W Schoels

Universität Heidelberg, Heidelburg, Baden-Württemberg, Germany

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Publications (57)236.11 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: Die invasive elektrophysiologische Untersuchung hat bei der Abklärung von Synkopen unklarer Genese einen hohen Stellenwert. Im höheren Lebensalter steht dem Wunsch nach einer richtungsweisenden Diagnostik eine gewisse Zurückhaltung gegenüber invasiven, potentiell komplikationsreichen Untersuchungen entgegen. Durch einen altersspezifischen Vergleich von diagnostischem Zugewinn, Komplikationsraten und elektrophysiologischen Parametern sollte in der vorliegenden Arbeit geklärt werden, ob die invasive elektrophysiologische Untersuchung auch bei älteren Patienten empfohlen werden kann und ob altersabhängige Schwankungen von Leitungs- und Refraktärmessungen berücksichtigt werden müssen. Invasive elektrophysiologische Untersuchungen wurden bei 96 Patienten im Alter zwischen 70 und 80 Jahren sowie bei 21 über Achtzigjährigen durchgeführt. Als Vergleichsgruppe dienten 65 Patienten mit einem Lebensalter unter 40 Jahren. Mit zunehmendem Lebensalter stieg die Wahrscheinlichkeit eines richtungsweisenden Befundes in der elektrophysiologischen Untersuchung von etwa 20% bei jüngeren auf 54% bei den ältesten untersuchten Patienten. Komplikationen waren mehrheitlich von untergeordneter klinischer Bedeutung, die Komplikationsraten unterschieden sich nicht signifikant zwischen den Altersgruppen. Auch zeigten die erhobenen Refraktär- und Leitungsparameter keine eindeutige Altersabhängigkeit. Gerade beim älteren Menschen erweist sich das Verhältnis zwischen diagnostischem Zugewinn und Komplikationsrate der invasiven elektrophysiologischen Untersuchung zur Synkopenabklärung als besonders günstig. Geltende Normalwerte für Refraktär- und Leitungsparameter scheinen altersunabhängig Gültigkeit zu besitzen. Invasive electrophysiologic study (EPS) is an important tool in the assessment of patients with unexplained syncope. Especially in the elderly, the need for a complete diagnostic work-up is counterbalanced by the fear of complications associated with invasive procedures. Thus, the present study specifically addressed the question whether the risk/benefit ratio of EPS in geriatric patients with unexplained syncope justifies this invasive procedure. An invasive EPS was performed in 96 patients between 70 and 80 years and 21 patients older than 80 years. The control group consisted of 65 patients younger than 40 years. With increasing age, the diagnostic yield of EPS also increased (positive EPS finding in 20% of the control group and in 54% of the oldest patients). The majority of complications were of minor clinical significance and no significant differences were found between the three groups. Finally, no age-related difference in measured standard electrophysiological parameters was evident. Due to the high diagnostic value and the low complication rate, EPS can be recommended in elderly patients with unexplained syncope. An age-specific standardization of electrophysiologic parameters, measured during EPS, does not seem to be required. Schlüsselwörter Synkope – geriatrische Patienten – ElektrophysiologieKey words Syncope – elderly – electrophysiology
    Zeitschrift für Kardiologie 04/2012; 89(11):1026-1031. · 0.97 Impact Factor
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    Heart (British Cardiac Society) 10/2006; 92(9):1323-4. · 5.01 Impact Factor
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    ABSTRACT: Functional re-entry is thought to represent the predominant mechanism underlying ventricular arrhythmias. Functional conduction block may be caused by regional dispersion of refractoriness (ERP). Dispersion of ERP may not be evident at baseline, but may occur with sudden changes in heart rate, as ventricular arrhythmias are commonly induced by short-long-short cycles. We examined the dynamics of local ERPs at two left ventricular (LV) sites in dogs with either no structural heart disease or biventricular hypertrophy (BVH). ERPs were determined at each of four bipoles of two adjacent needle electrodes in the LV apex and the lateral wall. The stimulation protocol included two different basic cycle lengths, one or two longer cycles after a train of 6 or 5 shorter cycles, and one shorter cycle after a train of 6 longer cycles. In normal dogs, a significant apicolateral ERP gradient was only evident with the longer basic cycle length. One shorter cycle was sufficient to dissolve that gradient. One longer cycle was enough to create a regional ERP gradient. Dynamic regional gradients occurred because the apex responded more markedly and more readily to abrupt changes in cycle length. BVH led to an increase in ERP at both LV sites and to an aggravation of regional ERP gradients. Dynamic ERP behavior seems to depend on topography and underlying pathology. Abrupt changes in heart rate might induce dynamic refractory gradients between various regions of the normal heart, but also between adjacent regions inhomogenously affected by hypertrophy.
