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| 2. |
- Alexander, JH, et al.
(författare)
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Prognostic importance of new small Q waves following non-ST-elevation acute coronary syndromes
- 2003
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Ingår i: American Journal of Medicine. - : Elsevier BV. - 0002-9343. ; 115:8, s. 613-619
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: to investigate the prognostic importance of new small Q waves following an acute coronary syndrome. METHODS: We assessed 6-month mortality in 10,501 patients with non-ST-elevation acute coronary syndromes who had survived 30 days and had both admission and 30-day electrocardiograms. Patients were stratified by whether they had no new Q waves (n = 9447), new 30- to 40-ms Q waves (n = 733), or new greater than or equal to40-ms Q waves (n = 321). RESULTS: Mortality was higher in patients with 30- to 40-ms Q waves than in those with no new Q waves (3.4% [25/733] vs. 2.4% [227/9447], P = 0.005), and even higher in those with greater than or equal to40-ms Q waves (5.3% [17/321], P = 0.002). After adjustment for baseline risk predictors, mortality remained higher in patients with new 30- to 40-ms Q waves (odds ratio [OR] = 1.30; 95% confidence interval [CI]: 0.85 to 1.98; P = 0.23) and those with new greater than or equal to40-ms Q waves (OR = 1.87; 95% Cl: 1.13 to 3.09; P = 0.01). CONCLUSION: Patients with new small Q waves following a non-ST-elevation acute coronary syndrome are at increased risk of adverse outcomes. These small Q waves should be considered diagnostic of myocardial infarction. Further research should investigate whether even smaller QRS changes are prognostically important. (C)2003 by Excerpta Medica Inc.
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| 3. |
- Billgren, T, et al.
(författare)
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Detailed definition and interobserver agreement for the electrocardiographic Sclarovsky-Birnbaum ischemia grading system
- 2002
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 35, s. 201-202
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Tidskriftsartikel (refereegranskat)abstract
- A generally implementable method for predicting salvageability on the presenting electrocardiogram (ECG) in patients with acute myocardial infarction (AMI) would be of great clinical importance. ECG-derived Grades of Ischemia (1) have been proven useful in predicting the extent and severity of left ventricular dysfunction after anterior MI, estimating short and long-term prognosis, final infarct size, and salvageability by reperfusion therapy (2).
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| 4. |
- Pahlm, Olle, et al.
(författare)
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Comparison of waveforms in conventional 12-lead ECGs and those derived from EASI leads in children
- 2003
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 36:1, s. 25-31
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the possibility of simplifying electrocardiogram (ECG) recording in children, we compared waveforms in conventional 12-lead ECGs to those derived from EASI leads in 221 children of various ages. The conventional 12-lead ECGs and the ECGs using EASI electrode positions were collected simultaneously. We developed and determined the value of age-specific transformation coefficients for use in deriving 12-lead ECGs from the signals recorded at the EASI sites. We compared the results of using age-specific coefficients to the results of using adult coefficients and studied the "goodness-of-fit" between the conventional and the derived 12-lead ECGs. The age-specific coefficients performed slightly better than the adult coefficients, and good agreement was usually attained between the conventional 12-lead ECG and the EASI-derived 12-lead ECG. Our conclusion is that EASI leads in children have the same high levels of "goodness-of-fit" to replicate conventional 12-lead ECG waveforms, as reported earlier in adults.
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| 5. |
- Rautaharju, PM, et al.
(författare)
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Comparability of 12-lead ECGs derived from EASI leads with standard 12-lead ECGs in the classification of acute myocardial ischemia and old myocardial infarction
- 2002
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 35:4, part 2, s. 35-39
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Tidskriftsartikel (refereegranskat)abstract
- We compared 12-lead electrocardiograms (ECGs) derived with an improved transformation matrix from EASI leads and standard 12-lead ECGs in the detection of acute myocardial ischemia and old infarction (MI). For the ischemia test, we used ECGs of 40 patients recorded prior to and at peak inflation during percutaneous transluminal coronary angioplasty, and for old MI we used test ECGs of 382 non-MI subjects and of 472 patients with prior MI documented by enzyme findings. Two experienced ECG readers served as separate, independent standards for lead-set comparisons, and the Philips ECG analysis program also classified the ECGs. The results showed no significant differences between the two lead sets in the detection of acute inflation-induced ischemia or of old MI according to coding by the electrocardiographers or the computer program. No significant differences were found between the electrocardiographers and the lead sets for acute ischemia. Classification differences between the electrocardiographers were larger than those between the lead sets for acute and old MI and were significant for the latter (P <.001). A more detailed comparison of the lead sets suggested a possible need for modified old-MI criteria and optimization of ST classification thresholds for acute ischemic injury, specific for the EASI 12-lead ECG. We conclude that the EASI-derived 12-lead ECG deserves serious consideration as an alternative to the standard 12-lead ECG in emergency situations and for monitoring in acute-care setting.
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| 6. |
- Sejersten, M, et al.
