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Lateral Leads (lateral + lead)
Selected AbstractsBrugada Syndrome with ST-Segment Elevation in the Lateral LeadsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2006MAARTEN P. VAN DEN BERG M.D., Ph.D. No abstract is available for this article. [source] Electrocardiogram-Based Algorithm to Predict the Left Ventricular Lead Position in Recipients of Cardiac Resynchronization SystemsPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2009SYLVAIN PLOUX M.D. Introduction: Biventricular pacing is associated with various electrocardiographic patterns depending on the position of the left ventricular (LV) lead. We aimed to develop an electrocardiogram-based algorithm to predict the position of the LV lead. Methods: The algorithm was developed in 100 consecutive recipients of cardiac resynchronization therapy (CRT) systems. QRS axis, morphology, and polarity were analyzed with a view to define the specific electrocardiographic characteristics associated with the various LV lead positions. The algorithm was prospectively validated in 50 consecutive CRT device recipients. Results: The first analysis of the algorithm was the QRS morphology in V1. A positive R wave in V1 suggested LV lateral or posterior wall stimulation. A QS pattern was specific of anterior LV leads. In the presence of an R wave in V1, V6 was analyzed to distinguish between an inferior and anterior LV lead. Inferior leads were never associated with a positive V6. To differentiate between lateral and posterior positions, we analyzed the pattern in V2. Lateral leads were associated with an R morphology in V1 and a negative V2. Posterior leads were associated with an R morphology in V1 and V2. The algorithm allowed a reliable distinction between an inferior or anterior and a lateral or posterior lead position in 90% of patients. Inferior, anterior, lateral, and posterior positions were reliably distinguished in 80% of patients. Conclusion: This algorithm predicted the position of the LV lead with a high sensitivity and predictive value. [source] Effect of temperature distribution and current crowding on the performance of lateral GaN-based light-emitting diodesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7-8 2010Dongpyo Han Abstract Current crowding effect is detrimental for the performance of light-emitting diodes (LEDs), causing non-uniform light emission and local heat generation. In particular, heat generated by non-uniform current distribution can badly influence the performance of LED devices. In this paper, we examine the temperature distributions of lateral InGaN/GaN multiple-quantum-well LEDs in relation to current crowding, using both simulation and experimental results. Simulation results are obtained from a 3-dimensional electrical circuit model consisting of resistances and intrinsic diodes. Temperature and luminance distributions are investigated by images taken by an infrared camera and a charge-coupled-device camera, respectively. Finally, the internal quantum efficiency is taken for each device and compared. We show that the thermal property in the lateral LED is affected by the current crowding due to the local Joule heating nearby electrodes. Therefore, uniform current spreading is very important not only for uniform luminance distribution but also for good thermal property in the LED device. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] ST Segment "Hump" during Exercise Testing and the Risk of Sudden Cardiac Death in Patients with Hypertrophic CardiomyopathyANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2009Andreas P. Michaelides M.D., F.A.C.C., F.E.S.C. Background: The appearance of a discrete upward deflection of the ST segment termed "the ST hump sign" (STHS) during exercise testing has been associated with resting hypertension and exaggerated blood pressure response to exercise. Objective: We investigated the prevalence and clinical significance of this sign in a population of patients with hypertrophic cardiomyopathy. Methods: Eighty-one patients with hypertrophic cardiomyopathy (HCM) who underwent cardiopulmonary exercise testing were followed in a retrospective cohort study for a mean period of 5.3 years. Results: The appearance of the STHS at the peak of exercise testing was observed in 42 patients (52%), particularly in the inferior and the lateral leads. Patients with the STHS had higher fractional shortening and maximum left ventricular wall thickness and exhibited more frequently outflow tract gradient >30 mmHg at rest. Furthermore, the presence of STHS was a strong independent predictor of the risk of sudden cardiac death (SCD), as the latter occurred in eight of the patients with this sign (8/42, 19%) and in none of the patients without it (0/39, 0%) (P < 0.001). Conclusion: The appearance of a "hump" at the ST segment during exercise testing appears to be a risk factor for SCD in patients with HCM. However, further studies are necessary to validate this finding in larger populations and to elucidate the mechanism of the appearance of the "hump." [source] | ||||||||||