    Archiv für Kreislaufforschung 10/2005; 100(5):433-8. · 5.90 Impact Factor
  • Journal of Heart and Lung Transplantation - J HEART LUNG TRANSPLANT. 01/2005; 24(2).
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    ABSTRACT: Romano-Ward syndrome (RWS), the autosomal dominant form of the congenital long QT syndrome, is characterised by prolongation of the cardiac repolarisation process associated with ventricular tachyarrhythmias of the torsades de pointes type. Genetic studies have identified mutations in six ion channel genes, KCNQ1, KCNH2, SCN5A, KCNE1 and KCNE2 and the accessory protein Ankyrin-B gene, to be responsible for this disorder. Single-strand conformation polymorphism (SSCP) analysis and subsequent DNA sequence analysis have identified a KCNQ1 mutation in a family that were clinically conspicuous due to several syncopes and prolonged QTc intervals in the ECG. The mutant subunit was expressed and functionally characterised in the Xenopus oocyte expression system. A novel heterozygous missense mutation with a C to T transition at the first position of codon 343 (CCA) of the KCNQ1 gene was identified in three concerned family members (QTc intervals: 500, 510 and 530 ms, respectively). As a result, proline 343 localised within the highly conserved transmembrane segment S6 of the KCNQ1 channel is replaced by a serine. Co-expression of mutant (KCNQ1-P343S) and wild-type (KCNQ1) cRNA in Xenopus oocytes produced potassium currents reduced by approximately 92%, while IKs reconstitution experiments with a combination of KCNQ1 mutant, wild-type and KCNE1 subunits yielded currents reduced by approximately 60%. A novel mutation (P343S) identified in the KCNQ1 subunit gene of three members of a RWS family showed a dominant-negative effect on native IKs currents leading to prolongation of the heart repolarisation and possibly increases the risk of malign arrhythmias with sudden cardiac death.
    Biochimica et Biophysica Acta 11/2004; 1690(3):185-92. · 4.66 Impact Factor
  • H A Katus, J Kreuzer, W Schoels
    DMW - Deutsche Medizinische Wochenschrift 11/2003; 128(41):2117. · 0.65 Impact Factor
  • Europace 01/2003; 4. · 2.77 Impact Factor
  • DMW - Deutsche Medizinische Wochenschrift 01/2003; 127(50):2679-81. · 0.65 Impact Factor
  • DMW - Deutsche Medizinische Wochenschrift 12/2001; 126(44):1245-8. · 0.65 Impact Factor
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    ABSTRACT: Initial experience with the Medtronic Jewel 7250, the ICD designed to detect and treat ventricular and supraventricular tachyarrhythmias, is very promising. Its effectiveness, however, depends on sensing performance, which has not yet been systematically examined. The aim of the study was to determine the incidence of, predisposing factors for, and practical implications of far-field R wave oversensing (FFRWOS) in this dual chamber ICD. During a total follow-up of 797 months in 48 patients who had the Jewel 7250, follow-up strip charts, 12-channel Holter recordings and, in particular cases, Holter recordings with intracardiac markers were analyzed for the presence of FFRWOS. FFRWOS was documented in ten (21.3%) patients. Compared to other lead locations, the right atrial appendage lead position was most frequently associated with FFRWOS (7/27 vs 3/21, P < 0.05). Patients with FFRWOS had significantly more treated and nontreated atrial episodes, many of which were judged to have been detected inappropriately. In one case, inappropriate atrial antitachycardia pacing due to R wave oversensing triggered sustained ventricular tachycardia, terminated eventually with a high energy shock. In dual chamber ICDs, FFRWOS may represent a frequent phenomenon possibly leading to serious consequences. For atrial leads, a lateral atrial wall position seems to be preferable. In most cases, FFRWOS can be eliminated by optimization of atrial sensing parameters. Given the possibility of ventricular proarrhythmia with atrial pacing therapy, the capability of ventricular backup defibrillation in respective devices is at least reassuring.
