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| 2. |
- 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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| 4. |
- 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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| 5. |
- Trägårdh, Elin, et al.
(författare)
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Avledningssystem
- 2006
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Ingår i: Elektrokardiologi : klinik och teknik. - 9144006152 ; , s. 1-16
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Trägårdh, Elin, et al.
(författare)
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Detection of acute myocardial infarction using the 12-lead ECG plus inverted leads versus the 16-lead ECG (with additional posterior and right-sided chest electrodes).
- 2007
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961. ; 27:6, s. 368-374
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Tidskriftsartikel (refereegranskat)abstract
- Background: The electrocardiographic (ECG) diagnosis of acute myocardial infarction (MI) should be improved. This might be done either by regarding all 24 aspects (both positive and negative leads), or a subset hereof (e.g. 19-lead ECG), of the conventional 12-lead ECG or by using additional electrodes. The purpose of this study was to investigate the accuracy of the different ECG methods in diagnosing acute ST-elevation MI. Methods: The study population consisted of 479 patients admitted to Lund University Hospital with acute chest pain. One conventional ECG plus leads V4R, V5R, V8 and V9 were recorded for each patient within 24 h of admittance. Biochemical markers were used as the 'gold standard' for diagnosis of MI. We measured ST-segment elevations in the 12-, 16- and 24-lead postadmission ECGs as well as in the 12-, 19- and 24-lead admission ECGs. Results: The sensitivity for detecting acute MI was 28% for the postadmission 12-lead ECG, 33% for the 16-lead ECG and 37% for the 24-lead ECG. The specificities were 97%, 93% and 95%, respectively. For admission ECGs, the sensitivity was 33% for the 12-lead ECG, 45% for the 19-lead ECG and 49% for the 24-lead ECG, with specificities of 97%, 96% and 94%, respectively. Conclusion: The sensitivity for detecting acute MI was higher for the 16-, 19- and 24-lead ECGs than for the conventional 12-lead ECGs. Their specificity, however, was slightly lower. If increased sensitivity for detecting MI is desired, the 24-lead or 19-lead should be used as no additional electrodes are required.
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| 9. |
- Trägårdh, Elin, et al.
(författare)
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How many ECG leads do we need?
- 2006
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Ingår i: Cardiology Clinics. - : Elsevier BV. - 1558-2264 .- 0733-8651. ; 24:3, s. 317-317
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Forskningsöversikt (refereegranskat)abstract
- The number of leads needed in clinical electrocardiography depends on the clinical problem to be solved. The standard 12-lead ECG is so well established that alternative lead systems must prove their advantage through well-conducted clinical studies to achieve clinical acceptance. Certain additional leads seem to add valuable information in specific patient groups. The use of a large number of leads (eg, in body surface potential mapping) may add clinically relevant information, but it is cumbersome and its clinical advantage is yet to be proven. Reduced lead sets emulate the 12-lead ECG reasonably well and are especially advantageous in emergency situations.
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| 10. |
- Trägårdh, Elin, et al.
(författare)
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Reduced high-frequency QRS components in electrocardiogram leads facing an area of the heart with intraventricular conduction delay due to bundle branch block.
- 2007
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 40:2, s. 127-132
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Tidskriftsartikel (refereegranskat)abstract
- Background: The mechanisms underlying high-frequency QRS components (HF-QRS) are incompletely understood. One theory is that HF-QRS are related to the conduction velocity of the heart. The purpose was to test this hypothesis by comparing HF-QRS in patients with left or right bundle branch block (LBBB and RBBB, respectively) to those in healthy subjects and in patients with ischemic heart disease (IHD). Methods: Twenty-two patients with LBBB, 19 patients with RBBB, 63 normal subjects, and 64 patients with IHD were included. Twelve-lead electrocardiograms were analyzed in the frequency interval 150 to 250 Hz. Results: The study showed reduced HF-QRS in patients with LBBB compared with healthy subjects and patients with IHD. The difference, however, was small in lead V-1 and V-2. In patients with RBBB, no differences in HF-QRS could be detected except in few leads; among those is lead V-1. Conclusion: The results support the theory that HF-QRS are related to the conduction velocity of the heart. (c) 2007 Elsevier Inc. All rights reserved.
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