| 1. |
- Almer, Jakob, et al.
(författare)
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Ischemic QRS prolongation as a biomarker of myocardial injury in STEMI patients
- 2019
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Ingår i: Annals of Noninvasive Electrocardiology. - : Wiley. - 1082-720X. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Patients with acute coronary occlusion (ACO) may not only have ischemia-related ST-segment changes but also changes in the QRS complex. It has recently been shown in dogs that a greater ischemic QRS prolongation (IQP) during ACO is related to lower collateral flow. This suggests that greater IQP could indicate more severe ischemia and thereby more rapid infarct development. Therefore, the purpose was to evaluate the relationship between IQP and measures of myocardial injury in patients presenting with acute ST-elevation myocardial infarction (STEMI).METHODS: Seventy-seven patients with first-time STEMI were retrospectively included from the recently published SOCCER trial. All patients underwent a cardiac magnetic resonance (CMR) examination 2-6 days after the acute event. Infarct size (IS), myocardium at risk (MaR), and myocardial salvage index (MSI) were assessed and related to IQP. IQP measures assessed were; computer-generated QRS duration, QRS duration at maximum ST deviation, absolute IQP and relative IQP, all derived from a pre-PCI, 12-lead ECG.RESULTS: Median absolute IQP was 10 ms (range 0-115 ms). There were no statistically significant correlations between measures of IQP and any of the CMR measures of myocardial injury (absolute IQP vs IS, r = 0.03, p = 0.80; MaR, r = -0.01, p = 0.89; MSI, r = -0.05, p = 0.68).CONCLUSIONS: Unlike previous experimental studies, the IQP was limited in patients presenting at the emergency room with first-time STEMI and no correlation was found between IQP and CMR variables of myocardial injury in these patients. Therefore, IQP does not seem to be a suitable biomarker for triaging patients in this clinical context.
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| 2. |
- Almer, Jakob, et al.
(författare)
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Ischemic QRS prolongation as a biomarker of severe myocardial ischemia.
- 2016
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 49:2, s. 139-147
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have shown that QRS prolongation is a sign of depressed collateral flow and increased rate of myocardial cell death during coronary occlusion. The aims of this study were to evaluate ischemic QRS prolongation as a biomarker of severe ischemia by establishing the relationship between prolongation and collateral flow experimentally in a dog model, and test if the same pattern of ischemic QRS prolongation occurs in man.
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| 3. |
- Almer, Jakob, et al.
(författare)
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Ischemic QRS prolongation as a predictor of ventricular fibrillation in a canine model
- 2018
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 52:5, s. 262-267
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. An acute coronary occlusion and its possible subsequent complications is one of the most common causes of death. One such complication is ventricular fibrillation (VF) due to myocardial ischemia. The severity of ischemia is related to the amount of coronary arterial collateral flow. In dog studies collateral flow has also been shown to be associated with QRS prolongation. The aim of this study was to investigate whether ischemic QRS prolongation (IQP) is associated with impending VF in an experimental acute ischemia dog model. Methods. Degree of IQP and occurrence of VF were measured in dogs (n = 21) during coronary occlusion for 15 min and also during subsequent reperfusion (experiments conducted in 1984). Results. There was a significant difference in absolute IQP between dogs which developed VF during reperfusion (47 ± 29 ms, mean ± SD) and those which did not (12 ± 10 ms; p =.001). Conclusions. IQP during acute coronary occlusion is associated with reperfusion VF in an experimental dog model and might therefore be a potential predictor of malignant arrhythmias in patients with acute coronary syndrome.
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| 4. |
- 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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| 5. |
- Elmberg, Viktor, et al.
(författare)
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A 12-lead ECG-method for quantifying ischemia-induced QRS prolongation to estimate the severity of the acute myocardial event.
- 2016
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 49:3, s. 272-277
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Tidskriftsartikel (refereegranskat)abstract
- Studies have shown terminal QRS distortion and resultant QRS prolongation during ischemia to be a sign of low cardiac protection and thus a faster rate of myocardial cell death. A recent study introduced a single lead method to quantify the severity of ischemia by estimating QRS prolongation. This paper introduces a 12-lead method that, in contrast to the previous method, does not require access to a prior ECG.
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| 6. |
- Holmqvist, Fredrik, et al.