    Pacing and Clinical Electrophysiology 09/2001; 24(8 Pt 1):1240-6. · 1.75 Impact Factor
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    ABSTRACT: Regular atrial tachycardias classically are classified into flutter or tachycardia, depending on the rate and presence of a stable baseline on the ECG. However, current understanding of electrophysiology atrial tachycardias makes this classification obsolete, because it does not correlate with mechanisms. The proposed classification is based on electrophysiologic mechanisms, defined by mapping and entrainment. Radiofrequency ablation of a critical focus or isthmus can afford proof. Focal tachycardias are characterized by radial spread of activation and endocardial activation not covering the whole cycle. Ablation of the focus of origin interrupts the tachycardia. The mechanism of focal firing is difficult to ascertain by clinical methods. Macroreentrant tachycardias are characterized by circular patterns of activation that cover the whole cycle. Fusion can be shown during entrainment on the ECG or by multiple endocardial recordings. Ablation of a critical isthmus interrupts the tachycardia. Macroreentry can occur around normal structures (terminal crest, eustachian ridge) or around atrial lesions. The anatomic bases of these tachycardias must be defined, to guide appropriate treatment. Atrial flutter is a mere description of continuous undulation on the ECG, and only some strictly defined typical flutter patterns correlate with right atrial macroreentry bounded by the tricuspid valve, terminal crest, and caval vein orifices. This classification should be considered open, as some classically described tachycardias, such as reentrant sinus tachycardia, inappropriate sinus tachycardia, and type II atrial flutter, cannot be classified accurately. Furthermore, the possibility of fibrillatory conduction makes the limits with atrial fibrillation still ill defined.
    Journal of Cardiovascular Electrophysiology 08/2001; 12(7):852-66. · 3.48 Impact Factor
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    ABSTRACT: New Classification of Atrial Tachycardia. Regular atrial tachycardias classically are classified into flutter or tachycardia, depending on the rate and presence of a stable baseline on the ECG. However, current understanding of electrophysiology atrial tachycardias makes this classification obsolete, because it does not correlate with mechanisms. The proposed classification is based on electrophysiologic mechanisms, defined by mapping and entrainment. Radiofrequency ablation of a critical focus or isthmus can afford proof. Focal tachycardias are characterized by radial spread of activation and endocardial activation not covering the whole cycle. Ablation of the focus of origin interrupts the tachycardia. The mechanism of focal firing is difficult to ascertain by clinical methods. Macroreentrant tachycardias are characterized by circular patterns of activation that cover the whole cycle. Fusion can be shown during entrainment on the ECG or by multiple endocardial recordings. Ablation of a critical isthmus interrupts the tachycardia. Macroreentry can occur around normal structures (terminal crest, eustachian ridge) or around atrial lesions. The anatomic bases of these tachycardias must be defined, to guide appropriate treatment. Atrial flutter is a mere description of continuous undulation on the ECG, and only some strictly defined typical flutter patterns correlate with right atrial macroreentry bounded by the tricuspid valve, terminal crest, and caval vein orifices. This classification should be considered open, as some classically described tachycardias, such as reentrant sinus tachycardia, inappropriate sinus tachycardia, and type II atrial flutter, cannot be classified accurately. Furthermore, the possibility of fibrillatory conduction makes the limits with atrial fibrillation still ill defined.
