Search

Your search keyword '"Scharf, Christoph"' showing total 243 results
Start Over Author "Scharf, Christoph" Publication Year Range Last 50 years
243 results on '"Scharf, Christoph"'

3. Electrophysiology of living organs from first principles

Author

Scharf, Günter and Scharf, Christoph

Subjects
Physics - Biological Physics, Quantitative Biology - Quantitative Methods
Abstract

Based on the derivation of the macroscopic Maxwell's equations by spatial averaging of the microscopic equations, we discuss the electrophysiology of living organs. Other methods of averaging (or homogenization) like the bidomain model are not compatible with Maxwell's theory. We also point out that modeling the active cells by source currents is not a suitable description of the situation from first principles. Instead, it turns out that the main source of the measured electrical potentials is the polarization charge density which exists at the membranes of the active cells and adds up to a macroscopic polarization. The latter is the source term in the Laplace equation, the solution of which gives the measured far-field potential. As a consequence it is the polarization or dipole density which is best suited for localization of cardiac arrhythmia., Comment: 11 pages, no figure

Published
2010

5. Barlow disease: effect of mitral valve repair on ventricular arrhythmias in 82 patients in a retrospective long-term study

Author

Brunec-Keller, Mira, Scharf, Christoph, Radulovic, Jovana, Berdat, Pascal A, Attenhofer Jost, Christine H, Vogt, Paul, Duru, Firat, Caselli, Stefano, University of Zurich, and Caselli, Stefano

Subjects
Male, Mitral Valve Prolapse, Mitral Valve Insufficiency, Arrhythmias, Cardiac, Stroke Volume, 610 Medicine & health, General Medicine, Ventricular Function, Left, 2705 Cardiology and Cardiovascular Medicine, 2746 Surgery, 10209 Clinic for Cardiology, Humans, Mitral Valve, Female, Surgery, Cardiology and Cardiovascular Medicine, Retrospective Studies
Abstract

Patients (pt) with mitral valve prolapse (MVP) due to Barlow disase (BD) have an increased incidence of ventricular arrhythmias (VA; including ventricular tachycardias VT) and sudden cardiac death (SCD). Data on the effect of MV repair on VA are scarce.Pre- and postoperative VA in severe mitral regurgitation (MR) with MVP due to BD undergoing surgical mitral valve repair were analyzed. Patients with degenerative mitral valve disease not fulfilling BD criteria were excluded. Information was from charts, ECG/Holter ECG and/or pacemaker/ implantable cardioverter defibrillator (ICD) data. SCD, sustained VT30 sec and/or ventricular fibrillation necessitating an ICD-shock were considered major events. Event probability was calculated using the Kaplan-Meier estimator throughout the follow-up period of 20.7 years.There were 82 pts (61% males), mean age at surgery 62±14 years. Bileaflet MVP was present in 54%, mitral annular dysjunction (MAD) in 37% and left ventricular ejection fraction (LVEF)50% in 12%. MV repair included ring annuloplasty in all and artificial chords in 48%. Mean follow-up was 3.1 years (0.2 to 14.2 years). Postoperative rhythm surveillance by Holter ECG and/or pacemaker was available in 67%. A VA load of ≥10% and/or any VT was noted in 26% before and 32% after surgery (P=0.44). Postoperative VA load was not predicted by MAD, artificial chords, LVEF of50%, age at surgery50 years and/or residual ≥moderate MR (all P0.05), it correlated only with bileaflet MVP (P=0.009). Major events occurred in 3 pts: SCD in 2 pts and ICD for sustained polymorphic VT in 1 pt (incidence 1.2%/year). The event probability of receiving a SCD or an ICD-shock was 4.9%.VA burden does not seem to change after MV repair in MVP due to BD. The occurrence of major arrhythmic events can not be predicted reliably, thus, patients with MVP due to BD may need lifelong postoperative follow-up, especially in bileaflet MVP which was an independent risk factor for increased VA burden in this retrospective long-term study in a small but well selected patient group.

