| 1. |
- Abrahamsson, Christina, et al.
(författare)
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DeltaT50 - a new method to assess temporal ventricular repolarization variability
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44:4
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Tidskriftsartikel (refereegranskat)abstract
- Background Increased beat-to-beat variability in cardiac repolarization time is a tentative risk marker of drug-induced torsades de pointes. We developed a new, automatic method based on the temporal variability of the T-wave down slope to assess this variability. Method and Results Leads V1 to V6 of resting electrocardiograms were recorded in 42 healthy subjects (18-68 years, 22 men). The temporal variability at 50% of the T-wave down slope, deltaT50 (1.5 ± 0.41 milliseconds; range, 0.86-2.66 milliseconds), was measured with an accuracy of 1 millisecond on at least 9 pairs of electrocardiogram complexes with a signal-to-noise ratio more than 10 and changes in the R-R interval less than 150 milliseconds. The correlation between repeated measurements of deltaT50 was high. DeltaT50 was measured without corrections for age, sex, heart rate, T-wave amplitude, signal-to-noise ratio, R-R variability, and QTcF because none of these factors explained more than 4% of the within-subject deltaT50 variability. Conclusion The beat-to-beat repolarization variability was measured with high fidelity with the deltaT50 method and was a robust measure in healthy volunteers.
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| 2. |
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| 3. |
- Alenius Dahlqvist, Jenny, et al.
(författare)
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Handheld ECG in analysis of arrhythmia and heart rate variability in children with Fontan circulation
- 2014
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736 .- 1532-8430. ; 47:3, s. 374-382
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Tidskriftsartikel (refereegranskat)abstract
- Background: Our aim was to evaluate the intermittent use of a handheld ECG system for detecting silent arrhythmias and cardiac autonomic dysfunction in children with univentricular hearts. Methods: Twenty-seven patients performed intermittent ECG recordings with handheld devices during a 14-day period. A manual arrhythmia analysis was performed. We analyzed heart rate variability (HRV) using scatter plots of all interbeat intervals (Poincare plots) from the total observation period. Reference values of HRV indices were determined from Holter-ECGs in 41 healthy children. Results: One asymptomatic patient had frequent ventricular extra systoles. Another patient had episodes with supraventricular tachycardia (with concomitant palpitations). Seven patients showed reduced HRV. Conclusions: Asymptomatic arrhythmia was detected in one patient. The proposed method for pooling of intermittent recordings from handheld or similar devices may be used for detection of arrhythmias as well as for cardiac autonomic dysfunction.
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| 4. |
- Aunes-Jansson, Maria, et al.
(författare)
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Decrease of the atrial fibrillatory rate, increased organization of the atrial rhythm and termination of atrial fibrillation by AZD7009
- 2013
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 46:1, s. 29-35
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Tidskriftsartikel (refereegranskat)abstract
- Background: The atrial fibrillatory rate (APR), on AZD7009 as compared to placebo, was investigated as a potential biomarker for electrophysiological effect in early antiarrhythmic drug development. Methods: Patients with permanent AF received infusions of AZD7009 and placebo in an exploratory two-way, single-blind, randomized cross-over study. The ECG was continuously recorded, and following QRST cancellation the APR, its standard deviation (SD), the exponential decay and the atrial electrogram amplitude were determined as 3-min averages. Results: The mean APR rapidly decreased by 43% from baseline (394 +/- 38 to 225 +/- 61 fibrillations/min, p = 0.0003) on AZD7009, but not on placebo. The SD of the AFR and the exponential decay decreased in parallel. In 2 of 8 patients, termination of AF occurred after the APR had decreased by 58% and 53%, respectively. Conclusions: The APR may potentially serve as a biomarker of electrophysiological effects in early evaluation of rhythm control agents. (C) 2013 Elsevier Inc. All rights reserved.
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| 5. |
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| 6. |
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| 7. |
- Bayes de Luna, Antonio, et al.
(författare)
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Interatrial blocks. A separate entity from left atrial enlargement: a consensus report
- 2012
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 45:5, s. 445-451
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Tidskriftsartikel (refereegranskat)abstract
- Impaired interatrial conduction or interatrial block is well documented but is not described as an individual electrocardiographic (ECG) pattern in most of ECG books, although the term atrial abnormalities to encompass both concepts, left atrial enlargement (LAE) and interatrial block, has been coined. In fact, LAE and interatrial block are often associated, similarly to what happens with ventricular enlargement and ventricular block. The interatrial blocks, that is, the presence of delay of conduction between the right and left atria, are the most frequent atrial blocks. These may be of first degree (P-wave duration > 120 milliseconds), third degree (longer P wave with biphasic [+/-] morphology in inferior leads), and second degree when these patterns appear transiently in the same ECG recording (atrial aberrancy). There are evidences that these electrocardiographic P-wave patterns are due to a block because they may (a) appear transiently, (b) be without associated atrial enlargement, and (c) may be reproduced experimentally. The presence of interatrial blocks may be seen in the absence of atrial enlargement but often are present in case of LAE. The most important clinical implications of interatrial block are the following: (a) the first degree interatrial blocks are very common, and their relation with atrial fibrillation and an increased risk for global and cardiovascular mortality has been demonstrated; (b) the third degree interatrial blocks are less frequent but are strong markers of LAE and paroxysmal supraventricular tachyarrhythmias. Their presence has been considered a true arrhythmological syndrome. (C) 2012 Elsevier Inc. All rights reserved.
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| 8. |
- Birnbaum, Yochai, et al.