    Journal of Cardiovascular Electrophysiology 06/2001; 12(7):852 - 866. · 3.48 Impact Factor
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    ABSTRACT: Management of atrial tachyarrhythmias represents a significant challenge in patients with implantable cardioverter defibrillators (ICDs). Drug therapy of these arrhythmias is limited by moderate efficacy, ventricular proarrhythmia, and drug-device interactions. This study tested the safety and efficacy of a new dual-chamber ICD to detect and treat atrial as well as ventricular tachyarrhythmias. A dual-chamber ICD (Medtronic 7250 Jewel AF) was implanted in 293 of 303 patients at 49 centers in Europe, Canada, and North America. Specific data were collected at implant and during a mean follow-up period of 7.9+/-4.7 months. There were no clinically evident failures to detect and treat ventricular arrhythmias. In patients with at least one of the dual-chamber detection criteria activated, 1,056 of 1,192 episodes of ventricular tachycardia or fibrillation detected were judged to be appropriate (89% positive predictive accuracy). Therapy efficacy was 100% in the ventricular fibrillation zone and 98% in the ventricular tachycardia zone. Positive predictive accuracy for detection of atrial episodes was 95% (1,052/1,107). For episodes classified as atrial tachycardia by the device, the efficacy of atrial antitachycardia pacing and high-frequency (50-Hz) burst pacing was 55% and 17%, respectively. High-frequency burst pacing terminated 16.8% of episodes classified as atrial fibrillation, and atrial defibrillation had an estimated efficacy of 76%. The actuarial estimates of 6-month complication-free survival and total survival were 88% and 94%, respectively. This novel dual-chamber ICD is capable of safely and effectively discriminating atrial from ventricular tachyarrhythmias and of treating atrial tachyarrhythmias without compromising detection and treatment of ventricular tachyarrhythmias.
    Journal of Cardiovascular Electrophysiology 06/2001; 12(5):521-8. · 3.48 Impact Factor
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    ABSTRACT: The intriguing monotony in the occurrence of intercaval conduction block during typical atrial flutter suggests an anatomic or electrophysiological predisposition for conduction abnormalities. To determine the location of and potential electrophysiological basis for conduction block in the terminal crest region, a high-density patch electrode (10x10 bipoles) was placed on the terminal crest and on the adjacent pectinate muscle region in 10 healthy foxhounds. With a multiplexer mapping system, local activation patterns were reconstructed during constant pacing (S(1)S(1)=200 ms) and introduction of up to 2 extrastimuli (S(2), S(3)). Furthermore, effective refractory periods were determined across the patch. If evident through online analysis, the epicardial location of conduction block was marked for postmortem verification of its endocardial projection. Marked directional differences in activation were found in the terminal crest region, with fast conduction parallel to and slow conduction perpendicular to the intercaval axis (1.1+/-0.4 versus 0.5+/-0.2 m/s, P<0.01). In the pectinate muscle region, however, conduction velocities were similar in both directions (0.5+/-0.3 versus 0.6+/-0.2 m/s, P=NS). Refractory patterns were relatively homogeneous in both regions, with local refractory gradients not >30 ms. During S(3) stimulation, conduction block parallel to the terminal crest was inducible in 40% of the dogs compared with 0% in the pectinate muscle region. Even in normal hearts, inducible intercaval block is a relatively common finding. Anisotropic conduction properties would not explain conduction block parallel to the intercaval axis in the terminal crest region, and obviously, refractory gradients do not seem to play a role either. Thus, the change in fiber direction associated with the terminal crest/pectinate muscle junction might form the anatomic/electrophysiological basis for intercaval conduction block.
