electrocardiography. While accelerated junctional rhythm was detected in three patients on standard electrocardiography, it was present in nine patients according to 24-hour electrocardiography. Premature contractions were present in 1.7% of standard electrocardiography, but in 29.7% of 24-hour electrocardiography. Absence of carditis was found to be related to the presence of accelerated junctional rhythm (p > 0.05), and the presence of carditis was found to be related to the presence of premature contractions (p = 0.000). In conclusion, our results suggest that in children with acute rheumatic fever, the prevalence of rhythm and conduction abnormalities may be much higher than determined on standard electrocardiography. Further studies are needed to clarify whether or not these abnormalities are specific to acute rheumatic fever.

  11. ECG-derived Cheyne-Stokes respiration and periodic breathing in healthy and hospitalized populations.

    PubMed

    Tinoco, Adelita; Drew, Barbara J; Hu, Xiao; Mortara, David; Cooper, Bruce A; Pelter, Michele M

    2017-06-15

    Cheyne-Stokes respiration (CSR) has been investigated primarily in outpatients with heart failure. In this study we compare CSR and periodic breathing (PB) between healthy and cardiac groups. We compared CSR and PB, measured during 24 hr of continuous 12-lead electrocardiographic (ECG) Holter recording, in a group of 90 hospitalized patients presenting to the emergency department with symptoms suggestive of acute coronary syndrome (ACS) to a group of 100 healthy ambulatory participants. We also examined CSR and PB in the 90 patients presenting with ACS symptoms, divided into a group of 39 (43%) with confirmed ACS, and 51 (57%) with a cardiac diagnosis but non-ACS. SuperECG software was used to derive respiration and then calculate CSR and PB episodes from the ECG Holter data. Regression analyses were used to analyze the data. We hypothesized SuperECG software would differentiate between the groups by detecting less CSR and PB in the healthy group than the group of patients presenting to the emergency department with ACS symptoms. Hospitalized patients with suspected ACS had 7.3 times more CSR episodes and 1.6 times more PB episodes than healthy ambulatory participants. Patients with confirmed ACS had 6.0 times more CSR episodes and 1.3 times more PB episodes than cardiac non-ACS patients. Continuous 12-lead ECG derived CSR and PB appear to differentiate between healthy participants and hospitalized patients. © 2017 Wiley Periodicals, Inc.

  12. A medical-grade wireless architecture for remote electrocardiography.

    PubMed

    Kang, Kyungtae; Park, Kyung-Joon; Song, Jae-Jin; Yoon, Chang-Hwan; Sha, Lui

    2011-03-01

    In telecardiology, electrocardiogram (ECG) signals from a patient are acquired by sensors and transmitted in real time to medical personnel across a wireless network. The use of IEEE 802.11 wireless LANs (WLANs), which are already deployed in many hospitals, can provide ubiquitous connectivity and thus allow cardiology patients greater mobility. However, engineering issues, including the error-prone nature of wireless channels and the unpredictable delay and jitter due to the nondeterministic nature of access to the wireless medium, need to be addressed before telecardiology can be safely realized. We propose a medical-grade WLAN architecture for remote ECG monitoring, which employs the point-coordination function (PCF) for medium access control and Reed-Solomon coding for error control. Realistic simulations with uncompressed two-lead ECG data from the MIT-BIH arrhythmia database demonstrate reliable wireless ECG monitoring; the reliability of ECG transmission exceeds 99.99% with the initial buffering delay of only 2.4 s.

  13. Wireless Sensor-Based Smart-Clothing Platform for ECG Monitoring

    PubMed Central

    Lin, Chung-Chih; Yu, Yan-Shuo

    2015-01-01

    The goal of this study is to use wireless sensor technologies to develop a smart clothes service platform for health monitoring. Our platform consists of smart clothes, a sensor node, a gateway server, and a health cloud. The smart clothes have fabric electrodes to detect electrocardiography (ECG) signals. The sensor node improves the accuracy of QRS complexes detection by morphology analysis and reduces power consumption by the power-saving transmission functionality. The gateway server provides a reconfigurable finite state machine (RFSM) software architecture for abnormal ECG detection to support online updating. Most normal ECG can be filtered out, and the abnormal ECG is further analyzed in the health cloud. Three experiments are conducted to evaluate the platform's performance. The results demonstrate that the signal-to-noise ratio (SNR) of the smart clothes exceeds 37 dB, which is within the “very good signal” interval. The average of the QRS sensitivity and positive prediction is above 99.5%. Power-saving transmission is reduced by nearly 1980 times the power consumption in the best-case analysis. PMID:26640512

  14. Stability of computer ECG amplitude measurements in the presence of noise. The CSE Working Party.

    PubMed

    Zywietz, C; Willems, J L; Arnaud, P; van Bemmel, J H; Degani, R; Macfarlane, P W

    1990-02-01

    An important feature of an ECG analysis program is its ability to provide reliable measurements under various operating conditions, e.g., on noise-free and noisy ECGs. Therefore, within the European cooperative project "Common Standards For Quantitative Electrocardiography" (CSE), the accuracy and stability of ECG measurements obtained by several computer programs has been compared. To investigate the stability of measurements two sets of 10 ECGs with and without seven different high- and low-frequency types of noise--altogether 160 electrocardiograms and 160 vectorcardiograms--have been analyzed by eight electrocardiographic and five vectorcardiographic computer programs. The stability of measurement was tested with respect to results obtained for the noise-free recordings. In a previous paper, the influence of noise on wave boundary recognition has been reported. In the present paper, the effect of noise on amplitude measurements and on problems of waveform definitions within the QRS complex are described. The results indicate that programs analyzing an averaged beat exhibit less variability than programs which measure every complex or a selected beat. Comparability and stability of measurements could be improved if a standardized procedure for amplitude references were to be introduced. In addition, the stability of QRS waveform labelling could be improved if waveforms' minimum amplitude and duration were to be validated against the noise level which itself should be determined by a standardized procedure.

  15. A modular low-complexity ECG delineation algorithm for real-time embedded systems.

    PubMed

    Bote, Jose Manuel; Recas, Joaquin; Rincon, Francisco; Atienza, David; Hermida, Roman

    2017-02-17

    This work presents a new modular and lowcomplexity algorithm for the delineation of the different ECG waves (QRS, P and T peaks, onsets and end). Involving a reduced number of operations per second and having a small memory footprint, this algorithm is intended to perform realtime delineation on resource-constrained embedded systems. The modular design allows the algorithm to automatically adjust the delineation quality in run time to a wide range of modes and sampling rates, from a Ultra-low power mode when no arrhythmia is detected, in which the ECG is sampled at low frequency, to a complete High-accuracy delineation mode in which the ECG is sampled at high frequency and all the ECG fiducial points are detected, in case of arrhythmia. The delineation algorithm has been adjusted using the QT database, providing very high sensitivity and positive predictivity, and validated with the MIT database. The errors in the delineation of all the fiducial points are below the tolerances given by the Common Standards for Electrocardiography (CSE) committee in the High-accuracy mode, except for the P wave onset, for which the algorithm is above the agreed tolerances by only a fraction of the sample duration. The computational load for the ultra-low-power 8-MHz TI MSP430 series microcontroller ranges from 0.2 to 8.5% according to the mode used.

  16. Wireless Sensor-Based Smart-Clothing Platform for ECG Monitoring.

    PubMed

    Wang, Jie; Lin, Chung-Chih; Yu, Yan-Shuo; Yu, Tsang-Chu

    2015-01-01

    The goal of this study is to use wireless sensor technologies to develop a smart clothes service platform for health monitoring. Our platform consists of smart clothes, a sensor node, a gateway server, and a health cloud. The smart clothes have fabric electrodes to detect electrocardiography (ECG) signals. The sensor node improves the accuracy of QRS complexes detection by morphology analysis and reduces power consumption by the power-saving transmission functionality. The gateway server provides a reconfigurable finite state machine (RFSM) software architecture for abnormal ECG detection to support online updating. Most normal ECG can be filtered out, and the abnormal ECG is further analyzed in the health cloud. Three experiments are conducted to evaluate the platform's performance. The results demonstrate that the signal-to-noise ratio (SNR) of the smart clothes exceeds 37 dB, which is within the "very good signal" interval. The average of the QRS sensitivity and positive prediction is above 99.5%. Power-saving transmission is reduced by nearly 1980 times the power consumption in the best-case analysis.

  17. The limited utility of electrocardiography variables used to predict arrhythmia in psychotropic drug overdose

    PubMed Central

    Buckley, Nicholas A; Chevalier, Stephan; Leditschke, I Anne; O'Connell, Dianne L; Leitch, James; Pond, Susan M

    2003-01-01

    Objective The aim of the present study was to examine the relationship between serious arrhythmias in patients with psychotropic drug overdose and electrocardiography (ECG) findings that have been suggested previously to predict this complication. Methods Thirty-nine patients with serious arrhythmias (ventricular tachycardia, supraventricular tachycardia or cardiac arrest) after tricyclic antidepressant overdose or thioridazine overdose were compared with 117 controls with clinically significant overdose matched to each case for the drug ingested. These patients with psychotropic drug overdose had presented for treatment to the Department of Clinical Toxicology, Newcastle and to the Princess Alexandra Hospital, Brisbane. The heart rate, the QRS width, the QTc and QT intervals, the QT dispersion, and the R wave and R/S ratios in aVR on the initial ECGs were compared in cases and controls. Results The cases had taken dothiepin (16 patients), doxepin (six patients), thioridazine (five patients), amitriptyline (five patients), nortriptyline (three patients), imipramine (one patient) and a combination of dothiepin and thioridazine (three patients). In 20 of the 39 patients with arrhythmias, the arrhythmia had been a presumed ventricular tachycardia. Of the other 19 patients, 15 patients had a supraventricular tachycardia, two patients had cardiac arrests (one asystole, one without ECG monitoring) and two patients had insufficient data recorded to make classification of the arrhythmias possible. The QRS was ≥ 100 ms in 82% of cases but also in 76% of controls. QRS ≥ 160 ms had a sensitivity of only 13% and occurred in 2% of controls. QRS > 120 ms, QTc > 500 and the R/S ratio in aVR appeared to have a stronger association with the occurrence of arrhythmia: QRS > 120 ms (odds ratio [OR], 3.56; 95% confidence interval [CI], 1.46–8.68), QTc > 500 (OR, 3.07; 95% CI, 1.33–7.07), and R/S ratio in aVR > 0.7 (OR, 16; 95% CI, 3.47–74). Excluding thioridazine overdoses

  18. Electrocardiography series. Narrow QRS-complex tachycardia: part 2.

    PubMed

    Singh, Devinder; Teo, Swee-Guan; Omar, Abdul Razakjr Bin; Poh, Kian Keong

    2014-09-01

    We discuss two cases of incessant atrial tachycardia (AT), including the presentation and clinical course. It is important to differentiate AT from other causes of supraventricular tachycardia, such as atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT), as it would have implications on clinical management. Electrocardiographic features of AT, especially the presence of an AV Wenckebach phenomenon with 'grouped beating', are critical for differentiating AT from AVRT and AVNRT. It is also vital to identify the P waves and their relations to QRS on electrocardiography, as this would aid in the differentiation of various supraventricular tachycardias.

  19. Piezoelectric extraction of ECG signal

    NASA Astrophysics Data System (ADS)

    Ahmad, Mahmoud Al

    2016-11-01

    The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other.

  20. Piezoelectric extraction of ECG signal.

    PubMed

    Ahmad, Mahmoud Al

    2016-11-17

    The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other.

  1. Coronary heart disease index based on longitudinal electrocardiography

    NASA Technical Reports Server (NTRS)

    Townsend, J. C.; Cronin, J. P.

    1977-01-01

    A coronary heart disease index was developed from longitudinal ECG (LCG) tracings to serve as a cardiac health measure in studies of working and, essentially, asymptomatic populations, such as pilots and executives. For a given subject, the index consisted of a composite score based on the presence of LCG aberrations and weighted values previously assigned to them. The index was validated by correlating it with the known presence or absence of CHD as determined by a complete physical examination, including treadmill, resting ECG, and risk factor information. The validating sample consisted of 111 subjects drawn by a stratified-random procedure from 5000 available case histories. The CHD index was found to be significantly more valid as a sole indicator of CHD than the LCG without the use of the index. The index consistently produced higher validity coefficients in identifying CHD than did treadmill testing, resting ECG, or risk factor analysis.

  2. Coronary heart disease index based on longitudinal electrocardiography

    NASA Technical Reports Server (NTRS)

    Townsend, J. C.; Cronin, J. P.

    1977-01-01

    A coronary heart disease index was developed from longitudinal ECG (LCG) tracings to serve as a cardiac health measure in studies of working and, essentially, asymptomatic populations, such as pilots and executives. For a given subject, the index consisted of a composite score based on the presence of LCG aberrations and weighted values previously assigned to them. The index was validated by correlating it with the known presence or absence of CHD as determined by a complete physical examination, including treadmill, resting ECG, and risk factor information. The validating sample consisted of 111 subjects drawn by a stratified-random procedure from 5000 available case histories. The CHD index was found to be significantly more valid as a sole indicator of CHD than the LCG without the use of the index. The index consistently produced higher validity coefficients in identifying CHD than did treadmill testing, resting ECG, or risk factor analysis.

  3. Biomedical engineering tasks. [electrode development for electrocardiography and electroencephalography

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Electrocardiographic and vectorcardiographic bioinstrumentation work centered on the development of a new electrode system harness for Project Skylab. Evaluation of several silver electrode configurations proved superior impedance voltage performance for silver/silver chloride electrodes mounted flush by using a paste adhesive. A portable ECG processor has been designed and a breadboard unit has been built to sample ECG input data at a rate of 500 samples per second for arrhythmia detection. A small real time display driver program has been developed for statistical analysis on selected QPS features. Engineering work on a sleep monitoring cap assembly continued.

  4. Deployment of an Advanced Electrocardiographic Analysis (A-ECG) to Detect Cardiovascular Risk in Career Firefighters

    NASA Technical Reports Server (NTRS)

    Dolezal, B. A.; Storer, T. W.; Abrazado, M.; Watne, R.; Schlegel, T. T.; Batalin, M.; Kaiser, W.; Smith, D. L.; Cooper, C. B.

    2011-01-01

    INTRODUCTION: Sudden cardiac death is the leading cause of line of duty death among firefighters, accounting for approximately 45% of fatalities annually. Firefighters perform strenuous muscular work while wearing heavy, encapsulating personal protective equipment in high ambient temperatures, under chaotic and emotionally stressful conditions. These factors can precipitate sudden cardiac events like myocardial infarction, serious dysrhythmias, or cerebrovascular accidents in firefighters with underlying cardiovascular disease. PURPOSE: The purpose of this study was to deploy and then evaluate the contribution of resting advanced ECG (A-ECG) in addition to other screening tools (family history, lipid profiles, and cardiopulmonary exercise tests, XT) in assessment of an individual fs cardiac risk profile. METHODS: Forty-four career firefighters were recruited to perform comprehensive baseline assessments including tests of aerobic performance, fasting lipids and glucose. Five-min resting 12-lead A-ECGs were obtained in a subset of firefighters (n=21) and transmitted over a secure networked system to a NASA physician collaborator. Using myocardial perfusion and other imaging as the gold standard, A-ECG scoring has been proven useful in accurately identifying a number of cardiac pathologies including coronary artery disease (CAD), left ventricular hypertrophy, hypertrophic cardiomyopathy, and non-ischemic and ischemic cardiomyopathy. RESULTS: Subjects f mean (SD) age was 43 (8) years, weight 91 (13) kg, and BMI 28 (3) kg/m2. Fifty-one percent of subjects had .3 cardiovascular risk factors. One subject had ST depression on XT ECG, at least one positive A-ECG score for CAD, and documented CAD based on cardiology referral. While all other subjects, including those with fewer risk factors, higher aerobic fitness, and normal exercise ECGs, were classified as healthy by A-ECG, there was no trend for association between risk factors and any of 20 A-ECG parameters in the

  5. Can Functional Cardiac Age be Predicted from ECG in a Normal Healthy Population

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd; Starc, Vito; Leban, Manja; Sinigoj, Petra; Vrhovec, Milos

    2011-01-01

    In a normal healthy population, we desired to determine the most age-dependent conventional and advanced ECG parameters. We hypothesized that changes in several ECG parameters might correlate with age and together reliably characterize the functional age of the heart. Methods: An initial study population of 313 apparently healthy subjects was ultimately reduced to 148 subjects (74 men, 84 women, in the range from 10 to 75 years of age) after exclusion criteria. In all subjects, ECG recordings (resting 5-minute 12-lead high frequency ECG) were evaluated via custom software programs to calculate up to 85 different conventional and advanced ECG parameters including beat-to-beat QT and RR variability, waveform complexity, and signal-averaged, high-frequency and spatial/spatiotemporal ECG parameters. The prediction of functional age was evaluated by multiple linear regression analysis using the best 5 univariate predictors. Results: Ignoring what were ultimately small differences between males and females, the functional age was found to be predicted (R2= 0.69, P < 0.001) from a linear combination of 5 independent variables: QRS elevation in the frontal plane (p<0.001), a new repolarization parameter QTcorr (p<0.001), mean high frequency QRS amplitude (p=0.009), the variability parameter % VLF of RRV (p=0.021) and the P-wave width (p=0.10). Here, QTcorr represents the correlation between the calculated QT and the measured QT signal. Conclusions: In apparently healthy subjects with normal conventional ECGs, functional cardiac age can be estimated by multiple linear regression analysis of mostly advanced ECG results. Because some parameters in the regression formula, such as QTcorr, high frequency QRS amplitude and P-wave width also change with disease in the same direction as with increased age, increased functional age of the heart may reflect subtle age-related pathologies in cardiac electrical function that are usually hidden on conventional ECG.

  6. Added value of a resting ECG neural network that predicts cardiovascular mortality.

    PubMed

    Perez, Marco V; Dewey, Frederick E; Tan, Swee Y; Myers, Jonathan; Froelicher, Victor F

    2009-01-01

    The resting 12-lead electrocardiogram (ECG) remains the most commonly used test in evaluating patients with suspected cardiovascular disease. Prognostic values of individual findings on the ECG have been reported but may be of limited use. The characteristics of 45,855 ECGs ordered by physician's discretion were first recorded and analyzed using a computerized system. Ninety percent of these ECGs were used to train an artifical neural network (ANN) to predict cardiovascular mortality (CVM) based on 132 ECG and four demographic characteristics. The ANN generated a Resting ECG Neural Network (RENN) score that was then tested in the remaining ECGs. The RENN score was finally assessed in a cohort of 2189 patients who underwent exercise treadmill testing and were followed for CVM. The RENN score was able to better predict CVM compared to individual ECG markers or a traditional Cox regression model in the testing cohort. Over a mean of 8.6 years, there were 156 cardiovascular deaths in the treadmill cohort. Among the patients who were classified as intermediate risk by Duke Treadmill Scoring (DTS), the third tertile of the RENN score demonstrated an adjusted Cox hazard ratio of 5.4 (95% CI 2.0-15.2) compared to the first RENN tertile. The 10-year CVM was 2.8%, 8.6% and 22% in the first, second and third RENN tertiles, respectively. An ANN that uses the resting ECG and demographic variables to predict CVM was created. The RENN score can further risk stratify patients deemed at moderate risk on exercise treadmill testing.

  7. The Telemetric and Holter ECG Warehouse Initiative (THEW): a Data Repository for the Design, Implementation and Validation of ECG-related Technologies

    PubMed Central

    Couderc, Jean-Philippe

    2011-01-01

    We present an initiative supported by the National Heart Lung, and Blood Institute and the Food and Drug Administration for the development of a repository containing continuous electrocardiographic information to be shared with the worldwide scientific community. We believe that sharing data reinforces open scientific inquiry. It encourages diversity of analysis and opinion while promoting new research and facilitating the education of new researchers. In this paper, we present the resources available in this initiative for the scientific community. We describe the set of ECG signals currently hosted and we briefly discuss the associated clinical information (medical history. Disease and study-specific endpoints) and software tools we propose. Currently, the repository contains more than 250GB of data from eight clinical studies including healthy individuals and cardiac patients. This data is available for the development, implementation and validation of technologies related to body-surface ECGs. To conclude, the Telemetric and Holter ECG Warehouse (THEW) is an initiative developed to benefit the scientific community and to advance the field of quantitative electrocardiography and cardiac safety. PMID:21097349

  8. Visualization of cardiac dipole using a current density map: detection of cardiac current undetectable by electrocardiography using magnetocardiography.

    PubMed

    Ikefuji, Hiroyuki; Nomura, Masahiro; Nakaya, Yutaka; Mori, Toshifumi; Kondo, Noriyasu; Ieishi, Kiyoshi; Fujimoto, Sayuri; Ito, Susumu

    2007-02-01

    A close relationship exists between electric current and the magnetic field. However, electricity and magnetism have different physical characteristics, and magnetocardiography (MCG) may provide information on cardiac current that is difficult to obtain by electrocardiography (ECG). In the present study, we investigated the issue of whether the current density map method, in which cardiac current is estimated from the magnetic gradient, facilitates the visualization of cardiac current undetectable by ECG. The subjects were 50 healthy adults (N group), 40 patients with left ventricular overloading (LVO group), 15 patients with right ventricular overloading (RVO group), 10 patients with an old inferior myocardial infarction (OMI group), and 30 patients with diabetes mellitus (DM group). MCGs were recorded with a second derivative superconducting quantum interference device (SQUID) gradiometer using liquid helium. Isopotential maps and current density maps from unipolar precordial ECG leads and MCGs, respectively, were prepared, and the cardiac electric current was examined. The current density map at the ventricular depolarization phase showed one peak of current density in the N group. However, in the OMI group, the current density map showed multiple peaks of current density areas. In the RVO group, two peaks of current densities were detected at the right superior region and left thoracic region and these two diploles appeared to be from the right and left ventricular derived cardiac currents, respectively. Moreover, there was a significant correlation between the magnitude of the current density from the right ventricle and the systolic pulmonary arterial pressure. The current density map at the ventricular repolarization phase in the N group showed only a single current source. However, abnormal current sources in the current density maps were frequently detected even in patients showing no abnormalities on isopotential maps in the LVO, DM, and OMI groups. The

  9. Localization of coronary artery disease with exercise electrocardiography: correlation with thallium-201 myocardial perfusion scanning

    SciTech Connect

    Dunn, R.F.; Freedman, B.; Bailey, I.K.; Uren, R.F.; Kelly, D.T.

    1981-11-01

    In 61 patients with single vessel coronary artery disease (70 percent or greater obstruction of luminal diameter in only one vessel) and no previous myocardial infarction, the sites of ischemic changes on 12 lead exercise electrocardiography and on thallium-201 myocardial perfusion scanning were related to the obstructed coronary artery. The site of exercise-induced S-T segment depression did not identify which coronary artery was obstructed. In the 37 patients with left anterior descending coronary artery disease S-T depression was most often seen in the inferior leads and leads V4 to V6, and in the 18 patients with right coronary artery disease and in the 6 patients with left circumflex artery disease S-T depression was most often seen in leads V5 and V6. Although S-T segment elevation was uncommon in most leads, it occurred in lead V1 or a VL, or both, in 51 percent of the patients with left anterior descending coronary artery disease. A reversible anterior defect on exercise thallium scanning correlated with left anterior descending coronary artery disease (probability (p) less than 0.0001) and a reversible inferior thallium defect correlated with right coronary or left circumflex artery disease (p less than 0.0001). In patients with single vessel disease, the site of S-T segment depression does not identify the obstructed coronary artery; S-T segment elevation in lead V1 or aVL, or both, identifies left anterior descending coronary artery disease; and the site of reversible perfusion defect on thallium scanning identifies the site of myocardial ischemia and the obstructed coronary artery.

  10. Case study of ECG signal used as a reference signal in optical pulse transit time measurement of blood flow: the effect of different electrode placements on pulse transit time

    NASA Astrophysics Data System (ADS)

    Myllylä, Teemu S.; Vihriälä, Erkki V.; Korhonen, Vesa O.; Sorvoja, Hannu S. S.

    2013-02-01

    The electrocardiography (ECG) signal is often used as a reference signal when calculating pulse transit times (PTT) measured by photoplethysmographic (PPG) sensors. In addition, ECG measurements are widely used in clinical health monitoring. In clinical measurements, small changes in the time delays of R waves in relation to blood flow pulsations between each ECG measurement are not relevant. In most cases, they would not even be observed, due to the rather low sampling rates used in clinical ECG devices. However, in PTT measurements, where time delays are measured with an accuracy of milliseconds, the placement of ECG electrodes can have a distinct effect on the results. This paper presents case studies of ECG signals measured simultaneously and independently by two ECG devices. We explore what effect different placements of ECG electrodes have on the R wave of the QRS complex and how it should be taken into account when used as a reference signal in pulse transit time measurements of blood flow. Additionally, we study what kind of ECG electrode placements are most suitable for PTT measurements.

  11. The future of remote ECG monitoring systems

    PubMed Central

    Guo, Shu-Li; Han, Li-Na; Liu, Hong-Wei; Si, Quan-Jin; Kong, De-Feng; Guo, Fu-Su

    2016-01-01

    Remote ECG monitoring systems are becoming commonplace medical devices for remote heart monitoring. In recent years, remote ECG monitoring systems have been applied in the monitoring of various kinds of heart diseases, and the quality of the transmission and reception of the ECG signals during remote process kept advancing. However, there remains accompanying challenges. This report focuses on the three components of the remote ECG monitoring system: patient (the end user), the doctor workstation, and the remote server, reviewing and evaluating the imminent challenges on the wearable systems, packet loss in remote transmission, portable ECG monitoring system, patient ECG data collection system, and ECG signals transmission including real-time processing ST segment, R wave, RR interval and QRS wave, etc. This paper tries to clarify the future developmental strategies of the ECG remote monitoring, which can be helpful in guiding the research and development of remote ECG monitoring. PMID:27582770

  12. Smart ECG Monitoring Patch with Built-in R-Peak Detection for Long-Term HRV Analysis.

    PubMed

    Lee, W K; Yoon, H; Park, K S

    2016-07-01

    Since heart rate variability (HRV) analysis is widely used to evaluate the physiological status of the human body, devices specifically designed for such applications are needed. To this end, we developed a smart electrocardiography (ECG) patch. The smart patch measures ECG using three electrodes integrated into the patch, filters the measured signals to minimize noise, performs analog-to-digital conversion, and detects R-peaks. The measured raw ECG data and the interval between the detected R-peaks can be recorded to enable long-term HRV analysis. Experiments were performed to evaluate the performance of the built-in R-wave detection, robustness of the device under motion, and applicability to the evaluation of mental stress. The R-peak detection results obtained with the device exhibited a sensitivity of 99.29%, a positive predictive value of 100.00%, and an error of 0.71%. The device also exhibited less motional noise than conventional ECG recording, being stable up to a walking speed of 5 km/h. When applied to mental stress analysis, the device evaluated the variation in HRV parameters in the same way as a normal ECG, with very little difference. This device can help users better understand their state of health and provide physicians with more reliable data for objective diagnosis.

  13. CSE database: extended annotations and new recommendations for ECG software testing.

    PubMed

    Smíšek, Radovan; Maršánová, Lucie; Němcová, Andrea; Vítek, Martin; Kozumplík, Jiří; Nováková, Marie

    2016-12-31

    Nowadays, cardiovascular diseases represent the most common cause of death in western countries. Among various examination techniques, electrocardiography (ECG) is still a highly valuable tool used for the diagnosis of many cardiovascular disorders. In order to diagnose a person based on ECG, cardiologists can use automatic diagnostic algorithms. Research in this area is still necessary. In order to compare various algorithms correctly, it is necessary to test them on standard annotated databases, such as the Common Standards for Quantitative Electrocardiography (CSE) database. According to Scopus, the CSE database is the second most cited standard database. There were two main objectives in this work. First, new diagnoses were added to the CSE database, which extended its original annotations. Second, new recommendations for diagnostic software quality estimation were established. The ECG recordings were diagnosed by five new cardiologists independently, and in total, 59 different diagnoses were found. Such a large number of diagnoses is unique, even in terms of standard databases. Based on the cardiologists' diagnoses, a four-round consensus (4R consensus) was established. Such a 4R consensus means a correct final diagnosis, which should ideally be the output of any tested classification software. The accuracy of the cardiologists' diagnoses compared with the 4R consensus was the basis for the establishment of accuracy recommendations. The accuracy was determined in terms of sensitivity = 79.20-86.81%, positive predictive value = 79.10-87.11%, and the Jaccard coefficient = 72.21-81.14%, respectively. Within these ranges, the accuracy of the software is comparable with the accuracy of cardiologists. The accuracy quantification of the correct classification is unique. Diagnostic software developers can objectively evaluate the success of their algorithm and promote its further development. The annotations and recommendations proposed in this work will allow

  14. Diagnostic grade wireless ECG monitoring.

    PubMed

    Garudadri, Harinath; Chi, Yuejie; Baker, Steve; Majumdar, Somdeb; Baheti, Pawan K; Ballard, Dan

    2011-01-01

    In remote monitoring of Electrocardiogram (ECG), it is very important to ensure that the diagnostic integrity of signals is not compromised by sensing artifacts and channel errors. It is also important for the sensors to be extremely power efficient to enable wearable form factors and long battery life. We present an application of Compressive Sensing (CS) as an error mitigation scheme at the application layer for wearable, wireless sensors in diagnostic grade remote monitoring of ECG. In our previous work, we described an approach to mitigate errors due to packet losses by projecting ECG data to a random space and recovering a faithful representation using sparse reconstruction methods. Our contributions in this work are twofold. First, we present an efficient hardware implementation of random projection at the sensor. Second, we validate the diagnostic integrity of the reconstructed ECG after packet loss mitigation. We validate our approach on MIT and AHA databases comprising more than 250,000 normal and abnormal beats using EC57 protocols adopted by the Food and Drug Administration (FDA). We show that sensitivity and positive predictivity of a state-of-the-art ECG arrhythmia classifier is essentially invariant under CS based packet loss mitigation for both normal and abnormal beats even at high packet loss rates. In contrast, the performance degrades significantly in the absence of any error mitigation scheme, particularly for abnormal beats such as Ventricular Ectopic Beats (VEB).

  15. Application of neural classifier to risk recognition of sustained ventricular tachycardia and flicker in patients after myocardial infarction based on high-resolution electrocardiography

    NASA Astrophysics Data System (ADS)

    Wydrzyński, Jacek; Jankowski, Stanisław; Piątkowska-Janko, Ewa

    2008-01-01

    This paper presents the application of neural networks to the risk recognition of sustained ventricular tachycardia and flicker in patients after myocardial infarction based on high-resolution electrocardiography. This work is based on dataset obtained from the Medical University of Warsaw. The studies were performed on one multiclass classifier and on binary classifiers. For each case the optimal number of hidden neurons was found. The effect of data preparation: normalization and the proper selection of parameters was considered, as well as the influence of applied filters. The best neural classifier contains 5 hidden neurons, the input ECG signal is represented by 8 parameters. The neural network classifier had high rate of successful recognitions up to 90% performed on the test data set.

  16. Prognostic usefulness of left ventricular hypertrophy by electrocardiography in patients with atrial fibrillation (from the Randomized Evaluation of Long-Term Anticoagulant Therapy Study).

    PubMed

    Verdecchia, Paolo; Reboldi, Gianpaolo; Di Pasquale, Giuseppe; Mazzotta, Giovanni; Ambrosio, Giuseppe; Yang, Sean; Pogue, Janice; Wallentin, Lars; Ezekowitz, Michael D; Connolly, Stuart J; Yusuf, Salim

    2014-02-15

    It is unknown whether left ventricular hypertrophy (LVH) diagnosis by electrocardiography improves risk stratification in patients with atrial fibrillation (AF). We investigated the prognostic impact of LVH diagnosis by electrocardiography in a large sample of anticoagulated patients with AF included in the Randomized Evaluation of Long-Term Anticoagulant Therapy (RE-LY) Study. We defined electrographic LVH (ECG-LVH) by strain pattern or Cornell voltage (R wave in aVL plus S wave in V3) >2.0 mV (women) or >2.4 mV (men). LVH prevalence was 22.7%. During a median follow-up of 2.0 years, 303 patients developed a stroke, 778 died (497 from cardiovascular causes), and 140 developed a myocardial infarction. LVH was associated with a greater risk of stroke (1.99% vs 1.32% per year, hazard ratio [HR] 1.51, 95% confidence interval [CI] 1.18 to 1.93, p <0.001), cardiovascular death (4.52% vs 1.80% per year, HR 2.56, 95% CI 2.14 to 3.06, p <0.0001), all-cause death (6.03% vs 3.11% per year, HR 1.95, 95% CI 1.68 to 2.26, p <0.0001), and myocardial infarction (1.11% vs 0.55% per year, HR 2.07, 95% CI 1.47 to 2.92, p <0.0001). In multivariate analysis, the prognostic value of LVH was additive to CHA2DS2-VASc score and other covariates. The category-free net reclassification index and integrated discrimination improvement increased significantly after adding LVH to multivariate models. In conclusion, our study demonstrates for the first time that ECG-LVH, a simple and easily accessible prognostic indicator, improves risk stratification in anticoagulated patients with AF. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Non-contact detection of myocardium's mechanical activity by ultrawideband RF-radar and interpretation applying electrocardiography.