(författare)
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A decade of catheter ablation of cardiac arrhythmias in Sweden : ablation practices and outcomes
- 2019
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 40:10, s. 820-830
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Catheter ablation is considered the treatment of choice for many tachyarrhythmias, but convincing 'real-world' data on efficacy and safety are lacking. Using Swedish national registry data, the ablation spectrum, procedural characteristics, as well as ablation efficacy and reported adverse events are reported.Methods and Results: Consecutive patients (≥18 years of age) undergoing catheter ablation in Sweden between 01 January 2006 and 31 December 2015 were included in the study. Follow-up (repeat ablation and vital status) was collected through 31 December 2016. A total of 26 642 patients (57 ± 15 years, 62% men), undergoing a total of 34 428 ablation procedures were included in the study. In total, 4034 accessory pathway/Wolff-Parkinson-White syndrome (12%), 7358 AV-nodal re-entrant tachycardia (21%), 1813 atrial tachycardia (5.2%), 5481 typical atrial flutter (16%), 11 916 atrial fibrillation (AF, 35%), 2415 AV-nodal (7.0%), 581 premature ventricular contraction (PVC, 1.7%), and 964 ventricular tachycardia (VT) ablations (2.8%) were performed. Median follow-up time was 4.7 years (interquartile range 2.7-7.0). The spectrum of treated arrhythmias changed over time, with a gradual increase in AF, VT, and PVC ablation (P < 0.001). Decreasing procedural times and utilization of fluoroscopy with time, were seen for all arrhythmia types. The rates of repeat ablation differed between ablation types, with the highest repeat ablation seen in AF (41% within 3 years). The rate of reported adverse events was low (n = 595, 1.7%). Death in the immediate period following ablation was rare (n = 116, 0.34%).Conclusion: Catheter ablations have shifted towards more complex procedures over the past decade. Fluoroscopy time has markedly decreased and the efficacy of catheter ablation seems to improve for AF.
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| 7. |
- Holmqvist, Fredrik, et al.
(författare)
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Increasing Ablation Volumes And A Shift Towards More Complex Arrhythmias : Data From The Swedish National Catheter Ablation Registry
- 2018
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Konferensbidrag (refereegranskat)abstract
- Background: Catheter ablation has become the treatment of choice for many tachyarrhythmias. The ablation techniques are continuously refined and the indications expanded, enabling treatment of more complex substrates. Hence, the spectrum of treated arrhythmias is likely to have changed over time, but compelling data on this are lacking.Objective: The present study set out to explore the changing pattern of ablations performed in the setting of a universal, single-payer healthcare system, using data from the Swedish national catheter ablation registry.Methods: The Swedish National Catheter Ablation Registry covers virtually all (>97%) catheter ablations performed in Sweden since 2005 and comprises 42,192 ablations on 32,237 individual patients. In the present analysis, all ablations performed between 2005 and 2016 were included.Results: In 2005, there were 7 ablation centers in Sweden performing a total of 1,584 ablations (226/center; 175/million). In 2016, 11 ablation centers performed 5,022 ablations (457/center; 502/million). Ablation of atrial fibrillation increased from 326 ablations (21% of all) in 2005 to 2,063 (41%) in 2016. Although, the number of ablation procedures for ventricular tachycardia and premature ventricular contractions is increasing, it is still on a relatively modest level (Figure). In contrast to other reports, there is no apparent decline in the number of accessory pathway ablations.Conclusion: In the setting of a universal, single-payer healthcare system, the number of ablations more than tripled over a 10-year period. Ablation of atrial fibrillation is the main driver behind this increase and accounted for 41% of all ablations in Sweden in 2016.
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| 8. |
- Martínez, Juan Pablo, et al.
(författare)
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The STAFF III Database : ECGs recorded during acutely induced myocardial ischemia
- 2017
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Ingår i: Computing in Cardiology. - 2325-8861. ; 44
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Tidskriftsartikel (refereegranskat)abstract
- The STAFF III database was acquired with the aim of better understanding the ECG signatures observed during acute ischemia, with special focus on high-frequency QRS components. The database contains recordings from 104 patients undergoing elective balloon percutaneous coronary intervention. The database has not only been analyzed in numerous clinical studies, but also turned out to be an excellent tool for methodological development. Its use has, by far, exceeded the original aim. Inspired by this fact, the database has now been made publicly available at Physionet.