(författare)
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Common pitfalls in the interpretation of electrocardiograms from patients with acute coronary syndromes with narrow QRS: a consensus report
- 2012
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 45:5, s. 463-475
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Tidskriftsartikel (refereegranskat)abstract
- Acute coronary syndromes (ACS) with narrow QRS are divided into 2 groups: ST-elevation ACS that requires emergency percutaneous coronary intervention, and non-ST elevation ACS. The classification of ACS into these 2 groups is not always straightforward. In this document, we discuss several electrocardiogram patterns of acute ischemia that are often misinterpreted. We suggest that any new recommendations or guidelines from the Scientific Societies should acknowledge these aspects of electrocardiogram interpretation by including appropriate diagnostic criteria that should prove helpful for the optimal management of patients with ACS. (C) 2012 Elsevier Inc. All rights reserved.
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| 9. |
- Carlsen, Esben A, et al.
(författare)
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The stability of myocardial area at risk estimated electrocardiographically in patients with ST elevation myocardial infarction.
- 2014
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 47:4, s. 540-545
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Tidskriftsartikel (refereegranskat)abstract
- In patients with ST-elevation myocardial infarction (STEMI) the amount of myocardial area at risk (MaR) indicates the maximal potential loss of myocardium if the coronary artery remains occluded. During the time course of infarct evolution ischemic MaR is replaced by necrosis, which results in a decrease in ST segment elevation and QRS complex distortion. Recently it has been shown that combining the electrocardiographic (ECG) Aldrich ST and Selvester QRS scores result in a more accurate estimate of MaR than using either method alone. Therefore, we hypothesized that the combined Aldrich and Selvester score, indicating MaR, is stable until myocardial reperfusion therapy. In a retrospective analysis of a study population of 114 patients, 33 patients were included. The combined Aldrich and Selvester score was determined in ECGs recorded in the ambulance (ECG1) and in the hospital before reperfusion (ECG2). The combined Aldrich and Selvester score was considered stable if the difference between ECG1 and ECG2 was <4.5-percentage point. Stability of the combined Aldrich and Selvester score was observed in 12/33 patients (36.4%), and in regards to anterior and inferior ST elevation in 4/14 patients (28.6%) and 8/19 patients (42.1%), respectively. The median time between the recording of ECG1 and ECG2 was 75minutes, however the changes in ECG scores were independent of the time between ECG recordings. Patients not meeting the stability criterion either had a decrease (9 patients) or increase (12 patients) of the combined Aldrich and Selvester score. In conclusion, the ECG estimated MaR was stable between the earliest recording time and initiation of reperfusion treatment only in a subgroup of the patients with STEMI. The findings of this study may suggest heterogeneity in regards to the development of the MaR and could indicate a potential need for differentiation in the acute treatment.
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| 10. |
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| 11. |
- Demidova, Marina, et al.
(författare)
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ST-segment dynamics during reperfusion period and the size of myocardial injury in experimental myocardial infarction.
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44:1, s. 74-81
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Tidskriftsartikel (refereegranskat)abstract
- Exacerbation of ST elevation associated with reperfusion has been reported in patients with myocardial infarction. However, the cause of the "reperfusion peak" and relation of its magnitude to the size of myocardial damage has not been explored. The aim of our study was to assess the correlation between the ST-dynamics during reperfusion, the myocardium at risk (MaR), and the infarct size (IS).
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| 12. |
- Demidova, Marina, et al.
(författare)
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T wave alternans in experimental myocardial infarction: Time course and predictive value for the assessment of myocardial damage.
- 2013
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 46:3, s. 263-269
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: T-wave alternans (TWA) is associated with prognosis after myocardial infarction (MI), however its link to the extent of ischemic injury has not been clarified. We analyzed the course of TWA and its relation to myocardial damage in experimental myocardial infarction. METHODS: In 21 pigs, infarction was induced by 40-minute long balloon inflation in LAD under continuous 12-lead ECG monitoring. TWA was assessed in a 32-beat sliding window, using periodic component analysis and the Laplacian Likelihood Ratio method. Myocardium at risk (MaR) and infarct size (IS) were evaluated by SPECT and magnetic resonance imaging respectively. RESULTS: TWA appeared at 7.2±4.5minutes of occlusion, reached its maximum at 12.7±6.3 and lasted until 26.5±9.2minutes. The maximal level of TWA was associated with both MaR (r=0.499, p=0.035) and IS (r=0.65, p=0.004). CONCLUSION: TWA magnitude is associated with both MaR and IS in experiment, which encourages further studies in clinical settings.
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| 13. |
- Diamant, Ulla-Britt, et al.
(författare)
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Two automatic QT algorithms compared with manual measurement in identification of long QT syndrome
- 2010
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736 .- 1532-8430. ; 43:1, s. 25-30
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Long QT syndrome (LQTS) is an inherited disorder that increases the risk of syncope and malignant ventricular arrhythmias, which may result in sudden death.METHODS: We compared manual measurement by 4 observers (QT(manual)) and 3 computerized measurements for QT interval accuracy in the diagnosis of LQTS: 1. QT measured from the vector magnitude calculated from the 3 averaged orthogonal leads X, Y, and Z (QTVCG) and classified using the same predefined QTc cut-points for classification of QT prolongation as in manual measurements; 2. QT measured by a 12-lead electrocardiogram (ECG) program (QTECG) and subsequently classified using the same cut-points as in (1) above; 3. The same QT value as in (2) above, automatically classified by a 12-lead ECG program with thresholds for QT prolongation adjusted for age and sex (QTinterpret). The population consisted of 94 genetically confirmed carriers of KCNQ1 (LQT1) and KCNH2 (LQT2) mutations and a combined control group of 28 genetically confirmed noncarriers and 66 unrelated healthy volunteers.RESULTS: QT(VCG) provided the best combination of sensitivity (89%) and specificity (90%) in diagnosing LQTS, with 0.948 as the area under the receiver operating characteristic curve. The evaluation of QT measurement by the 4 observers revealed a high interreader variability, and only 1 of 4 observers showed acceptable level of agreement in LQTS mutation carrier identification (kappa coefficient >0.75).CONCLUSION: Automatic QT measurement by the Mida1000/CoroNet system (Ortivus AB, Danderyd, Sweden) is an accurate, efficient, and easily applied method for initial screening for LQTS.