    PubMed

    Thiel, F; Kreiseler, D; Seifert, F

    2009-11-01

    can potentially be used to support standard electrocardiography (ECG) analysis by complementary information where sole ECG analysis fails, e.g., electromechanical dissociation.

  18. Non-contact detection of myocardium's mechanical activity by ultrawideband RF-radar and interpretation applying electrocardiography

    NASA Astrophysics Data System (ADS)

    Thiel, F.; Kreiseler, D.; Seifert, F.

    2009-11-01

    can potentially be used to support standard electrocardiography (ECG) analysis by complementary information where sole ECG analysis fails, e.g., electromechanical dissociation.

  19. The value of the 12-lead electrocardiogram in localizing the scar in non-ischaemic cardiomyopathy.

    PubMed

    Oloriz, Teresa; Wellens, Hein J J; Santagostino, Giulia; Trevisi, Nicola; Silberbauer, John; Peretto, Giovanni; Maccabelli, Giuseppe; Della Bella, Paolo

    2016-12-01

    Patients with non-ischaemic cardiomyopathy (NICM) and ventricular tachycardia can be categorized as anteroseptal (AS) or inferolateral (IL) scar sub-types based on imaging and voltage mapping studies. The aim of this study was to correlate the baseline electrocardiogram (ECG) with endo-epicardial voltage maps created during ablation procedures and identify the ECG characteristics that may help to distinguish the scar as AS or IL. We assessed 108 baseline ECGs; 72 patients fulfilled criteria for dilated cardiomyopathy whereas 36 showed minimal structural abnormalities. Based on the unipolar low-voltage distribution, the scar pattern was classified as predominantly AS (n = 59) or IL (n = 49). Three ECG criteria (PR interval < 170 ms or QRS voltage in inferior leads <0.6 mV or a lateral q wave) resulted in 92% sensitivity and 90% specificity for predicting an IL pattern in patients with preserved ejection fraction (EF). The four-step algorithm for dilated cardiomyopathy included a paced ventricular rhythm or PR > 230 ms or QRS > 170 ms or an r ≤ 0.3 mV in V3 having 92 and 81% of sensitivity and specificity, respectively, in predicting AS scar pattern. A significant negative correlation was found between the extension of the endocardial unipolar low voltage area and left ventricular EF (rs = -0.719, P < 0.001). The extent of endocardial AS unipolar low voltage was correlated with PR interval and QRS duration (rs = 0.583 and rs = 0.680, P < 0.001, respectively) and the IL epicardial unipolar low voltage with the mean voltage of the limb leads (rs = -0.639, P < 0.001). Baseline ECG features are well correlated with the distribution of unipolar voltage abnormalities in NICM and may help to predict the location of scar in this population. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  20. [THE IMPORTANCE OF LEAD AVR IN THE EVALUATION OF AN ECG STRIP].

    PubMed

    Shemer, Asaf; Halpern, Pinchas

    2017-08-01

    Over the years, the aVR lead has been overlooked by clinicians while observing a normal 12-lead ECG (electrocardiogram). A positive P-QRS complex in the aVR lead should raise prompt suspicion for either a congenital heart malrotation or a lead misplacement. In this article we present a case of an asymptomatic patient and a pathological ECG strip displaying ST elevations and a positive QRS in the aVR lead. A follow-up ECG was performed in the emergency department, and revealed a normal sinus rhythm with no abnormalities indicating acute ischemia. Through this case, we demonstrated the importance of proper examination of the aVR lead and its role in preventing unnecessary treatments.

  1. Comparison of Electrocardiography Markers and Speckle Tracking Echocardiography for Assessment of Left Ventricular Myocardial Scar Burden in Patients With Previous Myocardial Infarction.

    PubMed

    Nestaas, Eirik; Shih, Jhih-Yuan; Smedsrud, Marit K; Gjesdal, Ola; Hopp, Einar; Haugaa, Kristina H; Edvardsen, Thor

    2017-05-01

    Myocardial scar burden is an important prognostic factor after myocardial infarction. This cohort study compared assessment of left ventricle scar burden between pathological Q waves on electrocardiography (ECG), Selvester multiparametric ECG scoring system for scar burden, and global longitudinal strain (GLS) by speckle-tracking echocardiography 6 months after myocardial infarction. The scar burden was defined by late gadolinium enhancement cardiac magnetic resonance as fraction of total left ventricle tissue. ECG measures were presence of pathologic Q waves and Selvester scores. GLS was the average of peak strain from 16 left ventricle segments. In 34 patients aged 58 ± 10 years (mean ± SD), the scar burden was 19% (9, 26) (median [quartiles]) and 79% had scar burden >5%. Patients with scar burden >5% more frequently had pathologic Q waves (63% vs 14%) and had worse Selvester scores (5 [3, 7] vs 0 [0, 1]) and worse GLS (-16.6 ± 2.4% vs -19.9 ± 1.1%). Pathologic Q waves, Selvester scores, ejection fraction, and GLS related to scar burden in univariable analyses. Sensitivity and specificity for detecting scar burden >5% was 63% and 86% (pathologic Q waves), 89% and 86% (Selvester score), 81% and 86% (ejection fraction), 89% and 86% (GLS), and 96% and 71% (combination of Q waves, Selvester score, and GLS). In conclusion, Selvester score and GLS related to scars 6 months after myocardial infarction, and pathologic Q waves were only weakly associated with scar and GLS was associated with scar independently of ECG markers. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Arguing effectiveness of biomedical signal acquisition devices using colored Petri Nets models and assurance cases in GSN: an ECG case study.

    PubMed

    Sobrinho, Alvaro; Cunha, Paulo; Dias da Silva, Leandro; Perkusich, Angelo; Cordeiro, Thiago; Segundo, Jarbas

    2016-08-01

    Reported cases of adverse events and product recalls expose limitations of biomedical signal acquisition devices. Approximately, ninety percent of the 1.210 recalls reported by the US Food and Drug Administration (FDA) between 2006 and 2011 were of class 2 devices such as Electrocardiography (ECG) devices. We show in this paper how manufacturers of biomedical signal acquisition devices can argue effectiveness of these devices using Colored Petri Nets (CPN) models and assurance cases in Goal Structuring Notation (GSN) by means of an ECG case study. We illustrate how CPN models are used to generate effectiveness evidences in order to present them during certification. In this context, we use assurance cases in GSN to present evidences arguing effectiveness of the device. We were able to conclude based on the ECG case study that the use of CPN models of devices can decrease costs and development time once manufacturers reuse them during the development and certification process.

  3. Impact of the prehospital ECG on door-to-balloon time in ST elevation myocardial infarction.

    PubMed

    Rao, Anjani; Kardouh, Youssef; Darda, Saba; Desai, Devang; Devireddy, Lingareddy; Lalonde, Thomas; Rosman, Howard; David, Shukri

    2010-02-01

    National guidelines have been set to achieve door-to-balloon time (D2B) is less than 90 minutes to improve outcomes for patients with STEMI. The purpose of this study is to see if a more aggressive approach utilizing prehospital ECGs could improve reperfusion times. The EMS personnel obtained a 12-lead ECG during initial assessment in the field from patients with chest pain. The ECG was immediately transmitted to the ER physician by cellular link to a computer receiving station. The ER physician reviewed the ECG digital tracing. The cardiac catheterization laboratory (CCL) team was activated from the patients' homes. Patients were transported from the field directly to the CCL by EMS bypassing the emergency department. The mean D2B for patients with initial ECG in hospital in all three hospitals combined was 90.5 minutes, compared to 60.2 minutes in patients with prehospital ECG. (P < 0.0001). When analyzing the mean D2B in regards to times of presentation, we found a significant reduction in mean D2B in patients presenting during working hours (75 minutes) compared with those presenting during off hours (98 minutes) in the control group. However, with the use of prehospital ECGs, there was a significant reduction in D2B regardless of what time the patient arrived in the ER. Utilizing the prehospital ECG as a tool to bypass ER triage significantly decreases D2B times in patients with STEMI. This technology has the potential to substantially expedite reperfusion therapy in patients with STEMI.

  4. A combined application of lossless and lossy compression in ECG processing and transmission via GSM-based SMS.

    PubMed

    Mukhopadhyay, S K; Mitra, S; Mitra, M

    2015-02-01

    This paper presents a software-based scheme for reliable and robust Electrocardiogram (ECG) data compression and its efficient transmission using Second Generation (2G) Global System for Mobile Communication (GSM) based Short Message Service (SMS). To achieve a firm lossless compression in high standard deviating QRS complex regions and an acceptable lossy compression in the rest of the signal, two different algorithms have been used. The combined compression module is such that it outputs only American Standard Code for Information Interchange (ASCII) characters and, hence, SMS service is found to be most suitable for transmitting the compressed signal. At the receiving end, the ECG signal is reconstructed using just the reverse algorithm. The module has been tested to all the 12 leads of different types of ECG signals (healthy and abnormal) collected from the PTB Diagnostic ECG Database. The compression algorithm achieves an average compression ratio of ∼22.51, without any major alteration of clinical morphology.

  5. A New Algorithm to Diagnose Atrial Ectopic Origin from Multi Lead ECG Systems - Insights from 3D Virtual Human Atria and Torso

    PubMed Central

    Alday, Erick A. Perez; Colman, Michael A.; Langley, Philip; Butters, Timothy D.; Higham, Jonathan; Workman, Antony J.; Hancox, Jules C.; Zhang, Henggui

    2015-01-01

    Rapid atrial arrhythmias such as atrial fibrillation (AF) predispose to ventricular arrhythmias, sudden cardiac death and stroke. Identifying the origin of atrial ectopic activity from the electrocardiogram (ECG) can help to diagnose the early onset of AF in a cost-effective manner. The complex and rapid atrial electrical activity during AF makes it difficult to obtain detailed information on atrial activation using the standard 12-lead ECG alone. Compared to conventional 12-lead ECG, more detailed ECG lead configurations may provide further information about spatio-temporal dynamics of the body surface potential (BSP) during atrial excitation. We apply a recently developed 3D human atrial model to simulate electrical activity during normal sinus rhythm and ectopic pacing. The atrial model is placed into a newly developed torso model which considers the presence of the lungs, liver and spinal cord. A boundary element method is used to compute the BSP resulting from atrial excitation. Elements of the torso mesh corresponding to the locations of the placement of the electrodes in the standard 12-lead and a more detailed 64-lead ECG configuration were selected. The ectopic focal activity was simulated at various origins across all the different regions of the atria. Simulated BSP maps during normal atrial excitation (i.e. sinoatrial node excitation) were compared to those observed experimentally (obtained from the 64-lead ECG system), showing a strong agreement between the evolution in time of the simulated and experimental data in the P-wave morphology of the ECG and dipole evolution. An algorithm to obtain the location of the stimulus from a 64-lead ECG system was developed. The algorithm presented had a success rate of 93%, meaning that it correctly identified the origin of atrial focus in 75/80 simulations, and involved a general approach relevant to any multi-lead ECG system. This represents a significant improvement over previously developed algorithms. PMID

  6. A new algorithm to diagnose atrial ectopic origin from multi lead ECG systems--insights from 3D virtual human atria and torso.

    PubMed

    Alday, Erick A Perez; Colman, Michael A; Langley, Philip; Butters, Timothy D; Higham, Jonathan; Workman, Antony J; Hancox, Jules C; Zhang, Henggui

    2015-01-01

    Rapid atrial arrhythmias such as atrial fibrillation (AF) predispose to ventricular arrhythmias, sudden cardiac death and stroke. Identifying the origin of atrial ectopic activity from the electrocardiogram (ECG) can help to diagnose the early onset of AF in a cost-effective manner. The complex and rapid atrial electrical activity during AF makes it difficult to obtain detailed information on atrial activation using the standard 12-lead ECG alone. Compared to conventional 12-lead ECG, more detailed ECG lead configurations may provide further information about spatio-temporal dynamics of the body surface potential (BSP) during atrial excitation. We apply a recently developed 3D human atrial model to simulate electrical activity during normal sinus rhythm and ectopic pacing. The atrial model is placed into a newly developed torso model which considers the presence of the lungs, liver and spinal cord. A boundary element method is used to compute the BSP resulting from atrial excitation. Elements of the torso mesh corresponding to the locations of the placement of the electrodes in the standard 12-lead and a more detailed 64-lead ECG configuration were selected. The ectopic focal activity was simulated at various origins across all the different regions of the atria. Simulated BSP maps during normal atrial excitation (i.e. sinoatrial node excitation) were compared to those observed experimentally (obtained from the 64-lead ECG system), showing a strong agreement between the evolution in time of the simulated and experimental data in the P-wave morphology of the ECG and dipole evolution. An algorithm to obtain the location of the stimulus from a 64-lead ECG system was developed. The algorithm presented had a success rate of 93%, meaning that it correctly identified the origin of atrial focus in 75/80 simulations, and involved a general approach relevant to any multi-lead ECG system. This represents a significant improvement over previously developed algorithms.

  7. 3D Finite Element Electrical Model of Larval Zebrafish ECG Signals

    PubMed Central

    Crowcombe, James; Dhillon, Sundeep Singh; Hurst, Rhiannon Mary; Egginton, Stuart; Müller, Ferenc; Sík, Attila; Tarte, Edward

    2016-01-01

    Assessment of heart function in zebrafish larvae using electrocardiography (ECG) is a potentially useful tool in developing cardiac treatments and the assessment of drug therapies. In order to better understand how a measured ECG waveform is related to the structure of the heart, its position within the larva and the position of the electrodes, a 3D model of a 3 days post fertilisation (dpf) larval zebrafish was developed to simulate cardiac electrical activity and investigate the voltage distribution throughout the body. The geometry consisted of two main components; the zebrafish body was modelled as a homogeneous volume, while the heart was split into five distinct regions (sinoatrial region, atrial wall, atrioventricular band, ventricular wall and heart chambers). Similarly, the electrical model consisted of two parts with the body described by Laplace’s equation and the heart using a bidomain ionic model based upon the Fitzhugh-Nagumo equations. Each region of the heart was differentiated by action potential (AP) parameters and activation wave conduction velocities, which were fitted and scaled based on previously published experimental results. ECG measurements in vivo at different electrode recording positions were then compared to the model results. The model was able to simulate action potentials, wave propagation and all the major features (P wave, R wave, T wave) of the ECG, as well as polarity of the peaks observed at each position. This model was based upon our current understanding of the structure of the normal zebrafish larval heart. Further development would enable us to incorporate features associated with the diseased heart and hence assist in the interpretation of larval zebrafish ECGs in these conditions. PMID:27824910

  8. ECG is an inefficient screening-tool for left ventricular hypertrophy in normotensive African children population

    PubMed Central

    Creta, Antonio; Campanale, Cosimo Marco; Fittipaldi, Mario; Giorgino, Riccardo; Quintarelli, Fabio; Satriano, Umberto; Cruciani, Alessandro; Antinolfi, Vincenzo; Di Berardino, Stefano; Costanzo, Davide; Bettini, Ranieri; Mangiameli, Giuseppe; Caricato, Marco; Mottini, Giovanni

    2016-01-01

    Background Left ventricular hypertrophy (LVH) is a marker of pediatric hypertension and predicts development of cardiovascular events. Electrocardiography (ECG) screening is used in pediatrics to detect LVH thanks to major accessibility, reproducibility and easy to use compared to transthoracic echocardiography (TTE), that remains the standard technique. Several diseases were previously investigated, but no data exists regarding our study population. The aim of our study was to evaluate the relationship between electrocardiographic and echocardiographic criteria of LVH in normotensive African children. Methods We studied 313 children (mean age 7,8 ± 3 yo), in north-Madagascar. They underwent ECG and TTE. Sokolow-Lyon index was calculated to identify ECG-LVH (>35 mm). Left ventricle mass (LVM) with TTE was calculated and indexed by height2.7 (LVMI2.7) and weight (LVMIw). We report the prevalence of TTE-LVH using three methods: (1) calculating percentiles age- and sex- specific with values >95th percentile identifying LVH; (2) LVMI2.7 >51 g/m2.7; (3) LVMIw >3.4 g/weight. Results 40 (13%) children showed LVMI values >95th percentile, 24 children (8%) an LVMI2.7 >51 g/m2.7 while 19 children (6%) an LVMIw >3.4 g/kg. LVH-ECG by Sokolow-Lyon index was present in five, three and three children respectively, with poor values of sensitivity (ranging from 13 to 16%), positive predictive value (from 11 to 18%) and high values of specificity (up to 92%). The effects of anthropometrics parameters on Sokolow-Lyon were analyzed and showed poor correlation. Conclusion ECG is a poor screening test for detecting LVH in children. In clinical practice, TTE remains the only tool to be used to exclude LVH. PMID:27651998

  9. Agreement between clinical and portable EMG/ECG diagnosis of sleep bruxism.

    PubMed

    Castroflorio, T; Bargellini, A; Rossini, G; Cugliari, G; Deregibus, A; Manfredini, D

    2015-10-01

    The aim of this study was to compare clinical sleep bruxism (SB) diagnosis with an instrumental diagnosis obtained with a device providing electromyography/electrocardiography (EMG/ECG) recordings. Forty-five (N = 45) subjects (19 males and 26 females, mean age 28 ± 11 years) were selected among patients referring to the Gnathology Unit of the Dental School of the University of Torino. An expert clinician assessed the presence of SB based on the presence of one or more signs/symptoms (i.e., transient jaw muscle pain in the morning, muscle fatigue at awakening, presence of tooth wear, masseter hypertrophy). Furthermore, all participants underwent an instrumental recording at home with a portable device (Bruxoff; OT Bioelettronica, Torino, Italy) allowing a simultaneous recording of EMG signals from both the masseter muscles as well as heart frequency. Statistical procedures were performed with the software Statistical Package for the Social Science v. 20.0 (SPSS 20.0; IBM, Milan, Italy). Based on the EMG/ECG analysis, 26 subjects (11 males, 15 females, mean age 28 ± 10 years) were diagnosed as sleep bruxers, whilst 19 subjects (7 males, 12 females, mean age 30 ± 10 years) were diagnosed as non-bruxers. The correlation between the clinical and EMG/ECG SB diagnoses was low (ϕ value = 0.250), with a 62.2% agreement (28/45 subjects) between the two approaches (kappa = 0.248). Assuming instrumental EMG/ECG diagnosis as the standard of reference for definite SB diagnosis in this investigation, the false-positive and false-negative rates were unacceptable for all clinical signs/symptoms. In conclusion, findings from clinical assessment are not related with SB diagnosis performed with a portable EMG/ECG recorder. © 2015 John Wiley & Sons Ltd.

  10. 3D Finite Element Electrical Model of Larval Zebrafish ECG Signals.

    PubMed

    Crowcombe, James; Dhillon, Sundeep Singh; Hurst, Rhiannon Mary; Egginton, Stuart; Müller, Ferenc; Sík, Attila; Tarte, Edward

    2016-01-01

    Assessment of heart function in zebrafish larvae using electrocardiography (ECG) is a potentially useful tool in developing cardiac treatments and the assessment of drug therapies. In order to better understand how a measured ECG waveform is related to the structure of the heart, its position within the larva and the position of the electrodes, a 3D model of a 3 days post fertilisation (dpf) larval zebrafish was developed to simulate cardiac electrical activity and investigate the voltage distribution throughout the body. The geometry consisted of two main components; the zebrafish body was modelled as a homogeneous volume, while the heart was split into five distinct regions (sinoatrial region, atrial wall, atrioventricular band, ventricular wall and heart chambers). Similarly, the electrical model consisted of two parts with the body described by Laplace's equation and the heart using a bidomain ionic model based upon the Fitzhugh-Nagumo equations. Each region of the heart was differentiated by action potential (AP) parameters and activation wave conduction velocities, which were fitted and scaled based on previously published experimental results. ECG measurements in vivo at different electrode recording positions were then compared to the model results. The model was able to simulate action potentials, wave propagation and all the major features (P wave, R wave, T wave) of the ECG, as well as polarity of the peaks observed at each position. This model was based upon our current understanding of the structure of the normal zebrafish larval heart. Further development would enable us to incorporate features associated with the diseased heart and hence assist in the interpretation of larval zebrafish ECGs in these conditions.

  11. Diagnostic accuracy of a smartphone electrocardiograph in dogs: Comparison with standard 6-lead electrocardiography.

    PubMed

    Vezzosi, T; Buralli, C; Marchesotti, F; Porporato, F; Tognetti, R; Zini, E; Domenech, O

    2016-10-01

    The diagnostic accuracy of a smartphone electrocardiograph (ECG) in evaluating heart rhythm and ECG measurements was evaluated in 166 dogs. A standard 6-lead ECG was acquired for 1 min in each dog. A smartphone ECG tracing was simultaneously recorded using a single-lead bipolar ECG recorder. All ECGs were reviewed by one blinded operator, who judged if tracings were acceptable for interpretation and assigned an electrocardiographic diagnosis. Agreement between smartphone and standard ECG in the interpretation of tracings was evaluated. Sensitivity and specificity for the detection of arrhythmia were calculated for the smartphone ECG. Smartphone ECG tracings were interpretable in 162/166 (97.6%) tracings. A perfect agreement between the smartphone and standard ECG was found in detecting bradycardia, tachycardia, ectopic beats and atrioventricular blocks. A very good agreement was found in detecting sinus rhythm versus non-sinus rhythm (100% sensitivity and 97.9% specificity). The smartphone ECG provided tracings that were adequate for analysis in most dogs, with an accurate assessment of heart rate, rhythm and common arrhythmias. The smartphone ECG represents an additional tool in the diagnosis of arrhythmias in dogs, but is not a substitute for a 6-lead ECG. Arrhythmias identified by the smartphone ECG should be followed up with a standard ECG before making clinical decisions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Cardiorespiratory dynamics measured from continuous ECG monitoring improves detection of deterioration in acute care patients: A retrospective cohort study.

    PubMed

    Moss, Travis J; Clark, Matthew T; Calland, James Forrest; Enfield, Kyle B; Voss, John D; Lake, Douglas E; Moorman, J Randall

    2017-01-01

    Charted vital signs and laboratory results represent intermittent samples of a patient's dynamic physiologic state and have been used to calculate early warning scores to identify patients at risk of clinical deterioration. We hypothesized that the addition of cardiorespiratory dynamics measured from continuous electrocardiography (ECG) monitoring to intermittently sampled data improves the predictive validity of models trained to detect clinical deterioration prior to intensive care unit (ICU) transfer or unanticipated death. We analyzed 63 patient-years of ECG data from 8,105 acute care patient admissions at a tertiary care academic medical center. We developed models to predict deterioration resulting in ICU transfer or unanticipated death within the next 24 hours using either vital signs, laboratory results, or cardiorespiratory dynamics from continuous ECG monitoring and also evaluated models using all available data sources. We calculated the predictive validity (C-statistic), the net reclassification improvement, and the probability of achieving the difference in likelihood ratio χ2 for the additional degrees of freedom. The primary outcome occurred 755 times in 586 admissions (7%). We analyzed 395 clinical deteriorations with continuous ECG data in the 24 hours prior to an event. Using only continuous ECG measures resulted in a C-statistic of 0.65, similar to models using only laboratory results and vital signs (0.63 and 0.69 respectively). Addition of continuous ECG measures to models using conventional measurements improved the C-statistic by 0.01 and 0.07; a model integrating all data sources had a C-statistic of 0.73 with categorical net reclassification improvement of 0.09 for a change of 1 decile in risk. The difference in likelihood ratio χ2 between integrated models with and without cardiorespiratory dynamics was 2158 (p value: <0.001). Cardiorespiratory dynamics from continuous ECG monitoring detect clinical deterioration in acute care patients

  13. An improved adaptive power line interference canceller for electrocardiography.

    PubMed

    Martens, Suzanna M M; Mischi, Massimo; Oei, S Guid; Bergmans, Jan W M

    2006-11-01

    Power line interference may severely corrupt a biomedical recording. Notch filters and adaptive cancellers have been suggested to suppress this interference. We propose an improved adaptive canceller for the reduction of the fundamental power line interference component and harmonics in electrocardiogram (ECG) recordings. The method tracks. the amplitude, phase, and frequency of all the interference components for power line frequency deviations up to about 4 Hz. A comparison is made between the performance of our method, former adaptive cancellers, and a narrow and a wide notch filter in suppressing the fundamental power line interference component. For this purpose a real ECG signal is corrupted by an artificial power line interference signal. The cleaned signal after applying all methods is compared with the original ECG signal. Our improved adaptive canceller shows a signal-to-power-line-interference ratio for the fundamental component up to 30 dB higher than that produced by the other methods. Moreover, our method is also effective for the suppression of the harmonics of the power line interference.

  14. WaveformECG: A Platform for Visualizing, Annotating, and Analyzing ECG Data

    PubMed Central

    Winslow, Raimond L.; Granite, Stephen; Jurado, Christian

    2017-01-01

    The electrocardiogram (ECG) is the most commonly collected data in cardiovascular research because of the ease with which it can be measured and because changes in ECG waveforms reflect underlying aspects of heart disease. Accessed through a browser, WaveformECG is an open source platform supporting interactive analysis, visualization, and annotation of ECGs. PMID:28642673

  15. Deployment of an Advanced Electrocardiographic Analysis (A-ECG) to Detect Cardiovascular Risk in Career Firefighters

    NASA Technical Reports Server (NTRS)

    Dolezal, B. A.; Storer, T. W.; Abrazado, M.; Watne, R.; Schlegel, T. T.; Batalin, M.; Kaiser, W.; Smith, D. L.; Cooper, C. B.

    2011-01-01

    INTRODUCTION Sudden cardiac death is the leading cause of line of duty death among firefighters, accounting for approximately 45% of fatalities annually. Firefighters perform strenuous muscular work while wearing heavy, encapsulating personal protective equipment in high ambient temperatures, under chaotic and emotionally stressful conditions. These factors can precipitate sudden cardiac events like myocardial infarction, serious dysrhythmias, or cerebrovascular accidents in firefighters with underlying cardiovascular disease. Screening for cardiovascular risk factors is recommended but not always followed in this population. PHASER is a project charged with identifying and prioritizing risk factors in emergency responders. We have deployed an advanced ECG (A-ECG) system developed at NASA for improved sensitivity and specificity in the detection of cardiac risk. METHODS Forty-four professional firefighters were recruited to perform comprehensive baseline assessments including tests of aerobic performance and laboratory tests for fasting lipid profiles and glucose. Heart rate and conventional 12-lead ECG were obtained at rest and during incremental treadmill exercise testing (XT). In addition, a 5-min resting 12-lead A-ECG was obtained in a subset of firefighters (n=18) and transmitted over a secure networked system to a physician collaborator at NASA for advanced-ECG analysis. This A-ECG system has been proven, using myocardial perfusion and other imaging, to accurately identify a number of cardiac pathologies including coronary artery disease (CAD), left ventricular hypertrophy, hypertrophic cardiomyopathy, non-ischemic cardiomyopathy, and ischemic cardiomyopathy. RESULTS Subjects mean (SD) age was 43 (8) years, weight 91 (13) kg, and BMI of 28 (3) kg/square meter. Maximum oxygen uptake (VO2max) was 39 (9) ml/kg/min. This compares with the 45th %ile in healthy reference values and a recommended standard of 42 ml/kg/min for firefighters. The metabolic threshold (VO

  16. Piezoelectric extraction of ECG signal

    PubMed Central

    Ahmad, Mahmoud Al

    2016-01-01

    The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other. PMID:27853180

  17. Ambulatory respiratory rate detection using ECG and a triaxial accelerometer.

    PubMed

    Chan, Alexander M; Ferdosi, Nima; Narasimhan, Ravi

    2013-01-01

    Continuous monitoring of respiratory rate in ambulatory conditions has widespread applications for screening of respiratory diseases and remote patient monitoring. Unfortunately, minimally obtrusive techniques often suffer from low accuracy. In this paper, we describe an algorithm with low computational complexity for combining multiple respiratory measurements to estimate breathing rate from an unobtrusive chest patch sensor. Respiratory rates derived from the respiratory sinus arrhythmia (RSA) and modulation of the QRS amplitude of electrocardiography (ECG) are combined with a respiratory rate derived from tri-axial accelerometer data. The three respiration rates are combined by a weighted average using weights based on quality metrics for each signal. The algorithm was evaluated on 15 elderly subjects who performed spontaneous and metronome breathing as well as a variety of activities of daily living (ADLs). When compared to a reference device, the mean absolute error was 1.02 breaths per minute (BrPM) during metronome breathing, 1.67 BrPM during spontaneous breathing, and 2.03 BrPM during ADLs.

  18. Technology-Based vs. Traditional Instruction: A Comparison of Two Methods for Teaching the Skill of Performing a 12-Lead ECG.

    ERIC Educational Resources Information Center

    Jeffries, Pamela R.; Woolf, Shirley; Linde, Beverly

    2003-01-01

    Electrocardiogram technique was taught to 32 nursing students using a self-study module, lecture-demonstration, and hands-on learning laboratories and to 45 students using interactive multimedia CD-ROM with self-study module. Pre/postprogram data show satisfaction and score improvement was high for both, with no significant differences. (Contains…

  19. Technology-Based vs. Traditional Instruction: A Comparison of Two Methods for Teaching the Skill of Performing a 12-Lead ECG.

    ERIC Educational Resources Information Center

    Jeffries, Pamela R.; Woolf, Shirley; Linde, Beverly

    2003-01-01

    Electrocardiogram technique was taught to 32 nursing students using a self-study module, lecture-demonstration, and hands-on learning laboratories and to 45 students using interactive multimedia CD-ROM with self-study module. Pre/postprogram data show satisfaction and score improvement was high for both, with no significant differences. (Contains…

  20. Design, fabrication and skin-electrode contact analysis of polymer microneedle-based ECG electrodes

    NASA Astrophysics Data System (ADS)

    O'Mahony, Conor; Grygoryev, Konstantin; Ciarlone, Antonio; Giannoni, Giuseppe; Kenthao, Anan; Galvin, Paul

    2016-08-01

    Microneedle-based ‘dry’ electrodes have immense potential for use in diagnostic procedures such as electrocardiography (ECG) analysis, as they eliminate several of the drawbacks associated with the conventional ‘wet’ electrodes currently used for physiological signal recording. To be commercially successful in such a competitive market, it is essential that dry electrodes are manufacturable in high volumes and at low cost. In addition, the topographical nature of these emerging devices means that electrode performance is likely to be highly dependent on the quality of the skin-electrode contact. This paper presents a low-cost, wafer-level micromoulding technology for the fabrication of polymeric ECG electrodes that use microneedle structures to make a direct electrical contact to the body. The double-sided moulding process can be used to eliminate post-process via creation and wafer dicing steps. In addition, measurement techniques have been developed to characterize the skin-electrode contact force. We perform the first analysis of signal-to-noise ratio dependency on contact force, and show that although microneedle-based electrodes can outperform conventional gel electrodes, the quality of ECG recordings is significantly dependent on temporal and mechanical aspects of the skin-electrode interface.