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| 9. |
- Meijs, Loek P. B., et al.
(författare)
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An electrocardiographic sign of ischemic preconditioning
- 2014
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Ingår i: American Journal of Physiology: Heart and Circulatory Physiology. - : American Physiological Society. - 1522-1539 .- 0363-6135. ; 307:1, s. 80-87
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Tidskriftsartikel (refereegranskat)abstract
- Ischemic preconditioning is a form of intrinsic cardioprotection where an episode of sublethal ischemia protects against subsequent episodes of ischemia. Identifying a clinical biomarker of preconditioning could have important clinical implications, and prior work has focused on the electrocardiographic ST segment. However, the electrophysiology biomarker of preconditioning is increased action potential duration (APD) shortening with subsequent ischemic episodes, and APD shortening should primarily alter the T wave, not the ST segment. We translated findings from simulations to canine to patient models of preconditioning to test the hypothesis that the combination of increased [delta (Delta)] T wave amplitude with decreased ST segment elevation characterizes preconditioning. In simulations, decreased APD caused increased T wave amplitude with minimal ST segment elevation. In contrast, decreased action potential amplitude increased ST segment elevation significantly. In a canine model of preconditioning (9 mongrel dogs undergoing 4 ischemia-reperfusion episodes), ST segment amplitude increased more than T wave amplitude during the first ischemic episode [Delta T/Delta ST slope = 0.81, 95% confidence interval (CI) 0.46 -1.15]; however, during subsequent ischemic episodes the T wave increased significantly more than the ST segment (Delta T/Delta ST slope = 2.43, CI 2.07-2.80) (P = 0.001 for interaction of occlusions 2 vs. 1). A similar result was observed in patients (9 patients undergoing 2 consecutive prolonged occlusions during elective percutaneous coronary intervention), with an increase in slope of Delta T/Delta ST of 0.13 (CI = 0.15 to 0.42) in the first occlusion to 1.02 (CI 0.31-1.73) in the second occlusion (P = 0.02). This integrated analysis of the T wave and ST segment goes beyond the standard approach to only analyze ST elevation, and detects cellular electrophysiology changes of preconditioning.
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| 10. |
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| 11. |
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| 12. |
- Pettersson, Jonas, et al.
(författare)
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Changes in high-frequency QRS components are more sensitive than ST segment deviation for detecting acute coronary artery occlusion
- 2000
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Ingår i: Journal of the American College of Cardiology. - 0735-1097. ; 36:6, s. 1827-1834
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES This study describes changes in high-frequency QRS components (HF-QRS) during percutaneous transluminal coronary angioplasty (PTCA) and compares the ability of these changes in HF-QRS and ST-segment deviation in the standard 12-lead electrocardiogram (ECG) to detect acute coronary artery occlusion. BACKGROUND Previous studies have shown decreased HF-QRS in the frequency range of 150–250 Hz during acute myocardial ischemia. It would be important to know whether the high-frequency analysis could add information to that available from the ST segments in the standard ECG. METHODS The study population consisted of 52 patients undergoing prolonged balloon occlusion during PTCA. Signal-averaged electrocardiograms (SAECG) were recorded prior to and during the balloon inflation. The HF-QRS were determined within a bandwidth of 150–250 Hz in the preinflation and inflation SAECGs. The ST-segment deviation during inflation was determined in the standard frequency range. RESULTS The sensitivity for detecting acute coronary artery occlusion was 88% using the high-frequency method. In 71% of the patients there was ST elevation during inflation. If both ST elevation and depression were considered, the sensitivity was 79%. The sensitivity was significantly higher using the high-frequency method, p < 0.002, compared with the assessment of ST elevation. CONCLUSIONS Acute coronary artery occlusion is detected with higher sensitivity using high-frequency QRS analysis compared with conventional assessment of ST segments. This result suggests that analysis of HF-QRS could provide an adjunctive tool with high sensitivity for detecting acute myocardial ischemia.
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| 13. |
- Pettersson, Jonas, et al.