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| 14. |
- Engblom, Henrik, et al.
(författare)
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Quantification of myocardial salvage by myocardial perfusion SPECT and cardiac magnetic resonance - reference standards for ECG development.
- 2014
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 47:4, s. 525-534
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Forskningsöversikt (refereegranskat)abstract
- In order to determine the cardioprotective efficacy of acute reperfusion therapy, assessed as myocardial salvage, in patients with acute coronary occlusion, the final myocardial infarct (MI) size needs to be related to the amount of ischemic myocardium during coronary occlusion, referred to as the myocardium at risk (MaR). There are currently several imaging approaches available for quantification of both MI size and MaR in vivo of which some have been validated both in pre-clinical and clinical settings. These methods often involve the use of either myocardial perfusion SPECT or cardiac magnetic resonance (CMR). These imaging methods could potentially be used to further develop and validate ECG methods for determination of MI size and MaR. Therefore, the aim of the present review is to give an overview of myocardial perfusion SPECT and CMR methods available for assessment of myocardial salvage by determination of MI size and MaR.
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| 15. |
- Engblom, Henrik, et al.
(författare)
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The evaluation of an electrocardiographic myocardial ischemia acuteness score to predict the amount of myocardial salvage achieved by early percutaneous coronary intervention Clinical validation with myocardial perfusion single photon emission computed tomography and cardiac magnetic resonance.
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44, s. 525-532
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The time from symptom onset to reperfusion in acute myocardial infarction (MI) has been shown to be a poor predictor of patient outcome. Acute electrocardiographic (ECG) changes, however, have been shown useful for estimated acuteness of myocardial ischemia using the Anderson-Wilkins ECG ischemia acuteness score (AW-acuteness score). The aim was to study whether acute ischemic ECG changes can predict the amount of salvageable myocardium in patients with acute ST-elevation MI. METHODS: Thirty-eight patients treated with primary percutaneous coronary intervention for first-time ST-elevation MI were retrospectively enrolled. Myocardium at risk (MaR) was determined by myocardial perfusion single photon emission computed tomography acutely or by T2-weighted cardiac magnetic resonance after 1 week, at the same time when final MI size was determined by late gadolinium enhancement. Myocardial salvage was calculated as (MaR - MI size)/MaR and compared with AW-acuteness score and time from symptom onset to primary percutaneous coronary intervention. RESULTS: The AW-acuteness score correlated significantly with salvageable myocardium for right coronary artery (RCA) occlusions (r = -0.57; P = .02) but not for left anterior descending artery (LAD) occlusions (r = -0.04; P = .88). Time from symptom onset did not correlate with the amount of salvageable myocardium (LAD, r = 0.04 and P = .87; RCA, r = -0.40 and P = .13). CONCLUSIONS: There is a moderate correlation between AW-acuteness score and salvageable myocardium in patients with acute RCA occlusion but not in patients with LAD occlusion.
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| 16. |
- Enochson, Lars, et al.
(författare)
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Triphasic and quadriphasic waveforms are superior to biphasic waveforms for synchronized beating of cardiomyocytes.
- 2012
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Ingår i: Journal of electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 45:3, s. 305-11
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Tidskriftsartikel (refereegranskat)abstract
- Within pacemaker research few attempts have been made to find an optimal waveform phase sequence that synchronizes beating of cardiomyocytes at an electrode. Multielectrode arrays (MEAs) offer electrophysiological screening of cardiomyocytes serving as a system for preliminary screening of pacing waveform design.
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| 17. |
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| 18. |
- Gottfridsson, Christer, 1958, et al.
(författare)
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The signal-averaged electrocardiogram before and after electrical cardioversion of persistent atrial fibrillation-implications of the sudden change in rhythm.
- 2011
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Ingår i: Journal of electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44:2, s. 242-250
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Atrial fibrillation (AF), electrical cardioversion (direct current, or DC) shock energy, and a sudden change to sinus rhythm (SR) might all influence the interpretation of the signal-averaged electrocardiogram (SAECG) as risk markers of ventricular tachyarrhythmia. METHODS: The SAECG was recorded in 82 patients with persistent AF before and 2 hours after DC and analyzed for ventricular late potentials (LPs) and spectral turbulence. RESULTS: Sixty-nine patients (84%) obtained SR. Their mean (SD) heart rate decreased by 22 (20) beats/min, and the QTcF interval was significantly prolonged, 17 (38) milliseconds, as was the filtered QRS duration, 1.1 (4.7) milliseconds (40 Hz). The proportion of LP positivity (20%) did not change with the change in rhythm. Eight of 60 spectral turbulence-negative patients before DC became positive after DC (P = .01). The change in SAECG variables did not correlate significantly with the amount of energy delivered at DC. CONCLUSION: The LP analysis provided similar results in AF and SR, whereas the spectral turbulence analysis was more abnormal in SR. The electrical shock itself did not seem to explain this phenomenon.
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| 19. |
- Hakacova, Nina, et al.
(författare)
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Computer-based rhythm diagnosis and its possible influence on nonexpert electrocardiogram readers.