  1. Cardiac Autonomic Alteration and Metabolic Syndrome: An Ambulatory ECG-based Study in A General Population

    PubMed Central

    Ma, Yan; Tseng, Ping-Huei; Ahn, Andrew; Wu, Ming-Shiang; Ho, Yi-Lwun; Chen, Ming-Fong; Peng, Chung-Kang

    2017-01-01

    Metabolic syndrome (MetS) has been associated with chronic damage to the cardiovascular system. This study aimed to evaluate early stage cardiac autonomic dysfunction with electrocardiography (ECG)-based measures in MetS subjects. During 2012–2013, 175 subjects with MetS and 226 healthy controls underwent ECG recordings of at least 4 hours starting in the morning with ambulatory one-lead ECG monitors. MetS was diagnosed using the criteria defined in the Adult Treatment Panel III, with a modification of waist circumference for Asians. Conventional heart rate variability (HRV) analysis, and complexity index (CI1–20) calculated from 20 scales of entropy (multiscale entropy, MSE), were compared between subjects with MetS and controls. Compared with the healthy controls, subjects with MetS had significantly reduced HRV, including SDNN and pNN20 in time domain, VLF, LF and HF in frequency domain, as well as SD2 in Poincaré analysis. MetS subjects have significantly lower complexity index (CI1–20) than healthy subjects (1.69 ± 0.18 vs. 1.77 ± 0.12, p < 0.001). MetS severity was inversely associated with the CI1–20 (r = −0.27, p < 0.001). MetS is associated with significant alterations in heart rate dynamics, including HRV and complexity. PMID:28290487

  2. Development and evaluation of multilead wavelet-based ECG delineation algorithms for embedded wireless sensor nodes.

    PubMed

    Rincón, Francisco; Recas, Joaquin; Khaled, Nadia; Atienza, David

    2011-11-01

    This work is devoted to the evaluation of multilead digital wavelet transform (DWT)-based electrocardiogram (ECG) wave delineation algorithms, which were optimized and ported to a commercial wearable sensor platform. More specifically, we investigate the use of root-mean squared (RMS)-based multilead followed by a single-lead online delineation algorithm, which is based on a state-of-the-art offline single-lead delineator. The algorithmic transformations and software optimizations necessary to enable embedded ECG delineation notwithstanding the limited processing and storage resources of the target platform are described, and the performance of the resulting implementations are analyzed in terms of delineation accuracy, execution time, and memory usage. Interestingly, RMS-based multilead delineation is shown to perform equivalently to the best single-lead delineation for the 2-lead QT database (QTDB), within a fraction of a sample duration of the Common Standards for Electrocardiography (CSE) committee tolerances. Finally, a comprehensive evaluation of the energy consumption entailed by the considered algorithms is proposed, which allows very relevant insights into the dominant energy-draining functionalities and which suggests suitable design guidelines for long-lasting wearable ECG monitoring systems.

  3. High-Frequency Electrocardiography: Optimizing the Diagnosis of the Acute Myocardial Infarct with ST-Elevation

    NASA Astrophysics Data System (ADS)

    Naydenov, S.; Donova, T.; Matveev, M.; Gegova, A.; Popdimitrova, N.; Zlateva, G.; Vladimirova, D.

    2007-04-01

    The analysis of the received digital signal by computer microprocessor in high-frequency electrocardiography, used in our research, makes possible synthesis of vectorcardiographic images and loops, allowing improved qualitative and quantitative diagnosing of the myocardial injury.

  4. Simplified 2D Bidomain Model of Whole Heart Electrical Activity and ECG Generation

    NASA Astrophysics Data System (ADS)

    Sovilj, Siniša; Magjarević, Ratko; Abed, Amr Al; Lovell, Nigel H.; Dokos, Socrates

    2014-06-01

    The aim of this study was the development of a geometrically simple and highly computationally-efficient two dimensional (2D) biophysical model of whole heart electrical activity, incorporating spontaneous activation of the sinoatrial node (SAN), the specialized conduction system, and realistic surface ECG morphology computed on the torso. The FitzHugh-Nagumo (FHN) equations were incorporated into a bidomain finite element model of cardiac electrical activity, which was comprised of a simplified geometry of the whole heart with the blood cavities, the lungs and the torso as an extracellular volume conductor. To model the ECG, we placed four electrodes on the surface of the torso to simulate three Einthoven leads VI, VII and VIII from the standard 12-lead system. The 2D model was able to reconstruct ECG morphology on the torso from action potentials generated at various regions of the heart, including the sinoatrial node, atria, atrioventricular node, His bundle, bundle branches, Purkinje fibers, and ventricles. Our 2D cardiac model offers a good compromise between computational load and model complexity, and can be used as a first step towards three dimensional (3D) ECG models with more complex, precise and accurate geometry of anatomical structures, to investigate the effect of various cardiac electrophysiological parameters on ECG morphology.

  5. Competency in ECG Interpretation Among Medical Students

    PubMed Central

    Kopeć, Grzegorz; Magoń, Wojciech; Hołda, Mateusz; Podolec, Piotr

    2015-01-01

    Background Electrocardiogram (ECG) is commonly used in diagnosis of heart diseases, including many life-threatening disorders. We aimed to assess skills in ECG interpretation among Polish medical students and to analyze the determinants of these skills. Material/Methods Undergraduates from all Polish medical schools were asked to complete a web-based survey containing 18 ECG strips. Questions concerned primary ECG parameters (rate, rhythm, and axis), emergencies, and common ECG abnormalities. Analysis was restricted to students in their clinical years (4th–6th), and students in their preclinical years (1st–3rd) were used as controls. Results We enrolled 536 medical students (females: n=299; 55.8%), aged 19 to 31 (23±1.6) years from all Polish medical schools. Most (72%) were in their clinical years. The overall rate of good response was better in students in years 4th–5th than those in years 1st–3rd (66% vs. 56%; p<0.0001). Competency in ECG interpretation was higher in students who reported ECG self-learning (69% vs. 62%; p<0.0001) but no difference was found between students who attended or did not attend regular ECG classes (66% vs. 66%; p=0.99). On multivariable analysis (p<0.0001), being in clinical years (OR: 2.45 [1.35–4.46] and self-learning (OR: 2.44 [1.46–4.08]) determined competency in ECG interpretation. Conclusions Polish medical students in their clinical years have a good level of competency in interpreting the primary ECG parameters, but their ability to recognize ECG signs of emergencies and common heart abnormalities is low. ECG interpretation skills are determined by self-education but not by attendance at regular ECG classes. Our results indicate qualitative and quantitative deficiencies in teaching ECG interpretation at medical schools. PMID:26541993

  6. Competency in ECG Interpretation Among Medical Students.

    PubMed

    Kopeć, Grzegorz; Magoń, Wojciech; Hołda, Mateusz; Podolec, Piotr

    2015-11-06

    Electrocardiogram (ECG) is commonly used in diagnosis of heart diseases, including many life-threatening disorders. We aimed to assess skills in ECG interpretation among Polish medical students and to analyze the determinants of these skills. Undergraduates from all Polish medical schools were asked to complete a web-based survey containing 18 ECG strips. Questions concerned primary ECG parameters (rate, rhythm, and axis), emergencies, and common ECG abnormalities. Analysis was restricted to students in their clinical years (4th-6th), and students in their preclinical years (1st-3rd) were used as controls. We enrolled 536 medical students (females: n=299; 55.8%), aged 19 to 31 (23±1.6) years from all Polish medical schools. Most (72%) were in their clinical years. The overall rate of good response was better in students in years 4th-5th than those in years 1st-3rd (66% vs. 56%; p<0.0001). Competency in ECG interpretation was higher in students who reported ECG self-learning (69% vs. 62%; p<0.0001) but no difference was found between students who attended or did not attend regular ECG classes (66% vs. 66%; p=0.99). On multivariable analysis (p<0.0001), being in clinical years (OR: 2.45 [1.35-4.46] and self-learning (OR: 2.44 [1.46-4.08]) determined competency in ECG interpretation. Polish medical students in their clinical years have a good level of competency in interpreting the primary ECG parameters, but their ability to recognize ECG signs of emergencies and common heart abnormalities is low. ECG interpretation skills are determined by self-education but not by attendance at regular ECG classes. Our results indicate qualitative and quantitative deficiencies in teaching ECG interpretation at medical schools.

  7. Improving Door-to-balloon Time by Decreasing Door-to-ECG time for Walk-in STEMI Patients

    PubMed Central

    Coyne, Christopher J.; Testa, Nicholas; Desai, Shoma; Lagrone, Joy; Chang, Roger; Zheng, Ling; Kim, Hyung

    2015-01-01

    Introduction The American Heart Association/American College of Cardiology guidelines recommend rapid door-to-electrocardiography (ECG) times for patients with ST-segment elevation myocardial infarction (STEMI). Previous quality improvement research at our institution revealed that we were not meeting this benchmark for walk-in STEMI patients. The objective is to investigate whether simple, directed changes in the emergency department (ED) triage process for potential cardiac patients could decrease door-to-ECG times and secondarily door-to-balloon times. Methods We conducted an interventional study at a large, urban, public teaching hospital from April 2010 to June 2012. All patients who walked into the ED with a confirmed STEMI were enrolled in the study. The primary intervention involved creating a chief complaint-based “cardiac triage” designation that streamlined the evaluation of potential cardiac patients. A secondary intervention involved moving our ECG technician and ECG station to our initial triage area. The primary outcome measure was door-to-ECG time and the secondary outcome measure was door-to-balloon time. Results We enrolled 91 walk-in STEMI patients prior to the intervention period and 141 patients after the invention. We observed statistically significant reductions in door-to-ECG time (43±93 to 30±72 minutes, median 23 to 14 minutes p<0.01), ECG-to-activation time (87±134 to 52±82 minutes, median 43 to 31 minutes p<0.01), and door-to-balloon time (134±146 to 84±40 minutes, median 85 -75 minutes p=0.03). Conclusion By creating a chief complaint-based cardiac triage protocol and by streamlining ECG completion, walk-in STEMI patients are systematically processed through the ED. This is not only associated with a decrease in door-to-balloon time, but also a decrease in the variability of the time sensitive intervals of door-to-ECG and ECG-to-balloon time. PMID:25671039

  8. Value of Exercise ECG for Risk Stratification in Suspected or Known CAD in the Era of Advanced Imaging Technologies.

    PubMed

    Bourque, Jamieson M; Beller, George A

    2015-11-01

    Exercise stress electrocardiography (ExECG) is underutilized as the initial test modality in patients with interpretable electrocardiograms who are able to exercise. Although stress myocardial imaging techniques provide valuable diagnostic and prognostic information, variables derived from ExECG can yield substantial data for risk stratification, either supplementary to imaging variables or without concurrent imaging. In addition to exercise-induced ischemic ST-segment depression, such markers as ST-segment elevation in lead aVR, abnormal heart rate recovery post-exercise, failure to achieve target heart rate, and poor exercise capacity improve risk stratification of ExECG. For example, patients achieving ≥10 metabolic equivalents on ExECG have a very low prevalence of inducible ischemia and an excellent prognosis. In contrast, cardiac imaging techniques add diagnostic and prognostic value in higher-risk populations (e.g., poor functional capacity, diabetes, or chronic kidney disease). Optimal test selection for symptomatic patients with suspected coronary artery disease requires a patient-centered approach factoring in the risk/benefit ratio and cost-effectiveness.

  9. Morphological abnormalities in baseline ECGs in healthy normal volunteers participating in phase I studies

    PubMed Central

    Hingorani, Pooja; Natekar, Mili; Deshmukh, Sheetal; Karnad, Dilip R.; Kothari, Snehal; Narula, Dhiraj; Lokhandwala, Yash

    2012-01-01

    Background & objectives: Morphological abnormalities in 12-lead electrocardiograms (ECGs) are seen in subgroups of healthy individuals like athletes and air-force personnel. As these populations may not truly represent healthy individuals, we assessed morphological abnormalities in ECG in healthy volunteers participating in phase I studies, who are screened to exclude associated conditions. Methods: ECGs from 62 phase I studies analyzed in a central ECG laboratory were pooled. A single drug-free baseline ECG from each subject was reviewed by experienced cardiologists. ECG intervals were measured on five consecutive beats and morphological abnormalities identified using standard guidelines. Results: Morphological abnormalities were detected in 25.5 per cent of 3978 healthy volunteers (2495 males, 1483 females; aged 18-76 yr); the presence was higher in males (29.3% vs. 19.2% in females; P<0.001). Rhythm abnormalities were the commonest (11.5%) followed by conduction abnormalities (5.9%), axis deviation (4%), ST-T wave changes (3.1%) and chamber enlargement (1.4%). Incomplete right bundle branch block (RBBB), short PR interval and right ventricular hypertrophy were common in young subjects (<20 yr) while atrial fibrillation, first degree atrioventricular block, complete RBBB and left anterior fascicular block were more prevalent in elderly subjects (>65 yr). Prolonged PR interval, RBBB and intraventricular conduction defects were more common in males while sinus tachycardia, short PR interval and non-specific T wave changes were more frequent in females. Interpretation & Conclusions: Morphological abnormalities in ECG are commonly seen in healthy volunteers participating in phase I studies; and vary with age and gender. Further studies are required to determine whether these abnormalities persist or if some of these disappear on follow up. PMID:22561618

  10. Embroidered Electrode with Silver/Titanium Coating for Long-Term ECG Monitoring

    PubMed Central

    Weder, Markus; Hegemann, Dirk; Amberg, Martin; Hess, Markus; Boesel, Luciano F.; Abächerli, Roger; Meyer, Veronika R.; Rossi, René M.

    2015-01-01

    For the long-time monitoring of electrocardiograms, electrodes must be skin-friendly and non-irritating, but in addition they must deliver leads without artifacts even if the skin is dry and the body is moving. Today's adhesive conducting gel electrodes are not suitable for such applications. We have developed an embroidered textile electrode from polyethylene terephthalate yarn which is plasma-coated with silver for electrical conductivity and with an ultra-thin titanium layer on top for passivation. Two of these electrodes are embedded into a breast belt. They are moisturized with a very low amount of water vapor from an integrated reservoir. The combination of silver, titanium and water vapor results in an excellent electrode chemistry. With this belt the long-time monitoring of electrocardiography (ECG) is possible at rest as well as when the patient is moving. PMID:25599424

  11. Comparison of image quality and radiation dose between prospectively ECG-triggered and retrospectively ECG-gated CT angiography: Establishing heart rate cut-off values in first-generation dual-source CT.

    PubMed

    Ünal, Emre; Yıldız, A Elçin; Güler, Ezgi; Karcaaltıncaba, Muşturay; Akata, Deniz; Kılınçer, Abidin; Atlı, Eray; Topçuoğlu, Melih; Hazırolan, Tuncay

    2015-09-01

    To evaluate radiation dose and image quality of prospectively electrocardiography (ECG)-triggered and retrospectively ECG-gated coronary computed tomography (CT) angiography and to establish cut-off values of heart rates (HRs) for each technique in first-generation dual-source CT. A total of 200 consecutive patients with suspected coronary artery disease were accepted into the study. Patients were selected randomly for each technique (prospective triggering group n=99, mean age 55.85±10.74 and retrospective gating group n=101, mean age 53.38±11.58). Two independent radiologists scored coronary artery segments for image quality using a 5-point scale. Also, attenuation values of each coronary artery segment and dose-length product values were measured. For each technique, cut-off HR values were determined for the best image quality. Mean image quality scores and attenuation values were found to be higher in the prospective triggering group (p<0.05). Mean radiation dose was 73% lower for the prospective triggering group (p<0.01). The cut-off HR values for good image quality scores were ≤67 beats per minute (bpm) and ≤80 bpm for the prospective triggering and retrospective gating groups, respectively (p<0.05). Increased HR (≥68 and ≥81 bpm, respectively) had negative effects on image quality (p<0.05). The prospective ECG triggering technique has better image quality scores than retrospective ECG gating, particularly in patients who have an HR of less than 68 bpm. Also, a 73% radiation dose reduction can be achieved with prospective ECG triggering. In patients with higher heart rates, retrospective ECG gating is recommended.

  12. Two hybrid regularization frameworks for solving the electrocardiography inverse problem.

    PubMed

    Jiang, Mingfeng; Xia, Ling; Shou, Guofa; Liu, Feng; Crozier, Stuart

    2008-09-21

    In this paper, two hybrid regularization frameworks, LSQR-Tik and Tik-LSQR, which integrate the properties of the direct regularization method (Tikhonov) and the iterative regularization method (LSQR), have been proposed and investigated for solving ECG inverse problems. The LSQR-Tik method is based on the Lanczos process, which yields a sequence of small bidiagonal systems to approximate the original ill-posed problem and then the Tikhonov regularization method is applied to stabilize the projected problem. The Tik-LSQR method is formulated as an iterative LSQR inverse, augmented with a Tikhonov-like prior information term. The performances of these two hybrid methods are evaluated using a realistic heart-torso model simulation protocol, in which the heart surface source method is employed to calculate the simulated epicardial potentials (EPs) from the action potentials (APs), and then the acquired EPs are used to calculate simulated body surface potentials (BSPs). The results show that the regularized solutions obtained by the LSQR-Tik method are approximate to those of the Tikhonov method, the computational cost of the LSQR-Tik method, however, is much less than that of the Tikhonov method. Moreover, the Tik-LSQR scheme can reconstruct the epcicardial potential distribution more accurately, specifically for the BSPs with large noisy cases. This investigation suggests that hybrid regularization methods may be more effective than separate regularization approaches for ECG inverse problems.

  13. Atrial flutter: from ECG to electroanatomical 3D mapping

    PubMed Central

    PEDRINAZZI, CLAUDIO; DURIN, ORNELLA; MASCIOLI, GIOSUÈ; CURNIS, ANTONIO; RADDINO, RICCARDO; INAMA, GIUSEPPE; DEI CAS, LIVIO

    2006-01-01

    Atrial flutter is a common arrhythmia that may cause significant symptoms, including palpitations, dyspnea, chest pain and even syncope. Frequently it’s possible to diagnose atrial flutter with a 12-lead surface ECG, looking for distinctive waves in leads II, III, aVF, aVL, V1,V2. Puech and Waldo developed the first classification of atrial flutter in the 1970s. These authors divided the arrhythmia into type I and type II. Therefore, in 2001 the European Society of Cardiology and the North American Society of Pacing and Electrophysiology developed a new classification of atrial flutter, based not only on the ECG, but also on the electrophysiological mechanism. New developments in endocardial mapping, including the electroanatomical 3D mapping system, have greatly expanded our understanding of the mechanism of arrhythmias. More recently, Scheinman et al, provided an updated classification and nomenclature. The terms like common, uncommon, typical, reverse typical or atypical flutter are abandoned because they may generate confusion. The authors worked out a new terminology, which differentiates atrial flutter only on the basis of electrophysiological mechanism. PMID:21977266

  14. Severe hyperkalemia can be detected immediately by quantitative electrocardiography and clinical history in patients with symptomatic or extreme bradycardia: a retrospective cross-sectional study.

    PubMed

    Chon, Sung-Bin; Kwak, Young Ho; Hwang, Seung-Sik; Oh, Won Sup; Bae, Jun-Ho

    2013-12-01

    Detecting severe hyperkalemia is challenging. We explored its prevalence in symptomatic or extreme bradycardia and devised a diagnostic rule. This retrospective cross-sectional study included patients with symptomatic (heart rate [HR] ≤ 50/min with dyspnea, chest pain, altered mentality, dizziness/syncope/presyncope, general weakness, oliguria, or shock) or extreme (HR ≤ 40/min) bradycardia at an emergency department for 46 months. Risk factors for severe hyperkalemia were chosen by multiple logistic regression analysis from history (sex, age, comorbidities, and medications), vital signs, and electrocardiography (ECG; maximum precordial T-wave amplitude, PR, and QRS intervals). The derived diagnostic index was validated using bootstrapping method. Among the 169 participants enrolled, 87 (51.5%) were female. The mean (SD) age was 71.2 (12.5) years. Thirty-six (21.3%) had severe hyperkalemia. The diagnostic summed "maximum precordial T ≥ 8.5 mV (2)," "atrial fibrillation/junctional bradycardia (1)," "HR ≤ 42/min (1)," "diltiazem medication (2)," and "diabetes mellitus (1)." The C-statistics were 0.86 (0.80-0.93) and were validated. For scores of 4 or higher, sensitivity was 0.50, specificity was 0.92, and positive likelihood ratio was 6.02. The "ECG-only index," which sums the 3 ECG findings, had a sensitivity of 0.50, specificity of 0.90, and likelihood ratio (+) of 5.10 for scores of 3 or higher. Severe hyperkalemia is prevalent in symptomatic or extreme bradycardia and detectable by quantitative electrocardiographic parameters and history. © 2013.

  15. Month-to-Month and Year-to-Year Reproducibility of High Frequency QRS ECG signals

    NASA Technical Reports Server (NTRS)

    Batdorf, Niles; Feiveson, Alan H.; Schlegel, Todd T.

    2006-01-01

    High frequency (HF) electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. We therefore prospectively investigated the reproducibility of the root mean squared (RMS) voltage, kurtosis, and the presence versus absence of reduced amplitude zones (RAzs) in signal averaged 12-lead HF QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of RMS voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of RMS voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. RAzs were also reproducible at a rate of up to 87% and 8 1 %, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead HF QRS electrocardiograms are sufficiently reproducible for clinical use.

  16. Month-to-month and year-to-year reproducibility of high frequency QRS ECG signals

    NASA Technical Reports Server (NTRS)

    Batdorf, Niles J.; Feiveson, Alan H.; Schlegel, Todd T.

    2004-01-01

    High frequency electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. Therefore, we prospectively investigated the reproducibility of the root mean squared voltage, kurtosis, and the presence versus absence of reduced amplitude zones in signal averaged 12-lead high frequency QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of root mean squared voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of root mean squared voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. Reduced amplitude zones were also reproducible up to a rate of 87% and 81%, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead high frequency QRS electrocardiograms are sufficiently reproducible for clinical use.

  17. Month-to-month and year-to-year reproducibility of high frequency QRS ECG signals

    NASA Technical Reports Server (NTRS)

    Batdorf, Niles J.; Feiveson, Alan H.; Schlegel, Todd T.

    2004-01-01

    High frequency electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. Therefore, we prospectively investigated the reproducibility of the root mean squared voltage, kurtosis, and the presence versus absence of reduced amplitude zones in signal averaged 12-lead high frequency QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of root mean squared voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of root mean squared voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. Reduced amplitude zones were also reproducible up to a rate of 87% and 81%, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead high frequency QRS electrocardiograms are sufficiently reproducible for clinical use.

  18. T-wave alternans in LQTS: repolarization-rate dynamics from digital 12-lead Holter data.

    PubMed

    Brockmeier, K; Aslan, I; Hilbel, T; Eberle, T; Ulmer, H E; Lux, R L

    2001-01-01

    T-wave alternans (TWA) is a harbinger of ventricular vulnerability and an important prognostic indicator for torsade de pointes and likely sudden death in patients with LQTS. We analyzed the occurrence of TWA in 18 patients with LQTS (7 males, 11 females, ages ranging from 6 months to 32 years--median 8.4 years). Analysis was performed with software to investigate dynamics of cycle length mediated repolarization changes. Digital Holter ECG analysis revealed macroscopic, true TWA in 3 of 18 patients. TWA showed a variable morphological expression. One patient had continuous changes of T wave polarity, but not on a periodic beat-to-beat basis. Onsets of macroscopic TWA were preceded by long/short cycle length sequences and tachycardic rates above 130 to 140 bpm. Impact of ventricular premature beats on TWA onset was insignificant. Two of the identified patients with TWA had sudden cardiac death during follow-up (one refused PM therapy). At present, TWA cannot be detected automatically from Holter ECGs and therefore may be missed, despite the potential danger for the individuals. The observation that predominantly high beat rates and not beat rate changes, per se, triggered episodes of TWA renders difficult general therapeutic recommendations for the identified patients at risk.

  19. Adaptive Fourier decomposition based ECG denoising.

    PubMed

    Wang, Ze; Wan, Feng; Wong, Chi Man; Zhang, Liming

    2016-10-01

    A novel ECG denoising method is proposed based on the adaptive Fourier decomposition (AFD). The AFD decomposes a signal according to its energy distribution, thereby making this algorithm suitable for separating pure ECG signal and noise with overlapping frequency ranges but different energy distributions. A stop criterion for the iterative decomposition process in the AFD is calculated on the basis of the estimated signal-to-noise ratio (SNR) of the noisy signal. The proposed AFD-based method is validated by the synthetic ECG signal using an ECG model and also real ECG signals from the MIT-BIH Arrhythmia Database both with additive Gaussian white noise. Simulation results of the proposed method show better performance on the denoising and the QRS detection in comparing with major ECG denoising schemes based on the wavelet transform, the Stockwell transform, the empirical mode decomposition, and the ensemble empirical mode decomposition.

  20. Cost-effectiveness of pre-participation screening of athletes with ECG in Europe and Algeria.

    PubMed

    Assanelli, Deodato; Levaggi, Rosella; Carré, François; Sharma, Sanjay; Deligiannis, Asterios; Mellwig, Klaus Peter; Tahmi, Mohamed; Vinetti, Giovanni; Aliverti, Paola

    2015-03-01

    The aim of this study is to evaluate the cost-effectiveness of ECG in combination with family and personal history and physical examination in order to detect cardiovascular diseases that might cause sudden death in athletes. The study was conducted on a cohort of 6,634, mainly young professional and recreational athletes, 1,071 from Algeria and 5,563 from Europe (France, Germany and Greece). Each athlete underwent medical history, physical examination, and resting 12-lead ECG. 293 athletes (4.4 %), 149 in Europe (2.7 %) and 144 in Algeria (13.4 %) required further tests, and 56 were diagnosed with cardiovascular disease and thus disqualified. The cost-effectiveness ratio (CER) was calculated as the ratio between the cost of screening and the number of statistical life-years saved by the intervention. The estimated reduced risk of death deriving from treatment or disqualification resulted in the saving of 79.1 statistical life-years in Europe and 136.3 in Algeria. CER of screening was 4,071 purchasing-power-parity-adjusted US dollars ($PPP) in Europe and 582 $PPP in Algeria. The results of this study strongly support the utilisation of 12-lead ECG in the pre-participation screening of young athletes, especially in countries where secondary preventive care is not highly developed.

  1. ECG data compression using Jacobi polynomials.

    PubMed

    Tchiotsop, Daniel; Wolf, Didier; Louis-Dorr, Valérie; Husson, René

    2007-01-01

    Data compression is a frequent signal processing operation applied to ECG. We present here a method of ECG data compression utilizing Jacobi polynomials. ECG signals are first divided into blocks that match with cardiac cycles before being decomposed in Jacobi polynomials bases. Gauss quadratures mechanism for numerical integration is used to compute Jacobi transforms coefficients. Coefficients of small values are discarded in the reconstruction stage. For experimental purposes, we chose height families of Jacobi polynomials. Various segmentation approaches were considered. We elaborated an efficient strategy to cancel boundary effects. We obtained interesting results compared with ECG compression by wavelet decomposition methods. Some propositions are suggested to improve the results.

  2. Electrocardiography as the First Step for the Further Examination of Cardiac Involvement in Myasthenia Gravis.

    PubMed

    Kato, Takao; Hirose, Sayako; Kumagai, Shogo; Ozaki, Akihiko; Matsumoto, Sadayuki; Inoko, Moriaki

    2016-01-01

    Cardiac involvement of myasthenia gravis (MG) accompanies a poor prognosis. In the present study, we aimed to investigate the relationship between ECG abnormality and cardiac involvement. Of 178 patients diagnosed with MG between 2001 and 2013 at our hospital, we retrospectively analyzed consecutive 58 patients who underwent both ECG and echocardiography and without underlying cardiovascular disease. ECG abnormalities were defined by computer-assigned Minnesota-codes. Cardiac damage was defined as either (1) ejection fraction (EF) <55% on echocardiography or (2) elevated E/e', the ratio of mitral velocity to early diastolic velocity of the mitral annulus >8 on echocardiography. Thirty-three patients (56.8%) had ECG abnormality. An elevated E/e' was observed in patients with ECG abnormality compared to those without ECG abnormality (11.2 ± 3.2, 8.7 ± 2.2, resp., p = 0.03). Among patients with ECG abnormality, 14 of 15 patients showed cardiac damage. Among patients without ECG abnormality, 6 of 33 patients showed cardiac damage (p = 0.003). Reduced EF was observed in five patients (8.6%) with ECG abnormality and none in patients without ECG abnormality. ECG may aid as the first step for the further examination of cardiac damage in patients with MG.

  3. Association of Implementation of Practice Standards for Electrocardiographic Monitoring With Nurses' Knowledge, Quality of Care, and Patient Outcomes: Findings From the Practical Use of the Latest Standards of Electrocardiography (PULSE) Trial.

    PubMed

    Funk, Marjorie; Fennie, Kristopher P; Stephens, Kimberly E; May, Jeanine L; Winkler, Catherine G; Drew, Barbara J

    2017-02-01

    Although continuous electrocardiographic (ECG) monitoring is ubiquitous in hospitals, monitoring practices are inconsistent. We evaluated implementation of American Heart Association practice standards for ECG monitoring on nurses' knowledge, quality of care, and patient outcomes. The PULSE (Practical Use of the Latest Standards of Electrocardiography) Trial was a 6-year multisite randomized clinical trial with crossover that took place in 65 cardiac units in 17 hospitals. We measured outcomes at baseline, time 2 after group 1 hospitals received the intervention, and time 3 after group 2 hospitals received the intervention. Measurement periods were 15 months apart. The 2-part intervention consisted of an online ECG monitoring education program and strategies to implement and sustain change in practice. Nurses' knowledge (N=3013 nurses) was measured by a validated 20-item online test, quality of care related to ECG monitoring (N=4587 patients) by on-site observation, and patient outcomes (mortality, in-hospital myocardial infarction, and not surviving a cardiac arrest; N=95 884 hospital admissions) by review of administrative, laboratory, and medical record data. Nurses' knowledge improved significantly immediately after the intervention in both groups but was not sustained 15 months later. For most measures of quality of care (accurate electrode placement, accurate rhythm interpretation, appropriate monitoring, and ST-segment monitoring when indicated), the intervention was associated with significant improvement, which was sustained 15 months later. Of the 3 patient outcomes, only in-hospital myocardial infarction declined significantly after the intervention and was sustained. Online ECG monitoring education and strategies to change practice can lead to improved nurses' knowledge, quality of care, and patient outcomes. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01269736. © 2017 American Heart Association, Inc.

  4. The Moli-sani project: computerized ECG database in a population-based cohort study.

    PubMed

    Iacoviello, Licia; Rago, Livia; Costanzo, Simona; Di Castelnuovo, Augusto; Zito, Francesco; Assanelli, Deodato; Badilini, Fabio; Donati, Maria Benedetta; de Gaetano, Giovanni

    2012-01-01

    Computerized electrocardiogram (ECG) acquisition and interpretation may be extremely useful in handling analysis of data from large cohort studies and exploit research on the use of ECG data as prognostic markers for cardiovascular disease. The Moli-sani project (http://www.moli-sani.org) is a population-based cohort study aiming at evaluating the risk factors linked to chronic-degenerative disease with particular regard to cardiovascular disease and cancer and intermediate metabolic phenotypes such as hypertension, diabetes, dyslipidemia, obesity, and metabolic syndrome. Between March 2005 and April 2010, 24 325 people aged 35 years or older, living in the Molise region (Italy), were randomly recruited. A follow-up based on linkage with hospital discharge records and mortality regional registry and reexamination of the cohort is ongoing and will be repeated at prefixed times. Each subject was administered questionnaires on personal and medical history, food consumption, quality of life (FS36), and psychometry. Plasma serum, cellular pellet, and urinary spots were stored in liquid nitrogen. Subjects were measured blood pressure, weight, height, and waist and hip circumferences, and underwent spirometry to evaluate pulmonary diffusion capacity, gas diffusion, and pulmonary volumes. Standard 12-lead resting ECG was performed by a Cardiette ar2100-view electrocardiograph and tracings stored in digital standard communication protocol format for subsequent analysis. The digital ECG database of the Moli-sani project is currently being used to assess the association between physiologic variables and pathophyiosiologic conditions and parameters derived from the ECG signal. This computerized ECG database represents a unique opportunity to identify and assess prognostic factors associated with cardiovascular and metabolic diseases. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Spectral and spatiotemporal variability ECG parameters linked to catheter ablation outcome in persistent atrial fibrillation.

    PubMed

    Hidalgo-Muñoz, Antonio R; Latcu, Decebal G; Meo, Marianna; Meste, Olivier; Popescu, Irina; Saoudi, Nadir; Zarzoso, Vicente

    2017-09-01

    With the increasing prevalence of atrial fibrillation (AF), there is a strong clinical interest in determining whether a patient suffering from persistent AF will benefit from catheter ablation (CA) therapy at long term. This work presents several regression models based on noninvasive measures automatically computed from the standard 12-lead electrocardiogram (ECG) such as AF dominant frequency (DF), spectral concentration and spatiotemporal variability (STV). Sixty-two AF patients referred to CA were enrolled in this study. Forty-seven of them had no recurrence after CA during an average follow-up of 14 ± 8 months. The ECG features were extracted from an ECG recorded before the CA intervention and they were combined by means of logistic regression. The combination of DF and STV values from different precordial leads reached AUC = 0.939, outperforming the best results by using only one kind of features, such as DF (AUC = 0.801), and yielding a global accuracy of 93.5% for discriminating the best long-term responders to CA. These results point out the need to take into consideration the spatial variation of spectral ECG parameters to build predictive models dealing with AF. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. ECG abnormalities predict neurogenic pulmonary edema in patients with subarachnoid hemorrhage.