    Circulation 05/2001; 103(20):2521-6. · 15.20 Impact Factor
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    ABSTRACT: Identification of high risk patients with coronary artery disease (CAD) prone to sudden cardiac death still remains a difficult issue. In 211 patients with CAD diagnosed by coronary angiography and documented non-sustained ventricular tachycardia (NSVT), programmed ventricular stimulation (PVS) was performed. NSVTs documented during Holter monitoring were analysed concerning frequency, duration and rate. To relate those parameters to the inducibility of sustained monomorphic ventricular tachycardias (MVT) during PVS, the total population was divided in different groups; patients with 1, 2-5 or > 5 salvos within 24 h; patients having salvos with a rate of > or = 150/min or < 150/min; patients with 3-5, 6-10 or > 10 consecutive extra beats. It could be demonstrated that in patients with CAD and NSVTs, induction of MVTs during PVS is more likely if the rate of the spontaneously occurring NSVT is > or = 150/min (22.1 vs 8.9%; p = 0.042). In contrast, there is apparently no correlation between the duration and incidence of NSVTs and the prevalence of MVTs during PVS. Multivariate analysis revealed the rate of documented NSVTs (odds ratio 2.98, p = 0.0314) and a decrease of left ventricular ejection fraction (odds ratio 1.69; p = 0.0013) as independent risk factors for the inducibility of MVTs. Conclusions CAD patients with fast salvos (> or = 150 beats/min) and reduced left ventricular ejection fraction are more likely to reveal inducible MVT during PVS and should, therefore, preferably be subjected to invasive risk stratification. The number of salvos per day and the number of consecutive beats, on the other hand, do not seem to be of relevant predictive value.
    Zeitschrift für Kardiologie 03/2001; 90(3):177-83. · 0.97 Impact Factor
  • J Lü, Z Lu, F Voss, W Schöls
    Journal of Tongji Medical University = Tong ji yi ke da xue xue bao 02/2001; 21(2):89-92.
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    ABSTRACT: Die Risikostratifizierung von Patienten mit koronarer Herzerkrankung (KHK) und nicht anhaltenden ventrikulären Tachykardien (NSVTs) stellt weiterhin ein klinisches Problem dar.    Die Induzierbarkeit monomorpher ventrikulärer Tachykardien (MVT) während programmierter ventrikulärer Stimulation (PVS) wurde bei 211 Patienten mit angiographisch gesicherter KHK und NSVTs untersucht, wobei eine Unterteilung in verschiedene Gruppen erfolgte: Patienten mit einer, 2–5 oder >5 Salven innerhalb von 24 h; Patienten mit einer Frequenz der Salven ≥150/min oder <150/min, Patienten mit 3–5, 6–10 oder >10 konsekutiven Extrasystolen.    Es fand sich eine signifikant höhere Induktionsrate von MVTs bei Patienten mit schnellen (≥150/min) NSVTs als bei Patienten mit langsamen NSVTs (<150/min) (22,1 vs 8,9%; p=0,042). Im Gegensatz dazu ergab sich keine Korrelation zwischen der Häufigkeit der NSVTs bzw. der Anzahl konsekutiver Schläge und der Induzierbarkeit von MVTs. In der multivariaten Analyse konnten die Frequenz der Salven (odds ratio 2,98, p=0,0314) und eine eingeschränkte linksventrikuläre Pumpfunktion (odds ratio 1,69; p=0,0013) als unabhängige Prädiktoren für die Induzierbarkeit von MVTs identifiziert werden. Zusammenfassung Aufgrund der deutlich höheren Rate an induzierbaren MVTs bei Patienten mit schnellen Salven scheint für dieses Kollektiv die Durchführung einer PVS gerechtfertigt. Im Gegensatz dazu ist die Häufigkeit und die Dauer einer NSVT ohne relevanten prädiktiven Wert für das Ergebnis der PVS. Identification of high risk patients with coronary artery disease (CAD) prone to sudden cardiac death still remains a difficult issue.    