- 2012
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 45, s. 18-22
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Systems providing computer-based analysis of the resting electrocardiogram (ECG) seek to improve the quality of health care by providing accurate and timely automatic diagnosis of, for example, cardiac rhythm to clinicians. The accuracy of these diagnoses, however, remains questionable. OBJECTIVES: We tested the hypothesis that (a) 2 independent automated ECG systems have better accuracy in rhythm diagnosis than nonexpert clinicians and (b) both systems provide correct diagnostic suggestions in a large percentage of cases where the diagnosis of nonexpert clinicians is incorrect. METHODS: Five hundred ECGs were manually analyzed by 2 senior experts, 3 nonexpert clinicians, and automatically by 2 automated systems. The accuracy of the nonexpert rhythm statements was compared with the accuracy of each system statement. The proportion of rhythm statements when the clinician's diagnoses were incorrect and the systems instead provided correct diagnosis was assessed. RESULTS: A total of 420 sinus rhythms and 156 rhythm disturbances were recognized by expert reading. Significance of the difference in accuracy between nonexperts and systems was P = .45 for system A and P = .11 for system B. The percentage of correct automated diagnoses in cases when the clinician was incorrect was 28% ± 10% for system A and 25% ± 11% for system B (P = .09). CONCLUSION: The rhythm diagnoses of automated systems did not reach better average accuracy than those of nonexpert readings. The computer diagnosis of rhythm can be incorrect in cases where the clinicians fail in reaching the correct ECG diagnosis.
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| 20. |
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| 21. |
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| 22. |
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| 23. |
- Huo, Yan, et al.
(författare)
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P-wave characteristics and histological atrial abnormality.
- 2014
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 47:3, s. 275-280
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Tidskriftsartikel (refereegranskat)abstract
- Fibro-fatty transformation is believed to be the leading cause of deteriorated atrial conduction; however, any direct assessment in relation to P-wave characteristics is lacking. We sought to assess P-wave morphology (PWM) and duration (PWD) in relation to histology of the atrial myocardium.
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| 24. |
- I. Fernlund, Eva, et al.
(författare)
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Early repolarization in children with unexplained syncope
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44:2, s. 10-10
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Konferensbidrag (refereegranskat)abstract
- Introduction: It has traditionally been believed that early repolarization (ER) is benign. Significant association between ER and sudden cardiac arrest due to idiopathic ventricular fibrillation was recently found in a large cohort of adult survivors of sudden cardiac arrest. In some prior studies, unexplained syncope has been linked to risk of sudden death, but the mechanisms remain speculative.We assessed herein the prevalence of ER in children referred to our center for unexplained syncope. Methods: We evaluated retrospectively electrocardiograms from such children (n = 29; mean age, 12.1 years; range, 7-18 years) for presence of ER, which was defined as an elevation of the QRS-ST junction (J-point) in at least 2 leads of at least 1 mm (0.1 mV) above the baseline level. The anterior precordial leads (V1-V3) were excluded from the analysis to avoid inclusion of patients with right ventricular dysplasia or Brugada syndrome. Agematched children (n = 33; mean age, 12.3 years; range, 7-16 years) with noncardiac chest pain were included as controls. Results: Early repolarization was detected in 45% (13/29) of children with unexplained syncope vs 24% (8/33) in the chest pain group. Among children with syncope, ER was far more frequent in males than in females (8/12 vs 5/ 17, respectively). Echocardiography showed normal functional and structural findings in all children. Conclusion: In this relatively small-scale retrospective study of children with unexplained syncope with otherwise normal cardiac findings, we found particularly among those of male gender a greater prevalence of ER than in controls (noncardiac chest pain).With view to earlier findings of Haisaguerre et al (NEJM 2008), this intriguing association warrants further prospective studies addressing its precise clinical implication and underlying mechanisms.
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| 25. |
- Kongstad Rasmussen, Ole, et al.
(författare)
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Ventricular repolarization sequences on the epicardium and endocardium. Monophasic action potential mapping in healthy pigs
- 2012
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 45:1, s. 49-56
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Tidskriftsartikel (refereegranskat)abstract
- To investigate repolarization sequence, monophasic action potentials were recorded from a mean of 153 +/- 54 left and right ventricular epicardial and endocardial sites in 10 pigs using the CARTO mapping system (Biosense Webster, Waterloo, Belgium). The activation time and end-of-repolarization (EOR) time were measured and 3-dimensional maps of activation and repolarization sequences constructed. Results: In 8 of 9 pigs, both the activation and EOR times appeared first in the septum and last in the latero-basal areas on the endocardium, not on the epicardium. The EOR followed the activation sequence, both on the epicardium (in 8/9 pigs) and endocardium (in 8/8 pigs). The maximal EOR differences were 84 +/- 20 ms, whereas the local EOR differences between paired sites against each other on the tell ventricular epicardium and endocardium were 11 +/- 9 ms in the apex and 12 +/- 12 ms in the anterior wall. Conclusion: The EOR follows the activation sequence both on the epicardium and endocardium. The apico-basal gradients are predominant repolarization gradients, as compared with the epicardial-endocardial gradients. (C) 2012 Elsevier Inc. All rights reserved.
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| 26. |
- Laguna, Pablo, et al.