    PubMed

    Chen, Wei-Lung; Huang, Chi-Hung; Chen, Jiann-Hwa; Tai, Henry Chih-Hung; Chang, Su-Hen; Wang, Yung-Cheng

    2016-01-01

    The study aims to assess if electrocardiographic (ECG) abnormalities could predict the development of neurogenic pulmonary edema (NPE) within 24 hours in cases of spontaneous subarachnoid hemorrhage (SAH). We studied prospectively a cohort of 269 adult patients with nontraumatic SAH in an emergency department of a university-affiliated medical center. A 12-lead ECG was taken for these patients. The patients were stratified into NPE and non-NPE based on serially clinical and radiologic findings. The ECG abnormalities were compared between these 2 groups of patients. Compared with the non-NPE (n = 229), the NPE (n = 40) had significantly higher World Federation of Neurological Surgeons class (P < .001), higher Hunt-Hess scale (P < .001), and higher prevalence of diabetes mellitus (P = .033). In addition, the percentage of ECG morphological abnormality was significantly higher in NPE, in which nonspecific ST- or T-wave changes (NSSTTCs) are significantly higher. Multiple logistic regression model identified World Federation of Neurological Surgeons class (95% confidence interval [CI], 2.6-13.3; P < .001), abnormal Q or QS wave (95% CI, 1.1-9.1; P = .038), and NSSTTCs (95% CI, 1.2-7.5; P = .016) as the significant variables associated with NPE. Electrocardiographic abnormalities, especially abnormal Q or QS wave and NSSTTCs, may predict the development of NPE within 24 hours in adult patients with spontaneous SAH. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Modern standards of ECG interpretation in young athletes: yield and effectiveness.

    PubMed

    Asif, Irfan M; Prutkin, Jordan M

    2015-01-01

    Although cardiovascular screening is recommended before participating in competitive sports, the role of the 12-lead electrocardiogram (ECG) has been debated. When added to the medical history and physical examination, an ECG used during the pre-participation screening (PPS) of young athletes can greatly enhance the ability to detect underlying cardiovascular pathology. Concerns over false positive rates, however, have posed an obstacle to large-scale implementation. The recent development of modern athlete-specific ECG interpretation criteria has dramatically reduced false positive rates to levels below other commonly used screening tests (e.g. breast cancer, prostate cancer) and subsequently improved cost effectiveness. There are also emerging data that certain sub-groups have a higher prevalence of ECG abnormalities, including males, athletes of Afro-Caribbean descent, basketball players, and endurance athletes. While false positive rates from a number of studies are reduced with the improved standards, there may be room for continued improvements. Future efforts should focus on refining criteria based on age, race, gender, ethnicity, and sport, while also clearly delineating the appropriate work-up strategies for those with abnormal findings, as this can lead to improved resource utilization.

  8. [A wireless ECG monitor based on ARM].

    PubMed

    Fan, Ai-Hua; Bian, Chun-Hua; Ning, Xin-Bao; He, Ai-Jun; Zhuang, Jian-Jun; Wu, Xu-Hui

    2008-11-01

    This paper presents a novel monitor which uses ARM controller AT91SAM7S64 as its main processor, LCM (Liquid Crystal Display Module) for displaying ECG waves, SD (Secure Digital memory) card for data storage and RF module PTR8000 for radio data transmission. This portable monitor boasts alarm function for abnormality and can provide dynamic ECG monitoring for patients.

  9. A novel algorithm for Bluetooth ECG.

    PubMed

    Pandya, Utpal T; Desai, Uday B

    2012-11-01

    In wireless transmission of ECG, data latency will be significant when battery power level and data transmission distance are not maintained. In applications like home monitoring or personalized care, to overcome the joint effect of previous issues of wireless transmission and other ECG measurement noises, a novel filtering strategy is required. Here, a novel algorithm, identified as peak rejection adaptive sampling modified moving average (PRASMMA) algorithm for wireless ECG is introduced. This algorithm first removes error in bit pattern of received data if occurred in wireless transmission and then removes baseline drift. Afterward, a modified moving average is implemented except in the region of each QRS complexes. The algorithm also sets its filtering parameters according to different sampling rate selected for acquisition of signals. To demonstrate the work, a prototyped Bluetooth-based ECG module is used to capture ECG with different sampling rate and in different position of patient. This module transmits ECG wirelessly to Bluetooth-enabled devices where the PRASMMA algorithm is applied on captured ECG. The performance of PRASMMA algorithm is compared with moving average and S-Golay algorithms visually as well as numerically. The results show that the PRASMMA algorithm can significantly improve the ECG reconstruction by efficiently removing the noise and its use can be extended to any parameters where peaks are importance for diagnostic purpose.

  10. Non-constrained blood pressure monitoring using ECG and PPG for personal healthcare.

    PubMed

    Yoon, Youngzoon; Cho, Jung H; Yoon, Gilwon

    2009-08-01

    Blood pressure (BP) is one of the important vital signs that need to be monitored for personal healthcare. Arterial blood pressure (BP) was estimated from pulse transit time (PTT) and PPG waveform. PTT is a time interval between an R-wave of electrocardiography (ECG) and a photoplethysmography (PPG) signal. This method does not require an aircuff and only a minimal inconvenience of attaching electrodes and LED/photo detector sensors on a subject. PTT computed between the ECG R-wave and the maximum first derivative PPG was strongly correlated with systolic blood pressure (SBP) (R = -0.712) compared with other PTT values, and the diastolic time proved to be appropriate for estimation diastolic blood pressure (DBP) (R = -0.764). The percent errors of SBP using the individual regression line (4-11%) were lower than those using the regression line obtained from all five subjects (9-14%). On the other hand, the DBP estimation did not show much difference between the individual regression (4-10%) and total regression line (6-10%). Our developed device had a total size of 7 x 13.5 cm and was operated by single 3-V battery. Biosignals can be measured for 72 h continuously without external interruptions. Through a serial network communication, an external personal computer can monitor measured waveforms in real time. Our proposed method can be used for non-constrained, thus continuous BP monitoring for the purpose of personal healthcare.

  11. A Wavelet-Based ECG Delineation Method: Adaptation to an Experimental Electrograms with Manifested Global Ischemia.

    PubMed

    Hejč, Jakub; Vítek, Martin; Ronzhina, Marina; Nováková, Marie; Kolářová, Jana

    2015-09-01

    We present a novel wavelet-based ECG delineation method with robust classification of P wave and T wave. The work is aimed on an adaptation of the method to long-term experimental electrograms (EGs) measured on isolated rabbit heart and to evaluate the effect of global ischemia in experimental EGs on delineation performance. The algorithm was tested on a set of 263 rabbit EGs with established reference points and on human signals using standard Common Standards for Quantitative Electrocardiography Standard Database (CSEDB). On CSEDB, standard deviation (SD) of measured errors satisfies given criterions in each point and the results are comparable to other published works. In rabbit signals, our QRS detector reached sensitivity of 99.87% and positive predictivity of 99.89% despite an overlay of spectral components of QRS complex, P wave and power line noise. The algorithm shows great performance in suppressing J-point elevation and reached low overall error in both, QRS onset (SD = 2.8 ms) and QRS offset (SD = 4.3 ms) delineation. T wave offset is detected with acceptable error (SD = 12.9 ms) and sensitivity nearly 99%. Variance of the errors during global ischemia remains relatively stable, however more failures in detection of T wave and P wave occur. Due to differences in spectral and timing characteristics parameters of rabbit based algorithm have to be highly adaptable and set more precisely than in human ECG signals to reach acceptable performance.

  12. EEG and ECG changes during simulator operation reflect mental workload and vigilance.

    PubMed

    Dussault, Caroline; Jouanin, Jean-Claude; Philippe, Matthieu; Guezennec, Charles-Yannick

    2005-04-01

    Performing mission tasks in a simulator influences many neurophysiological measures. Quantitative assessments of electroencephalography (EEG) and electrocardiography (ECG) have made it possible to develop indicators of mental workload and to estimate relative physiological responses to cognitive requirements. To evaluate the effects of mental workload without actual physical risk, we studied the cortical and cardiovascular changes that occurred during simulated flight. There were 12 pilots (8 novices and 4 experts) who simulated a flight composed of 10 sequences that induced several different mental workload levels. EEG was recorded at 12 electrode sites during rest and flight sequences; ECG activity was also recorded. Subjective tests were used to evaluate anxiety and vigilance levels. Theta band activity was lower during the two simulated flight rest sequences than during visual and instrument flight sequences at central, parietal, and occipital sites (p < 0.05). On the other hand, rest sequences resulted in higher beta (at the C4 site; p < 0.05) and gamma (at the central, parietal, and occipital sites; p < 0.05) power than active segments. The mean heart rate (HR) was not significantly different during any simulated flight sequence, but HR was lower for expert subjects than for novices. The subjective tests revealed no significant anxiety and high values for vigilance levels before and during flight. The different flight sequences performed on the simulator resulted in electrophysiological changes that expressed variations in mental workload. These results corroborate those found during study of real flights, particularly during sequences requiring the heaviest mental workload.

  13. Heritability of ECG Biomarkers in the Netherlands Twin Registry Measured from Holter ECGs.

    PubMed

    Hodkinson, Emily C; Neijts, Melanie; Sadrieh, Arash; Imtiaz, Mohammad S; Baumert, Mathias; Subbiah, Rajesh N; Hayward, Christopher S; Boomsma, Dorret; Willemsen, Gonneke; Vandenberg, Jamie I; Hill, Adam P; De Geus, Eco

    2016-01-01

    The resting ECG is the most commonly used tool to assess cardiac electrophysiology. Previous studies have estimated heritability of ECG parameters based on these snapshots of the cardiac electrical activity. In this study we set out to determine whether analysis of heart rate specific data from Holter ECGs allows more complete assessment of the heritability of ECG parameters. Holter ECGs were recorded from 221 twin pairs and analyzed using a multi-parameter beat binning approach. Heart rate dependent estimates of heritability for QRS duration, QT interval, Tpeak-Tend and Theight were calculated using structural equation modeling. QRS duration is largely determined by environmental factors whereas repolarization is primarily genetically determined. Heritability estimates of both QT interval and Theight were significantly higher when measured from Holter compared to resting ECGs and the heritability estimate of each was heart rate dependent. Analysis of the genetic contribution to correlation between repolarization parameters demonstrated that covariance of individual ECG parameters at different heart rates overlap but at each specific heart rate there was relatively little overlap in the genetic determinants of the different repolarization parameters. Here we present the first study of heritability of repolarization parameters measured from Holter ECGs. Our data demonstrate that higher heritability can be estimated from the Holter than the resting ECG and reveals rate dependence in the genetic-environmental determinants of the ECG that has not previously been tractable. Future applications include deeper dissection of the ECG of participants with inherited cardiac electrical disease.

  14. Heritability of ECG Biomarkers in the Netherlands Twin Registry Measured from Holter ECGs

    PubMed Central

    Hodkinson, Emily C.; Neijts, Melanie; Sadrieh, Arash; Imtiaz, Mohammad S.; Baumert, Mathias; Subbiah, Rajesh N.; Hayward, Christopher S.; Boomsma, Dorret; Willemsen, Gonneke; Vandenberg, Jamie I.; Hill, Adam P.; De Geus, Eco

    2016-01-01

    Introduction: The resting ECG is the most commonly used tool to assess cardiac electrophysiology. Previous studies have estimated heritability of ECG parameters based on these snapshots of the cardiac electrical activity. In this study we set out to determine whether analysis of heart rate specific data from Holter ECGs allows more complete assessment of the heritability of ECG parameters. Methods and Results: Holter ECGs were recorded from 221 twin pairs and analyzed using a multi-parameter beat binning approach. Heart rate dependent estimates of heritability for QRS duration, QT interval, Tpeak–Tend and Theight were calculated using structural equation modeling. QRS duration is largely determined by environmental factors whereas repolarization is primarily genetically determined. Heritability estimates of both QT interval and Theight were significantly higher when measured from Holter compared to resting ECGs and the heritability estimate of each was heart rate dependent. Analysis of the genetic contribution to correlation between repolarization parameters demonstrated that covariance of individual ECG parameters at different heart rates overlap but at each specific heart rate there was relatively little overlap in the genetic determinants of the different repolarization parameters. Conclusions: Here we present the first study of heritability of repolarization parameters measured from Holter ECGs. Our data demonstrate that higher heritability can be estimated from the Holter than the resting ECG and reveals rate dependence in the genetic—environmental determinants of the ECG that has not previously been tractable. Future applications include deeper dissection of the ECG of participants with inherited cardiac electrical disease. PMID:27199769

  15. ECG signal denoising via empirical wavelet transform.

    PubMed

    Singh, Omkar; Sunkaria, Ramesh Kumar

    2016-12-29

    This paper presents new methods for baseline wander correction and powerline interference reduction in electrocardiogram (ECG) signals using empirical wavelet transform (EWT). During data acquisition of ECG signal, various noise sources such as powerline interference, baseline wander and muscle artifacts contaminate the information bearing ECG signal. For better analysis and interpretation, the ECG signal must be free of noise. In the present work, a new approach is used to filter baseline wander and power line interference from the ECG signal. The technique utilized is the empirical wavelet transform, which is a new method used to compute the building modes of a given signal. Its performance as a filter is compared to the standard linear filters and empirical mode decomposition.The results show that EWT delivers a better performance.

  16. III Lead ECG Pulse Measurement Sensor

    NASA Astrophysics Data System (ADS)

    Thangaraju, S. K.; Munisamy, K.

    2015-09-01

    Heart rate sensing is very important. Method of measuring heart pulse by using an electrocardiogram (ECG) technique is described. Electrocardiogram is a measurement of the potential difference (the electrical pulse) generated by a cardiac tissue, mainly the heart. This paper also reports the development of a three lead ECG hardware system that would be the basis of developing a more cost efficient, portable and easy to use ECG machine. Einthoven's Three Lead method [1] is used for ECG signal extraction. Using amplifiers such as the instrumentation amplifier AD620BN and the conventional operational amplifier Ua741 that would be used to amplify the ECG signal extracted develop this system. The signal would then be filtered from noise using Butterworth filter techniques to obtain optimum output. Also a right leg guard was implemented as a safety feature to this system. Simulation was carried out for development of the system using P-spice Program.

  17. Unsupervised learning applied in MER and ECG signals through Gaussians mixtures with the Expectation-Maximization algorithm and Variational Bayesian Inference.

    PubMed

    Vargas Cardona, Hernán Darío; Orozco, Álvaro Ángel; Álvarez, Mauricio A

    2013-01-01

    Automatic identification of biosignals is one of the more studied fields in biomedical engineering. In this paper, we present an approach for the unsupervised recognition of biomedical signals: Microelectrode Recordings (MER) and Electrocardiography signals (ECG). The unsupervised learning is based in classic and bayesian estimation theory. We employ gaussian mixtures models with two estimation methods. The first is derived from the frequentist estimation theory, known as Expectation-Maximization (EM) algorithm. The second is obtained from bayesian probabilistic estimation and it is called variational inference. In this framework, both methods are used for parameters estimation of Gaussian mixtures. The mixtures models are used for unsupervised pattern classification, through the responsibility matrix. The algorithms are applied in two real databases acquired in Parkinson's disease surgeries and electrocardiograms. The results show an accuracy over 85% in MER and 90% in ECG for identification of two classes. These results are statistically equal or even better than parametric (Naive Bayes) and nonparametric classifiers (K-nearest neighbor).

  18. aVR, an index of all ECG limb leads, with clinical utility for monitoring of patients with edematous states, including heart failure.

    PubMed

    Madias, John E

    2009-12-01

    Nonreproducibility of precordial electrocardiogram (ECG) leads in serial ECGs has led to emphasis on the limb leads for some applications. Since modern electrocardiographs measure leads I and II and calculate on line the other four limb leads, the former can substitute for the set of six limb leads. Furthermore, based on the mathematical relationship of lead aVR and leads I and II, it was hypothesized that aVR could be used as a representative index of the set of the six limb leads. The aim of this study was to evaluate whether ECG lead aVR could function as an index of all limb leads, in clinical electrocardiography. Automation-derived and manually derived QRS voltage amplitude measurements of all limb leads in ECGs of a series of 100 randomly selected consecutive patients, and ECGs of 36 patients with various edematous states (EDST), congestive heart failure (CHF), or undergoing hemodialysis (HD), and aVR were inter-correlated with the sums of leads I and II (SigmaI&II), and the entire set of the six limb leads (Sigma6LbLds). Correlation of aVR with SigmaI&II and Sigma6LbLds was excellent (P < 0.00005); also, aVR was found to be a reliable index of the six limb leads in repeat ECGs in the patients with various EDST, CHF, or undergoing HD, in whom changes in aVR correlated with changes in patients' body weight. aVR could be taken as an index of all ECG limb leads in analysis in general, and in monitoring patients with EDST, CHF, and HD in particular.

  19. High dose droperidol and QT prolongation: analysis of continuous 12-lead recordings

    PubMed Central

    Calver, Leonie; Isbister, Geoffrey K

    2014-01-01

    Aims To investigate the QT interval after high dose droperidol using continuous 12-lead Holter recordings. Methods This was a prospective study of patients given droperidol with a continuous Holter recording. Patients were recruited from the DORM II study which included patients with aggression presenting to the emergency department. Patients initially received 10 mg droperidol as part of a standardized sedation protocol. An additional 10 mg dose was given after 15 min if required and further doses at the clinical toxicologist's discretion. Continuous 12-lead Holter recordings were obtained for 2–24 h utilizing high resolution digital recordings with automated QT interval measurement. Electrocardiograms were extracted hourly from Holter recordings. The QT interval was plotted against heart rate (HR) on the QT nomogram to determine if it was abnormal. QTcF (Fridericia's HR correction) was calculated and >500 ms was defined as abnormal. Results Forty-six patients had Holter recordings after 10–40 mg droperidol and 316 QT–HR pairs were included. There were 32 abnormal QT measurements in four patients, three given 10 mg and one 20 mg. In three of the four patients QTcF >500 ms but only in one taking methadone was the timing of QTcF >500 ms consistent with droperidol dosing. Of the three other patients, one took amphetamines, one still had QT prolongation 24 h after droperidol and one took a lamotrigine overdose. No patient given >30 mg had a prolonged QT. There were no arrhythmias. Conclusion QT prolongation was observed with high dose droperidol. However, there was little evidence supporting droperidol being the cause and QT prolongation was more likely due to pre-existing conditions or other drugs. PMID:24168079

  20. How can computerized interpretation algorithms adapt to gender/age differences in ECG measurements?

    PubMed

    Xue, Joel; Farrell, Robert M

    2014-01-01

    It is well known that there are gender differences in 12 lead ECG measurements, some of which can be statistically significant. It is also an accepted practice that we should consider those differences when we interpret ECGs, by either a human overreader or a computerized algorithm. There are some major gender differences in 12 lead ECG measurements based on automatic algorithms, including global measurements such as heart rate, QRS duration, QT interval, and lead-by-lead measurements like QRS amplitude, ST level, etc. The interpretation criteria used in the automatic algorithms can be adapted to the gender differences in the measurements. The analysis of a group of 1339 patients with acute inferior MI showed that for patients under age 60, women had lower ST elevations at the J point in lead II than men (57±91μV vs. 86±117μV, p<0.02). This trend was reversed for patients over age 60 (lead aVF: 102±126μV vs. 84±117μV, p<0.04; lead III: 130±146μV vs. 103±131μV, p<0.007). Therefore, the ST elevation thresholds were set based on available gender and age information, which resulted in 25% relative sensitivity improvement for women under age 60, while maintaining a high specificity of 98%. Similar analyses were done for prolonged QT interval and LVH cases. The paper uses several design examples to demonstrate (1) how to design a gender-specific algorithm, and (2) how to design a robust ECG interpretation algorithm which relies less on absolute threshold-based criteria and is instead more reliant on overall morphology features, which are especially important when gender information is unavailable for automatic analysis.

  1. Validation of a Novel Digital Tool in Automatic Scoring of an Online ECG Examination at an International Cardiology Meeting.

    PubMed

    Quinn, Kieran L; Crystal, Eugene; Lashevsky, Ilan; Arouny, Banafsheh; Baranchuk, Adrian

    2016-07-01

    We have previously developed a novel digital tool capable of automatically recognizing correct electrocardiography (ECG) diagnoses in an online exam and demonstrated a significant improvement in diagnostic accuracy when utilizing an inductive-deductive reasoning strategy over a pattern recognition strategy. In this study, we sought to validate these findings from participants at the International Winter Arrhythmia School meeting, one of the foremost electrophysiology events in Canada. Preregistration to the event was sent by e-mail. The exam was administered on day 1 of the conference. Results and analysis were presented the following morning to participants. Twenty-five attendees completed the exam, providing a total of 500 responses to be marked. The online tool accurately identified 195 of a total of 395 (49%) correct responses (49%). In total, 305 responses required secondary manual review, of which 200 were added to the correct responses pool. The overall accuracy of correct ECG diagnosis for all participants was 69% and 84% when using pattern recognition or inductive-deductive strategies, respectively. Utilization of a novel digital tool to evaluate ECG competency can be set up as a workshop at international meetings or educational events. Results can be presented during the sessions to ensure immediate feedback. © 2015 Wiley Periodicals, Inc.

  2. QRS complex duration enhancement as ventricular late potential indicator by signal-averaged ECG using time-amplitude alignments.

    PubMed

    Avitia, Roberto L; Reyna, Marco A; Bravo-Zanoguera, Miguel E; Cetto, Lucio A

    2013-04-01

    Ventricular late potentials (VLPs) are small-amplitude waves with a short duration that appear at the end part of the QRS complex, making a QRS complex duration larger. The signal-averaged electrocardiography (ECG) technique enhances VLPs and beats, assuming noise as the only random variable. However, ECG signals are not completely stationary and different elongations appear in both time and amplitude in each beat. This research proposes to use piecewise linear approximation to segment each beat and performs the alignment of the beats using the technique known as derivative dynamic time-warping to have beats better aligned and consequently enhance the presence of VLPs. We recorded high-resolution ECGs (HRECGs) from 50 subjects in supine position with no heart-stroke antecedents. VLPs were created synthetically and added to the HRECGs. Two cases were evaluated: (i) duration of the QRS complexes with VLPs without beats alignment, and (ii) duration of QRS complexes with VLPs using beats alignment in time and amplitude. Considering QRS duration as an indicative of VLP presence, results show that when using beats alignment in time and amplitude it is possible to reach a sensitivity of 0.96 and a specificity of 0.52, as opposed to 0.72 and 0.40, respectively, when using only averaging without beats alignment in time and amplitude.

  3. ECG-Based Detection of Early Myocardial Ischemia in a Computational Model: Impact of Additional Electrodes, Optimal Placement, and a New Feature for ST Deviation

    PubMed Central

    Schulze, Walther H. W.; Jiang, Yuan; Wilhelms, Mathias; Luik, Armin; Dössel, Olaf; Seemann, Gunnar

    2015-01-01

    In case of chest pain, immediate diagnosis of myocardial ischemia is required to respond with an appropriate treatment. The diagnostic capability of the electrocardiogram (ECG), however, is strongly limited for ischemic events that do not lead to ST elevation. This computational study investigates the potential of different electrode setups in detecting early ischemia at 10 minutes after onset: standard 3-channel and 12-lead ECG as well as body surface potential maps (BSPMs). Further, it was assessed if an additional ECG electrode with optimized position or the right-sided Wilson leads can improve sensitivity of the standard 12-lead ECG. To this end, a simulation study was performed for 765 different locations and sizes of ischemia in the left ventricle. Improvements by adding a single, subject specifically optimized electrode were similar to those of the BSPM: 2–11% increased detection rate depending on the desired specificity. Adding right-sided Wilson leads had negligible effect. Absence of ST deviation could not be related to specific locations of the ischemic region or its transmurality. As alternative to the ST time integral as a feature of ST deviation, the K point deviation was introduced: the baseline deviation at the minimum of the ST-segment envelope signal, which increased 12-lead detection rate by 7% for a reasonable threshold. PMID:26587538

  4. Differences in alarm events between disposable and reusable electrocardiography lead wires.

    PubMed

    Albert, Nancy M; Murray, Terri; Bena, James F; Slifcak, Ellen; Roach, Joel D; Spence, Jackie; Burkle, Alicia

    2015-01-01

    Disposable electrocardiographic lead wires (ECG-LWs) may not be as durable as reusable ones. To examine differences in alarm events between disposable and reusable ECG-LWs. Two cardiac telemetry units were randomized to reusable ECG-LWs, and 2 units alternated between disposable and reusable ECG-LWs for 4 months. A remote monitoring team, blinded to ECG-LW type, assessed frequency and type of alarm events by using total counts and rates per 100 patient days. Event rates were compared by using generalized linear mixed-effect models for differences and noninferiority between wire types. In 1611 patients and 9385.5 patient days of ECG monitoring, patient characteristics were similar between groups. Rates of alarms for no telemetry, leads fail, or leads off were lower in disposable ECG-LWs (adjusted relative risk [95% CI], 0.71 [0.53-0.96]; noninferiority P < .001; superiority P = .03) and monitoring (artifact) alarms were significantly noninferior (adjusted relative risk [95% CI]: 0.88, [0.62-1.24], P = .02; superiority P = .44). No between-group differences existed in false or true crisis alarms. Disposable ECG-LWs were noninferior to reusable ECG-LWs for all false-alarm events (N [rate per 100 patient days], disposable 2029 [79.1] vs reusable 6673 [97.9]; adjusted relative risk [95% CI]: 0.81 [0.63-1.06], P = .002; superiority P = .12.) Disposable ECG-LWs with patented push-button design had superior performance in reducing alarms created by no telemetry, leads fail, or leads off and significant noninferiority in all false-alarm rates compared with reusable ECG-LWs. Fewer ECG alarms may save nurses time, decrease alarm fatigue, and improve patient safety. ©2015 American Association of Critical-Care Nurses.

  5. Improving ECG Services at a Children's Hospital: Implementation of a Digital ECG System

    PubMed Central

    Osei, Frank A.; Gates, Gregory J.; Choi, Steven J.; Hsu, Daphne T.; Pass, Robert H.; Ceresnak, Scott R.

    2015-01-01

    Background. The use of digital ECG software and services is becoming common. We hypothesized that the introduction of a completely digital ECG system would increase the volume of ECGs interpreted at our children's hospital. Methods. As part of a hospital wide quality improvement initiative, a digital ECG service (MUSE, GE) was implemented at the Children's Hospital at Montefiore in June 2012. The total volume of ECGs performed in the first 6 months of the digital ECG era was compared to 18 months of the predigital era. Predigital and postdigital data were compared via t-tests. Results. The mean ECGs interpreted per month were 53 ± 16 in the predigital era and 216 ± 37 in the postdigital era (p < 0.001), a fourfold increase in ECG volume after introduction of the digital system. There was no significant change in inpatient or outpatient service volume during that time. The mean billing time decreased from 21 ± 27 days in the postdigital era to 12 ± 5 days in the postdigital era (p < 0.001). Conclusion. Implementation of a digital ECG system increased the volume of ECGs officially interpreted and reported. PMID:26451150

  6. Extraction of fetal ECG signal by an improved method using extended Kalman smoother framework from single channel abdominal ECG signal.

    PubMed

    Panigrahy, D; Sahu, P K

    2017-02-16

    This paper proposes a five-stage based methodology to extract the fetal electrocardiogram (FECG) from the single channel abdominal ECG using differential evolution (DE) algorithm, extended Kalman smoother (EKS) and adaptive neuro fuzzy inference system (ANFIS) framework. The heart rate of the fetus can easily be detected after estimation of the fetal ECG signal. The abdominal ECG signal contains fetal ECG signal, maternal ECG component, and noise. To estimate the fetal ECG signal from the abdominal ECG signal, removal of the noise and the maternal ECG component presented in it is necessary. The pre-processing stage is used to remove the noise from the abdominal ECG signal. The EKS framework is used to estimate the maternal ECG signal from the abdominal ECG signal. The optimized parameters of the maternal ECG components are required to develop the state and measurement equation of the EKS framework. These optimized maternal ECG parameters are selected by the differential evolution algorithm. The relationship between the maternal ECG signal and the available maternal ECG component in the abdominal ECG signal is nonlinear. To estimate the actual maternal ECG component present in the abdominal ECG signal and also to recognize this nonlinear relationship the ANFIS is used. Inputs to the ANFIS framework are the output of EKS and the pre-processed abdominal ECG signal. The fetal ECG signal is computed by subtracting the output of ANFIS from the pre-processed abdominal ECG signal. Non-invasive fetal ECG database and set A of 2013 physionet/computing in cardiology challenge database (PCDB) are used for validation of the proposed methodology. The proposed methodology shows a sensitivity of 94.21%, accuracy of 90.66%, and positive predictive value of 96.05% from the non-invasive fetal ECG database. The proposed methodology also shows a sensitivity of 91.47%, accuracy of 84.89%, and positive predictive value of 92.18% from the set A of PCDB.

  7. QT interval prolongation in opioid agonist treatment: analysis of continuous 12-lead electrocardiogram recordings.

    PubMed

    Isbister, Geoffrey K; Brown, Amanda L; Gill, Anthony; Scott, Alexander J; Calver, Leonie; Dunlop, Adrian J

    2017-10-01

    Methadone is a widely used opioid agonist treatment associated with QT prolongation and torsades de pointes. We investigated the QT interval in patients treated with methadone or buprenorphine using continuous 12-lead Holter recordings. We prospectively made 24-h Holter recordings in patients prescribed methadone or buprenorphine, compared to controls. After their normal dose a continuous 12-lead Holter recorder was attached for 24 h. Digital electrocardiograms were extracted hourly from the Holter recordings. The QT interval was measured automatically (H-scribe software, Mortara Pty Ltd) and checked manually. The QT interval was plotted against heart rate (HR) on the QT nomogram to determine abnormality. Demographics, dosing, medical history and laboratory investigations were recorded. There were 58 patients (19 methadone, 20 buprenorphine and 19 control); median age 35 years (20-56 years); 33 males. Baseline characteristics were similar. Median dose of methadone was 110 mg day(-1) (70-170 mg day(-1) ) and buprenorphine was 16 mg day(-1) (12-32 mg day(-1) ). Seven participants had abnormal QT intervals. There was a significant difference in the proportion of prescribed methadone with abnormal QT intervals, 7/19 (37%; 95% confidence interval: 17-61%), compared to controls 0/19 (0%; 95% confidence interval: 0-21%; P = 0.008), but no difference between buprenorphine and controls (0/20). QT vs. HR plots showed patients prescribed methadone had higher QT-HR pairs over 24 h compared to controls. There was no difference in dose for patients prescribed methadone with abnormal QT intervals and those without. Methadone is associated with prolonged QT intervals, but there was no association with dose. Buprenorphine did not prolong the QT interval. Twenty four-hour Holter recordings using the QT nomogram is a feasible method to assess the QT interval in patients prescribed methadone. © 2017 The Authors. British Journal of Clinical Pharmacology published by John

  8. [A USB-Based Digital ECG Sensor].

    PubMed

    Shi Bol; Kong, Xiangyong; Ma, Xiaozhi; Zhang, Genxuan

    2016-01-01

    Based on the ECG-specific BMD 101 integrated circun chip, this study designed a digital ECG sensor. In practical application, users just need to connect the ECG sensor 'o upper computer (such as PC or mobile phone) through USB interface, to realize the functions including display, alarm, saving, transfer etc. After tests, They demonstrate that the sensor can be applied to the detection of arrhythmia, such as bigeminy coupled rhythm, proiosystole etc. Besides, the sensor has various advantages in monitoring an managing the heart health of people out of hospital, including low cost, small volume, usableness, simplicity of operation etc.