(författare)
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Spatial, individual and temporal variation of the high frequency QRS amplitudes in the 12 standard electrocardiographic leads
- 2000
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Ingår i: American Heart Journal. - 1097-6744. ; 139:2, part 1, s. 352-358
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Analysis of high-frequency QRS amplitudes (HF-QRS) may provide an additional diagnostic tool in patients with heart disease, but the basic properties of these waveforms have not been sufficiently investigated. This study describes the spatial, individual, and temporal variation at rest of HF-QRS recorded with the 12 standard electrocardiographic leads in patients with ischemic heart disease. METHODS AND RESULTS: Two consecutive electrocardiographic recordings from 67 patients were signal averaged and analyzed within a bandwidth of 150 to 250 Hz. The HF-QRS values were expressed as root mean square values. There was a spatial variation in HF-QRS among the 12 leads, with higher amplitudes in V(2) through V(4), II, aVF, and III. The individual variation among the patients was large for all leads. The sum of the HF-QRS for all 12 leads in each patient ranged from 20 to 75 microV (mean 36 +/- 11 microV). The mean of the temporal variation in HF-QRS for all 12 leads between the 2 recordings was only 0.10 +/- 0. 09 microV. CONCLUSIONS: Because of the large individual variation, analysis of HF-QRS is probably most applicable in monitoring situations when it is possible to track changes in a patient over time. The temporal variation in HF-QRS at rest is small, both in patients with and those without prior myocardial infarction.
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| 14. |
- Reid, Brandon J., et al.
(författare)
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Immediate recruitment of dormant coronary collaterals can provide more than half of normal resting perfusion during coronary occlusion in patients with coronary artery disease
- 2023
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Ingår i: Journal of Nuclear Cardiology. - 1071-3581. ; 30:6, s. 2338-2345
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dormant coronary collaterals are highly prevalent and clinically beneficial in cases of coronary occlusion. However, the magnitude of myocardial perfusion provided by immediate coronary collateral recruitment during acute occlusion is unknown. We aimed to quantify collateral myocardial perfusion during balloon occlusion in patients with coronary artery disease (CAD). Methods: Patients without angiographically visible collaterals undergoing elective percutaneous transluminal coronary angioplasty (PTCA) to a single epicardial vessel underwent two scans with 99mTc-sestamibi myocardial perfusion single-photon emission computed tomography (SPECT). All subjects underwent at least three minutes of angiographically verified complete balloon occlusion, at which time an intravenous injection of the radiotracer was administered, followed by SPECT imaging. A second radiotracer injection followed by SPECT imaging was performed 24 h after PTCA. Results: The study included 22 patients (median [interquartile range] age 68 [54-72] years. The perfusion defect extent was 19 [11-38] % of the LV, and the collateral perfusion at rest was 64 [58-67]% of normal. Conclusion: This is the first study to describe the magnitude of short-term changes in coronary microvascular collateral perfusion in patients with CAD. On average, despite coronary occlusion and an absence of angiographically visible collateral vessels, collaterals provided more than half of the normal perfusion.
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| 15. |
- 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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| 16. |
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| 17. |
- 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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| 18. |
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| 19. |
- Ringborn, Michael, et al.
(författare)
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The absence of high-frequency QRS changes in the presence of standard electrocardiographic QRS changes of old myocardial infarction
- 2001
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Ingår i: American Heart Journal. - : Elsevier BV. - 1097-6744 .- 0002-8703. ; 141:4, s. 573-579
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: This study compares the high-frequency QRS components (HF-QRS) in patients with and without standard electrocardiogram (ECG) changes indicative of old myocardial infarction (MI). Previous studies have indicated that patients with an old MI differ in their HF-QRS compared with healthy subjects. The HF-QRS has been reported to be decreased during acute coronary occlusion and increased after reperfusion. However, there is controversy about the appearance of HF-QRS after the acute phase of MI. METHODS: A total of 154 patients were included, 57 with and 97 without QRS changes of old MI on the standard ECG. The patients with old MI were divided into subgroups on the basis of the MI location indicated by the standard ECG. Signal-averaged ECGs from the 12 standard leads were recorded. The root-mean-square values of the HF-QRS were determined within two frequency bands: 150 to 250 Hz and 80 to 300 Hz. RESULTS: There was a large interindividual variation in HF-QRS in patients without MI as well as in those with different MI locations. There were no significant differences between the groups in the summed HF-QRS of all 12 leads or in the pattern of lead distribution of the HF-QRS. Not even the patients with the greatest QRS changes of old MI could be differentiated from those without any changes of old MI on the standard ECG. The results were the same in both analyzed frequency bands. CONCLUSIONS: This study shows, contrary to previous studies, that analysis of HF-QRS cannot differentiate between patients with and without old MI.