(författare)
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The STAFF III ECG database and its significance for methodological development and evaluation
- 2014
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 47:4, s. 408-417
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Forskningsöversikt (refereegranskat)abstract
- The development of new techniques for detection and characterization of transient myocardial ischemia has benefited considerably from the STAFF database, acquired in patients receiving elective prolonged percutaneous transluminal coronary angiography. The present article reviews a range of techniques developed and/or evaluated on the ECG signals of this database, including techniques for exploring abnormal intra-QRS potentials, QRS slopes, QRS angles, T wave morphology, T wave alternans, spatiotemporal ECG information, as well as heart rate dynamics. The detection of changes in body position is also briefly reviewed as it is intimately related to ischemia detection. (c) 2014 Elsevier Inc. All rights reserved.
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| 27. |
- Lingman, Markus, 1975, et al.
(författare)
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Transient repolarization alterations dominate the initial phase of an acute anterior infarction-a vectorcardiography study
- 2014
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Ingår i: Journal of Electrocardiology. - : Churchill Livingstone. - 0022-0736 .- 1532-8430. ; 47:4, s. 478-485
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To study effects of ischemia-reperfusion on ventricular electrophysiology in humans by three-dimensional electrocardiography. METHODS: Fifty-seven patients with first-time acute anterior ST elevation myocardial infarction were monitored from admission and >24h after symptom onset with continuous vectorcardiography (VCG; modified Frank orthogonal leads). Global ventricular depolarization and repolarization (VR) measures were compared at maximum vs. minimum ST vector magnitude (STVM) (median 208; 111-303 vs. 362; 165-1359min after symptom onset). RESULTS: At maximum vs. minimum STVM the Tarea (overall VR dispersion) almost tripled (118 vs. 41μVs; p<0.0001), the T-loop bulginess was 90% greater (Tavplan 0.91 vs 0.48μV; p<0.0001), and Tpeak-end/QT was 39% larger (0.32 vs 0.23; p<0.0001). QRSarea (overall dispersion of depolarization) was 12% larger at maximum STVM, while QRS duration was 10% longer at minimum STVM. CONCLUSIONS: Ischemia-reperfusion was accompanied by profound and transient alterations of VR dispersion, while changes in depolarization were modest and delayed.
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| 28. |
- Nikus, Kjell, et al.
(författare)
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Electrocardiographic classification of acute coronary syndromes: a review by a committee of the International Society for Holter and Non-Invasive Electrocardiology
- 2010
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 43:2, s. 91-103
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Tidskriftsartikel (refereegranskat)abstract
- The electrocardiogram (ECG) remains the most immediately accessible and widely used diagnostic tool for guiding emergency treatment strategies. The ECG recorded during acute myocardial ischemia is of diagnostic, therapeutic, and prognostic significance. In patients with myocardial ischemia as a result of decreased blood supply, the initial 12-lead ECG typically shows (1) predominant ST-segment elevation (STE) as part of STE acute coronary syndrome (STE-ACS), or (2) no predominant STE, that is, non STE ACS (NSTE-ACS). Patients with predominant STE are classified as having either aborted myocardial infarction (MI) or ST-elevation MI (STEMI) based on the absence or presence of biomarkers of myocardial necrosis. The MI may be aborted either by spontaneous or therapeutic reperfusion of the ischemic myocardium before development of myocardial cell necrosis. NSTE-ACS patients are classified as having either unstable angina or NSTE-MI, based also on the absence or presence of biomarkers of mycardial necrosis. The information obtained from the 12-lead ECG at presentation should be complemented by repeated ECGs especially during symptoms indicative of ischemia and, if applicable, by comparing the findings with reference ECGs. Also, continuous ECG recording in a coronary care setting, including the comparison of ECGs with and without pain, adds to the information gained at patient presentation. In this article, mechanisms of ischemic ECG changes and the ECG patterns recorded in both STE-ACS and NSTE-ACS are described. ECG patterns of NSTE-ACS, which include ST depression, negative T wave, and even normal ECG, need to be better defined in future studies to correlate them with the severity and extent of ischemia and to explore to what extent they are explained by acute active ischemia or represent consequences of ischemia. One of the aims of this article is to propose a classification of the ECG patterns encountered in different clinical scenarios of ACS. How these patterns will aid in guiding the diagnostic and therapeutic process is discussed. (c) 2010 Elsevier Inc. All rights reserved.
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| 29. |
- Nikus, Kjell, et al.
(författare)
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Report of the third International Society for Holter and Noninvasive Electrocardiology working group on improved electrocardiographic criteria for acute and chronic ischemic heart disease-Lund, Sweden: June 2010
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44:1, s. 84-86
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Tidskriftsartikel (refereegranskat)abstract
- The third meeting of the International Society for Holter and Noninvasive Electrocardiology working group was convened in Lund, Sweden, in June 2010 to consider the key clinical challenge of developing electrocardiographic (ECG) criteria for identification of the global subendocardial ischemia that results from subtotal occlusion of either the left main coronary artery or its equivalent. The participants considered the specific abnormalities typical of global subendocardial ischemia on the presenting ECG and outlined further studies to establish the optimal quantitative ECG criteria. Subgroups on Electrocardiology, Myocardial Imaging, and Coronary Intervention met separately to establish priorities on their topic and then joined together in a final session of the entire working group. The principles for a retrospective and then a prospective study were identified, and a writing group was formed. (C) 2011 Elsevier Inc. All rights reserved.
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| 30. |
- Nimmermark, Magnus O, et al.
(författare)
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The impact of numeric and graphic displays of ST-segment deviation levels on cardiologists' decisions of reperfusion therapy for patients with acute coronary occlusion.