  9. Myocardial perfusion imaging with thallium-201: correlation with coronary arteriography and electrocardiography.

    PubMed

    Sternberg, L; Wald, R W; Feiglin, D H; Morch, J E

    1978-02-04

    Myocardial perfusion imaging with thallium-201 and electrocardiography with the subject at rest and undergoing submaximal treadmill exercise were performed in 19 men and 3 women. Selective coronary arteriography and left ventriculography showed that 7 had normal coronary arteries and 15 had coronary artery disease.The 11 persons with electrocardiographic evidence of an old myocardial infarct (q waves) had a perfusion defect at rest in the area of the infarct and a segmental abnormality of wall motion apparent on the left ventriculogram corresponding to the perfusion defect.MYOCARDIAL PERFUSION IMAGING AND ELECTROCARDIOGRAPHY WERE EQUALLY SENSITIVE IN DETECTING CORONARY ARTERY DISEASE IN EXERCISING INDIVIDUALS: perfusion defects were noted in 7 of the 15 persons with coronary artery disease, and diagnostic ST-segment depression was present in 8 of the 15. Combination of the results of the two tests with exercise permitted the identification of 11 of the 15 persons and improved the sensitivity. Combination of the results of rest and exercise imaging and electrocardiography permitted the identification of 94% of the patients with coronary artery disease.Myocardial perfusion imaging with (201)TI in the subject at rest is a sensitive indicator of previous myocardial infarction. Imaging after the subject has exercised is a useful adjunct to conventional exercise electrocardiography, especially in those whose exercise electrocardiogram is non-interpretable.

  10. Myocardial perfusion imaging with thallium-201: correlation with coronary arteriography and electrocardiography

    PubMed Central

    Sternberg, Leonard; Wald, Robert W.; Feiglin, David H.I.; Morch, John E.

    1978-01-01

    Myocardial perfusion imaging with thallium-201 and electrocardiography with the subject at rest and undergoing submaximal treadmill exercise were performed in 19 men and 3 women. Selective coronary arteriography and left ventriculography showed that 7 had normal coronary arteries and 15 had coronary artery disease. The 11 persons with electrocardiographic evidence of an old myocardial infarct (q waves) had a perfusion defect at rest in the area of the infarct and a segmental abnormality of wall motion apparent on the left ventriculogram corresponding to the perfusion defect. Myocardial perfusion imaging and electrocardiography were equally sensitive in detecting coronary artery disease in exercising individuals: perfusion defects were noted in 7 of the 15 persons with coronary artery disease, and diagnostic ST-segment depression was present in 8 of the 15. Combination of the results of the two tests with exercise permitted the identification of 11 of the 15 persons and improved the sensitivity. Combination of the results of rest and exercise imaging and electrocardiography permitted the identification of 94% of the patients with coronary artery disease. Myocardial perfusion imaging with 201TI in the subject at rest is a sensitive indicator of previous myocardial infarction. Imaging after the subject has exercised is a useful adjunct to conventional exercise electrocardiography, especially in those whose exercise electrocardiogram is non-interpretable. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5 PMID:630487

  11. The role of electrocardiography in the elaboration of a new paradigm in cardiac resynchronization therapy for patients with nonspecific intraventricular conduction disturbance

    PubMed Central

    Vereckei, András; Katona, Gábor; Szelényi, Zsuzsanna; Szénási, Gábor; Kozman, Bálint; Karádi, István

    2016-01-01

    Cardiac resynchronization therapy (CRT) is associated with a favorable outcome only in patients with left bundle branch block (LBBB) pattern and in patients with a QRS duration > 150 ms, in patients with non-LBBB pattern with a QRS duration of 120–150 ms usually is not beneficial. After adjusting for QRS duration, QRS morphology was no longer a determinant of the clinical response to CRT. In contrast to the mainstream view, we hypothesized that the unfavorable CRT outcome in patients with non-LBBB and a QRS duration of 120–150 ms is not due to the QRS morphology itself, but to less dyssynchrony and unfavorable patient characteristics in this subgroup, such as more ischemic etiology and greater prevalence of male patients compared with patients with LBBB pattern. Further, the current CRT technique is devised to eliminate the dyssynchrony present in patients with LBBB pattern and inappropriate to eliminate the dyssynchrony in patients with non-LBBB pattern. We also hypothesized that electrocardiography may also provide information about the presence of interventricular and left intraventricular dyssynchrony and the approximate location of the latest activated left ventricular (LV) region. To this end, we devised new ECG criteria to estimate interventricular and LV intraventricular dyssynchrony and the approximate location of the latest activated LV region. Our preliminary data demonstrated that the latest activated LV region in patients with nonspecific intraventricular conduction disturbance (NICD) pattern might be at a remote site from that present in patients with LBBB pattern, which might necessitate the invention of a novel CRT technique for patients with NICD pattern. The application of the new interventricular and LV intraventricular dyssynchrony ECG criteria and a potential novel CRT technique might decrease the currently high nonresponder rate in patients with NICD pattern. PMID:27168736

  12. ECG findings after myocardial infarction in children after Kawasaki disease

    SciTech Connect

    Nakanishi, T.; Takao, A.; Kondoh, C.; Nakazawa, M.; Hiroe, M.; Matsumoto, Y.

    1988-10-01

    Standard 12-lead ECGs were evaluated in 17 children with myocardial infarction and 78 children without myocardial infarction after Kawasaki disease; sensitivity and specificity of the ECG infarction criteria were determined. The presence or absence of myocardial infarction was determined from either clinical examination results (coronary angiography, ventriculography, and thallium-201 myocardial imaging) or autopsy findings. Of seven patients with inferior infarction, abnormally deep Q waves in lead II, III, or aVF were observed in six, but the duration was greater than 0.04 second in only one (14%). The sensitivity and specificity of inferior infarction criteria based on Q wave amplitude were 86% and 97%, respectively. Of eight patients with anterior infarction, seven (88%) had abnormally deep and wide (greater than or equal to 0.04 second) Q waves in anterior chest leads. The sensitivity and specificity of the infarction criteria based on the amplitude and duration of the Q wave were 75% and 99%, respectively. Of seven patients with lateral infarction, Q waves were observed in lead I, aVL, or both in four patients, and in all of these patients Q waves were wider than 0.04 second. In two patients with both inferior and anterior infarction, Q waves were observed only in leads II, III, and aVF; in only one patient were the Q waves wider than 0.04 second. Thus deep Q waves in lead II, III, or aVF that are not wider than 0.04 second may indicate inferior infarction in children. Q waves in lead I, aVL, and chest leads associated with anterolateral infarction are in most instances deep and wide.

  13. Atrial Fibrillation and Beta Thalassemia Major: The Predictive Role of the 12-lead Electrocardiogram Analysis.

    PubMed

    Russo, Vincenzo; Rago, Anna; Pannone, Bruno; Papa, Andrea Antonio; Mayer, Maria Carolina; Spasiano, Anna; Calabro, Raffaele; Russo, Maria Giovanna; Gerardo, Nigro

    2014-05-01

    Paroxysmal atrial tachyarrhythmias frequently occur in beta-thalassemia major (β-TM) patients.The aim of our study was to investigate the role of maximum P-wave duration (P max) and dispersion (PD), calculated trough a new manually performed measurement with the use of computer software from all 12-ECG-leads,as predictors of atrial-fibrillation (AF) in β-TM patients with conserved systolic or diastolic cardiac function during a twelve-months follow-up. 50 β-TM-patients (age38.4±10.1; 38M) and 50-healthy subjects used as controls, matched for age and gender, were studied for the occurrence of atrial arrhythmias during a 1-year follow-up, through ECG-Holter-monitoring performed every three months. The β-TM-patients were divided into two groups according to number and complexity of premature-supraventricular-complexes at the Holter-Monitoring (Group1: <30/h and no repetitive forms, n:35; Group2: >30/h or couplets, or run of supraventricular tachycardia and AF, n:15). Compared to the healthy control-group, β-TM patients presented increased P-max (107.5± 21.2 vs 92.1±11ms, P=0.03) and PD-values (41.2±13 vs 25.1±5 ms,P=0.03). In the β-TM population, the Group2 showed a statistically significant increase in PD (42.8±8.6 vs 33.2±6.5ms, P<0.001) and P-max (118.1±8.7 vs 103.1±7.5ms, P<0.001) compared to the Group1. Seven β-TM patients who showed paroxysmal AF during this study had significantly increased P-max and PD than the other patients of the Group2. Moreover, P-max (OR:2.01; CI:1.12-3.59; P=0.01) and PD (OR=2.06;CI:1.17-3.64;P=0.01) demonstrated a statistically significant association with the occurrence of paroxysmal AF,P min was not associated with AF-risk (OR=0.99; CI:0.25-3.40; P=0.9) in β-TM-patients. A cut-off value of 111ms for P-max had a sensitivity of 80% and a specificity of 87%, a cut-off value of 35.5ms for PD had a sensitivity of 90% and a specificity of 85% in identifying β-TM patients at risk for AF. Our results indicate that P-max and

  14. High-frequency QRS analysis compared to conventional ST-segment analysis in patients with chest pain and normal ECG referred for exercise tolerance test.

    PubMed

    Conti, Alberto; Alesi, Andrea; Aspesi, Giovanna; De Bernardis, Niccolò; Bianchi, Simone; Coppa, Alessandro; Donnini, Chiara; Grifoni, Caterina; Becucci, Alessandro; Casula, Claudia

    2015-01-01

    The novel analysis of high-frequency QRS components (HFQRS-analysis) has been proposed in patients with chest pain (CP) and normal electrocardiography (ECG) referred for exercise tolerance test (ex-ECG). The aim of the study was to compare the diagnostic value of ex-ECG with ex-HFQRS-analysis. Patients with CP and normal ECG, troponin, and echocardiography were considered. All patients underwent ex-ECG for conventional ST-segment-analysis and ex-HFQRS-analysis. A decrease ≥ 50% of the HFQRS signal intensity recorded in at least 2 contiguous leads was considered an index of ischemia, as ST-segment depression ≥ 2 mm or ≥ 1 mm and CP on ex-ECG. Exclusion criteria were: QRS duration ≥ 120 ms and inability to exercise. End-point: The composite of coronary stenosis ≥ 70% or acute coronary syndrome, revascularization, cardiovascular death at 3-month follow-up. Three-hundred thirty-seven patients were enrolled (age 60 ± 15 years). The percent-age of age-adjusted maximal predicted heart rate was 89 ± 10 beat per minute and the maximal systolic blood pressure was 169 ± 23 mm Hg. Nineteen patients achieved the end-point. In multivariate analysis, both ex-ECG and ex-HFQRS were predictors of the end-point. The ex-HFQRS-analysis showed higher sensitivity (63% vs. 26%; p < 0.05), lower specificity (68% vs. 95%; p < 0.001), and comparable negative predictive value (97% vs. 96%; p = 0.502) when compared to ex-ECG-analysis. Receiver operator characteristics analysis showed the incremental diagnostic value of HFQRS (area: 0.655, 95% CI 0.60-0.71) over conventional ex-ECG (0.608, CI 0.55-0.66) and CP score (0.530, CI 0.48-0.59), however without statistical significance in pairwise comparison by C-statistic. In patients with CP submitted to ex-ECG, the novel ex-HFQRS-analysis shows a valuable incremental diagnostic value over ST-segment-analysis.

  15. Intermittent short ECG recording is more effective than 24-hour Holter ECG in detection of arrhythmias.

    PubMed

    Hendrikx, Tijn; Rosenqvist, Mårten; Wester, Per; Sandström, Herbert; Hörnsten, Rolf

    2014-04-01

    Many patients report symptoms of palpitations or dizziness/presyncope. These patients are often referred for 24-hour Holter ECG, although the sensitivity for detecting relevant arrhythmias is comparatively low. Intermittent short ECG recording over a longer time period might be a convenient and more sensitive alternative. The objective of this study is to compare the efficacy of 24-hour Holter ECG with intermittent short ECG recording over four weeks to detect relevant arrhythmias in patients with palpitations or dizziness/presyncope. prospective, observational, cross-sectional study. Clinical Physiology, University Hospital. 108 consecutive patients referred for ambiguous palpitations or dizziness/presyncope. All individuals underwent a 24-hour Holter ECG and additionally registered 30-second handheld ECG (Zenicor EKG® thumb) recordings at home, twice daily and when having cardiac symptoms, during 28 days. Significant arrhythmias: atrial fibrillation (AF), paroxysmal supraventricular tachycardia (PSVT), atrioventricular (AV) block II-III, sinus arrest (SA), wide complex tachycardia (WCT). 95 patients, 42 men and 53 women with a mean age of 54.1 years, completed registrations. Analysis of Holter registrations showed atrial fibrillation (AF) in two patients and atrioventricular (AV) block II in one patient (= 3.2% relevant arrhythmias [95% CI 1.1-8.9]). Intermittent handheld ECG detected nine patients with AF, three with paroxysmal supraventricular tachycardia (PSVT) and one with AV-block-II (= 13.7% relevant arrhythmias [95% CI 8.2-22.0]). There was a significant difference between the two methods in favour of intermittent ECG with regard to the ability to detect relevant arrhythmias (P = 0.0094). With Holter ECG, no symptoms were registered during any of the detected arrhythmias. With intermittent ECG, symptoms were registered during half of the arrhythmia episodes. Intermittent short ECG recording during four weeks is more effective in detecting AF and PSVT in

  16. Wavelets for full reconfigurable ECG acquisition system

    NASA Astrophysics Data System (ADS)

    Morales, D. P.; García, A.; Castillo, E.; Meyer-Baese, U.; Palma, A. J.

    2011-06-01

    This paper presents the use of wavelet cores for a full reconfigurable electrocardiogram signal (ECG) acquisition system. The system is compound by two reconfigurable devices, a FPGA and a FPAA. The FPAA is in charge of the ECG signal acquisition, since this device is a versatile and reconfigurable analog front-end for biosignals. The FPGA is in charge of FPAA configuration, digital signal processing and information extraction such as heart beat rate and others. Wavelet analysis has become a powerful tool for ECG signal processing since it perfectly fits ECG signal shape. The use of these cores has been integrated in the LabVIEW FPGA module development tool that makes possible to employ VHDL cores within the usual LabVIEW graphical programming environment, thus freeing the designer from tedious and time consuming design of communication interfaces. This enables rapid test and graphical representation of results.

  17. Development and significance of a fetal electrocardiogram recorded by signal-averaged high-amplification electrocardiography.

    PubMed

    Hayashi, Risa; Nakai, Kenji; Fukushima, Akimune; Itoh, Manabu; Sugiyama, Toru

    2009-03-01

    Although ultrasonic diagnostic imaging and fetal heart monitors have undergone great technological improvements, the development and use of fetal electrocardiograms to evaluate fetal arrhythmias and autonomic nervous activity have not been fully established. We verified the clinical significance of the novel signal-averaged vector-projected high amplification ECG (SAVP-ECG) method in fetuses from 48 gravidas at 32-41 weeks of gestation and in 34 neonates. SAVP-ECGs from fetuses and newborns were recorded using a modified XYZ-leads system. Once noise and maternal QRS waves were removed, the P, QRS, and T wave intervals were measured from the signal-averaged fetal ECGs. We also compared fetal and neonatal heart rates (HRs), coefficients of variation of heart rate variability (CV) as a parasympathetic nervous activity, and the ratio of low to high frequency (LF/HF ratio) as a sympathetic nervous activity. The rate of detection of a fetal ECG by SAVP-ECG was 72.9%, and the fetal and neonatal QRS and QTc intervals were not significantly different. The neonatal CVs and LF/HF ratios were significantly increased compared with those in the fetus. In conclusion, we have developed a fetal ECG recording method using the SAVP-ECG system, which we used to evaluate autonomic nervous system development.

  18. [Changes in ST segment on ECG of hypertensive patients].

    PubMed

    Riabykina, G V; Liutikova, L N; Saidova, M A; Botvina, Iu V; Kozhemiakina, E Sh; Shchedrina, E V; Sobolev, A V

    2008-01-01

    To evaluate ST depression in hypertensive patients with electrocardiographic signs of left ventricular hypertrophy (LVH), correlation of ST segment changes with heart rate (HR) and blood pressure (BP) during Holter monitoring (HM) and bi-functional ECG and BP monitoring (BFM), and to compare ST depression and local left ventricular contractility during stress-echocardiography in hypertensive patients with unaffected coronary arteries according to the data of coronary angiography. We examined 344 hypertensive patients without clinical signs of ischemic heart disease. Correlation between ST segment depression and ECG signs of LVH was evaluated in 192 patients. 180 patients underwent HM, 122--BFM and 30 hypertensive patients with normal coronary arteries according to the data of coronary angiography underwent stress-echocardiography. According to the data of 12 lead ECG 40 cases of ST depression were found, with LVH signs in 26 (65%) of these patients. During HM in 34 of 180 patients 2 types of ST depression were found: type 1--short periods of transient ST depression without persistent ST depression was fond in 8 patients; type 2--persistent ST depression more than 1 mm during the whole time of recording--in 26 patients. In 7 of 8 cases of type 1 and in 5 of 26 cases of type 2 ST depression had rhythm-dependent character. During BFM in 9 cases ST depression during HR or BP increase was found. In 2 cases ST depression during BP increase was unrelated to HR increase which may be consequence of systolic myocardial strain syndrome. In 7 of 30 hypertensive patients with normal coronary arteries and without local myocardial contractility disturbances according to the data of stress-echocardiography positive criteria of ischemia were found. The cause of ST segment depression in hypertensive patients more often are secondary disturbances of repolarizaion processes related with LVH development. In some cases such patients during HM show rhythm-dependent valuable ST

  19. Highly Reliable Key Generation from Electrocardiogram (ECG).

    PubMed

    Karimian, Nima; Guo, Zimu; Tehranipoor, Mark; Forte, Domenic

    2016-09-08

    Traditional passwords are inadequate as cryptographic keys, as they are easy to forge and are vulnerable to guessing. Human biometrics have been proposed as a promising alternative due to their intrinsic nature. Electrocardiogram (ECG) is an emerging biometric that is extremely difficult to forge and circumvent, but has not yet been heavily investigated for cryptographic key generation. ECG has challenges with respect to immunity to noise, abnormalities, etc. In this paper, we propose a novel key generation approach that extracts keys from real valued ECG features with high reliability and entropy in mind. Our technique, called interval optimized mapping bit allocation (IOMBA), is applied to normal and abnormal ECG signals under multiple session conditions. We also investigate IOMBA in the context of different feature extraction methods, such as wavelet, discrete cosine transform, etc. to find the best method for feature extraction. Experiments of IOMBA show that 217-bit, 38-bit, and 100-bit keys with 99.9%, 97.4%, and 95% average reliability and high entropy can be extracted from normal, abnormal, and multiple session ECG signals, respectively. By allowing more errors or lowering entropy, key lengths can be further increased by tunable parameters of IOMBA which can be useful in other applications. While IOMBA is demonstrated on ECG, it should be useful for other biometrics as well.

  20. The Cardiac Safety Research Consortium ECG database.

    PubMed

    Kligfield, Paul; Green, Cynthia L

    2012-01-01

    The Cardiac Safety Research Consortium (CSRC) ECG database was initiated to foster research using anonymized, XML-formatted, digitized ECGs with corresponding descriptive variables from placebo- and positive-control arms of thorough QT studies submitted to the US Food and Drug Administration (FDA) by pharmaceutical sponsors. The database can be expanded to other data that are submitted directly to CSRC from other sources, and currently includes digitized ECGs from patients with genotyped varieties of congenital long-QT syndrome; this congenital long-QT database is also linked to ambulatory electrocardiograms stored in the Telemetric and Holter ECG Warehouse (THEW). Thorough QT data sets are available from CSRC for unblinded development of algorithms for analysis of repolarization and for blinded comparative testing of algorithms developed for the identification of moxifloxacin, as used as a positive control in thorough QT studies. Policies and procedures for access to these data sets are available from CSRC, which has developed tools for statistical analysis of blinded new algorithm performance. A recently approved CSRC project will create a data set for blinded analysis of automated ECG interval measurements, whose initial focus will include comparison of four of the major manufacturers of automated electrocardiographs in the United States. CSRC welcomes application for use of the ECG database for clinical investigation.

  1. Modest agreement in ECG interpretation limits the application of ECG screening in young athletes.

    PubMed

    Brosnan, Maria; La Gerche, Andre; Kumar, Saurabh; Lo, Wilson; Kalman, Jonathan; Prior, David

    2015-01-01

    Athlete ECG screening has been recommended by several international sporting bodies; however, a number of controversies remain regarding the accuracy of ECG screening. An important component that has not been assessed is the reproducibility of ECG interpretation. The purpose of this study was to assess the variability of ECG interpretation among experienced physicians when screening a large number of athletes. A sports cardiologist, a sports medicine physician, and an electrophysiologist analyzed 440 consecutive screening ECGs from asymptomatic athletes and were asked to classify the ECGs according to the 2010 European Society of Cardiology criteria as normal (or demonstrating training related ECG changes) or abnormal. When an abnormal ECG was identified, they were asked to outline what follow-up investigations they would recommend. The reported prevalence of abnormal ECGs ranged from 13.4% to 17.5%. Agreement on which ECGs were abnormal ranged from poor (κ = 0.297) to moderate (κ = 0.543) between observers. Suggested follow-up investigations were varied, and follow-up costs ranged from an additional A$30-A$129 per screening episode. Neither of the 2 subjects (0.45%) in the cohort with significant pathology diagnosed as a result of screening were identified correctly by all 3 physicians. Even when experienced physicians interpret athletes' ECGs according to current standards, there is significant interobserver variability that results in false-positive and false-negative results, thus reducing the effectiveness and increasing the social and economic cost of screening. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  2. ECG patch monitors for assessment of cardiac rhythm abnormalities.

    PubMed

    Lobodzinski, S Suave

    2013-01-01

    The primary goal of long-term monitoring is the improvement of diagnostic yield. Despite the clear utility of Holter monitoring in clinical cardiology, issues of relatively low diagnostic yield, cost and inconvenience have motivated the development of ultra-portable devices referred to as ECG patch monitors. Although the "gold standard" for assessing cardiac rhythm abnormalities remains a 12-lead Holter, there is an increasing interest in portable monitoring devices that provide the opportunity for evaluating cardiac rhythm in real-world environments such as the workplace or home. To facilitate patient acceptance these monitors underwent a radical miniaturization and redesign to include wireless communication, water proofing and a patch carrier for attaching devices directly to the skin. We review recent developments in the field of "patch" devices primarily designed for very long-term monitoring of cardiac arrhythmic events. As the body of supporting clinical validation data grows, these devices hold promise for a variety of cardiac monitoring applications. From a clinical and research standpoint, the capacity to obtain longitudinal cardiac activity data by patch devices may have significant implications for device selection, monitoring duration, and care pathways for arrhythmia evaluation and atrial fibrillation surveillance. From a research standpoint, the new devices may allow for the development of novel diagnostic algorithms with the goal of finding patterns and correlations with exercise and drug regimens. © 2013.

  3. [Wireless ECG transfer and centralized system of ECG analysis and storage. Experience with easy ECG usage in the Russian Cardiological Research Center].

    PubMed

    2012-01-01

    Methods of wire and wireless ECG remote registration anda centralized system of ECG reception, analysis and storage are outlined in the context of setting up computer case history. Qualitative assessment of an algorithm of computer syndromal diagnosis used in the Easy ECG system is presented. The system comprises an ECG recorder digital amplifier and software. The system is easy to use and is recommended for introduction into wide medical practice.

  4. Noninvasive quantification of blood potassium concentration from ECG in hemodialysis patients.

    PubMed

    Corsi, Cristiana; Cortesi, Marilisa; Callisesi, Giulia; De Bie, Johan; Napolitano, Carlo; Santoro, Antonio; Mortara, David; Severi, Stefano

    2017-02-15

    Blood potassium concentration ([K(+)]) influences the electrocardiogram (ECG), particularly T-wave morphology. We developed a new method to quantify [K(+)] from T-wave analysis and tested its clinical applicability on data from dialysis patients, in whom [K(+)] varies significantly during the therapy. To elucidate the mechanism linking [K(+)] and T-wave, we also analysed data from long QT syndrome type 2 (LQT2) patients, testing the hypothesis that our method would have underestimated [K(+)] in these patients. Moreover, a computational model was used to explore the physiological processes underlying our estimator at the cellular level. We analysed 12-lead ECGs from 45 haemodialysis and 12 LQT2 patients. T-wave amplitude and downslope were calculated from the first two eigenleads. The T-wave slope-to-amplitude ratio (TS/A) was used as starting point for an ECG-based [K(+)] estimate (KECG). Leave-one-out cross-validation was performed. Agreement between KECG and reference [K(+)] from blood samples was promising (error: -0.09 ± 0.59 mM, absolute error: 0.46 ± 0.39 mM). The analysis on LQT2 patients, also supported by the outcome of computational analysis, reinforces our interpretation that, at the cellular level, delayed-rectifier potassium current is a main contributor of KECG correlation to blood [K(+)]. Following a comprehensive validation, this method could be effectively applied to monitor patients at risk for hyper/hypokalemia.

  5. Inter-lead correlation analysis for automated detection of cable reversals in 12/16-lead ECG.

    PubMed

    Jekova, Irena; Krasteva, Vessela; Leber, Remo; Schmid, Ramun; Twerenbold, Raphael; Müller, Christian; Reichlin, Tobias; Abächerli, Roger

    2016-10-01

    A crucial factor for proper electrocardiogram (ECG) interpretation is the correct electrode placement in standard 12-lead ECG and extended 16-lead ECG for accurate diagnosis of acute myocardial infarctions. In the context of optimal patient care, we present and evaluate a new method for automated detection of reversals in peripheral and precordial (standard, right and posterior) leads, based on simple rules with inter-lead correlation dependencies. The algorithm for analysis of cable reversals relies on scoring of inter-lead correlations estimated over 4s snapshots with time-coherent data from multiple ECG leads. Peripheral cable reversals are detected by assessment of nine correlation coefficients, comparing V6 to limb leads: (I, II, III, -I, -II, -III, -aVR, -aVL, -aVF). Precordial lead reversals are detected by analysis of the ECG pattern cross-correlation progression within lead sets (V1-V6), (V4R, V3R, V3, V4), and (V4, V5, V6, V8, V9). Disturbed progression identifies the swapped leads. A test-set, including 2239 ECGs from three independent sources-public 12-lead (PTB, CSE) and proprietary 16-lead (Basel University Hospital) databases-is used for algorithm validation, reporting specificity (Sp) and sensitivity (Se) as true negative and true positive detection of simulated lead swaps. Reversals of limb leads are detected with Se = 95.5-96.9% and 100% when right leg is involved in the reversal. Among all 15 possible pairwise reversals in standard precordial leads, adjacent lead reversals are detected with Se = 93.8% (V5-V6), 95.6% (V2-V3), 95.9% (V3-V4), 97.1% (V1-V2), and 97.8% (V4-V5), increasing to 97.8-99.8% for reversals of anatomically more distant electrodes. The pairwise reversals in the four extra precordial leads are detected with Se = 74.7% (right-sided V4R-V3R), 91.4% (posterior V8-V9), 93.7% (V4R-V9), and 97.7% (V4R-V8, V3R-V9, V3R-V8). Higher true negative rate is achieved with Sp > 99% (standard 12-lead ECG), 81.9% (V4R-V3R), 91

  6. Molecular Imaging of Mesothelioma with 99mTc-ECG and 68Ga-ECG

    PubMed Central

    Zhang, Yin-Han; Bryant, Jerry; Kong, Fan-Lin; Yu, Dong-Fang; Mendez, Richard; Edmund Kim, E.; Yang, David J.

    2012-01-01

    We have developed ethylenedicysteine-glucosamine (ECG) as an alternative to 18F-fluoro-2-deoxy-D-glucose (18F-FDG) for cancer imaging. ECG localizes in the nuclear components of cells via the hexosamine biosynthetic pathway. This study was to evaluate the feasibility of imaging mesothelioma with 99mTc-ECG and 68Ga-ECG. ECG was synthesized from thiazolidine-4-carboxylic acid and 1,3,4,6-tetra-O-acetyl-2-amino-D-glucopyranose, followed by reduction in sodium and liquid ammonia to yield ECG (52%). ECG was chelated with 99mTc/tin (II) and 68Ga/69Ga chloride for in vitro and in vivo studies in mesothelioma. The highest tumor uptake of 99mTc-ECG is 0.47 at 30 min post injection, and declined to 0.08 at 240 min post injection. Tumor uptake (%ID/g), tumor/lung, tumor/blood, and tumor/muscle count density ratios for 99mTc-ECG (30–240 min) were 0.47 ± 0.06 to 0.08 ± 0.01; 0.71 ± 0.07 to 0.85 ± 0.04; 0.47 ± 0.03 to 0.51 ± 0.01, and 3.49 ± 0.24 to 5.06 ± 0.25; for 68Ga-ECG (15–60 min) were 0.70 ± 0.06 to 0.92 ± 0.08; 0.64 ± 0.05 to 1.15 ± 0.08; 0.42 ± 0.03 to 0.67 ± 0.07, and 3.84 ± 0.52 to 7.00 ± 1.42; for 18F-FDG (30–180 min) were 1.86 ± 0.22 to 1.38 ± 0.35; 3.18 ± 0.44 to 2.92 ± 0.34, 4.19 ± 0.44 to 19.41 ± 2.05 and 5.75 ± 2.55 to 3.33 ± 0.65, respectively. Tumor could be clearly visualized with 99mTc-ECG and 68Ga-ECG in mesothelioma-bearing rats. 99mTc-ECG and 68Ga-ECG showed increased uptake in mesothelioma, suggesting they may be useful in diagnosing mesothelioma and also monitoring therapeutic response. PMID:22645409

  7. Quality assessment of digital annotated ECG data from clinical trials by the FDA ECG Warehouse.

    PubMed

    Sarapa, Nenad

    2007-09-01

    The FDA mandates that digital electrocardiograms (ECGs) from 'thorough' QTc trials be submitted into the ECG Warehouse in Health Level 7 extended markup language format with annotated onset and offset points of waveforms. The FDA did not disclose the exact Warehouse metrics and minimal acceptable quality standards. The author describes the Warehouse scoring algorithms and metrics used by FDA, points out ways to improve FDA review and suggests Warehouse benefits for pharmaceutical sponsors. The Warehouse ranks individual ECGs according to their score for each quality metric and produces histogram distributions with Warehouse-specific thresholds that identify ECGs of questionable quality. Automatic Warehouse algorithms assess the quality of QT annotation and duration of manual QT measurement by the central ECG laboratory.