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| 20. |
- Ringborn, Michael
(författare)
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Ventricular Depolarization in Ischemic Heart Disease.Value of Electrocardiography in Assessment of Severity and Extent of Acute Myocardial Ischemia.
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background In patients with symptoms compatible with acute myocardial infarction (MI), early triage by ECG in the pre-hospital phase by ST-segment elevation myocardial infarction (STEMI) criteria is important for direct transport of these patients to a regional center for primary percutaneous coronary intervention (pPCI). The time from first medical contact to pPCI should, due to present guidelines, be no longer than two hours. One main determinant of final infarct size (IS), in addition to myocardium at risk (MaR) and time to treatment, is the severity of ischemia, which relates to the rate of progression of the infarction wavefront. Presently, no assessment of severity is made. Patients with severe ischemia may have changes within the QRS complex in addition to ST-T changes, making it possible to identify these high-risk patients. QRS changes are, however more difficult to determine and to quantify correctly as compared to the changes within the ST segment. Aims and methods The overall objective was to increase the understanding of depolarization changes during myocardial ischemia and to evaluate whether these changes have possible clinical implications in patients with acute MI. Different QRS methods are applied in patients during ischemia produced by elective, prolonged PCI as well as during STEMI, and comparisons are made with conventional ECG parameters as well as single-photon emission computed tomography (SPECT) images. Results and conclusions Study I compared the computer-derived high-frequency QRS components (HF-QRS) in patients with and without standard ECG changes indicative of old MI. In contrast to previous findings we found that HF-QRS cannot differentiate between patients with and without old MI. Study II tested the ability of HF-QRS versus conventional ST-segment measurements to detect and quantify myocardial ischemia, as determined by SPECT, in a group of patients undergoing elective balloon PCI. We showed that HF-QRS can provide valuable information both for detecting acute ischemia and for quantifying MaR and its severity. Study III evaluated a potentially more readily available (compared with HF-QRS) new marker of ventricular depolarization distortion, which is based on calculation of up- and downslope within the QRS complex, in patients undergoing coronary intervention that includes temporary occlusion of a coronary artery. We found that in particular the downward slope between R and S waves better correlates with ischemia than conventional QRS parameters, as quantified by SPECT, and thus can be of value in risk stratification of patients with ischemia in addition to conventional ST-segment analysis. Study IV, in a large cohort of STEMI patients, assessed the value of the conventional Sclarovsky-Birnbaum ischemia grading system that includes terminal QRS distortion in addition to ST elevation, on pre-hospital ECG and its dynamic behavior during transport time to the PCI center for prediction of final infarct size and salvage, as estimated by SPECT imaging. The study explored the temporal behavior of the ischemia grading and showed the strong association of ischemia grade assessed from pre-hospital ECG, as well as the dynamic patterns, with infarct size, independent of ST-segment analysis. It also demonstrated the importance of early intervention, which was found to be particularly important in patients who had advanced, QRS-based ischemia grade.
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| 21. |
- Romero, Daniel, et al.
(författare)
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Characterization of ventricular depolarization and repolarization changes in a porcine model of myocardial infarction
- 2012
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Ingår i: Physiological Measurement. - : IOP Publishing. - 0967-3334 .- 1361-6579. ; 33:12, s. 1975-1991
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Tidskriftsartikel (refereegranskat)abstract
- In this study, several electrocardiogram (ECG)-derived indices corresponding to both ventricular depolarization and repolarization were evaluated during acute myocardial ischemia in an experimental model of myocardial infarction produced by 40 min coronary balloon inflation in 13 pigs. Significant changes were rapidly observed from minute 4 after the start of coronary occlusion, achieving their maximum values between 11 and 22 min for depolarization and between 9 and 12 min for repolarization indices, respectively. Subsequently, these maximum changes started to decrease during the latter part of the occlusion. Depolarization changes associated with the second half of the QRS complex showed a significant but inverse correlation with the myocardium at risk (MaR) estimated by scintigraphic images. The correlation between MaR and changes of the downward slope of the QRS complex, I-DS, evaluated at the two more relevant peaks observed during the occlusion, was r = -0.75, p < 0.01 and r = -0.79, p < 0.01 for the positive and negative deflections observed in I-DS temporal evolution, respectively. Repolarization changes, analyzed by evaluation of ST segment elevation at the main observed positive peak, also showed negative, however non-significant correlation with MaR: r = -0.34, p = 0.28. Our results suggest that changes evaluated in the latter part of the depolarization, such as those described by I-DS, which are influenced by R-wave amplitude, QRS width and ST level variations simultaneously, correlate better with the amount of ischemia than other indices evaluated in the earlier part of depolarization or during the ST segment.
