The inverse problem of electrocardiography: A solution in terms of single- and double-layer sources on the epicardial surface

Horáček, B. Milan; Clements, John

doi:10.1016/s0025-5564(97)00024-2

Cited by 81 publications

(54 citation statements)

References 24 publications

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“…[17][18][19] The linear model relating epicardial potentials (ϕ H ) and measured body surface potentials (ϕ B ) through the transfer matrix A at every time instant can be expressed by the following equation:…”

Section: Modeling and Data Processing Methodsmentioning

confidence: 99%

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Inverse Solution Mapping of Epicardial Potentials

Sapp

Dawoud

Clements

et al. 2012

Circ: Arrhythmia and Electrophysiology

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Background-Catheter ablation of ventricular tachycardia (VT) is still one of the most challenging procedures in cardiac electrophysiology, limited, in part, by unmappable arrhythmias that are nonsustained or poorly tolerated. Calculation of the inverse solution from body surface potential mapping (sometimes known as ECG imaging) has shown tremendous promise and can rapidly map these arrhythmias, but we lack quantitative assessment of its accuracy in humans. We compared inverse solution mapping with computed tomography-registered electroanatomic epicardial contact catheter mapping to study the resolution of this technique, the influence of myocardial scar, and the ability to map VT. Methods and Results-For 4 patients undergoing epicardial catheter mapping and ablation of VT, 120-lead body surface potential mappings were obtained during implantable defibrillator pacing, catheter pacing from 79 epicardial sites, and induced VT. Inverse epicardial electrograms computed using individualized torso/epicardial surface geometries extracted from computed tomography images were compared with registered electroanatomic contact maps. The distance between estimated and actual epicardial pacing sites was 13±9 mm over normal myocardium with no stimulus-QRS delay but increased significantly over scar (P=0.013) or was close to scar (P=0.014). Contact maps during right ventricular pacing correlated closely to inverse solution isochrones. Maps of inverse epicardial potentials during 6 different induced VTs indicated areas of earliest activation, which correlated closely with clinically identified VT exit sites for 2 epicardial VTs. Conclusions-Inverse solution maps can identify sites of epicardial pacing with good accuracy, which diminishes over myocardial scar or over slowly conducting tissue. This approach can also identify epicardial VT exit sites and ventricular activation sequences. (Circ Arrhythm Electrophysiol. 2012;5:1001-1009.)

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Section: Modeling and Data Processing Methodsmentioning

confidence: 99%

“…17 Consistent lead position was assured by the use of bony landmarks and prefabricated electrode strips, with fixed interelectrode spacing of 50 mm. Recordings were made using a 128-channel acquisition system, with 1000-Hz sampling rate (Mark 6, BioSemi, Amsterdam, the Netherlands).…”

Section: Bspm and Ctmentioning

confidence: 99%

Inverse Solution Mapping of Epicardial Potentials

Sapp

Dawoud

Clements

et al. 2012

Circ: Arrhythmia and Electrophysiology

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“…In some cases, the second-order regularization provided unstable solutions, so zero-order regularization was utilized. For comparison, the inverse solution was performed using both a standard and a patient-specific geometry set [6,7].…”

Section: Methodsmentioning

confidence: 99%

Use of body-surface potential mapping and computer model simulations for optimal programming of cardiac resynchronization therapy devices

Mohindra

Sapp

Clements

et al. 2007

2007 Computers in Cardiology

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It has been proposed that by optimizing the timing of activation between the ventricles (V-V interval), with the aid of body-surface potential mapping (BSPM), IntroductionMany patients with heart failure have an underlying abnormality in the cardiac conduction system [1], such that the timing of the ventricular contractions becomes dyssynchronous, which further impairs cardiac output [2]. In these cases, restoration of ventricular synchrony is accomplished by use of an implantable pacemaker, which activates both ventricles in a process known as cardiac resynchronization therapy (CRT) or biventricular pacing (BVP).While CRT is successful in many cases, at least 30% of patients do not respond to CRT [3]. Recently, it has been proposed that if the ventricles are paced sequentially (V-V timing), instead of simultaneously, the ventricular synchrony of the heart can be further improved. This could help to maximize the mechanical efficiency of the heart, allowing more patients to benefit from CRT [4].One possible non-invasive method for evaluating ventricular electrical synchrony during different pacing modes is body-surface potential mapping (BSPM). It requires the placement of at least 100 electrocardiographic leads on the patient torso, in a variety of configurations. Because of the increased spatial resolution, BSPM provides a comprehensive three-dimensional picture of cardiac electrical activity that is not possible with the conventional 12-lead electrocardiogram (ECG). Moreover, it is possible to incorporate patient-specific torso geometry from computed tomography (CT) scans and calculate activation sequences (depicted as isochrones of activation times) on the epicardial surface of the heart. Epicardial potential maps and isochrones can be used to asses the electrical synchrony of the ventricles and are, therefore, valuable tools for determining the optimal inter-ventricular pacing delay. MethodsBody-surface potential recordings were performed on two patients with implanted Medtronic CRT devices (InSync III and Concerto) at the QEII Health Sciences Centre in Halifax. Ethics approval was obtained from the Research Ethics Board. One hundred and twenty disposable radiolucent Ag/AgCl surface electrodes (FoxMed, Idstein, Germany) were attached to the patients' torso in the Dalhousie mapping configuration. The V-V timing was varied from L80R (indicating LV lead activation, 80 ms delay and then RV lead activation) to R80L. 15 seconds of recording was done for each setting. Data were acquired via a custom acquistion system (BioSemi, Amsterdam, The Netherlands) at 2000 Hz and digitized with 16-bit quantization. All recordings were stored off-line for later analysis.Axial CT scans of the upper torso were performed for each patient using a Siemens SOMATOM Sensations 64-slice CT scanner (Siemens Medical, USA) at the QEII Health Sciences Centre. The spacing between each scan was 1 mm and the resulting images were stored in the DI-COM format for analysis with Amira 4.0 software (Mer-

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“…Он основан на решении обратной задачи ЭКГ -реконструкции внутрисердечных электрограмм на основе поверхностного ЭКГ-карти ро-вания. Пионером этого направления в 1988 г. был Y. Rudy [13], который в 2015 г. в соавторстве с J. Zhang и M. Haissaguerre [14] продемонстрировали результаты, сопоставимые с данными К. Nademanee. Обследованы 25 пациентов с 1-м типом СБ и группа контроля, кото рую составили пациенты с блокадой правой ножки пучка Ги са и с нормальным ЭКГ.…”

Section: рис 1 экг-картина синдрома бругадаunclassified