  8. Signal processing using sparse derivatives with applications to chromatograms and ECG

    NASA Astrophysics Data System (ADS)

    Ning, Xiaoran

    In this thesis, we investigate the sparsity exist in the derivative domain. Particularly, we focus on the type of signals which posses up to Mth (M > 0) order sparse derivatives. Efforts are put on formulating proper penalty functions and optimization problems to capture properties related to sparse derivatives, searching for fast, computationally efficient solvers. Also the effectiveness of these algorithms are applied to two real world applications. In the first application, we provide an algorithm which jointly addresses the problems of chromatogram baseline correction and noise reduction. The series of chromatogram peaks are modeled as sparse with sparse derivatives, and the baseline is modeled as a low-pass signal. A convex optimization problem is formulated so as to encapsulate these non-parametric models. To account for the positivity of chromatogram peaks, an asymmetric penalty function is also utilized with symmetric penalty functions. A robust, computationally efficient, iterative algorithm is developed that is guaranteed to converge to the unique optimal solution. The approach, termed Baseline Estimation And Denoising with Sparsity (BEADS), is evaluated and compared with two state-of-the-art methods using both simulated and real chromatogram data. Promising result is obtained. In the second application, a novel Electrocardiography (ECG) enhancement algorithm is designed also based on sparse derivatives. In the real medical environment, ECG signals are often contaminated by various kinds of noise or artifacts, for example, morphological changes due to motion artifact, non-stationary noise due to muscular contraction (EMG), etc. Some of these contaminations severely affect the usefulness of ECG signals, especially when computer aided algorithms are utilized. By solving the proposed convex l1 optimization problem, artifacts are reduced by modeling the clean ECG signal as a sum of two signals whose second and third-order derivatives (differences) are sparse

  9. Sleep stage and obstructive apneaic epoch classification using single-lead ECG

    PubMed Central

    2010-01-01

    Background Polysomnography (PSG) is used to define physiological sleep and different physiological sleep stages, to assess sleep quality and diagnose many types of sleep disorders such as obstructive sleep apnea. However, PSG requires not only the connection of various sensors and electrodes to the subject but also spending the night in a bed that is different from the subject's own bed. This study is designed to investigate the feasibility of automatic classification of sleep stages and obstructive apneaic epochs using only the features derived from a single-lead electrocardiography (ECG) signal. Methods For this purpose, PSG recordings (ECG included) were obtained during the night's sleep (mean duration 7 hours) of 17 subjects (5 men) with ages between 26 and 67. Based on these recordings, sleep experts performed sleep scoring for each subject. This study consisted of the following steps: (1) Visual inspection of ECG data corresponding to each 30-second epoch, and selection of epochs with relatively clean signals, (2) beat-to-beat interval (RR interval) computation using an R-peak detection algorithm, (3) feature extraction from RR interval values, and (4) classification of sleep stages (or obstructive apneaic periods) using one-versus-rest approach. The features used in the study were the median value, the difference between the 75 and 25 percentile values, and mean absolute deviations of the RR intervals computed for each epoch. The k-nearest-neighbor (kNN), quadratic discriminant analysis (QDA), and support vector machines (SVM) methods were used as the classification tools. In the testing procedure 10-fold cross-validation was employed. Results QDA and SVM performed similarly well and significantly better than kNN for both sleep stage and apneaic epoch classification studies. The classification accuracy rates were between 80 and 90% for the stages other than non-rapid-eye-movement stage 2. The accuracies were 60 or 70% for that specific stage. In five

  10. ECG telemetry in conscious guinea pigs.

    PubMed

    Ruppert, Sabine; Vormberge, Thomas; Igl, Bernd-Wolfgang; Hoffmann, Michael

    2016-01-01

    During preclinical drug development, monitoring of the electrocardiogram (ECG) is an important part of cardiac safety assessment. To detect potential pro-arrhythmic liabilities of a drug candidate and for internal decision-making during early stage drug development an in vivo model in small animals with translatability to human cardiac function is required. Over the last years, modifications/improvements regarding animal housing, ECG electrode placement, and data evaluation have been introduced into an established model for ECG recordings using telemetry in conscious, freely moving guinea pigs. Pharmacological validation using selected reference compounds affecting different mechanisms relevant for cardiac electrophysiology (quinidine, flecainide, atenolol, dl-sotalol, dofetilide, nifedipine, moxifloxacin) was conducted and findings were compared with results obtained in telemetered Beagle dogs. Under standardized conditions, reliable ECG data with low variability allowing largely automated evaluation were obtained from the telemetered guinea pig model. The model is sensitive to compounds blocking cardiac sodium channels, hERG K(+) channels and calcium channels, and appears to be even more sensitive to β-blockers as observed in dogs at rest. QT interval correction according to Bazett and Sarma appears to be appropriate methods in conscious guinea pigs. Overall, the telemetered guinea pig is a suitable model for the conduct of early stage preclinical ECG assessment. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Sensitivity of transesophageal electrophysiologic study in children with supraventricular tachycardia on electrocardiography.

    PubMed

    Akin, Alper; Özer, Sema; Karagöz, Tevfık; Aykan, Hayrettın Hakan; Gülgün, Mustafa; Özkutlu, Süheyla; Alehan, Dursun; Çelıker, Alpay

    2014-08-01

    The aim of this study was to evaluate the inducibility of tachycardia by transesophageal electrophysiologic study (TEEPS) in patients with documented supraventricular tachycardia (SVT) on electrocardiography and to investigate the accuracy of TEEPS records by comparing with intracardiac electrophysiologic study (IEPS). The TEEPS records of patients having documented electrocardiography during SVT were reviewed. The results of TEEPS in 43 of 85 patients were compared with results of IEPS for compatibility of diagnosis. A total 85 patients, 46 male and 39 female, mean weight 35.1 kg (36-87), aged 1 month-17 years, were included. Tachycardia was induced by TEEPS in 79 of 85 patients with documented electrocardiography (sensitivity 92.9%). IEPS for diagnosis or ablation was conducted in 40 patients having inducible tachycardia and three of six who had no inducible tachycardia by TEEPS. Tachycardia was induced by IEPS in 39 of 40 (97.5%) patients who had inducible tachycardia and two of three who had no inducible tachycardia by TEEPS. Mechanisms of tachycardias were similar in 97.5% of patients (37/39) who had inducible tachycardia in TEEPS and IEPS. One of the patients with atrioventricular reentry tachycardia by TEEPS was diagnosed as atrioventricular nodal reentry tachycardia (AVNRT) and the other one was diagnosed as atypical AVNRT and atrial tachycardia by IEPS. The rates of inducibility and mechanisms of tachycardias by TEEPS in children having documented SVT were similar with those obtained from IEPS. ©2014 Wiley Periodicals, Inc.

  12. Robust human identification using ecg: eigenpulse revisited

    NASA Astrophysics Data System (ADS)

    Jang, Daniel; Wendelken, Suzanne; Irvine, John M.

    2010-04-01

    Biometrics, such as fingerprint, iris scan, and face recognition, offer methods for identifying individuals based on a unique physiological measurement. Recent studies indicate that a person's electrocardiogram (ECG) may also provide a unique biometric signature. Several methods for processing ECG data have appeared in the literature and most approaches rest on an initial detection and segmentation of the heartbeats. Various sources of noise, such as sensor noise, poor sensor placement, or muscle movements, can degrade the ECG signal and introduce errors into the heartbeat segmentation. This paper presents a screening technique for assessing the quality of each segmented heartbeat. Using this technique, a higher quality signal can be extracted to support the identification task. We demonstrate the benefits of this quality screening using a principal component technique known as eigenpulse. The analysis demonstrated the improvement in performance attributable to the quality screening.

  13. Automatic pattern recognition in ECG time series.

    PubMed

    Sternickel, Karsten

    2002-05-01

    In this paper, a technique for the automatic detection of any recurrent pattern in ECG time series is introduced. The wavelet transform is used to obtain a multiresolution representation of some example patterns for signal structure extraction. Neural Networks are trained with the wavelet transformed templates providing an efficient detector even for temporally varying patterns within the complete time series. The method is also robust against offsets and stable for signal to noise ratios larger than one. Its reliability was tested on 60 Holter ECG recordings of patients at the Department of Cardiology (University of Bonn). Due to the convincing results and its fast implementation the method can easily be used in clinical medicine. In particular, it solves the problem of automatic P wave detection in Holter ECG recordings.

  14. A spline framework for ECG analysis.

    PubMed

    Guilak, Farzin G; McNames, James

    2011-01-01

    In this effort we introduce a spline framework for ECG waveform analysis, with initial application to the ECG delineation (segmentation) problem. The framework comprises knot initialization, spline interpolant, error metric, and knot location optimization to parametrically represent the waveform for analysis, classification, or compression. Choice of these constituents is driven by the application of the framework. For our initial application of ECG delineation, we use the framework to identify characteristic points corresponding to waveform onset and offset times, peak values, and junction points. These are represented mathematically as critical points and points of inflection, which serve as knot locations for linear or cubic Hermite interpolants in the framework. Preliminary tests on a limited but diverse set of morphologies from the European ST-T database indicate that the framework obtains knot locations corresponding to characteristic points, and the resultant interpolated waveform represents the original signal well with low mean squared error.

  15. [Risk stratification of asymptomatic subjects using resting ECG and stress ECG].

    PubMed

    Möhlenkamp, Stefan; Wieneke, Heinrich; Sack, Stefan; Erbel, Raimund

    2007-08-01

    The resting electrocardiogram (ECG) and stress ECG are established tests in the array of cardiovascular diagnostic modalities. In addition to their diagnostic value for structural heart disease and rhythm disorders, ECGs at rest or during stress also contain prognostically relevant information. Several ECG abnormalities, e.g., left ventricular hypertrophy (LVH), Q waves, ST segment changes, left bundle branch block, atrial fibrillation or QT interval prolongation, were shown to be associated with cardiovascular events. Differences in study design, the cohorts of investigation and morphological definitions of ECG abnormalities may in part be responsible for the abnormalities not being implemented in risk stratification algorithms. The non-ST-segment-related variables in stress testing, e.g., functional capacity, chronotropic (in)competence, heart rate (HR) recovery, and the HR/ST index and slope, could be identified as prognostically relevant markers in population-based studies. For many of these resting and stress ECG-based abnormalities, associations with the extent of subclinical atherosclerosis in persons without established coronary heart disease were observed, indicating a preclinical relationship between epicardial atherosclerosis and myocardial pathology. The resting and the stress ECG provide a number of prognostically relevant indices that can easily be obtained in routine clinical practice, but have thus far found little acceptance for risk stratification of asymptomatic individuals.

  16. The Value of Routine Preoperative Electrocardiography in Predicting Myocardial Infarction After Noncardiac Surgery

    PubMed Central

    van Klei, Wilton A.; Bryson, Gregory L.; Yang, Homer; Kalkman, Cor J.; Wells, George A.; Beattie, W Scott

    2007-01-01

    Objective: The added value of a preoperative electrocardiogram (ECG) in the prediction of postoperative myocardial infarction (POMI) and death was compared with clinical risk factors identified from the patient's history. Summary of Background Data: An ECG is frequently performed before surgery to screen for asymptomatic coronary artery disease. However, the value of ECG abnormalities to predict POMI has been questioned. Methods: The study included 2967 noncardiac surgery patients >50 years of age from 2 university hospitals, who were expected to stay in the hospital for >24 hours. All data were obtained from electronic record-keeping systems. Patient history and ECG abnormalities were considered as potential predictors. Multivariate logistic regression analysis was used to obtain the independent predictors of POMI and all-cause in-hospital mortality. The area under the receiver operating characteristic curve (ROC area) was estimated to evaluate the ability of different models to discriminate between patients with and without the outcome. Results: A preoperative ECG was available in 2422 patients (80%) and 1087 (45%) of the ECGs showed at least one abnormality. The ROC area of the model that included the independent predictors of POMI obtained from patient history, ie, ischemic heart disease and high-risk surgery, was 0.80. ECG abnormalities that were associated with POMI were a right and a left bundle branch block. After adding these abnormalities in the regression model, the ROC area remained 0.80. Similar results were found for all-cause mortality. Conclusions: Bundle branch blocks identified on the preoperative ECG were related to POMI and death but did not improve prediction beyond risk factors identified on patient history. PMID:17667491

  17. Comparison of heart rate variability signal features derived from electrocardiography and photoplethysmography in healthy individuals.

    PubMed

    Bolanos, M; Nazeran, H; Haltiwanger, E

    2006-01-01

    The heart rate variability (HRV) signal is indicative of autonomic regulation of the heart rate (HR). It could be used as a noninvasive marker in monitoring the physiological state of an individual. Currently, the primary method of deriving the HRV signal is to acquire the electrocardiogram (ECG) signal, apply appropriate QRS detection algorithms to locate the R wave and its peak, find the RR intervals, and perform suitable interpolation and resampling to produce a uniformly sampled tachogram. This process could sometimes result in errors in the HRV signal due to drift, electromagnetic and biologic interference, and the complex morphology of the ECG signal. The photoplethysmographic (PPG) signal has the potential to eliminate the problems with the ECG signal to derive the HRV signal. To investigate this point, a PDA-based system was developed to simultaneously record ECG and PPG signals to facilitate accurately controlled sampling and recording durations. Two healthy young volunteers participated in this pilot study to evaluate the applicability of our approach. To improve data quality, ECG and PPG recordings were acquired three times/subject. A comparison between different features of the HRV signals derived from both methods was performed to test the validity of using PPG signals in HRV analysis. We used autoregressive (AR) modeling, Poincare' plots, cross correlation, standard deviation, arithmetic mean, skewness, kurtosis, and approximate entropy (ApEn) to derive and compare different measures from both ECG and PPG signals. This study demonstrated that our PDA-based system was a convenient and reliable means for acquisition of PPG-derived and ECG-derived HRV signals. The excellent agreement between different measures of HRV signals acquired from both methods provides potential support for the idea of using PPGs instead of ECGs in HRV signal derivation and analysis in ambulatory cardiac monitoring of healthy individuals.

  18. Principal Component Analysis in ECG Signal Processing

    NASA Astrophysics Data System (ADS)

    Castells, Francisco; Laguna, Pablo; Sörnmo, Leif; Bollmann, Andreas; Roig, José Millet

    2007-12-01

    This paper reviews the current status of principal component analysis in the area of ECG signal processing. The fundamentals of PCA are briefly described and the relationship between PCA and Karhunen-Loève transform is explained. Aspects on PCA related to data with temporal and spatial correlations are considered as adaptive estimation of principal components is. Several ECG applications are reviewed where PCA techniques have been successfully employed, including data compression, ST-T segment analysis for the detection of myocardial ischemia and abnormalities in ventricular repolarization, extraction of atrial fibrillatory waves for detailed characterization of atrial fibrillation, and analysis of body surface potential maps.

  19. A Mixed Approach Of Automated ECG Analysis

    NASA Astrophysics Data System (ADS)

    De, A. K.; Das, J.; Majumder, D. Dutta

    1982-11-01

    ECG is one of the non-invasive and risk-free technique for collecting data about the functional state of the heart. However, all these data-processing techniques can be classified into two basically different approaches -- the first and second generation ECG computer program. Not the opposition, but simbiosis of these two approaches will lead to systems with the highest accuracy. In our paper we are going to describe a mixed approach which will show higher accuracy with lesser amount of computational work. Key Words : Primary features, Patients' parameter matrix, Screening, Logical comparison technique, Multivariate statistical analysis, Mixed approach.

  20. ECG Parameters and Exposure to Carbon Ultrafine Particles in Young Healthy Subjects

    PubMed Central

    Zareba, Wojciech; Couderc, Jean Philippe; Oberdörster, Günter; Chalupa, David; Cox, Christopher; Huang, Li-Shan; Peters, Annette; Utell, Mark J.; Frampton, Mark W.

    2010-01-01

    The mechanisms underlying the association between air pollution and cardiovascular morbidity and mortality are unknown. This study aimed to determine whether controlled exposure to elemental carbon ultrafine particles (UFP) affects electrocardiogram (ECG) parameters describing heart rate variability; repolarization duration, morphology, and variability; and changes in the ST segment. Two separate controlled studies (12 subjects each) were performed using a crossover design, in which each subject was exposed to filtered air and carbon UFP for 2 hours. The first protocol involved 2 exposures to air and 10 µg/m3 (~ 2 × 106 particles/cm3, count median diameter ~25 nm, geometric standard deviation ~1.6), at rest. The second protocol included 3 exposures to air, 10, and 25 µg/m3 UFP (~ 7 × 106 particles/cm3), with repeated exercise. Each subject underwent a continuous digital 12-lead ECG Holter recording to analyze the above ECG parameters. Repeated measures analysis of variance (ANOVA) was used to compare tested parameters between exposures. The observed responses to UFP exposure were small and generally not significant, although there were trends indicating an increase in parasympathetic tone, which is most likely also responsible for trends toward ST elevation, blunted QTc shortening, and increased variability of T-wave complexity after exposure to UFP. Recovery from exercise showed a blunted response of the parasympathetic system after exposure to UFP in comparison to air exposure. In conclusion, transient exposure to 10–25 µg/m3 ultrafine carbon particles does not cause marked changes in ECG-derived parameters in young healthy subjects. However, trends are observed indicating that some subjects might be susceptible to air pollution, with a response involving autonomic modulation of the heart and repolarization of the ventricular myocardium. PMID:18991063

  1. ECG parameters and exposure to carbon ultrafine particles in young healthy subjects.

    PubMed

    Zareba, Wojciech; Couderc, Jean Philippe; Oberdörster, Günter; Chalupa, David; Cox, Christopher; Huang, Li-Shan; Peters, Annette; Utell, Mark J; Frampton, Mark W

    2009-02-01

    The mechanisms underlying the association between air pollution and cardiovascular morbidity and mortality are unknown. This study aimed to determine whether controlled exposure to elemental carbon ultrafine particles (UFP) affects electrocardiogram (ECG) parameters describing heart rate variability; repolarization duration, morphology, and variability; and changes in the ST segment. Two separate controlled studies (12 subjects each) were performed using a crossover design, in which each subject was exposed to filtered air and carbon UFP for 2 hours. The first protocol involved 2 exposures to air and 10 microg/m(3) (approximately 2 x 10(6) particles/cm(3), count median diameter approximately 25 nm, geometric standard deviation approximately 1.6), at rest. The second protocol included 3 exposures to air, 10, and 25 microg/m(3) UFP (approximately 7 x 10(6) particles/cm(3)), with repeated exercise. Each subject underwent a continuous digital 12-lead ECG Holter recording to analyze the above ECG parameters. Repeated measures analysis of variance (ANOVA) was used to compare tested parameters between exposures. The observed responses to UFP exposure were small and generally not significant, although there were trends indicating an increase in parasympathetic tone, which is most likely also responsible for trends toward ST elevation, blunted QTc shortening, and increased variability of T-wave complexity after exposure to UFP. Recovery from exercise showed a blunted response of the parasympathetic system after exposure to UFP in comparison to air exposure. In conclusion, transient exposure to 10-25 microg/m(3) ultrafine carbon particles does not cause marked changes in ECG-derived parameters in young healthy subjects. However, trends are observed indicating that some subjects might be susceptible to air pollution, with a response involving autonomic modulation of the heart and repolarization of the ventricular myocardium.

  2. Association of apolipoprotein E genotypes, blood pressure, blood lipids and ECG abnormalities in a general population aged 85+

    PubMed Central

    Rastas, Sari; Mattila, Kimmo; Verkkoniemi, Auli; Niinistö, Leena; Juva, Kati; Sulkava, Raimo; Länsimies, Esko

    2004-01-01

    Background Several studies have linked apolipoprotein E (ApoE) ε4 allele with elevated cholesterol and blood pressure levels. Data on the association of APOE genotypes with blood pressure, lipids, atrial fibrillation and ECG abnormalities in individuals aged 85 years and over is sparse. Methods This cross sectional study consisted of all residents of the city of Vantaa (N = 601) aged 85 years or over of whom 505 participated in the study. Blood pressure was measured by using mercury sphygmomanometer. 12-Lead ECG, short ambulatory ECG, or both were taken from all study subjects to diagnose atrial fibrillation (AF). Ambulatory ECG was carried out home or in the institute. APOE genotyping was performed using a combination of the polymerase chain reaction (PCR) and solid-phase minisequencing technique. Statistical analysis was made by using Kruskall-Wallis-test (continuous data) and χ2-test (rates and proportions). Results In these very elderly individuals, APOE 4 allele was significantly associated with elevated cholesterol and low-density lipoprotein (LDL) levels. Blood pressure or cardiac arrhythmias did not differ between APOE genotypes. Conclusions These observations suggest that the important role of APOE genotype still influences cardiovascular risk profile even among the very elderly people. PMID:15050032

  3. Association of apolipoprotein E genotypes, blood pressure, blood lipids and ECG abnormalities in a general population aged 85+.

    PubMed

    Rastas, Sari; Mattila, Kimmo; Verkkoniemi, Auli; Niinistö, Leena; Juva, Kati; Sulkava, Raimo; Länsimies, Esko

    2004-03-29

    Several studies have linked apolipoprotein E (ApoE) epsilon4 allele with elevated cholesterol and blood pressure levels. Data on the association of APOE genotypes with blood pressure, lipids, atrial fibrillation and ECG abnormalities in individuals aged 85 years and over is sparse. This cross sectional study consisted of all residents of the city of Vantaa (N = 601) aged 85 years or over of whom 505 participated in the study. Blood pressure was measured by using mercury sphygmomanometer. 12-Lead ECG, short ambulatory ECG, or both were taken from all study subjects to diagnose atrial fibrillation (AF). Ambulatory ECG was carried out home or in the institute. APOE genotyping was performed using a combination of the polymerase chain reaction (PCR) and solid-phase minisequencing technique. Statistical analysis was made by using Kruskall-Wallis-test (continuous data) and chi2-test (rates and proportions). In these very elderly individuals, APOE 4 allele was significantly associated with elevated cholesterol and low-density lipoprotein (LDL) levels. Blood pressure or cardiac arrhythmias did not differ between APOE genotypes. These observations suggest that the important role of APOE genotype still influences cardiovascular risk profile even among the very elderly people.

  4. Effects of noise and filtering on SVD-based morphological parameters of the T wave in the ECG.

    PubMed

    Lehtola, L; Karsikas, M; Koskinen, M; Huikuri, H; Seppanen, T

    2008-01-01

    Singular value decomposition (SVD) based electrocardiogram (ECG) morphology analysis is a novel method in the assessment of subtle abnormalities in the T wave morphology of 12-lead ECG. As various types of noise contaminate the ECG signal and create a bias for the morphological analyses, this study was designed to estimate the effects of noise on the SVD method in an experimental setup. Ideal signals were generated by filtering real ECG signals several times with the Savitzky-Golay filter. Random and real noise samples were superimposed on the ideal signals. The noisy signals were filtered with a power line interference filter combined with the Savitzky-Golay or the wavelet filter. Results show that noise increased both the dipolar and non-dipolar components significantly unless filtering was applied. R-TWR (relative T wave residuum) and A-TWR (absolute T wave residuum) were four to eight times higher in noisy signals. The experiments with patient data demonstrated that certain types of noise may even lead to erroneous classification of patients. Filtering brings the median values closer to the correct ones and decreases significantly the variance of the values of parameters.

  5. A preliminary study of the effect of electrode placement in order to define a suitable location for two electrodes and obtain sufficiently reliable ECG signals when monitoring with wireless system.

    PubMed

    Noh, Hyung Wook; Jang, Yongwon; Lee, I B; Song, Yoonseon; Jeong, Ji-Wook; Lee, Sooyeul

    2012-01-01

    Most countries face high and increasing rates of cardiovascular disease. Each year, heart disease kills more Americans than cancer. Therefore, there has been a promising market for portable ECG equipment and it is increasing. To use portable ECG measuring devices, it is essential to define a suitable location for the measuring as we need to reduced electrode size and distance. This research proposes to study how the inter-electrode distance affects the signal and how the electrode pair should be placed on the chest in order to obtain a sufficiently reliable ECG signal to detect heart arrhythmias in any environment, such as home or work. Therefore, we developed a compact, portable patch type ambulatory ECG monitoring system, Heart Tracker, using a microprocessor for preliminary study of signal analysis. To optimize the electrode arrangement in wireless environment, we compared HT and standard 12 lead with changing electrode position.

  6. High Resolution ECG for Evaluation of Heart Function During Exposure to Subacute Hypobaric Hypoxia

    NASA Technical Reports Server (NTRS)

    Zupet, Petra; Finderle, Zarko; Schlegel, Todd T.; Princi, Tanja; Starc, Vito

    2010-01-01

    High altitude climbing presents a wide spectrum of health risks, including exposure to hypobaric hypoxia. Risks are also typically exacerbated by the difficulty in appropriately monitoring for early signs of organ dysfunction in remote areas. We investigated whether high resolution advanced ECG analysis might be helpful as a non-invasive and easy-to-use tool (e.g., instead of Doppler echocardiography) for evaluating early signs of heart overload in hypobaric hypoxia. Nine non-acclimatized healthy trained alpine rescuers (age 43.7 plus or minus 7.3 years) climbed in four days to the altitude of 4,200 m on Mount Ararat. Five-minute high-resolution 12-lead electrocardiograms (ECGs) were recorded (Cardiosoft) in each subject at rest in the supine position on different days but at the same time of day at four different altitudes: 400 m (reference altitude), 1,700 m, 3,200 m and 4,200 m. Changes in conventional and advanced resting ECG parameters, including in beat-to-beat QT and RR variability, waveform complexity, signal-averaged, high-frequency and spatial/spatiotemporal ECG was estimated by calculation of the regression coefficients in independent linear regression models. A p-value of less than 0.05 was adopted as statistically significant. As expected, the RR interval and its variability both decreased with increasing altitude, with trends k = -96 ms/1000 m with p = 0.000 and k = -9 ms/1000 m with p = 0.001, respectively. Significant changes were found in P-wave amplitude, which nearly doubled from the lowest to the highest altitude (k = 41.6 microvolt/1000 m with p = 0.000), and nearly significant changes in P-wave duration (k = 2.9 ms/1000 m with p = 0.059). Changes were less significant or non-significant in other studied parameters including those of waveform complexity, signal-averaged, high-frequency and spatial/spatiotemporal ECG. High resolution ECG analysis, particularly of the P wave, shows promise as a tool for monitoring early changes in heart function

  7. Developing a DICOM Middleware to Implement ECG Conversion and Viewing.

    PubMed

    Ling-Ling, Wang; Ni-Ni, Rao; Li-Xin, Pu; Gang, Wang

    2005-01-01

    Nowadays, medical environment is integrated and complicated, involving large amounts of various medical data, such as images, waveforms and other digital data. For the interoperability of images and waveforms in imaging context, the images and waveforms usually need to be interchanged and stored using one standard. DICOM is the best choice, which is an international standard for the communication and storage of medical information. In this paper, we developed a DICOM middleware with capability of converting SCP-ECG, the European standard for resting ECGs, into DICOM ECGs. Then an ECG viewing component is implemented, which can parse and display SCP-ECG records and DICOM ECGs. The research results show that our work can realize seamless workflows in multi-vendor environment, contribute to the harmonization of ECG standards, and facilitate digital ECG applications.

  8. In-Hospital Tele-ECG Triage and Interventional Cardiologist Activation of the Infarct Team for STEMI Patients is Associated with Improved Late Clinical Outcomes

    PubMed Central

    Chen, Kuan-Chun; Yin, Wei-Hsian; Young, Mason Shing; Wei, Jeng

    2016-01-01

    Background Due to recent advances, door-to-balloon time (D2BT) has been reduced significantly for patients with ST-segment elevation myocardial infarction (STEMI). However, whether this reduction can be translated into a concrete mortality or morbidity benefit is still the subject of controversy. We conducted a before-and-after study to determine the impact of in-hospital tele-electrocardiography (ECG) triage and interventional cardiologist activation of the infarct team on D2BT and long-term clinical outcomes in STEMI patients undergoing primary percutaneous coronary intervention (PPCI). Methods A total of 272 consecutive patients with acute STEMI undergoing PPCI were enrolled in our study, comprising 102 tele-ECG patients and 170 conventional triage patients. Major adverse cardiovascular and cerebral vascular events (MACCE), including death, recurrent nonfatal MI, nonfatal stroke, and angina-driven target vessel revascularization were recorded during a 3-year follow-up. Results The median D2BT of the tele-ECG group was significantly shorter than control group (79 minutes vs. 109 minutes, p < 0.001). The tele-ECG triage group had a higher percentage of patients reaching the D2BT goal (< 90 minutes) (78% vs. 55%; p < 0.001). The MACCE rate was significantly lower in the Tele-ECG versus the control group (23.5% vs. 38.2%, p = 0.012). Tele-ECG group had a lower mortality rate which did not reached statistical significance (2% vs. 5.9%, p = 0.102). In multivariable Cox proportional hazards analyses, the implementation of tele-ECG triage (HR = 0.43, p = 0.003) and the presence of moderate or severe mitral regurgitation at presentation (HR = 1.87, p = 0.029) were discovered as independently associated with MACCE. Conclusions In-hospital tele-ECG triage and interventional cardiologist activation can shorten D2BT and is associated with improved late clinical outcomes during a 3-year follow-up in STEMI patients undergoing PPCI. PMID:27471356

  9. [Implementation of ECG Monitoring System Based on Internet of Things].

    PubMed

    Lu, Liangliang; Chen, Minya

    2015-11-01

    In order to expand the capabilities of hospital's traditional ECG device and enhance medical staff's work efficiency, an ECG monitoring system based on internet of things is introduced. The system can monitor ECG signals in real time and analyze data using ECG sensor, PDA, Web servers, which embeds C language, Android systems, .NET, wireless network and other technologies. After experiments, it can be showed that the system has high reliability and stability and can bring the convenience to medical staffs.

  10. ECG Beats Classification Using Mixture of Features

    PubMed Central

    Ari, Samit

    2014-01-01

    Classification of electrocardiogram (ECG) signals plays an important role in clinical diagnosis of heart disease. This paper proposes the design of an efficient system for classification of the normal beat (N), ventricular ectopic beat (V), supraventricular ectopic beat (S), fusion beat (F), and unknown beat (Q) using a mixture of features. In this paper, two different feature extraction methods are proposed for classification of ECG beats: (i) S-transform based features along with temporal features and (ii) mixture of ST and WT based features along with temporal features. The extracted feature set is independently classified using multilayer perceptron neural network (MLPNN). The performances are evaluated on several normal and abnormal ECG signals from 44 recordings of the MIT-BIH arrhythmia database. In this work, the performances of three feature extraction techniques with MLP-NN classifier are compared using five classes of ECG beat recommended by AAMI (Association for the Advancement of Medical Instrumentation) standards. The average sensitivity performances of the proposed feature extraction technique for N, S, F, V, and Q are 95.70%, 78.05%, 49.60%, 89.68%, and 33.89%, respectively. The experimental results demonstrate that the proposed feature extraction techniques show better performances compared to other existing features extraction techniques. PMID:27350985

  11. Multichannel ECG and Noise Modeling: Application to Maternal and Fetal ECG Signals

    NASA Astrophysics Data System (ADS)

    Sameni, Reza; Clifford, Gari D.; Jutten, Christian; Shamsollahi, Mohammad B.

    2007-12-01

    A three-dimensional dynamic model of the electrical activity of the heart is presented. The model is based on the single dipole model of the heart and is later related to the body surface potentials through a linear model which accounts for the temporal movements and rotations of the cardiac dipole, together with a realistic ECG noise model. The proposed model is also generalized to maternal and fetal ECG mixtures recorded from the abdomen of pregnant women in single and multiple pregnancies. The applicability of the model for the evaluation of signal processing algorithms is illustrated using independent component analysis. Considering the difficulties and limitations of recording long-term ECG data, especially from pregnant women, the model described in this paper may serve as an effective means of simulation and analysis of a wide range of ECGs, including adults and fetuses.

  12. ECG in neonate mice with spinal muscular atrophy allows assessment of drug efficacy.

    PubMed

    Heier, Christopher R; DiDonato, Christine J

    2015-01-01

    Molecular technologies have produced diverse arrays of animal models for studying genetic diseases and potential therapeutics. Many have neonatal phenotypes. Spinal muscular atrophy (SMA) is a neuromuscular disorder primarily affecting children, and is of great interest in translational medicine. The most widely used SMA mouse models require all phenotyping to be performed in neonates since they do not survive much past weaning. Pre-clinical studies in neonate mice can be hindered by toxicity and a lack of quality phenotyping assays, since many assays are invalid in pups or require subjective scoring with poor inter-rater variability. We find, however, that passive electrocardiography (ECG) recording in conscious 11-day old SMA mice provides sensitive outcome measures, detecting large differences in heart rate, cardiac conduction, and autonomic control resulting from disease. We find significant drug benefits upon treatment with G418, an aminoglycoside targeting the underlying protein deficiency, even in the absence of overt effects on growth and survival. These findings provide several quantitative physiological biomarkers for SMA preclinical studies, and will be of utility to diverse disease models featuring neonatal cardiac arrhythmias.

  13. [Research of DICOM-ECG implementation based on DCMTK].

    PubMed

    Wang, Xiang; Wu, Jian; Ma, Yaquanz; Peng, Cheng

    2013-11-01

    Parsed the ECG descriptions in DICOM 3.0 standard and accomplished a DICOM-ECG file which conforms to the DICOM standard by a toolkit DCMTK. The DICOM-ECG file can communicate with systems which support DICOM standard directly.

  14. Factors associated with diagnostic discrepancy for left ventricular hypertrophy between electrocardiography and echocardiography.

    PubMed

    Petersen, Søren Sandager; Pedersen, Line Reinholdt; Pareek, Manan; Nielsen, Mette Lundgren; Diederichsen, Søren Zöga; Leósdóttir, Margrét; Nilsson, Peter M; Diederichsen, Axel Cosmus Pyndt; Olsen, Michael Hecht

    2017-02-01

    To investigate the influence of cardiovascular risk factors, including fasting plasma glucose (FPG), on the association between electrocardiographic (ECG) and echocardiographic left ventricular hypertrophy (LVH) in an elderly population. We tested cross-sectional associations between electrocardiographic and echocardiographic LVH, defining LVH according to the Sokolow-Lyon voltage combination, Cornell voltage-duration product, or left ventricular mass index (LVMI). Differences between standardized LVMI and Sokolow-Lyon voltage combination or Cornell voltage-duration product (absolute value/cut-off value for LVH) were used as outcome variables in order to identify explanatory variables associated with diagnostic discrepancies between ECG and echocardiography. Of the 1382 subjects included, 77% did not display any signs of LVH, 6% had LVH defined by ECG only, 13% had LVH defined by echocardiography only, and 5% had LVH on both ECG and echocardiography. Older subjects and those with higher blood pressure and RWT were more likely to have a relatively greater LVMI on echocardiography than that predicted on ECG (odds ratio: 1.65 per 10 years (95% confidence interval (CI): 1.27-2.15), p = .0002, odds ratio: 1.17 per 10 mmHg (95% CI: 1.09-1.25), p < .0001, and odds ratio: 1.21 per 0.10 (95% CI: 1.02-1.42), p = .03). In addition, discrepancy was also seen in females and subjects receiving antihypertensive medication (odds ratio: 1.41 (95% CI: 1.04-1.89), p = .03 and odds ratio: 1.41 (95% CI: 1.06-1.87), p = .02), but FPG did not independently influence discrepancy between ECG and echocardiography. Age, blood pressure, female sex, greater RWT and use of antihypertensive medication were associated with a greater risk of non-consistency between LVH determined by ECG and echocardiography.