Published
2022

14. Paroxysmal and persistent atrial fibrillation ablation outcomes with the pulmonary vein ablation catheter GOLD duty-cycled phased radiofrequency ablation catheter: quality of life and 12-month efficacy results from the GOLD Atrial Fibrillation Registry

Author

Boersma, Lucas, primary, Koźluk, Edward, primary, Maglia, Giampiero, primary, de Sousa, João, primary, Grebe, Olaf, primary, Eckardt, Lars, primary, Hokanson, Robert B, primary, Hemingway, Lauren A, primary, Ostern, Ekaterina, primary, Park, Hyoung-Seob, primary, Rovaris, Giovanni, primary, Arribas, Fernando, primary, Scharf, Christoph, primary, Csanádi, Zoltán, primary, Arenal, Ángel, primary, Laurenzi, Francesco, primary, Klaver, Martijn, primary, and Goette, Andreas, primary

Published
2020
Full Text
View/download PDF

17. Cardiac Interventions in Symptomatic Patients ≥ 90-Years-Old (Nonagenarians): A Single-Center Retrospective Analysis of Spectrum and Outcome

Author

Bertel Osmund, Levis Pierre, Naegeli Barbara, Straumann Edwin, Amann Franz Wolfgang, Seifert Burkhardt, Franzen Olaf, Müller Philippe N, Scharf Christoph, Maurer Dominik, and Jost Christine H Attenhofer

Subjects
Pediatrics, medicine.medical_specialty, business.industry, Cardiac interventions, Retrospective analysis, Medicine, business, Single Center, Outcome (game theory)
Published
2019

29. Effects of AV delay programming on ventricular resynchronisation: role of radionuclide ventriculography

Author

Siegrist, Patrick, Comte, Nathalie, Holzmeister, Johannes, Sütsch, Gabor, Koepfli, Pascal, Namdar, Mehdi, Duru, Firat, Brunckhorst, Corinna, Scharf, Christoph, Kaufmann, Philipp, Siegrist, Patrick, Comte, Nathalie, Holzmeister, Johannes, Sütsch, Gabor, Koepfli, Pascal, Namdar, Mehdi, Duru, Firat, Brunckhorst, Corinna, Scharf, Christoph, and Kaufmann, Philipp

Abstract

Purpose: Optimal atrioventricular delay (AVD) setting for cardiac resynchronisation therapy, i.e. biventricular pacing in patients with heart failure, remains a formidable challenge. Thus, the purpose of this study was to evaluate the effects of different AVD on inter- and intra-ventricular resynchronisation using phase histograms of radionuclide ventriculography (RNV). Methods: In 17 consecutive patients (mean age 64 ± 6years), RNV was performed 236 ± 350days after pacemaker implantation for cardiac resynchronisation therapy. Images were acquired during atrial pacing at 80bpm and during biventricular pacing with AVD ranging from 80 to 160ms. Inter-ventricular dyssynchrony was measured by the delay between the mean phase angles of the left and right ventricles. Intra-ventricular dyssynchrony was measured by the standard deviation (SD) of left ventricular phase histograms. Results: Left ventricular (LV) ejection fraction (EF) was inversely correlated to LV dyssynchrony (SD of LV phase histogram, R = −0.82, p < 0.0001). However, the increase in LVEF by biventricular pacing (mean +4.4 ± 4%) showed only modest correlation to the resulting resynchronisation effect (characterised by a −13 ± 8° decrease in LV phase histogram SD, R = −0.38, p < 0.0001). Conclusion: RNV is helpful in optimising pacing parameters for resynchronisation therapy. Varying AVD did not have a major impact on intra- or inter-ventricular resynchronisation. Thus, the benefit of AVD-based LVEF optimisation seems to result from atrioventricular resynchronisation

Published
2018

31. Das Herz im Alter

Author

Attenhofer Jost, Christine, primary, Müller, Philippe, additional, Bertel, Osmund, additional, Naegeli, Barbara, additional, Scharf, Christoph, additional, Wenaweser, Peter, additional, and Amann, Franz Wolfgang, additional

Published
2018
Full Text
View/download PDF

33. Leadless pacing using the transcatheter pacing system (Micra TPS) in the real world: initial Swiss experience from the Romandie region.