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44:5, s. 502-508
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Tidskriftsartikel (refereegranskat)abstract
- he study purpose is to determine whether numeric and/or graphic ST measurements added to the display of the 12-lead electrocardiogram (ECG) would influence cardiologists' decision to provide myocardial reperfusion therapy. Twenty ECGs with borderline ST-segment deviation during elective percutaneous coronary intervention and 10 controls before balloon inflation were included. Only 5 of the 20 ECGs during coronary balloon occlusion met the 2007 American Heart Association guidelines for ST-elevation myocardial infarction (STEMI). Fifteen cardiologists read 4 sets of these ECGs as the basis for a "yes/no" reperfusion therapy decision. Sets 1 and 4 were the same 12-lead ECGs alone. Set 2 also included numeric ST-segment measurements, and set 3 included both numeric and graphically displayed ST measurements ("ST Maps"). The mean (range) positive reperfusion decisions were 10.6 (2-15), 11.4 (1-19), 9.7 (2-14), and 10.7 (1-15) for sets 1 to 4, respectively. The accuracies of the observers for the 5 STEMI ECGs were 67%, 69%, and 77% for the standard format, the ST numeric format, and the ST graphic format, respectively. The improved detection rate (77% vs 67%) with addition of both numeric and graphic displays did achieve statistical significance (P < .025). The corresponding specificities for the 10 control ECGs were 85%, 79%, and 89%, respectively. In conclusion, a wide variation of reperfusion decisions was observed among clinical cardiologists, and their decisions were not altered by adding ST deviation measurements in numeric and/or graphic displays. Acute coronary occlusion detection rate was low for ECGs meeting STEMI criteria, and this was improved by adding ST-segment measurements in numeric and graphic forms. These results merit further study of the clinical value of this technique for improved acute coronary occlusion treatment decision support.
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| 31. |
- Olson, Charles W, et al.
(författare)
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Olson method for locating and calculating the extent of transmural ischemic areas at risk of infarction.
- 2014
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 47:4, s. 430-437
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study is to present a new and improved method for translating the electrocardiographic changes of acute myocardial ischemia into a display which reflects the location and extent of the ischemic area and the associated culprit coronary artery. This method could be automated to present a graphic image of the ischemic area in a manner understandable by all levels of caregivers; from emergency transport personnel to the consulting cardiologist.
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| 32. |
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| 33. |
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| 34. |
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| 35. |
- Pahlm, Ulrika, et al.
(författare)
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The 24-lead ECG display for enhanced recognition of STEMI-equivalent patterns in the 12-lead ECG.
- 2014
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 47:4, s. 425-429
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Forskningsöversikt (refereegranskat)abstract
- 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.
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| 36. |
- Petersson, Richard, et al.
(författare)
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Noninvasive estimation of organization in atrial fibrillation as a predictor of sinus rhythm maintenance.
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44:2, s. 171-175
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies indicate that the predictive value of atrial fibrillatory rate in patients undergoing cardioversion of atrial fibrillation (AF) of long duration is limited. The present study investigates signal entropy in this setting. Standard 12-lead electrocardiograms (ECGs) were recorded from 66 consecutive patients with AF undergoing cardioversion and sample entropy estimated. Patients were followed for 4 weeks. At follow-up, 59% of the patients had relapsed to AF. The AF signal entropy of these patients before cardioversion was 0.099 ± 0.015, whereas it was 0.093 ± 0.012 among the 41% maintaining sinus rhythm (P = .02). As hypothesized, signal entropy was lower in patients who maintained sinus rhythm 4 weeks after cardioversion than in those who did not. However, the overlap was large, making its clinical value limited.
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| 37. |
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| 38. |
- Pettersson, Jonas, et al.
(författare)
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High-frequency electrocardiogram as a supplement to standard 12-lead ischemia monitoring during reperfusion therapy of acute inferior myocardial infarction.
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44, s. 11-17
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Resolution of ST-segment elevation in the electrocardiogram (ECG) is used as a reperfusion sign during thrombolytic therapy in acute myocardial infarction. Analysis of high-frequency QRS components (HF-QRS) might provide additional information. The study compares changes in HF-QRS (150-250 Hz) to ST-segment changes in the standard ECG during thrombolytic therapy. METHODS: Twelve patients receiving intravenous thrombolytic therapy were included. A continuous 12-lead ECG recording was acquired for 4 hours. RESULTS: After 1 hour of therapy, 3 patients showed ST-elevation resolution as well as an increase in HF-QRS. These changes in ST and HF-QRS occurred simultaneously. No other patient showed significant changes in ST or HF-QRS after 1 hour. After 2 and 4 hours, there was less concordance between the standard and high-frequency ECGs. CONCLUSIONS: In patients with early ST-elevation resolution, the standard and high-frequency ECGs show similar results. Later changes are more disparate and may provide different clinical information.
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| 39. |
- Platonov, Pyotr, et al.
(författare)
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Abnormal atrial activation is common in patients with arrhythmogenic right ventricular cardiomyopathy.
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44, s. 237-241
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Structural right atrial abnormalities have been described in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). However, little is known about electrocardiographic signs of atrial involvement in ARVC because no systematic studies have been conducted. METHODS: P-wave-triggered signal-averaged orthogonal electrocardiogram from 40 ARVC patients (46 ± 15 years, 16 females) was compared with recordings from age- and sex-matched healthy control subjects for assessment of P-wave duration and morphology. P-wave morphology was classified with regard to the P-wave polarity in leads X, Y, and Z. RESULTS: P-wave duration was longer in patients (135 ± 18 vs 124 ± 12 milliseconds; P = .003). Two typical P-wave morphologies were identified in the controls: positive in X and Y and negative (45%) or biphasic (55%) in Z. In patients with ARVC , typical P waves were seen in only 60%, whereas 15 patients (37%) had atypical P-wave positive in all 3 leads (P < .0001). The presence of atypical P waves in the ARVC group was not associated with the presence of either structural or functional right ventricular abnormality. CONCLUSIONS: Patients with ARVC commonly demonstrate deteriorated atrial activation expressed either as prolonged P-wave duration or abnormal P-wave morphology. The P-wave abnormalities were not secondary to right ventricular dilatation. These findings show that atrial involvement is common in ARVC and may represent yet another manifestation of the disease to be considered for inclusion in ARVC diagnostic workup.