  15. Diagnosing Stroke in Acute Vertigo: The HINTS Family of Eye Movement Tests and the Future of the "Eye ECG".

    PubMed

    Newman-Toker, David E; Curthoys, Ian S; Halmagyi, G Michael

    2015-10-01

    Patients who present to the emergency department with symptoms of acute vertigo or dizziness are frequently misdiagnosed. Missed opportunities to promptly treat dangerous strokes can result in poor clinical outcomes. Inappropriate testing and incorrect treatments for those with benign peripheral vestibular disorders leads to patient harm and unnecessary costs. Over the past decade, novel bedside approaches to diagnose patients with the acute vestibular syndrome have been developed and refined. A battery of three bedside tests of ocular motor physiology known as "HINTS" (head impulse, nystagmus, test of skew) has been shown to identify acute strokes more accurately than even magnetic resonance imaging with diffusion-weighted imaging (MRI-DWI) when applied in the early acute period by eye-movement specialists. Recent advances in lightweight, high-speed video-oculography (VOG) technology have made possible a future in which HINTS might be applied by nonspecialists in frontline care settings using portable VOG. Use of technology to measure eye movements (VOG-HINTS) to diagnose stroke in the acute vestibular syndrome is analogous to the use of electrocardiography (ECG) to diagnose myocardial infarction in acute chest pain. This "eye ECG" approach could transform care for patients with acute vertigo and dizziness around the world. In the United States alone, successful implementation would likely result in improved quality of emergency care for hundreds of thousands of peripheral vestibular patients and tens of thousands of stroke patients, as well as an estimated national health care savings of roughly $1 billion per year. In this article, the authors review the origins of the HINTS approach, empiric evidence and pathophysiologic principles supporting its use, and possible uses for the eye ECG in teleconsultation, teaching, and triage.

  16. Electrocardiography at Diagnosis and Close to the Time of Death in Pulmonary Arterial Hypertension

    PubMed Central

    Tonelli, Adriano R.; Baumgartner, Manfred; Alkukhun, Laith; Minai, Omar A.; Dweik, Raed A.

    2014-01-01

    Background Scarce information exits on the electrocardiographic (ECG) characteristics of PAH patients close to their death and whether observed abnormalities progress from the time of PAH diagnosis. Methods We analyzed the characteristics of the ECG performed at initial diagnosis, during the course of the disease and close to the time of death on consecutive PAH patients followed at our institution between June 2008 and December 2010. Results We included 50 patients with PAH (76 % women) with mean (SD) age of 58 (14) years. Median heart rate (83 vs 89 bpm, p=0.001), PR interval (167 vs 176 ms, p=0.03), QRS duration (88 vs 90 ms, p=0.02), R/S ratio in lead V1 (1 vs 2, p=0.01) and QTc duration (431 vs 444 ms, p=0.02) significantly increased from the initial to the last ECG. In addition, the frontal QRS axis rotated to the right (97 vs 112 degrees, p=0.003) and we more commonly observed RBBB (5 vs 8 %, p=0.03) and negative T waves in inferior leads (31 vs 60 %, p=0.004). No patient had normal ECG at the time of death. Conclusions Significant changes progressively occur in a variety of ECG parameters between the time of the initial PAH diagnosis and close to death. PMID:24372670

  17. Adaptive Noise Cancellation to Suppress Electrocardiography Artifacts During Real-time Interventional MRI

    PubMed Central

    Wu, Vincent; Barbash, Israel M.; Ratnayaka, Kanishka; Saikus, Christina E.; Sonmez, Merdim; Kocaturk, Ozgur; Lederman, Robert J.; Faranesh, Anthony Z.

    2011-01-01

    PURPOSE To develop a system for artifact suppression in electrocardiogram (ECG) recordings obtained during interventional real-time magnetic resonance imaging. MATERIALS AND METHODS We characterized ECG artifacts due to radiofrequency pulses and gradient switching during MRI in terms of frequency content. A combination of analog filters and digital least mean squares adaptive filters were used to filter the ECG during in vivo experiments and the results were compared with those obtained with simple low-pass filtering. The system performance was evaluated in terms of artifact suppression and ability to identify arrhythmias during real-time MRI. RESULTS Analog filters were able to suppress artifacts from high-frequency radiofrequency pulses and gradient switching. Remaining pulse artifacts caused by intermittent preparation sequences or spoiler gradients required adaptive filtering because their bandwidth overlapped with that of the ECG. Using analog and adaptive filtering, a mean improvement of 38dB (n=11, peak QRS signal to pulse artifact noise) was achieved. This filtering system was successful in removing pulse artifacts which obscured arrhythmias such as premature ventricular complexes and complete atrioventricular block. CONCLUSION We have developed an online ECG monitoring system employing digital adaptive filters which enables the identification of cardiac arrhythmias during real-time MRI-guided interventions. PMID:21509878

  18. Sparse Matrix for ECG Identification with Two-Lead Features

    PubMed Central

    Tseng, Kuo-Kun; Luo, Jiao; Wang, Wenmin; Haiting, Dong

    2015-01-01

    Electrocardiograph (ECG) human identification has the potential to improve biometric security. However, improvements in ECG identification and feature extraction are required. Previous work has focused on single lead ECG signals. Our work proposes a new algorithm for human identification by mapping two-lead ECG signals onto a two-dimensional matrix then employing a sparse matrix method to process the matrix. And that is the first application of sparse matrix techniques for ECG identification. Moreover, the results of our experiments demonstrate the benefits of our approach over existing methods. PMID:25961074

  19. [Development of multi-function ECG signal generator].

    PubMed

    Cheng, F; Wei, Y X

    2000-07-01

    This paper describes the development of a portable multi-function ECG signal generator, which is based on micro-controller. It uses technique of LCD screen, and realizes man-machine interaction by keyboard. In constructing and disposing data module of the ECG signal, Eigen-heartbeat Code mapping method gets ROM saved greatly. Therefore it can generate all kinds of user-defined ECG signal sequence with no extension of on-board memory chips. This system can also simulate kinds of ECG signals, which have various heart rates and symptoms. It can meet the needs of researching and maintenance of kinds of ECG instruments.

  20. The Development of a Portable ECG Monitor Based on DSP

    NASA Astrophysics Data System (ADS)

    Nan, CHI Jian; Tao, YAN Yan; Meng Chen, LIU; Li, YANG

    With the advent of global information, researches of Smart Home system are in the ascendant, the ECG real-time detection, and wireless transmission of ECG become more useful. In order to achieve the purpose we developed a portable ECG monitor which achieves the purpose of cardiac disease remote monitoring, and will be used in the physical and psychological disease surveillance in smart home system, we developed this portable ECG Monitor, based on the analysis of existing ECG Monitor, using TMS320F2812 as the core controller, which complete the signal collection, storage, processing, waveform display and transmission.

  1. Hyperkalemia Induced Brugada Phenocopy: A Rare ECG Manifestation

    PubMed Central

    Akbar, Ghulam; Mirrani, Ghazi

    2017-01-01

    Brugada syndrome (BrS) is an inherited disorder of cardiac ion channels characterized by peculiar ECG findings predisposing individuals to ventricular arrhythmias, syncope, and sudden cardiac death (SCD). Various electrolyte disturbances and ion channels blocking drugs could also provoke BrS ECG findings without genetic BrS. Clinical differentiation and recognition are essential for guiding the legitimate action. Hyperkalemia is well known to cause a wide variety of ECG manifestations. Severe hyperkalemia can even cause life threatening ventricular arrhythmias and cardiac conduction abnormalities. Most common ECG findings include peaked tall T waves with short PR interval and wide QRS complex. Since it is very commonly encountered disorder, physicians need to be aware of even its rare ECG manifestations, which include ST segment elevation and Brugada pattern ECG (BrP). We are adding a case to the limited literature about hyperkalemia induced reversible Brugada pattern ECG changes. PMID:28326201

  2. Identifying UMLS concepts from ECG Impressions using KnowledgeMap.

    PubMed

    Denny, Joshua C; Spickard, Anderson; Miller, Randolph A; Schildcrout, Jonathan; Darbar, Dawood; Rosenbloom, S Trent; Peterson, Josh F

    2005-01-01

    Electrocardiogram (ECG) impressions represent a wealth of medical information for potential decision support and drug-effect discovery. Much of this information is inaccessible to automated methods in the free-text portion of the ECG report. We studied the application of the KnowledgeMap concept identifier (KMCI) to map Unified Medical Language System (UMLS) concepts from ECG impressions. ECGs were processed by KMCI and the results scored for accuracy by multiple raters. Reviewers also recorded unidentified concepts through the scoring interface. Overall, KMCI correctly identified 1059 out of 1171 concepts for a recall of 0.90. Precision, indicating the proportion of ECG concepts correctly identified, was 0.94. KMCI was particularly effective at identifying ECG rhythms (330/333), perfusion changes (65/66), and noncardiac medical concepts (11/11). In conclusion, KMCI is an effective method for mapping ECG impressions to UMLS concepts.

  3. The effectiveness of screening history, physical exam, and ECG to detect potentially lethal cardiac disorders in athletes: a systematic review/meta-analysis.

    PubMed

    Harmon, Kimberly G; Zigman, Monica; Drezner, Jonathan A

    2015-01-01

    The optimal cardiovascular preparticipation screen is debated. The purpose of this study was to perform a systematic review/meta-analysis of evidence comparing screening strategies. PRIMSA guidelines were followed. Electronic databases were searched from January 1996 to November 2014 for articles examining the efficacy of screening with history and physical exam (PE) based on the American Heart Association (AHA) or similar recommendations and electrocardiogram (ECG). Pooled data was analyzed for sensitivity, specificity, false positive rates and positive and negative likelihood ratios. Secondary outcomes included rate of potentially lethal cardiovascular conditions detected with screening and the etiology of pathology discovered. Fifteen articles reporting on 47,137 athletes were reviewed. After meta-analysis the sensitivity and specificity of ECG was 94%/93%, history 20%/94%, and PE 9%/97%. The overall false positive rate of ECG (6%) was less than that of history (8%), or physical exam (10%). Positive likelihood ratios were ECG 14.8, history 3.22 and PE 2.93 and negative likelihood ratios were ECG 0.055, history 0.85, and PE 0.93. There were a total of 160 potentially lethal cardiovascular conditions detected for a rate of 0.3% or 1 in 294. The most common pathology was Wolff-Parkinson-White (67, 42%), Long QT Syndrome (18, 11%), hypertrophic cardiomyopathy (18, 11%), dilated cardiomyopathy (11, 7%), coronary artery disease or myocardial ischemia (9, 6%) and arrhythmogenic right ventricular cardiomyopathy (4, 3%). The most effective strategy for screening for cardiovascular disease in athletes is ECG. It is 5 times more sensitive than history, 10 times more sensitive than physical exam, has higher positive likelihood ratio, lower negative likelihood ratio and a lower false positive rate. 12-lead ECG interpreted using modern criteria should be considered best practice in screening for cardiovascular disease in athletes while the use of history and physical alone as

  4. Cardiovascular screening in adolescents and young adults: a prospective study comparing the Pre-participation Physical Evaluation Monograph 4th Edition and ECG.

    PubMed

    Fudge, Jessie; Harmon, Kimberly G; Owens, David S; Prutkin, Jordan M; Salerno, Jack C; Asif, Irfan M; Haruta, Alison; Pelto, Hank; Rao, Ashwin L; Toresdahl, Brett G; Drezner, Jonathan A

    2014-08-01

    This study compares the accuracy of cardiovascular screening in active adolescents and young adults using a standardised history, physical examination and resting 12-lead ECG. Participants were prospectively screened using a standardised questionnaire based on the Pre-participation Physical Evaluation Monograph 4th Edition (PPE-4), physical examination and ECG interpreted using modern standards. Participants with abnormal findings had focused echocardiography and further evaluation. Primary outcomes included disorders associated with sudden cardiac arrest (SCA). From September 2010 to July 2011, 1339 participants underwent screening: age 13-24 (mean 16) years, 49% male, 68% Caucasian, 17% African-American and 1071 (80%) participating in organised sports. Abnormal history responses were reported on 916 (68%) questionnaires. After physician review, 495/916 (54%) participants with positive questionnaires were thought to have non-cardiac symptoms and/or a benign family history and did not warrant additional evaluation. Physical examination was abnormal in 124 (9.3%) participants, and 72 (5.4%) had ECG abnormalities. Echocardiograms were performed in 586 (44%) participants for abnormal history (31%), physical examination (8%) or ECG (5%). Five participants (0.4%) were identified with a disorder associated with SCA, all with ECG-detected Wolff-Parkinson-White. The false-positive rates for history, physical examination and ECG were 31.3%, 9.3% and 5%, respectively. A standardised history and physical examination using the PPE-4 yields a high false-positive rate in a young active population with limited sensitivity to identify those at risk for SCA. ECG screening has a low false-positive rate using modern interpretation standards and improves detection of primary electrical disease at risk of SCA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. Cardiovascular screening in adolescents and young adults: a prospective study comparing the Pre-participation Physical Evaluation Monograph 4th Edition and ECG

    PubMed Central

    Fudge, Jessie; Harmon, Kimberly G; Owens, David S; Prutkin, Jordan M; Salerno, Jack C; Asif, Irfan M; Haruta, Alison; Pelto, Hank; Rao, Ashwin L; Toresdahl, Brett G; Drezner, Jonathan A

    2015-01-01

    Background This study compares the accuracy of cardiovascular screening in active adolescents and young adults using a standardised history, physical examination and resting 12-lead ECG. Methods Participants were prospectively screened using a standardised questionnaire based on the Pre-participation Physical Evaluation Monograph 4th Edition (PPE-4), physical examination and ECG interpreted using modern standards. Participants with abnormal findings had focused echocardiography and further evaluation. Primary outcomes included disorders associated with sudden cardiac arrest (SCA). Results From September 2010 to July 2011, 1339 participants underwent screening: age 13–24 (mean 16) years, 49% male, 68% Caucasian, 17% African-American and 1071 (80%) participating in organised sports. Abnormal history responses were reported on 916 (68%) questionnaires. After physician review, 495/ 916 (54%) participants with positive questionnaires were thought to have non-cardiac symptoms and/or a benign family history and did not warrant additional evaluation. Physical examination was abnormal in 124 (9.3%) participants, and 72 (5.4%) had ECG abnormalities. Echocardiograms were performed in 586 (44%) participants for abnormal history (31%), physical examination (8%) or ECG (5%). Five participants (0.4%) were identified with a disorder associated with SCA, all with ECG-detected Wolff-Parkinson-White. The false-positive rates for history, physical examination and ECG were 31.3%, 9.3% and 5%, respectively. Conclusions A standardised history and physical examination using the PPE-4 yields a high false-positive rate in a young active population with limited sensitivity to identify those at risk for SCA. ECG screening has a low false-positive rate using modern interpretation standards and improves detection of primary electrical disease at risk of SCA. PMID:24948082

  6. Single frequency RF powered ECG telemetry system

    NASA Technical Reports Server (NTRS)

    Ko, W. H.; Hynecek, J.; Homa, J.

    1979-01-01

    It has been demonstrated that a radio frequency magnetic field can be used to power implanted electronic circuitry for short range telemetry to replace batteries. A substantial reduction in implanted volume can be achieved by using only one RF tank circuit for receiving the RF power and transmitting the telemetered information. A single channel telemetry system of this type, using time sharing techniques, was developed and employed to transmit the ECG signal from Rhesus monkeys in primate chairs. The signal from the implant is received during the period when the RF powering radiation is interrupted. The ECG signal is carried by 20-microsec pulse position modulated pulses, referred to the trailing edge of the RF powering pulse. Satisfactory results have been obtained with this single frequency system. The concept and the design presented may be useful for short-range long-term implant telemetry systems.

  7. Comparison of exercise electrocardiography and quantitative thallium imaging for one-vessel coronary artery disease

    SciTech Connect

    Kaul, S.; Kiess, M.; Liu, P.; Guiney, T.E.; Pohost, G.M.; Okada, R.D.; Boucher, C.A.

    1985-08-01

    The relative value of exercise electrocardiography and computer analyzed thallium-201 imaging was compared in 124 patients with 1-vessel coronary artery disease (CAD). Of these, 78 had left anterior descending (LAD), 32 right and 14 left circumflex (LC) CAD. In patients with no previous myocardial infarction (MI), thallium imaging was more sensitive than the electrocardiogram (78% vs 64%, p less than 0.01), but in patients with previous MI, sensitivity was similar. Further, thallium imaging was more sensitive only in LAD and LC disease. Redistribution was compared with ST-segment depression as a marker of ischemia. Only in patients with prior MI (76% vs 44%, p less than 0.01) and only in LC and right CAD did redistribution occur more often than ST depression. Thallium imaging was more accurate in localizing stenoses than the electrocardiogram (p less than 0.001), but did not always correctly predict coronary anatomy. Septal thallium defects were associated with LAD disease in 84%, inferior defects with right CAD in 40% and posterolateral lesion defects with LC CAD in 22%. The results indicate the overall superiority of thallium imaging in 1-vessel CAD compared with exercise electrocardiography; however, there is a wide spectrum of extent and location of perfusion defects associated with each coronary artery. Thallium imaging complements coronary angiography by demonstrating the functional impact of CAD on myocardial perfusion.

  8. ECG Sensor Card with Evolving RBP Algorithms for Human Verification

    PubMed Central

    Tseng, Kuo-Kun; Huang, Huang-Nan; Zeng, Fufu; Tu, Shu-Yi

    2015-01-01

    It is known that cardiac and respiratory rhythms in electrocardiograms (ECGs) are highly nonlinear and non-stationary. As a result, most traditional time-domain algorithms are inadequate for characterizing the complex dynamics of the ECG. This paper proposes a new ECG sensor card and a statistical-based ECG algorithm, with the aid of a reduced binary pattern (RBP), with the aim of achieving faster ECG human identity recognition with high accuracy. The proposed algorithm has one advantage that previous ECG algorithms lack—the waveform complex information and de-noising preprocessing can be bypassed; therefore, it is more suitable for non-stationary ECG signals. Experimental results tested on two public ECG databases (MIT-BIH) from MIT University confirm that the proposed scheme is feasible with excellent accuracy, low complexity, and speedy processing. To be more specific, the advanced RBP algorithm achieves high accuracy in human identity recognition and is executed at least nine times faster than previous algorithms. Moreover, based on the test results from a long-term ECG database, the evolving RBP algorithm also demonstrates superior capability in handling long-term and non-stationary ECG signals. PMID:26307995

  9. ECG Sensor Card with Evolving RBP Algorithms for Human Verification.

    PubMed

    Tseng, Kuo-Kun; Huang, Huang-Nan; Zeng, Fufu; Tu, Shu-Yi

    2015-08-21

    It is known that cardiac and respiratory rhythms in electrocardiograms (ECGs) are highly nonlinear and non-stationary. As a result, most traditional time-domain algorithms are inadequate for characterizing the complex dynamics of the ECG. This paper proposes a new ECG sensor card and a statistical-based ECG algorithm, with the aid of a reduced binary pattern (RBP), with the aim of achieving faster ECG human identity recognition with high accuracy. The proposed algorithm has one advantage that previous ECG algorithms lack-the waveform complex information and de-noising preprocessing can be bypassed; therefore, it is more suitable for non-stationary ECG signals. Experimental results tested on two public ECG databases (MIT-BIH) from MIT University confirm that the proposed scheme is feasible with excellent accuracy, low complexity, and speedy processing. To be more specific, the advanced RBP algorithm achieves high accuracy in human identity recognition and is executed at least nine times faster than previous algorithms. Moreover, based on the test results from a long-term ECG database, the evolving RBP algorithm also demonstrates superior capability in handling long-term and non-stationary ECG signals.

  10. ECG-derived spatial QRS-T angle is associated with ICD implantation, mortality and heart failure admissions in patients with LV systolic dysfunction

    PubMed Central

    Dugo, Clementina; Cave, Andrew; Zhou, Lifeng; Ayar, Zina; Christiansen, Jonathan; Scott, Tony; Dawson, Liane; Gavin, Andrew

    2017-01-01

    Background Increased spatial QRS-T angle has been shown to predict appropriate implantable cardioverter defibrilIator (ICD) therapy in patients with left ventricular systolic dysfunction (LVSD). We performed a retrospective cohort study in patients with left ventricular ejection fraction (LVEF) 31–40% to assess the relationship between the spatial QRS-T angle and other advanced ECG (A-ECG) as well as echocardiographic metadata, with all-cause mortality or ICD implantation for secondary prevention. Methods 534 patients ≤75 years of age with LVEF 31–40% were identified through an echocardiography reporting database. Digital 12-lead ECGs were retrospectively matched to 295 of these patients, for whom echocardiographic and A-ECG metadata were then generated. Data mining was applied to discover novel ECG and echocardiographic markers of risk. Machine learning was used to develop a model to predict possible outcomes. Results 49 patients (17%) had events, defined as either mortality (n = 16) or ICD implantation for secondary prevention (n = 33). 72 parameters (58 A-ECG, 14 echocardiographic) were univariately different (p<0.05) in those with vs. without events. After adjustment for multiplicity, 24 A-ECG parameters and 3 echocardiographic parameters remained different (p<2x10-3). These included the posterior-to-leftward QRS loop ratio from the derived vectorcardiographic horizontal plane (previously associated with pulmonary artery pressure, p = 2x10-6); spatial mean QRS-T angle (134 vs. 112°, p = 1.6x10-4); various repolarisation vectors; and a previously described 5-parameter A-ECG score for LVSD (p = 4x10-6) that also correlated with echocardiographic global longitudinal strain (R2 = - 0.51, P < 0.0001). A spatial QRS-T angle >110° had an adjusted HR of 3.4 (95% CI 1.6 to 7.4) for secondary ICD implantation or all-cause death and adjusted HR of 4.1 (95% CI 1.2 to 13.9) for future heart failure admission. There was a loss of complexity between A-ECG and

  11. Feasibility and cost-effectiveness of stroke prevention through community screening for atrial fibrillation using iPhone ECG in pharmacies. The SEARCH-AF study.

    PubMed

    Lowres, Nicole; Neubeck, Lis; Salkeld, Glenn; Krass, Ines; McLachlan, Andrew J; Redfern, Julie; Bennett, Alexandra A; Briffa, Tom; Bauman, Adrian; Martinez, Carlos; Wallenhorst, Christopher; Lau, Jerrett K; Brieger, David B; Sy, Raymond W; Freedman, S Ben

    2014-06-01

    Atrial fibrillation (AF) causes a third of all strokes, but often goes undetected before stroke. Identification of unknown AF in the community and subsequent anti-thrombotic treatment could reduce stroke burden. We investigated community screening for unknown AF using an iPhone electrocardiogram (iECG) in pharmacies, and determined the cost-effectiveness of this strategy.Pharmacists performedpulse palpation and iECG recordings, with cardiologist iECG over-reading. General practitioner review/12-lead ECG was facilitated for suspected new AF. An automated AF algorithm was retrospectively applied to collected iECGs. Cost-effectiveness analysis incorporated costs of iECG screening, and treatment/outcome data from a United Kingdom cohort of 5,555 patients with incidentally detected asymptomatic AF. A total of 1,000 pharmacy customers aged ≥65 years (mean 76 ± 7 years; 44% male) were screened. Newly identified AF was found in 1.5% (95% CI, 0.8-2.5%); mean age 79 ± 6 years; all had CHA2DS2-VASc score ≥2. AF prevalence was 6.7% (67/1,000). The automated iECG algorithm showed 98.5% (CI, 92-100%) sensitivity for AF detection and 91.4% (CI, 89-93%) specificity. The incremental cost-effectiveness ratio of extending iECG screening into the community, based on 55% warfarin prescription adherence, would be $AUD5,988 (€3,142; $USD4,066) per Quality Adjusted Life Year gained and $AUD30,481 (€15,993; $USD20,695) for preventing one stroke. Sensitivity analysis indicated cost-effectiveness improved with increased treatment adherence.Screening with iECG in pharmacies with an automated algorithm is both feasible and cost-effective. The high and largely preventable stroke/thromboembolism risk of those with newly identified AF highlights the likely benefits of community AF screening. Guideline recommendation of community iECG AF screening should be considered.

  12. High Resolution ECG for Evaluation of QT Interval Variability during Exposure to Acute Hypoxia

    NASA Technical Reports Server (NTRS)

    Zupet, P.; Finderle, Z.; Schlegel, Todd T.; Starc, V.

    2010-01-01

    Ventricular repolarization instability as quantified by the index of QT interval variability (QTVI) is one of the best predictors for risk of malignant ventricular arrhythmias and sudden cardiac death. Because it is difficult to appropriately monitor early signs of organ dysfunction at high altitude, we investigated whether high resolution advanced ECG (HR-ECG) analysis might be helpful as a non-invasive and easy-to-use tool for evaluating the risk of cardiac arrhythmias during exposure to acute hypoxia. 19 non-acclimatized healthy trained alpinists (age 37, 8 plus or minus 4,7 years) participated in the study. Five-minute high-resolution 12-lead electrocardiograms (ECGs) were recorded (Cardiosoft) in each subject at rest in the supine position breathing room air and then after breathing 12.5% oxygen for 30 min. For beat-to-beat RR and QT variability, the program of Starc was utilized to derive standard time domain measures such as root mean square of the successive interval difference (rMSSD) of RRV and QTV, the corrected QT interval (QTc) and the QTVI in lead II. Changes were evaluated with paired-samples t-test with p-values less than 0.05 considered statistically significant. As expected, the RR interval and its variability both decreased with increasing altitude, with p = 0.000 and p = 0.005, respectively. Significant increases were found in both the rMSSDQT and the QTVI in lead II, with p = 0.002 and p = 0.003, respectively. There was no change in QTc interval length (p = non significant). QT variability parameters may be useful for evaluating changes in ventricular repolarization caused by hypoxia. These changes might be driven by increases in sympathetic nervous system activity at ventricular level.

  13. High Resolution ECG for Evaluation of QT Interval Variability during Exposure to Acute Hypoxia

    NASA Technical Reports Server (NTRS)

    Zupet, P.; Finderle, Z.; Schlegel, Todd T.; Starc, V.

    2010-01-01

    Ventricular repolarization instability as quantified by the index of QT interval variability (QTVI) is one of the best predictors for risk of malignant ventricular arrhythmias and sudden cardiac death. Because it is difficult to appropriately monitor early signs of organ dysfunction at high altitude, we investigated whether high resolution advanced ECG (HR-ECG) analysis might be helpful as a non-invasive and easy-to-use tool for evaluating the risk of cardiac arrhythmias during exposure to acute hypoxia. 19 non-acclimatized healthy trained alpinists (age 37, 8 plus or minus 4,7 years) participated in the study. Five-minute high-resolution 12-lead electrocardiograms (ECGs) were recorded (Cardiosoft) in each subject at rest in the supine position breathing room air and then after breathing 12.5% oxygen for 30 min. For beat-to-beat RR and QT variability, the program of Starc was utilized to derive standard time domain measures such as root mean square of the successive interval difference (rMSSD) of RRV and QTV, the corrected QT interval (QTc) and the QTVI in lead II. Changes were evaluated with paired-samples t-test with p-values less than 0.05 considered statistically significant. As expected, the RR interval and its variability both decreased with increasing altitude, with p = 0.000 and p = 0.005, respectively. Significant increases were found in both the rMSSDQT and the QTVI in lead II, with p = 0.002 and p = 0.003, respectively. There was no change in QTc interval length (p = non significant). QT variability parameters may be useful for evaluating changes in ventricular repolarization caused by hypoxia. These changes might be driven by increases in sympathetic nervous system activity at ventricular level.

  14. Noninvasive quantification of blood potassium concentration from ECG in hemodialysis patients

    PubMed Central

    Corsi, Cristiana; Cortesi, Marilisa; Callisesi, Giulia; De Bie, Johan; Napolitano, Carlo; Santoro, Antonio; Mortara, David; Severi, Stefano

    2017-01-01

    Blood potassium concentration ([K+]) influences the electrocardiogram (ECG), particularly T-wave morphology. We developed a new method to quantify [K+] from T-wave analysis and tested its clinical applicability on data from dialysis patients, in whom [K+] varies significantly during the therapy. To elucidate the mechanism linking [K+] and T-wave, we also analysed data from long QT syndrome type 2 (LQT2) patients, testing the hypothesis that our method would have underestimated [K+] in these patients. Moreover, a computational model was used to explore the physiological processes underlying our estimator at the cellular level. We analysed 12-lead ECGs from 45 haemodialysis and 12 LQT2 patients. T-wave amplitude and downslope were calculated from the first two eigenleads. The T-wave slope-to-amplitude ratio (TS/A) was used as starting point for an ECG-based [K+] estimate (KECG). Leave-one-out cross-validation was performed. Agreement between KECG and reference [K+] from blood samples was promising (error: −0.09 ± 0.59 mM, absolute error: 0.46 ± 0.39 mM). The analysis on LQT2 patients, also supported by the outcome of computational analysis, reinforces our interpretation that, at the cellular level, delayed-rectifier potassium current is a main contributor of KECG correlation to blood [K+]. Following a comprehensive validation, this method could be effectively applied to monitor patients at risk for hyper/hypokalemia. PMID:28198403

  15. Improvements in ECG accuracy for diagnosis of left ventricular hypertrophy in obesity

    PubMed Central

    Rider, Oliver J; Ntusi, Ntobeko; Bull, Sacha C; Nethononda, Richard; Ferreira, Vanessa; Holloway, Cameron J; Holdsworth, David; Mahmod, Masliza; Rayner, Jennifer J; Banerjee, Rajarshi; Myerson, Saul; Watkins, Hugh; Neubauer, Stefan

    2016-01-01

    Objectives The electrocardiogram (ECG) is the most commonly used tool to screen for left ventricular hypertrophy (LVH), and yet current diagnostic criteria are insensitive in modern increasingly overweight society. We propose a simple adjustment to improve diagnostic accuracy in different body weights and improve the sensitivity of this universally available technique. Methods Overall, 1295 participants were included—821 with a wide range of body mass index (BMI 17.1–53.3 kg/m2) initially underwent cardiac magnetic resonance evaluation of anatomical left ventricular (LV) axis, LV mass and 12-lead surface ECG in order to generate an adjustment factor applied to the Sokolow–Lyon criteria. This factor was then validated in a second cohort (n=520, BMI 15.9–63.2 kg/m2). Results When matched for LV mass, the combination of leftward anatomical axis deviation and increased BMI resulted in a reduction of the Sokolow–Lyon index, by 4 mm in overweight and 8 mm in obesity. After adjusting for this in the initial cohort, the sensitivity of the Sokolow–Lyon index increased (overweight: 12.8% to 30.8%, obese: 3.1% to 27.2%) approaching that seen in normal weight (37.8%). Similar results were achieved in the validation cohort (specificity increased in overweight: 8.3% to 39.1%, obese: 9.4% to 25.0%) again approaching normal weight (39.0%). Importantly, specificity remained excellent (>93.1%). Conclusions Adjusting the Sokolow–Lyon index for BMI (overweight +4 mm, obesity +8 mm) improves the diagnostic accuracy for detecting LVH. As the ECG, worldwide, remains the most widely used screening tool for LVH, implementing these findings should translate into significant clinical benefit. PMID:27486142

  16. Improvements in ECG accuracy for diagnosis of left ventricular hypertrophy in obesity.

    PubMed

    Rider, Oliver J; Ntusi, Ntobeko; Bull, Sacha C; Nethononda, Richard; Ferreira, Vanessa; Holloway, Cameron J; Holdsworth, David; Mahmod, Masliza; Rayner, Jennifer J; Banerjee, Rajarshi; Myerson, Saul; Watkins, Hugh; Neubauer, Stefan

    2016-10-01

    The electrocardiogram (ECG) is the most commonly used tool to screen for left ventricular hypertrophy (LVH), and yet current diagnostic criteria are insensitive in modern increasingly overweight society. We propose a simple adjustment to improve diagnostic accuracy in different body weights and improve the sensitivity of this universally available technique. Overall, 1295 participants were included-821 with a wide range of body mass index (BMI 17.1-53.3 kg/m(2)) initially underwent cardiac magnetic resonance evaluation of anatomical left ventricular (LV) axis, LV mass and 12-lead surface ECG in order to generate an adjustment factor applied to the Sokolow-Lyon criteria. This factor was then validated in a second cohort (n=520, BMI 15.9-63.2 kg/m(2)). When matched for LV mass, the combination of leftward anatomical axis deviation and increased BMI resulted in a reduction of the Sokolow-Lyon index, by 4 mm in overweight and 8 mm in obesity. After adjusting for this in the initial cohort, the sensitivity of the Sokolow-Lyon index increased (overweight: 12.8% to 30.8%, obese: 3.1% to 27.2%) approaching that seen in normal weight (37.8%). Similar results were achieved in the validation cohort (specificity increased in overweight: 8.3% to 39.1%, obese: 9.4% to 25.0%) again approaching normal weight (39.0%). Importantly, specificity remained excellent (>93.1%). Adjusting the Sokolow-Lyon index for BMI (overweight +4 mm, obesity +8 mm) improves the diagnostic accuracy for detecting LVH. As the ECG, worldwide, remains the most widely used screening tool for LVH, implementing these findings should translate into significant clinical benefit. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  17. Electrocardiography in two subspecies of manatee (Trichechus manatus latirostris and Trichechus manatus manatus)

    USGS Publications Warehouse

    Siegal-Willott, J.; Estrada, A.; Bonde, R.K.; Wong, A.; Estrada, D.J.; Harr, K.