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| 22. |
- Romero, Daniel, et al.
(författare)
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Depolarization Changes During Acute Myocardial Ischemia by Evaluation of QRS Slopes: Standard Lead and Vectorial Approach
- 2011
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Ingår i: IEEE Transactions on Biomedical Engineering. - 1558-2531. ; 58:1, s. 110-120
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Tidskriftsartikel (refereegranskat)abstract
- Diagnosis and risk stratification of patients with acute coronary syndromes can be improved by adding information from the depolarization phase (QRS complex) to the conventionally used ST-T segment changes. In this study, ischemia-induced changes in the main three slopes of the QRS complex, upward (I-US) and downward (I-DS) slopes of the R wave as well as the upward (I-TS) slope of the terminal S wave, were evaluated as to represent a robust measure of pathological changes within the depolarization phase. From ECG recordings both in a resting state (control recordings) and during percutaneous coronary intervention (PCI)-induced transmural ischemia, we developed a method for quantification of I-US, I-DS, and I-TS that incorporates dynamic ECG normalization so as to improve the sensitivity in the detection of ischemia-induced changes. The same method was also applied on leads obtained by projection of QRS loops onto their dominant directions. We show that I-US, I-DS, and I-TS present high stability in the resting state, thus providing a stable reference for ischemia characterization. Maximum relative factors of change (R-I) during PCI were found in leads derived from the QRS loop, reaching 10.5 and 13.7 times their normal variations in the control for I-US and I-DS, respectively. For standard leads, the relative factors of change were 6.01 and 9.31. The I-TS index presented a similar behavior to that of I-DS. The timing for the occurrence of significant changes in I-US and I-DS varied with lead, ranging from 30 s to 2 min after initiation of coronary occlusion. In the present ischemia model, relative I-DS changes were smaller than ST changes in most leads, however with only modest correlation between the two indices, suggesting they present different information about the ischemic process. We conclude that QRS slopes offer a robust tool for evaluating depolarization changes during myocardial ischemia.
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| 23. |
- 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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| 24. |
- ter Haar, C. Cato, et al.
(författare)
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Difference vectors to describe dynamics of the ST segment and the ventricular gradient in acute ischemia
- 2013
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 1532-8430 .- 0022-0736. ; 46:4, s. 302-311
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Tidskriftsartikel (refereegranskat)abstract
- Background: The ECG is important in the diagnosis and triage of the acute coronary syndrome (ACS), especially in the hyperacute phase, the "golden hours," during which myocardial salvage possibilities are largest. An important triaging decision to be taken is whether or not a patient requires primary PCI, for which, as mentioned in the guidelines, the presence of an ST elevation (STE) pattern in the ECG is a major criterion. However, preexisting non-zero ST amplitudes (diagnostic, but also non-diagnostic) can obscure or even preclude this diagnosis. Methods: In this study, we investigated the potential diagnostic possibilities of ischemia detection by means of changes in the ST vector, Delta ST, and changes in the VG (QRST integral) vector, Delta VG. We studied the vectorcardiograms (VCGs) synthesized of the ECGs of 84 patients who underwent elective PTCA. Mean +/- SD balloon occlusion times were 260 +/- 76 s. The ECG ischemia diagnosis (ST elevation, STE, or non-ST-elevation, NSTE), magnitudes and orientations of the ST and VG vectors, and the differences Delta ST and Delta VG with the baseline ECG were measured after 3 min of balloon occlusion. Results: Planar angles between the Delta ST and Delta VG vectors were 14.9 +/- 14.0 degrees. Linear regression of Delta VG on Delta ST yielded Delta VG = 324. Delta ST (r = 0.85; P < 0.0001, Delta ST in mV). We adopted Delta ST > 0.05 mV, and the corresponding Delta VG > 16.2 mV.ms as ischemia thresholds. The classical criteria characterized the ECGs of 46/84 (55%) patients after 3 min of occlusion as STE ECGs. Combined application of the Delta ST and Delta VG criteria identified 73/84 (87%) of the patients as ischemic. Conclusion: Differential diagnosis by Delta ST and Delta VG (requiring an earlier made non-ischemic baseline ECG) could dramatically improve ECG guided detection of patients who urgently require catheter intervention. (C) 2013 Elsevier Inc. All rights reserved.