Author

Valiton, Valérian, Graf, Denis, Pruvot, Etienne, Carroz, Patrice, Fromer, Martin, Bisch, Laurence, Tran, Vân Nam, Cook, Stéphane, Scharf, Christoph, and Burri, Haran

Abstract

Aims: Leadless pacemakers are implanted in Switzerland since June 2015. Large worldwide registries have shown high implant success, low complication rates, and good electrical parameters up to 12 months' follow-up. However, data are scarce outside the investigational setting. The purpose of this study is to assess the real-world experience regarding clinical safety and efficacy of Micra TPS (transcatheter pacing system) leadless pacemakers.Methods and Results: Retrospective observational, multi-centre study designed to assess initial safety and efficacy of the Micra TPS in the Swiss Romande region. A total of 92 patients were included from four different centres with an implantation success rate of 97.8% (90 of 92). Thresholds were overall low at implantation (median 0.38 V/0.24 ms, ranging from 0.13 to 2.88 V/0.24 ms) and remained stable over 1-year follow-up. The perioperative serious adverse event rate was 6.5% in six patients which lead to prolonged hospitalization in five patients and death in one patient. In addition, three further major events (3.3%) occurred during an average follow-up of 1 year, requiring implantation of a standard transvenous pacemaker in two patients, and surgical explantation of the Micra TPS in one patient due to intractable ventricular tachycardia.Conclusion: Leadless pacemakers are a valuable adjunct for treating selected patients requiring single-chamber pacing. However, in this initial experience, major complication rates were high (9.8%). The implant procedure requires proper training and should be performed in an adequate setting. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

36. Left Ventricular Cardiomyopathy in Mitral Valve Prolapse: Fact or Fiction?

Author

Attenhofer Jost, Christina, primary, Greutmann, Matthias, additional, Connolly, Heidi M., additional, Naegeli, Barbara, additional, Faeh-Gunz, Anja, additional, Scharf, Christoph, additional, Candinas, Reto, additional, Valsangiacomo Buechel, Emanuela, additional, Weber, Roland, additional, Binggeli, Christian, additional, Franzen, Olaf, additional, and Medeiros-Domingo, Argelia, additional

Published
2015
Full Text
View/download PDF

38. Das Herz im Alter

Author

Jost, Christine Attenhofer, Müller, Philippe, Bertel, Osmund, Naegeli, Barbara, Scharf, Christoph, Wenaweser, Peter, and Amann, Franz Wolfgang

Abstract

Zusammenfassung.Das Wissen um kardiovaskuläre Veränderungen im Alter und deren therapeutische Optionen ist wichtig. Es kann zur Hypertrophie des linken Ventrikels, zur diastolischen Dysfunktion, Herzklappenveränderungen und pulmonaler Hypertonie kommen. Im Alter entwickeln Patienten häufig eine arterielle Hypertonie. Bei über 100-Jährigen sind valvuläre Veränderungen häufig (Aortenstenose und Mitralinsuffizienz). Das Risiko einer koronaren Herzkrankheit beträgt 35 % für Männer und 24 % für Frauen. Im Alter sind Sinusknotendysfunktion und Vorhofflimmern gehäuft. 25 % aller Schlaganfälle sind kardiale Embolien bei Vorhofflimmern. Kardiale Interventionen bei Betagten werden zunehmend häufiger durchgeführt und beinhalten koronare kathetertechnische Revaskularisationen oder Klappeneingriffe (perkutaner Aortenklappenersatz oder MitraClip). Die optimale Therapie im Alter beinhaltet neben kardiovaskulären Interventionen auch Medikamente und eine Lebensstilmodifikation und dient vor allem der Verbesserung der Lebensqualität.

Published
2018
Full Text
View/download PDF

49. Catheter Ablation for Paroxysmal Atrial Fibrillation

Author

Oral, Hakan, primary, Scharf, Christoph, additional, Chugh, Aman, additional, Hall, Burr, additional, Cheung, Peter, additional, Good, Eric, additional, Veerareddy, Srikar, additional, Pelosi, Frank, additional, and Morady, Fred, additional

Published
2003
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results