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| 40. |
- Platonov, Pyotr, et al.
(författare)
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Analysis of atrial fibrillatory rate during spontaneous episodes of atrial fibrillation in humans using implantable loop recorder electrocardiogram.
- 2012
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736.
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Tidskriftsartikel (refereegranskat)abstract
- Atrial fibrillatory rate (AFR) can predict outcome of interventions for atrial fibrillation (AF); however, AFR behavior at AF onset in humans is poorly described. We studied AFR during spontaneous AF episodes in patients with lone paroxysmal AF who received implantable loop recorders and had AF episodes of 1 hour or more recorded (n=4). Mean AFR per minute was assessed from continuous implantable loop recorder electrocardiogram using spatiotemporal QRST cancellation and time-frequency analysis. Atrial fibrillatory rate increased from 290±20 to 326±39 fibrillations per minute during the first 3 hours (P<.05) and reached plateau then. Atrial fibrillatory rate beyond the initial 3 hours can, therefore, be considered stable and may be evaluated for prediction of intervention effect.
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| 41. |
- Platonov, Pyotr, et al.
(författare)
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Atrial fibrillatory rate and irregularity of ventricular response as predictors of clinical outcome in patients with atrial fibrillation
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44:6, s. 673-677
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Konferensbidrag (refereegranskat)abstract
- Atrial fibrillation (AF) remains the most common arrhythmia encountered in clinical practice. Electrocardiogram (ECG)-based predictors of clinical outcome, however, have mostly been studied during sinus rhythm, whereas noninvasive risk stratification of patients with AF remains largely unexplored. Advances in ECG signal processing have led to the development of noninvasive methods of atrial fibrillatory rate (AFR) assessment using spatiotemporal QRST cancellation and time frequency analysis that demonstrated its predictive value for the outcome of pharmacologic and catheter-based interventions for AF. Recently, the prognostic value of AFR was evaluated in patients with congestive heart failure and indicated that reduced AFR may be an independent predictor of total and congestive heart failure-related mortality. A high degree of irregularity of the RR intervals during AF and its dependence on the modulation of the atrioventricular conduction rather than sinus node automaticity hampers the use of conventional heart rate variability approach in patients with AF. However, RR irregularity measures that can be applied to short-time ECG recordings appear to be promising predictors of clinical outcome. (C) 2011 Elsevier Inc. All rights reserved.
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| 42. |
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| 43. |
- Platonov, Pyotr, et al.
(författare)
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Preferential conduction patterns along the coronary sinus during atrial fibrillation in humans and their modification by pulmonary vein isolation.
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44, s. 157-163
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Correlation function analysis applied to endocardial electrograms has earlier been used for analysis of agreement between signals and direction of activation during atrial fibrillation (AF). This study was aimed at evaluating whether preferential activation patterns along the coronary sinus (CS) exist in patients with AF. METHODS: Twenty-seven patients (57 ± 10 years old) admitted for electrophysiological (EP) study (10 patients) and/or AF ablation (17 patients) were studied, 8 with permanent and 19 with persistent AF. Unipolar signals were recorded during 60 seconds from a 10-pole CS catheter during AF at baseline (BL) and after isolation of left and right pulmonary veins and after additional lines in the left atrium (LA) (End). Correlation function analysis was applied to signals from each pair of adjacent electrodes, and graphs of cumulated time delay were made to enable interpretation of direction of activation. RESULTS: Correlation between paired signals was highest in the distal and middle parts of CS and lowest in the proximal CS. In 21 patients, correlation values greater than 0.8 between closely spaced electrodes suggested uniform propagation of the fibrillatory waves. In 18 of 21 patients, preferential conduction pattern along CS was seen. Of those, 15 patients had left-to-right conduction, and 3 had right-to-left conduction. During ablation, atrial fibrillation cycle length increased from 184 ± 32 milliseconds at BL to 193 ± 39 milliseconds after pulmonary vein isolation and 215 ± 39 milliseconds at the end of ablation (P = .03, BL vs End). Because of ablation, preferential conduction along CS changed in 4 patients from left to right at BL to simultaneous CS activation or right to left. In 1 of 3 patients with simultaneous activation at BL, the direction changed to right to left. No direction change was observed in any of the 3 patients with right-to-left activation at BL. CONCLUSIONS: Atrial activation during AF exhibits a high degree of organization in distal and middle CS. Preferential conduction patterns observed in most patients may indicate either relatively dominant stable reentry circuits in the LA or activation spread from a focal source. The changes in preferential conduction during ablation of AF may reflect modification of AF substrate and indicate persistent right atrial sources not affected by ablation in the LA only.
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| 44. |
- Potter, Samara L. Poplack, et al.