(författare)
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Comparison of EASI-derived 12-lead electrocardiograms versus paramedic-acquired 12-lead electrocardiograms using Mason-Likar limb lead configuration in patients with chest pain
- 2006
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 39:1, s. 13-21
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Monitoring of serial 12-lead electrocardiogram (ECG) recordings is the accepted requirement for prehospital data acquisition in patients with chest pain. The purpose of this study was to determine whether waveforms and clinical triage decisions are similar for EASI-derived ECGs and paramedic-acquired 12-lead ECGs using Mason-Likar limb lead configuration when compared with standard 12-lead ECGs (stdECG). Method: Twenty patients with chest pain had a prehospital 12-lead ECG recorded in the ambulance, and paramedic-applied electrodes retained in place at hospital arrival. An ECG technician applied standard precordial and EASI electrodes in their Correct positions. Twelve-lead ECGs were obtained from the paramedic-applied electrodes using their Mason-Likar limb lead configuration, and derived from the EASI leads for comparison with the stdECG. Three computer-measured QRS-T waveform parameters were considered, and differences in waveform measurement between EASI and stdECG (EASI Delta stdECG) versus differences in waveform measurements between paramedic Mason-Likar and stdECG (PML Delta stdECG) were calculated. Two emergency physicians determined whether the EASI-derived or the paramedic Mason-Likar ECG contained information that would change their clinical triage decision from that indicated by the stdECG. Results: EASI Delta stdECG and PML Delta stdECG were identical in 28%, whereas EASI Delta stdECG was more than PML Delta stdECG in 35%, and PML Delta stdECG was accurate (both times) than EASI Delta stdECG in 37% (P = .62). The physicians were more likely to change the level of patient care based on the EASI-derived ECGs compared with the paramedic ECGs; however, this difference was not statistically significant (P = .27), but this may only be caused by the small study population. Conclusions: There are similar differences from stdECG waveforms in EASI-derived ECGs and those acquired via paramedic-applied precordial electrodes using Mason-Likar limb lead configuration. Either method can be used as a substitute for monitoring, but neither should be considered equivalent to the stdECG for diagnostic purposes. (c) 2006 Elsevier Inc. All rights reserved.
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| 7. |
- Sejersten, M, et al.
(författare)
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The relative accuracies of ECG precordial lead waveforms derived from EASI leads and those acquired from paramedic applied standard leads
- 2003
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Ingår i: Journal of Electrocardiology. - 1532-8430. ; 36:3, s. 179-185
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Tidskriftsartikel (refereegranskat)abstract
- Accurate precordial electrode placement can be difficult in emergency situations leading either to loss of time or diminished accuracy. A possible solution is the quasi-orthogonal EASI lead system, with only five electrodes and easily defined landmarks to provide a derived 12-lead electrocardiogram (ECG). The purpose of this study was to test the hypothesis that precordial waveforms in EASI-derived ECGs have no greater deviation from those in gold standard ECGs, than do the precordial waveforms in paramedic acquired standard ECGs. Twenty paramedics applied the standard precordial electrodes employing the routine procedure. A certified ECG technician applied the 6 standard precordial electrodes in their correct gold standard positions, and the EASI electrodes. 12-lead ECGs were obtained from the paramedics' standard leads, and derived from the EASI leads, for comparison with the gold standard ECG. In each precordial lead recording, 6 computer-measured QRS-T waveform parameters were considered. Differences between DeltaEASI-gold standard versus Deltaparamedic-gold standard were calculated for every waveform in every lead resulting in 720 comparisons. EASI and paramedic results were "equally accurate" in 47%, the paramedic was more accurate in 31%, and EASI was more accurate in the remaining 22%. The differences from gold standard recording of precordial waveforms in ECGs derived from the EASI leads and those acquired via paramedic-applied standard electrodes are similar. The results suggest that the EASI lead system may provide an alternative,to the standard ECG precordial leads to facilitate data acquisition and possibly save valuable time in emergency situations.
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| 8. |
- Sgarbossa, EB, et al.
(författare)
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Twelve-lead electrocardiogram: The advantages of an orderly frontal lead display including lead -aVR
- 2004
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 37:3, s. 141-147
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is possible that efforts in ECG review by both young experienced clinicians are currently discouraged-and risk to be completely dismissed-by the conventional (ie, disorderly) display of the frontal plane leads, with lead aVR at -150degrees. Methods: We reviewed studies on the usefulness of leads aVR and -aVR as well as on the history of the frontal leads in electrocardiography. Results: Lead aVR and particularly, lead -aVR, provide useful information when systematically analyzed. in addition, if lead -aVR is examined in its anatomically logical sequence, ie, aVL, 1, -aVR, 11, aVF, and 111, the frontal plane of the 12-lead ECG is more easily understood. This "panoramic" or "orderly" display is in common use in countries such as Sweden, but it is rarely seen in the United States. Conclusions: ECG interpretation would be enhanced by displaying the limb leads in an orderly arrangement that starts with lead aVL and ends with lead 111, and many ECG changes would be ideally displayed by a lead -aVR at 30degrees.
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| 9. |
- 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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