In 211 patients with CAD diagnosed by coronary angiography and documented non-sustained ventricular tachycardia (NSVT), programmed ventricular stimulation (PVS) was performed. NSVTs documented during Holter monitoring were analysed concerning frequency, duration and rate. To relate those parameters to the inducibility of sustained monomorphic ventricular tachycardias (MVT) during PVS, the total population was divided in different groups; patients with 1, 2–5 or >5 salvos within 24 h; patients having salvos with a rate of ≥150/min or <150/min; patients with 3–5, 6–10 or >10 consecutive extra beats. It could be demonstrated that in patients with CAD and NSVTs, induction of MVTs during PVS is more likely if the rate of the spontaneously occurring NSVT is ≥150/min (22.1 vs 8.9%; p=0.042). In contrast, there is apparently no correlation between the duration and incidence of NSVTs and the prevalence of MVTs during PVS. Multivariate analysis revealed the rate of documented NSVTs (odds ratio 2.98, p=0.0314) and a decrease of left ventricular ejection fraction (odds ratio 1.69; p=0.0013) as independent risk factors for the inducibility of MVTs. Conclusions CAD patients with fast salvos (≥150 beats/min) and reduced left ventricular ejection fraction are more likely to reveal inducible MVT during PVS and should, therefore, preferably be subjected to invasive risk stratification. The number of salvos per day and the number of consecutive beats, on the other hand, do not seem to be of relevant predictive value. Schlüsselwörter Ventrikuläre Salven–programmierte–Stimulation–Langzeit-EKG–KammertachykardienKey words Ventricular–salvos–programmed stimulation–holter ECG–ventricular–tachycardia
    Zeitschrift für Kardiologie 01/2001; 90(3):177-183. · 0.97 Impact Factor
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    ABSTRACT: Because the role of sodium channels in the initiation and maintenance of VF is not fully elucidated, we studied the significance of sodium channel activity in VF using sodium channel blockers. In nonischemic isolated feline hearts, the following electrophysiologic parameters were measured before and after application of tetrodotoxin (5 x 10(-7) M, n = 6) or lidocaine (1 x 10(-5) M, n = 8): (a) during pacing, epicardial conduction time; refractoriness; the fastest rate for 1:1 pacing/response capture, and all tissue resistivity, indirectly reflecting intercellular electrical resistance; (b) during 8 min of electrically induced tachyarrhythmias, all tissue resistivity; peak frequency (to measure average frequency based on fast-Fourier transformation analysis); and normalized entropy (to measure the degree of arrhythmia organization). In nonischemic isolated rabbit hearts (n = 4), three-dimensional mapping was performed before and after application of lidocaine (1 x 10(-5) M). In feline hearts, lidocaine and tetrodotoxin application resulted in: (a) more spontaneous arrhythmia termination (63-67%) than in nontreated hearts (7%); (b) transformation from mainly VF into ventricular tachycardia with increased organization; and (c) prolongation of conduction time (155-248%) (p < 0.01 for all parameters). The ventricular refractory period was slightly prolonged by tetrodotoxin in the right ventricle and exhibited rate-dependent shortening in control and with lidocaine. Tetrodotoxin and lidocaine reduced the pacing rate for 1:1 pacing/response capture, and all tissue resistivity was not significantly affected. Peak frequency was decreased by tetrodotoxin and lidocaine mainly in the left ventricle (p < 0.01). In nontreated left ventricles, peak frequency was increased over time but was attenuated by lidocaine. In isolated rabbit hearts, several simultaneous wave fronts were detected during VF in nontreated hearts and were reduced to only one or two major wavefronts after application of lidocaine. Suppression of sodium channel activity that primarily slowed conduction time and had little or no effect on ventricular refractory period and all tissue resistivity resulted in less stable and more organized arrhythmias and reduced tachyarrhythmia rate compared with nontreated hearts. These results suggest an active role for sodium channels in the maintenance of ventricular fibrillation.