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| 25. |
- von Olshausen, Gesa, et al.
(författare)
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Cardiac tamponades related to interventional electrophysiology procedures are associated with higher risk of short-term hospitalization for pericarditis but favourable long-term outcome
- 2023
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Ingår i: Europace. - : Oxford University Press. - 1099-5129 .- 1532-2092. ; 25:6
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: To investigate the association of iatrogenic cardiac tamponades as a complication of invasive electrophysiology procedures (EPs) and mortality as well as serious cardiovascular events in a nationwide patient cohort during long-term follow-up.METHODS: From the Swedish Catheter Ablation Registry between 2005 and 2019, a total of 58 770 invasive EPs in 44 497 patients were analysed. From this, all patients with periprocedural cardiac tamponades related to invasive EPs were identified (n = 200; tamponade group) and matched (1:2 ratio) to a control group (n = 400). Over a follow-up of 5 years, the composite primary endpoint-death from any cause, acute myocardial infarction, transitory ischaemic attack (TIA)/stroke, and hospitalization for heart failure-revealed no statistically significant association with cardiac tamponade [hazard ratio (HR) 1.22 (95% CI, 0.79-1.88)]. All single components of the primary endpoint as well as cardiovascular death revealed no statistically significant association with cardiac tamponade. Cardiac tamponade was associated with a significantly higher risk with hospitalization for pericarditis [HR 20.67 (95% CI, 6.32-67.60)].CONCLUSION: In this nationwide cohort of patients undergoing invasive EPs, iatrogenic cardiac tamponade was associated with an increased risk of hospitalization for pericarditis during the first months after the index procedure. In the long-term, however, cardiac tamponade revealed no significant association with mortality or other serious cardiovascular events.
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| 26. |
- von Olshausen, Gesa, et al.
(författare)
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Cardiac tamponades related to interventional electrophysiology procedures are associated with higher risk of short-term hospitalization for pericarditis but favourable long-term outcome.
- 2023
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Ingår i: Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology. - : Oxford University Press. - 1532-2092 .- 1099-5129. ; 25:6
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the association of iatrogenic cardiac tamponades as a complication of invasive electrophysiology procedures (EPs) and mortality as well as serious cardiovascular events in a nationwide patient cohort during long-term follow-up.From the Swedish Catheter Ablation Registry between 2005 and 2019, a total of 58 770 invasive EPs in 44 497 patients were analysed. From this, all patients with periprocedural cardiac tamponades related to invasive EPs were identified (n = 200; tamponade group) and matched (1:2 ratio) to a control group (n = 400). Over a follow-up of 5 years, the composite primary endpoint-death from any cause, acute myocardial infarction, transitory ischaemic attack (TIA)/stroke, and hospitalization for heart failure-revealed no statistically significant association with cardiac tamponade [hazard ratio (HR) 1.22 (95% CI, 0.79-1.88)]. All single components of the primary endpoint as well as cardiovascular death revealed no statistically significant association with cardiac tamponade. Cardiac tamponade was associated with a significantly higher risk with hospitalization for pericarditis [HR 20.67 (95% CI, 6.32-67.60)].In this nationwide cohort of patients undergoing invasive EPs, iatrogenic cardiac tamponade was associated with an increased risk of hospitalization for pericarditis during the first months after the index procedure. In the long-term, however, cardiac tamponade revealed no significant association with mortality or other serious cardiovascular events.
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