(författare)
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Detection of hypertrophic cardiomyopathy is improved when using advanced rather than strictly conventional 12-lead electrocardiogram
- 2010
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 43:6, s. 713-718
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Twelve-lead electrocardiogram (ECG) is used to screen for hypertrophic cardiomyopathy (HCM), but up to 25% of HCM patients do not have distinctly abnormal ECGs, whereas up to 5% to 15% of healthy athletes do. We hypothesized that an approximately 5-minute resting advanced 12-lead ECG test ("A-ECG score") could detect HCM with greater sensitivity than pooled conventional ECG criteria and distinguish healthy athletes from HCM with greater specificity. Materials and methods: Five-minute 12-lead ECGs were obtained from 56 HCM patients, 56 age/sex-matched healthy controls, and 69 younger endurance-trained athletes. Electrocardiograms were analyzed using recently suggested pooled conventional ECG criteria and also A-ECG scoring techniques that considered results from multiple advanced and conventional ECG parameters. Results: Compared with pooled criteria from the strictly conventional ECG, an A-ECG logistic score incorporating results from just 3 advanced ECG parameters (spatial QRS-T angle, unexplained portion of QT variability, and T-wave principal component analysis ratio) increased the sensitivity of ECG for identifying HCM from 89% (78%-96%) to 98% (89%-100%; P = .025), while increasing specificity from 90% (83%-94%) to 95% (92%-99%; P = .020). Conclusions: Resting 12-lead A-ECG scores that are simultaneously more sensitive than pooled conventional ECG criteria for detecting HCM and more specific for distinguishing healthy athletes and other healthy controls from HCM can be constructed. Pending further prospective validation, such scores may lead to improved ECG-based screening for HCM. Published by Elsevier Inc.
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| 45. |
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| 46. |
- Ringborn, Michael, et al.
(författare)
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Comparison of high-frequency QRS components and ST-segment elevation to detect and quantify acute myocardial ischemia.
- 2010
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 43, s. 113-120
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This study tests the ability of high-frequency components of the depolarization phase (HF-QRS) vs conventional ST-elevation criteria to detect and quantify myocardial ischemia. METHODS: Twenty-one patients admitted for elective percutaneous coronary intervention were included. Quantification of the ischemia was made by myocardial scintigraphy. High-resolution electrocardiogram before and during percutaneous coronary intervention was recorded and signal averaged. The HF-QRS were determined within the frequency band 150 to 250 Hz. ST-segment deviation was measured in the standard frequency range (<100 Hz). RESULTS: HF-QRS criteria were met by 76% of the patients, whereas 38% met the ST-elevation criteria (P = .008). Both HF-QRS reduction and ST elevation correlated significantly with the amount of ischemia (HF-QRS: r = 0.59, P = .005 for extent and r = 0.69, P = .001 for severity; ST elevation: r = 0.49, P = .023 for extent and r = 0.57, P = .007 for severity). CONCLUSIONS: This study suggests that HF-QRS analysis could provide valuable information both to detect acute ischemia and to quantify myocardial area at risk.
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| 47. |
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| 48. |
- Ringborn, Michael, et al.
(författare)
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Evaluation of depolarization changes during acute myocardial ischemia by analysis of QRS slopes.
- 2011
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 44:4, s. 416-424
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This study evaluates depolarization changes in acute myocardial ischemia by analysis of QRS slopes. METHODS: In 38 patients undergoing elective percutaneous coronary intervention, changes in upward slope between Q and R waves and downward slope between R and S waves (DS) were analyzed. In leads V1 to V3, upward slope of the S wave was additionally analyzed. Ischemia was quantified by myocardial scintigraphy. Also, conventional QRS and ST measures were determined. RESULTS: QRS slope changes correlated significantly with ischemia (for DS: r = 0.71, P < .0001 for extent, and r = 0.73, P < .0001 for severity). Best corresponding correlation for conventional electrocardiogram parameters was the sum of R-wave amplitude change (r = 0.63, P < .0001; r = 0.60, P < .0001) and the sum of ST-segment elevation (r = 0.67, P < .0001; r = 0.73, P < .0001). Prediction of extent and severity of ischemia increased by 12.2% and 7.1% by adding DS to ST. CONCLUSIONS: The downward slope between R and S waves correlates with ischemia and could have potential value in risk stratification in acute ischemia in addition to ST-T analysis.
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| 49. |
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| 50. |
- Romero, Daniel, et al.
(författare)
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Detection and quantification of acute myocardial ischemia by morphologic evaluation of QRS changes by an angle-based method
- 2013
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 46:3, s. 204-214
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Tidskriftsartikel (refereegranskat)abstract
- Objective: In acute myocardial ischemia changes within the QRS complex can add valuable information to that from the repolarization phase. This study evaluates three angles obtained from the main slopes of the R-wave within the QRS complex to assess acute myocardial ischemia. Methods: The QRS angles, denoted by empty set(R) (R-wave angle), empty set(U) (up-stroke angle) and empty set(D) (down-stroke angle), were evaluated in 12-lead electrocardiogram (ECG) recordings of 79 patients before and during coronary occlusion by elective percutaneous coronary intervention (PCI). In a subset of 38 patients, ischemia was quantified by myocardial scintigraphy. Results: At baseline the QRS angles presented low variations. During occlusion, empty set(U) and empty set(D) developed a fast and abrupt change, whereas empty set(R) showed a smaller and gradual change. There were significant correlations between both maximal and sum of positive change in empty set(R) and ischemia: r = 0.67; p < 0:001 and r = 0.78; p <0.001, for extent, and r = 0.60; p < 0.001 and r = 0.73; p <0.001, for severity, respectively. Prediction of extent and severity of ischemia increased by 50% by adding empty set(R) changes to ST-segment changes, for LCX occlusions, whereas increased by 12.1% and 24.6% for LAD and RCA occlusions, respectively. No significant correlation was seen between empty set(u) and empty set(D) angles and ischemia. Conclusions: Evaluation of QRS angles from the standard 12-lead ECG represents a sensitive marker for detection of acute myocardial ischemia, whereas, empty set(R) changes can be used for prediction of its extent and severity. (C) 2013 Elsevier Inc. All rights reserved.
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