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- 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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| 4. |
- 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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| 5. |
- Trägårdh, Elin, et al.
(författare)
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Reduced high-frequency QRS components in patients with ischemic heart disease compared to normal subjects
- 2004
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 37:3, s. 157-162
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of high-frequency QRS components (HF-QRS) might provide an additional method when diagnosing various heart diseases, for example ischemic heart disease (HID). This study compares HF-QRS in normal Subjects to those in patients with HID, and also analyzes HF-QRS considering gender and age. A total of 63 normal subjects and 64 patients with IHD were included. Signal-averaged electrocardiograms (ECGs) from the 12 standard leads were analyzed in the frequency interval of 150-250 Hz. The results showed that the summed 12 lead HF-QRS in patients with IHD were significantly lower than in normal subjects (mean summed HF-QRS was 33.5 muV in the HID group, 43.7 muV in normal individuals, P < .0005). HF-QRS were not statistically associated with gender or age (P = .820 and P = .573, respectively). However, the inter-individual variation of HF-QRS was large in both groups which probably limits the clinical usefulness of the method.
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