    2006-01-01

    Electrocardiographic (ECG) measurements were recorded in two subspecies of awake, apparently healthy, wild manatees (Trichechus manatus latirostris and T. m. manatus) undergoing routine field examinations in Florida and Belize. Six unsedated juveniles (dependent and independent calves) and 6 adults were restrained in ventral recumbency for ECG measurements. Six lead ECGs were recorded for all manatees and the following parameters were determined: heart rate and rhythm; P, QRS, and T wave morphology, amplitude, and duration; and mean electrical axis (MEA). Statistical differences using a t-test for equality of means were determined. No statistical difference was seen based on sex or subspecies of manatees in the above measured criteria. Statistical differences existed in heart rate (P = 0.047), P wave duration (P = 0.019), PR interval (P = 0.025), and MEA (P = 0.021) between adult manatees and calves. Our findings revealed normal sinus rhythms, no detectable arrhythmias, prolonged PR and QT intervals, prolonged P wave duration, and small R wave amplitude as compared with cetacea and other marine mammals. This paper documents the techniques for and baseline recordings of ECGs in juvenile and adult free-living manatees. It also demonstrates that continual assessment of cardiac electrical activity in the awake manatee can be completed and can be used to aid veterinarians and biologists in routine health assessment, during procedures, and in detecting the presence of cardiac disease or dysfunction.

  18. Electrocardiography in two subspecies of manatee (Trichechus manatus latirostris and T. m. manatus).

    PubMed

    Siegal-Willott, Jessica; Estrada, Amara; Bonde, Robert; Wong, Arthur; Estrada, Daniel J; Harr, Kendal

    2006-12-01

    Electrocardiographic (ECG) measurements were recorded in two subspecies of awake, apparently healthy, wild manatees (Trichechus manatus latirostris and T. m. manatus) undergoing routine field examinations in Florida and Belize. Six unsedated juveniles (dependent and independent calves) and 6 adults were restrained in ventral recumbency for ECG measurements. Six lead ECGs were recorded for all manatees and the following parameters were determined: heart rate and rhythm; P, QRS, and T wave morphology, amplitude, and duration; and mean electrical axis (MEA). Statistical differences using a t-test for equality of means were determined. No statistical difference was seen based on sex or subspecies of manatees in the above measured criteria. Statistical differences existed in heart rate (P = 0.047), P wave duration (P = 0.019), PR interval (P = 0.025), and MEA (P = 0.021) between adult manatees and calves. Our findings revealed normal sinus rhythms, no detectable arrhythmias, prolonged PR and QT intervals, prolonged P wave duration, and small R wave amplitude as compared with cetacea and other marine mammals. This paper documents the techniques for and baseline recordings of ECGs in juvenile and adult free-living manatees. It also demonstrates that continual assessment of cardiac electrical activity in the awake manatee can be completed and can be used to aid veterinarians and biologists in routine health assessment, during procedures, and in detecting the presence of cardiac disease or dysfunction.

  19. Separation and Analysis of Fetal-ECG Signals From Compressed Sensed Abdominal ECG Recordings.

    PubMed

    Da Poian, Giulia; Bernardini, Riccardo; Rinaldo, Roberto

    2016-06-01

    Analysis of fetal electrocardiogram (f-ECG) waveforms as well as fetal heart-rate (fHR) evaluation provide important information about the condition of the fetus during pregnancy. A continuous monitoring of f-ECG, for example using the technologies already applied for adults ECG tele-monitor-ing (e.g., Wireless Body Sensor Networks (WBSNs)), may increase early detection of fetal arrhythmias. In this study, we propose a novel framework, based on compressive sensing (CS) theory, for the compression and joint detection/classification of mother and fetal heart beats. Our scheme is based on the sparse representation of the components derived from independent component analysis (ICA), which we propose to apply directly in the compressed domain. Detection and classification is based on the activated atoms in a specifically designed reconstruction dictionary. Validation of the proposed compression and detection framework has been done on two publicly available datasets, showing promising results (sensitivity S = 92.5 %, P += 92 % , F1 = 92.2 % for the Silesia dataset and S = 78 % , P += 77 %, F1 = 77.5 % for the Challenge dataset A, with average reconstruction quality PRD = 8.5 % and PRD = 7.5 %, respectively). The experiments confirm that the proposed framework may be used for compression of abdominal f-ECG and to obtain real-time information of the fHR, providing a suitable solution for real time, very low-power f-ECG monitoring. To the authors' knowledge, this is the first time that a framework for the low-power CS compression of fetal abdominal ECG is proposed combined with a beat detector for an fHR estimation.

  20. A model-based approach to human identification using ECG

    NASA Astrophysics Data System (ADS)

    Homer, Mark; Irvine, John M.; Wendelken, Suzanne

    2009-05-01

    Biometrics, such as fingerprint, iris scan, and face recognition, offer methods for identifying individuals based on a unique physiological measurement. Recent studies indicate that a person's electrocardiogram (ECG) may also provide a unique biometric signature. Current techniques for identification using ECG rely on empirical methods for extracting features from the ECG signal. This paper presents an alternative approach based on a time-domain model of the ECG trace. Because Auto-Regressive Integrated Moving Average (ARIMA) models form a rich class of descriptors for representing the structure of periodic time series data, they are well-suited to characterizing the ECG signal. We present a method for modeling the ECG, extracting features from the model representation, and identifying individuals using these features.

  1. Reliability and validity of clinician ECG interpretation for athletes.

    PubMed

    Magee, Charles; Kazman, Joshua; Haigney, Mark; Oriscello, Ralph; DeZee, Kent J; Deuster, Patricia; Depenbrock, Patrick; O'Connor, Francis G

    2014-07-01

    Electrocardiogram (ECG) with preparticipation evaluation (PPE) for athletes remains controversial in the United States and diagnostic accuracy of clinician ECG interpretation is unclear. This study aimed to assess reliability and validity of clinician ECG interpretation using expert-validated ECGs according to the 2010 European Society of Cardiology (ESC) interpretation criteria. This is a blinded, prospective study of diagnostic accuracy of clinician ECG interpretation. Anonymized ECGs were validated for normal and abnormal patterns by blinded expert interpreters according to the ESC interpretation criteria from October 2011 through March 2012. Six pairs of clinician interpreters were recruited from relevant clinical specialties in an academic medical center in March 2012. Each clinician interpreted 85 ECGs according to the ESC interpretation guidelines. Cohen and Fleiss' kappa, sensitivity, and specificity were calculated within specialties and across primary care and cardiology specialty groups. Experts interpreted 189 ECGs yielding a kappa of 0.63, demonstrating "substantial" inter-rater agreement. A total of 85 validated ECGs, including 26 abnormals, were selected for clinician interpretation. The kappa across cardiology specialists was "substantial" and "moderate" across primary care (0.69 vs 0.52, respectively, P < 0.001). Sensitivity and specificity to detect abnormal patterns were similar between cardiology and primary care groups (sensitivity 93.3% vs 81.3%, respectively, P = 0.31; specificity 88.8% vs 89.8%, respectively, P = 0.91). Clinician ECG interpretation according to the ESC interpretation criteria appears to demonstrate limited reliability and validity. Before widespread adoption of ECG for PPE of U.S. athletes, further research of training focused on improved reliability and validity of clinician ECG interpretation is warranted. © 2014 Wiley Periodicals, Inc.

  2. Compressed domain ECG biometric with two-lead features

    NASA Astrophysics Data System (ADS)

    Lee, Wan-Jou; Chang, Wen-Whei

    2016-07-01

    This study presents a new method to combine ECG biometrics with data compression within a common JPEG2000 framework. We target the two-lead ECG configuration that is routinely used in long-term heart monitoring. Incorporation of compressed-domain biometric techniques enables faster person identification as it by-passes the full decompression. Experiments on public ECG databases demonstrate the validity of the proposed method for biometric identification with high accuracies on both healthy and diseased subjects.

  3. [Practical experience about the compatibility of PDF converter in ECG information system].

    PubMed

    Yang, Gang; Lu, Weishi; Zhou, Jiacheng

    2009-11-01

    To find a way to view ECG from different manufacturers in electrocardiogram information system. Different format ECG data were transmitted to ECG center by different ways. Corresponding analysis software was used to make the diagnosis reports in the center. Then we use PDF convert to change all ECG reports into PDF format. The electrocardiogram information system manage these PDF format ECG data for clinic user. The ECG reports form several major ECG manufacturers were transformed to PDF format successfully. In the electrocardiogram information system it is freely to view the ECG figure. PDF format ECG report is a practicable way to solve the compatibility problem in electrocardiogram information system.

  4. A nonlinear Bayesian filtering framework for ECG denoising.

    PubMed

    Sameni, Reza; Shamsollahi, Mohammad B; Jutten, Christian; Clifford, Gari D

    2007-12-01

    In this paper, a nonlinear Bayesian filtering framework is proposed for the filtering of single channel noisy electrocardiogram (ECG) recordings. The necessary dynamic models of the ECG are based on a modified nonlinear dynamic model, previously suggested for the generation of a highly realistic synthetic ECG. A modified version of this model is used in several Bayesian filters, including the Extended Kalman Filter, Extended Kalman Smoother, and Unscented Kalman Filter. An automatic parameter selection method is also introduced, to facilitate the adaptation of the model parameters to a vast variety of ECGs. This approach is evaluated on several normal ECGs, by artificially adding white and colored Gaussian noises to visually inspected clean ECG recordings, and studying the SNR and morphology of the filter outputs. The results of the study demonstrate superior results compared with conventional ECG denoising approaches such as bandpass filtering, adaptive filtering, and wavelet denoising, over a wide range of ECG SNRs. The method is also successfully evaluated on real nonstationary muscle artifact. This method may therefore serve as an effective framework for the model-based filtering of noisy ECG recordings.

  5. Arrhythmia ECG Noise Reduction by Ensemble Empirical Mode Decomposition

    PubMed Central

    Chang, Kang-Ming

    2010-01-01

    A novel noise filtering algorithm based on ensemble empirical mode decomposition (EEMD) is proposed to remove artifacts in electrocardiogram (ECG) traces. Three noise patterns with different power—50 Hz, EMG, and base line wander – were embedded into simulated and real ECG signals. Traditional IIR filter, Wiener filter, empirical mode decomposition (EMD) and EEMD were used to compare filtering performance. Mean square error between clean and filtered ECGs was used as filtering performance indexes. Results showed that high noise reduction is the major advantage of the EEMD based filter, especially on arrhythmia ECGs. PMID:22219702

  6. Denoising of ECG signal during spaceflight using singular value decomposition

    NASA Astrophysics Data System (ADS)

    Li, Zhuo; Wang, Li

    2009-12-01

    The Singular Value Decomposition (SVD) method is introduced to denoise the ECG signal during spaceflight. The theory base of SVD method is given briefly. The denoising process of the strategy is presented combining a segment of real ECG signal. We improve the algorithm of calculating Singular Value Ratio (SVR) spectrum, and propose a constructive approach of analysis characteristic patterns. We reproduce the ECG signal very well and compress the noise effectively. The SVD method is proved to be suitable for denoising the ECG signal.

  7. 3-lead acquisition using single channel ECG device developed on AD8232 analog front end for wireless ECG application

    NASA Astrophysics Data System (ADS)

    Agung, Mochammad Anugrah; Basari

    2017-02-01

    Electrocardiogram (ECG) devices measure electrical activity of the heart muscle to determine heart conditions. ECG signal quality is the key factor in determining the diseases of the heart. This paper presents the design of 3-lead acquistion on single channel wireless ECG device developed on AD8232 chip platform using microcontroller. To make the system different from others, monopole antenna 2.4 GHz is used in order to send and receive ECG signal. The results show that the system still can receive ECG signal up to 15 meters by line of sight (LOS) condition. The shape of ECG signals is precisely similar with the expected signal, although some delays occur between two consecutive pulses. For further step, the system will be applied with on-body antenna in order to investigate body to body communication that will give variation in connectivity from the others.

  8. Prognostic significance of T-wave amplitude in lead aVR on the admission electrocardiography in patients with anterior wall ST-elevation myocardial infarction treated by primary percutaneous intervention.

    PubMed

    Ayhan, Erkan; Isık, Turgay; Uyarel, Huseyin; Ergelen, Mehmet; Cicek, Gokhan; Ghannadian, Bahman; Eren, Mehmet

    2013-01-01

    T-wave positivity in aVR lead patients with heart failure and anterior wall old ST-segment elevation myocardial infarction (STEMI) are shown to have a higher frequency of cardiovascular mortality, although the effects on patients with STEMI treated with primary percutaneous coronary intervention (PCI) has not been investigated. In this study, we sought to determine the prognostic value of T wave in lead aVR on admission electrocardiography (ECG) for in-hospital mortality in patients with anterior wall STEMI treated with primary PCI. After exclusion, 169 consecutive patients with anterior wall STEMI (mean age: 55 ± 12.9 years; 145 men) undergoing primary PCI were prospectively enrolled in this study. Patients were classified as a T-wave positive (n = 53, group 1) or T-wave negative (n = 116, group 2) in aVR based upon the admission ECG. All patients were evaluated with respect to clinical features, primary PCI findings, and in-hospital clinical results. T-wave positive patients who received primary PCI were older, multivessel disease was significantly more frequent and the duration of the patient's hospital stay was longer than T-wave negative patients. In-hospital mortality tended to be higher in the group 1 when compared with group 2 (7.5% vs 1.7% respectively, P = 0.05). After adjusting the baseline characteristics, positive T wave remained an independent predictor of in hospital mortality (odds ratio: 4.41; 95% confidence interval 1.2-22.1, P = 0.05). T-wave positivity in lead aVR among patients with an anterior wall STEMI treated with primary PCI is associated with an increase in hospital cardiovascular mortality. ©2012, Wiley Periodicals, Inc.

  9. Assessing ethical and social issues of transtelephonic electrocardiography (TTEGG) in Chile.

    PubMed

    Lamas, Eugenia; Miguel, Silvia; Muehlan, Holger; Schmidt, Silke; Salinas, Rodrigo A

    2014-12-01

    The aim of this study was to focus on the ethical and social issues derived from the implementation of transtelephonic electrocardiography (TTECG) in the public healthcare sector in Chile, studying patients and healthcare providers' acceptance and expectations concerning: (a) TTECG effectiveness and safety; and (b) data protection issues, such as confidentiality, privacy and security. For this purpose, we developed two psychosocial surveys; the first was addressed to patients receiving transtelephonic electrocardiogram (either in the emergency services of hospitals or in distant primary care services) and the second one aimed at healthcare providers involved in either administering and/or interpreting it. Results included: (a) major acceptability of TTECG in terms of safety and security; (b) privacy and confidentiality of the patients were considered to be well protected; and (c) the patient-doctor relationship was not affected by this device.

  10. Solving the inverse problem of electrocardiography using a Duncan and Horn formulation of the Kalman filter.

    PubMed

    Berrier, Keith L; Sorensen, Danny C; Khoury, Dirar S

    2004-03-01

    Numeric regularization methods most often used to solve the ill-posed inverse problem of electrocardiography are spatial and ignore the temporal nature of the problem. In this paper, a Kalman filter reformulation incorporated temporal information to regularize the inverse problem, and was applied to reconstruct left ventricular endocardial electrograms based on cavitary electrograms measured by a noncontact, multielectrode probe. These results were validated against in situ electrograms measured with an integrated, multielectrode basket-catheter. A three-dimensional, probe-endocardium model was determined from multiplane fluoroscopic images. The boundary element method was applied to solve the boundary value problem and determine a linear relationship between endocardial and probe potentials. The Duncan and Horn formulation of the Kalman filter was employed and was compared to the commonly used zero- and first-order Tikhonov spatial regularization as well as the Twomey temporal regularization method. Endocardial electrograms were reconstructed during both sinus and paced rhythms. The Paige and Saunders solution of the Duncan and Horn formulation reconstructed endocardial electrograms at an amplitude relative error of 13% (potential amplitude) which was superior to solutions obtained with zero-order Tikhonov (relative error, 31%), first-order Tikhonov (relative error, 19%), and Twomey regularization (relative error, 44%). Likewise, activation time error in the inverse solution using the Duncan and Horn formulation (2.9 ms) was smaller than that of zero-order Tikhonov (4.8 ms), first-order Tikhonov (5.4 ms), and Twomey regularization (5.8 ms). Therefore, temporal regularization based on the Duncan and Horn formulation of the Kalman filter improves the solution of the inverse problem of electrocardiography.

  11. Long-Term Continuous Ambulatory ECG Monitors and External Cardiac Loop Recorders for Cardiac Arrhythmia: A Health Technology Assessment

    PubMed Central

    Kabali, Conrad; Xie, Xuanqian; Higgins, Caroline

    2017-01-01

    Background Ambulatory electrocardiography (ECG) monitors are often used to detect cardiac arrhythmia. For patients with symptoms, an external cardiac loop recorder will often be recommended. The improved recording capacity of newer Holter monitors and similar devices, collectively known as longterm continuous ambulatory ECG monitors, suggests that they will perform just as well as, or better than, external loop recorders. This health technology assessment aimed to evaluate the effectiveness, cost-effectiveness, and budget impact of longterm continuous ECG monitors compared with external loop recorders in detecting symptoms of cardiac arrhythmia. Methods Based on our systematic search for studies published up to January 15, 2016, we did not identify any studies directly comparing the clinical effectiveness of longterm continuous ECG monitors and external loop recorders. Therefore, we conducted an indirect comparison, using a 24-hour Holter monitor as a common comparator. We used a meta-regression model to control for bias due to variation in device-wearing time and baseline syncope rate across studies. We conducted a similar systematic search for cost-utility and cost-effectiveness studies comparing the two types of devices; none were found. Finally, we used historical claims data (2006–2014) to estimate the future 5-year budget impact in Ontario, Canada, of continued public funding for both types of longterm ambulatory ECG monitors. Results Our clinical literature search yielded 7,815 non-duplicate citations, of which 12 cohort studies were eligible for indirect comparison. Seven studies assessed the effectiveness of longterm continuous monitors and five assessed external loop recorders. Both types of devices were more effective than a 24-hour Holter monitor, and we found no substantial difference between them in their ability to detect symptoms (risk difference 0.01; 95% confidence interval −0.18, 0.20). Using GRADE for network meta-analysis, we evaluated the

  12. A novel biometric authentication approach using ECG and EMG signals.

    PubMed

    Belgacem, Noureddine; Fournier, Régis; Nait-Ali, Amine; Bereksi-Reguig, Fethi

    2015-05-01

    Security biometrics is a secure alternative to traditional methods of identity verification of individuals, such as authentication systems based on user name and password. Recently, it has been found that the electrocardiogram (ECG) signal formed by five successive waves (P, Q, R, S and T) is unique to each individual. In fact, better than any other biometrics' measures, it delivers proof of subject's being alive as extra information which other biometrics cannot deliver. The main purpose of this work is to present a low-cost method for online acquisition and processing of ECG signals for person authentication and to study the possibility of providing additional information and retrieve personal data from an electrocardiogram signal to yield a reliable decision. This study explores the effectiveness of a novel biometric system resulting from the fusion of information and knowledge provided by ECG and EMG (Electromyogram) physiological recordings. It is shown that biometrics based on these ECG/EMG signals offers a novel way to robustly authenticate subjects. Five ECG databases (MIT-BIH, ST-T, NSR, PTB and ECG-ID) and several ECG signals collected in-house from volunteers were exploited. A palm-based ECG biometric system was developed where the signals are collected from the palm of the subject through a minimally intrusive one-lead ECG set-up. A total of 3750 ECG beats were used in this work. Feature extraction was performed on ECG signals using Fourier descriptors (spectral coefficients). Optimum-Path Forest classifier was used to calculate the degree of similarity between individuals. The obtained results from the proposed approach look promising for individuals' authentication.

  13. Comparative electrocardiography in four species of macaws (genera Anodorhynchus and Ara).

    PubMed

    Casares, M; Enders, F; Montoya, J A

    2000-06-01

    Electrocardiograms (ECGs) were recorded during isoflurane anaesthesia from 52 macaws of four species of the genera Anodorhynchus and Ara in order to establish electrocardiographic reference values. The birds examined were clinically healthy macaws of the following species: hyacinth macaw (HM; Anodorhynchus hyacinthinus, n = 14); green-winged macaw (GWM; Ara chloroptera, n = 11); blue-throated macaw (BTM; Ara glaucogularis, n = 15); and red-fronted macaw (RFM; Ara rubrogenys, n = 12). All ECGs were recorded using a paper speed of 50 mm/s and a calibration of 10 mm = 1 mV. Significant differences were determined between species for the heart rate, duration and amplitude of the P wave, amplitude of the T wave, and amplitude of the QRS complex, specially comparing the RFM to the other macaw species. No significant differences were found between two species of similar body weight: the HM and the GWM.

  14. Smart Helmet: Wearable Multichannel ECG and EEG

    PubMed Central

    Chanwimalueang, Theerasak; Goverdovsky, Valentin; Looney, David; Sharp, David; Mandic, Danilo P.

    2016-01-01

    Modern wearable technologies have enabled continuous recording of vital signs, however, for activities such as cycling, motor-racing, or military engagement, a helmet with embedded sensors would provide maximum convenience and the opportunity to monitor simultaneously both the vital signs and the electroencephalogram (EEG). To this end, we investigate the feasibility of recording the electrocardiogram (ECG), respiration, and EEG from face-lead locations, by embedding multiple electrodes within a standard helmet. The electrode positions are at the lower jaw, mastoids, and forehead, while for validation purposes a respiration belt around the thorax and a reference ECG from the chest serve as ground truth to assess the performance. The within-helmet EEG is verified by exposing the subjects to periodic visual and auditory stimuli and screening the recordings for the steady-state evoked potentials in response to these stimuli. Cycling and walking are chosen as real-world activities to illustrate how to deal with the so-induced irregular motion artifacts, which contaminate the recordings. We also propose a multivariate R-peak detection algorithm suitable for such noisy environments. Recordings in real-world scenarios support a proof of concept of the feasibility of recording vital signs and EEG from the proposed smart helmet. PMID:27957405

  15. [Dynamics of ECG voltage in changing gravity].

    PubMed

    Saltykova, M M; At'kov, O Iu; Capderou, A; Morgun, V V; Gusakov, V A; Kheĭmets, G I; Konovalov, G A; Kondratiuk, L L; Kataev, Iu V; Voronin, L I; Kaspranskiĭ, R R; Vaida, P

    2006-01-01

    Comparative analysis of the QRS voltage response to gravity variations was made using the data about 26 normal human subjects collected in parabolic flights (CNERS-AIRBUS A300 Zero-G, n=23; IL-76MD, n=3) and during the tilt test (head-up tilt at 70 degrees for a min and head-down tilt at-15 degrees for 5 min, n=14). Both the parabolic flights and provocative tilt tests affected R-amplitude in the Z lead. During the hypergravity episodes it was observed in 95% of cases with the mean gain of 16% and maximal--56%. On transition to the horizontal position, the Rz-amplitude showed a rise in each subject (16% on the average). In microgravity, the Rz-amplitude reduced in 95% of the observations. The voltage decline averaged 18% and reached 49% at the maximum. The head-down tilt was conducive to Rz reduction in 78% of observations averaging 2%. Analysis of the ECG records under changing gravity when blood redistribution developed within few seconds not enough for serious metabolic shifts still revealed QRS deviations associated exclusively with the physical factors, i.e., alteration in tissue conduction and distance to electrodes. Our findings can stand in good stead in evaluation of the dynamics of predictive ECG parameters during long-term experiments leading to changes as in tissue conduction, so metabolism.

  16. The evolution of ambulatory ECG monitoring.

    PubMed

    Kennedy, Harold L

    2013-01-01

    Ambulatory Holter electrocardiographic (ECG) monitoring has undergone continuous technological evolution since its invention and development in the 1950s era. With commercial introduction in 1963, there has been an evolution of Holter recorders from 1 channel to 12 channel recorders with increasingly smaller storage media, and there has evolved Holter analysis systems employing increasingly technologically advanced electronics providing a myriad of data displays. This evolution of smaller physical instruments with increasing technological capacity has characterized the development of electronics over the past 50 years. Currently the technology has been focused upon the conventional continuous 24 to 48 hour ambulatory ECG examination, and conventional extended ambulatory monitoring strategies for infrequent to rare arrhythmic events. However, the emergence of the Internet, Wi-Fi, cellular networks, and broad-band transmission has positioned these modalities at the doorway of the digital world. This has led to an adoption of more cost-effective strategies to these conventional methods of performing the examination. As a result, the emergence of the mobile smartphone coupled with this digital capacity is leading to the recent development of Holter smartphone applications. The potential of point-of-care applications utilizing the Holter smartphone and a vast array of new non-invasive sensors is evident in the not too distant future. The Holter smartphone is anticipated to contribute significantly in the future to the field of global health.

  17. ST/HR hysteresis: exercise and recovery phase ST depression/heart rate analysis of the exercise ECG.

    PubMed

    Lehtinen, R

    1999-01-01

    ST segment depression/heart rate (ST/HR) hysteresis is a recently introduced novel computer method for integrating the exercise and recovery phase ST/HR analysis for improved detection of coronary artery disease (CAD). It is a continuous diagnostic variable that extracts the prevailing direction and average magnitude of the hysteresis in ST depression against HR during the first 3 consecutive minutes of postexercise recovery. This article reviews the development and evaluation of this new method in a clinical population of 347 patients referred for a routine bicycle exercise electrocardiographic (ECG) test at Tampere University Hospital, Finland. Of these patients, 127 had angiographically proven CAD, whereas 13 had no CAD according to angiography, 18 had no perfusion defect according to Tc-99m-sestamibi myocardial imaging and single photon emission computed tomography, and 189 were clinically normal with respect to cardiac diseases. For each patient, the values for ST/HR hysteresis, ST/HR index, end-exercise ST depression, and recovery ST depression were determined for each lead of the Mason-Likar modification of the standard 12-lead exercise ECG and maximum value from the lead system (aVL, aVR, and V1 excluded). The area under the receiver operating characteristics curve (ie, the discriminative capacity) of the ST/HR hysteresis was 89%, which was significantly larger than that of the end-exercise ST depression (76%, P < .0001), recovery ST depression (84%, P = .0063) or ST/HR index (83%, P = .0023), indicating the best diagnostic performance of the ST/HR hysteresis in detection of CAD regardless of the partition value selection. Furthermore, the superior diagnostic performance of the method was relatively insensitive to the ST segment measurement point or to the ECG lead selection. These results suggest that the ST/HR hysteresis improves the clinical utility of the exercise ECG test in detection of CAD.

  18. Assessment of Cardiac Rate and Rhythm in Fetuses with Arrhythmia via Maternal Abdominal Fetal Electrocardiography

    PubMed Central

    Narayan, Hari K.; Vignola, Emilia F.; Fifer, William P.; Williams, Ismee A.

    2015-01-01

    Objective This study aims to report our experience using the Monica AN24 (Monica Healthcare Ltd., Nottingham, United Kingdom), a maternal transabdominal fetal electrocardiographic monitor, in a case series of fetuses with arrhythmias. Study Design We recorded fetal electrocardiograms (fECGs) on subjects with fetal arrhythmias diagnosed by fetal echocardiogram. Fetal heart rate and rhythm were determined via manual fECG analysis. Results Overall, 20 fECGs were recorded from a pool of 13 subjects. Fetal heart rate acquisition was determined to be high, medium, and poor quality in 10, 3, and 7 tracings, respectively. High-quality tracings were obtained in 9 of 11 subjects with gestational age < 26 or > 34 weeks. P waves were detectable in five tracings. Conclusion In subjects < 26 or > 34 weeks' gestational age, there was reasonable success in fetal heart rate acquisition. Further study is warranted to determine the potential role of this device in the monitoring of subjects with fetal arrhythmias. PMID:26495180

  19. [Transtelephonic electrocardiography in Mexico. A report of the first 3434 cases].

    PubMed

    González-Espino, J F; Robledo Nolasco, R; Alcedo Miranda, J A; Vadillo Ortega, E; Iturralde Torres, P; Colín Lizalde, L; Kershenovich, S; de la Fuente Magallanes, F; Gershoni, O

    1995-01-01

    The transtelephonic electrocardiographic system started in the 70's and it was used mainly in the study of heart disease, cardiac arrhythmias, syncope and sudden death. This report, include 3434 electrocardiogram (ECG) of patients whom visit the emergency room at the General Hospital and private clinic, using three different forms of transtelephonic monitors. The total population were 1715 males and 1719 females with average age of 52.2 +/- 28.8 years. 26.9% had was present in history of systemic hypertension, non-insulin dependent diabetes 12.3% and myocardial ischemic disease in 5.3%. The main ECG indications were chest pain 38.7%, most of them atypical angina, palpitations in 6.9% and dyspnea in 6.5%. 50.1% of the ECG were abnormal. The most important diagnosis were: tachyarrhythmias (25.2%), intraventricular conduction abnormalities (17.7%), myocardial ischemic disease (16%), and premature ventricular and supraventricular beats (11.6%). We concluded that the transtelephonic electrocardiographic system is a very useful method, and available now in Mexico. We detected a high percentage of electrocardiographic abnormalities, it was possible to give the right diagnosis of arrhythmias, acute myocardial infarction, old infarction, and to evaluate the pacemaker functionality. Finally, it helped to get in brief time the diagnosis and treatment in cases of acute myocardial infarction or severe arrhythmias.

  20. Comparison of the spatial QRS-T angle derived from digital ECGs recorded using conventional electrode placement with that derived from Mason-Likar electrode position.

    PubMed

    Salvi, Vaibhav; Clark, Elaine; Karnad, Dilip R; Macfarlane, Peter W; Panicker, Gopi Krishna; Hingorani, Pooja; Kothari, Snehal

    2016-01-01

    The spatial QRS-T angle is ideally derived from orthogonal leads. We compared the spatial QRS-T angle derived from orthogonal leads reconstructed from digital 12-lead ECGs and from digital Holter ECGs recorded with the Mason-Likar (M-L) electrode positions. Orthogonal leads were constructed by the inverse Dower method and used to calculate spatial QRS-T angle by (1) a vector method and (2) a net amplitude method, in 100 volunteers. Spatial QRS-T angles from standard and M-L ECGs differed significantly (57°±18° vs 48°±20° respectively using net amplitude method and 53°±28° vs 48°±23° respectively by vector method; p<0.001). Difference in amplitudes in leads V4-V6 was also observed between Holter and standard ECGs, probably due to a difference in electrical potential at the central terminal. Mean spatial QRS-T angles derived from standard and M-L lead systems differed by 5°-9°. Though statistically significant, these differences may not be clinically significant. Copyright © 2016 Elsevier Inc. All rights reserved.