    Journal of Cardiovascular Pharmacology 01/2001; 36(6):785-93. · 2.38 Impact Factor
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    ABSTRACT: Invasive electrophysiologic study (EPS) is an important tool in the assessment of patients with unexplained syncope. Especially in the elderly, the need for a complete diagnostic work-up is counterbalanced by the fear of complications associated with invasive procedures. Thus, the present study specifically addressed the question whether the risk/benefit ratio of EPS in geriatric patients with unexplained syncope justifies this invasive procedure. An invasive EPS was performed in 96 patients between 70 and 80 years and 21 patients older than 80 years. The control group consisted of 65 patients younger than 40 years. With increasing age, the diagnostic yield of EPS also increased (positive EPS finding in 20% of the control group and in 54% of the oldest patients). The majority of complications were of minor clinical significance and no significant differences were found between the three groups. Finally, no age-related difference in measured standard electrophysiological parameters was evident. Due to the high diagnostic value and the low complication rate, EPS can be recommended in elderly patients with unexplained syncope. An age-specific standardization of electrophysiologic parameters, measured during EPS, does not seem to be required.
    Zeitschrift für Kardiologie 12/2000; 89(11):1026-31. · 0.97 Impact Factor
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    ABSTRACT: The slow component of the delayed rectifier potassium current (IKs) plays an important role during repolarization in the human heart. Life-threatening arrhythmias can be triggered by sympathetic stimulation, presumably acting on IKs. The ion channel responsible for the IKs current is made of two proteins, the KvLQT1 protein and the MinK protein. In this study, we investigated the effects of adrenergic stimulation on the KvLQT1/MinK channel by coexpressing KvLQT1/MinK channels with the human beta(3)-adrenoreceptor subunit heterologously in Xenopus oocytes. Western blot experiments revealed that beta(3)-adrenoreceptor proteins appear in the cell membrane of Xenopus oocytes, when the corresponding cRNA was injected. In electrophysiological measurements we found that stimulation with the beta-adrenergic agonist isoproterenol increased the current amplitude of the beta(3)/KvLQT1/MinK complex up to 237% with an ED(50) of 8 nm, a value similar to that found on IKs in guinea pig cardiomyocytes. When oocytes with beta(3)/KvLQT1/MinK were preincubated with cholera toxin (2 microg/ml), an activator of G(S) proteins, the basal current amplitude of the beta(3)/KvLQT1/MinK complex was increased 3.1-fold, and the current amplitude increase by isoproterenol was drastically reduced, indicating that the signal transduction cascade was mediated via G(s) proteins. The knowledge about functional coupling of the human beta(3)-adrenoreceptor to KvLQT1/MinK channels reveals interesting aspects about the genesis and therapy of arrhythmias.
    Journal of Biological Chemistry 10/2000; 275(35):26743-7. · 4.65 Impact Factor

Publication Stats

673 Citations
25 Downloads
236.11 Total Impact Points

Institutions

  • 1989–2004
    • Universität Heidelberg
      • • Department of Cardiology
      • • Department of Medicine III: Cardiology, Angiology and Pneumology
      • • II. Medical Clinic
      Heidelburg, Baden-Württemberg, Germany
  • 2001
    • Princess Grace Hospital Centre
      Monaco-Ville, Monaco
  • 1999
    • Friedrich Ebert Stiftung
      Berlín, Berlin, Germany
  • 1996
    • MediClin Herzzentrum Lahr/Baden
      Lahr/Schwarzwald, Baden-Württemberg, Germany
  • 1991
    • ATOS Klinik Heidelberg
      Heidelburg, Baden-Württemberg, Germany
  • 1990–1991
    • State University of New York
      New York City, New York, United States