Dispersion of repolarization in cardiac resynchronization therapy

Huysduynen, Bart Hooft van; Swenne, Cees A.; Bax, Jeroen J.; Bleeker, Gabe B.; Draisma, Harmen H.M.; Erven, Lieselot van; Molhoek, Sander G.; Vooren, Hedde van de; Wall, Ernst E. van der; Schalij, Martin J.

doi:10.1016/j.hrthm.2005.08.031

Cited by 40 publications

(28 citation statements)

References 35 publications

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“…Because right ventricular pacing alters normal cardiac conduction and results, by definition, in an abnormal QRS-T angle, patients with a pacemaker were excluded from the analysis. 25 Subsequently, the ECGs were analyzed with a dedicated computer program (LEADS, Leiden ECG Analysis and Decomposition Software). 26 Full details on the computation method and LEADS based values of vector characteristics in healthy subjects have been extensively described earlier.…”

Section: Ecg Analysismentioning

confidence: 99%

Predicting Ventricular Arrhythmias in Patients With Ischemic Heart Disease

Borleffs

Scherptong

Man

et al. 2009

Circ: Arrhythmia and Electrophysiology

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139

122

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Background-In patients with primary prevention implantable cardioverter-defibrillators (ICDs), the incidence of life-threatening ventricular arrhythmias resulting in ICD therapy is relatively low, prompting for better risk stratification. The aim of this study was to assess the value of the QRS-T angle for prediction of ICD therapy and mortality in primary prevention patients with ischemic heart disease. Methods and Results-ICD patients (nϭ412, 361 men; age, 63Ϯ11 years) with ischemic heart disease and a left ventricular ejection fraction Յ40% were included. After device implantation, the occurrence of appropriate ICD therapy and mortality was noted. A survival analysis was performed comparing patients with a planar QRS-T angle Յ90°( nϭ124, 30%) with patients with a planar QRS-T angle Ͼ90°before device implantation. Furthermore, patients with a spatial QRS-T angle Յ100°(nϭ56, 14%) were compared with patients with a spatial QRS-T angle Ͼ100°, before implantation. For patients with a planar QRS-T angle Ͼ90°as compared with Յ90°, the adjusted hazard ratio for the occurrence of appropriate device therapy was 2.4 (95% CI, 1.1 to 5.2); a spatial QRS-T angle Ͼ100°was associated with an adjusted hazard ratio of 7.3 (95% CI, 1.0 to 53.8). Furthermore, a spatial QRS-T angle Յ100°exhibited a positive predictive value of 98% (95% CI, 95 to 100) for the prediction of an appropriate therapy-free follow-up. Conclusions-A wide QRS-T angle is a strong predictor of appropriate device therapy in primary prevention ICD recipients with ischemic heart disease. Furthermore, a spatial QRS-T angle Յ100°might be of value in the identification of patients in whom, although currently indicated, ICD treatment should be reconsidered. (Circ Arrhythmia Electrophysiol. 2009;2:548-554.)

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Section: Ecg Analysismentioning

confidence: 99%

Predicting Ventricular Arrhythmias in Patients With Ischemic Heart Disease

Borleffs

Scherptong

Man

et al. 2009

Circ: Arrhythmia and Electrophysiology

Self Cite

139

122

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“…The number of students required was determined by estimating the expected difference in performance between the two groups of students and by the statistical significance required. A similar published study was used as a guide [2] .The students participated on a voluntary basis.…”

Section: Study Populationmentioning

confidence: 99%

Comparison of teaching basic electrocardiographic concepts with and without ECGSIM, an interactive program for electrocardiography

Patuwo

Wagner

Ajijola

2007

2007 Computers in Cardiology

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“…org) version 2.2.1 was used in this study (47). ECGSIM is a software for computer simulations used in research and in education that uses the equivalent surface source model to compute ECG signals on the body surface, as well as electrograms on both the endocardium and epicardium (13,32,45,46,47). Ischemia was simulated by altering combinations of APD and AP amplitude in a similar fashion as in a prior study on ischemia with ECGSIM (12).…”

Section: Methodsmentioning

confidence: 99%

An electrocardiographic sign of ischemic preconditioning

Meijs

Galeotti

Pueyo

et al. 2014

American Journal of Physiology-Heart and Circulatory Physiology

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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 (⌬)] 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 [⌬T/⌬ST slope ϭ 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 (⌬T/⌬ST slope ϭ 2.43, CI 2.07-2.80) (P Ͻ 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 ⌬T/⌬ST of 0.13 (CI Ϫ0.15 to 0.42) in the first occlusion to 1.02 (CI 0.31-1.73) in the second occlusion (P ϭ 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. acute myocardial infarction; electrocardiology; electrophysiology; quantitative modeling IN PATIENTS WITH ACUTE MYOCARDIAL infarction, a primary therapeutic goal is protection of the area at risk that remains in potentially reversible ischemia, to minimize infarct size and maximize ventricular function (30). Ischemic preconditioning is a form of intrinsic cardioprotection where an episode of sublethal ischemia protects against subsequent episodes of ischemia (30). Identifying electrocardiographic (ECG) signs of preconditioning at the time of patient presentation could have clinical importance in guiding decisions for cardioprotective interventions.The cellular electrophysiological effects of acute myocardial ischemia have been characterized in experimental studies and integrated in computer simulation models to demonstrate the effect of individual metabolic and ion current changes on the cellular action potential (AP) (27). The principal AP changes (and associated extracellular electrogram changes) occurring during acute ischemia are depolarization of the resting membrane potential (causing TQ segment depression that appears as ST segment elev...

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Dispersion of repolarization in cardiac resynchronization therapy

Cited by 40 publications

References 35 publications

Predicting Ventricular Arrhythmias in Patients With Ischemic Heart Disease

Predicting Ventricular Arrhythmias in Patients With Ischemic Heart Disease

Comparison of teaching basic electrocardiographic concepts with and without ECGSIM, an interactive program for electrocardiography

An electrocardiographic sign of ischemic preconditioning

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