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32 results on '"Maier, Sebastian K.G."'

10. Intraaortic balloon counterpulsation in acute myocardial infarction complicated by cardiogenic shock: Design and rationale of the Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) trial

Author

Thiele, Holger, Schuler, Gerhard, Neumann, Franz-Josef, Hausleiter, Jörg, Olbrich, Hans-Georg, Schwarz, Bettina, Hennersdorf, Marcus, Empen, Klaus, Fuernau, Georg, Desch, Steffen, de Waha, Suzanne, Eitel, Ingo, Hambrecht, Rainer, Böhm, Michael, Kurowski, Volkhard, Lauer, Bernward, Minden, Hans-Heinrich, Figulla, Hans-Reiner, Braun-Dullaeus, Rüdiger C., Strasser, Ruth H., Rochor, Kristin, Maier, Sebastian K.G., Möllmann, Helge, Schneider, Steffen, Ebelt, Henning, Werdan, Karl, and Zeymer, Uwe

Published
2015
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11. Hemodynamic monitoring by intracardiac impedance measured by cardiac resynchronization defibrillators:Evaluation in a controlled clinical setting (BIO.Detect HF II study)

Author

Delnoy, Peter Paul Henri Marie, Gutleben, Klaus Jürgen, Bruun, Niels Eske, Maier, Sebastian K.G., Oswald, Hanno, Stellbrink, Christoph, Johansen, Jens Brock, Paule, Stefan, Søgaard, Peter, Delnoy, Peter Paul Henri Marie, Gutleben, Klaus Jürgen, Bruun, Niels Eske, Maier, Sebastian K.G., Oswald, Hanno, Stellbrink, Christoph, Johansen, Jens Brock, Paule, Stefan, and Søgaard, Peter

Abstract

Background: In patients with cardiac resynchronization therapy defibrillators (CRT-Ds), intracardiac impedance measured by dedicated CRT-D software may be used to monitor hemodynamic changes. We investigated the relationship of hemodynamic parameters assessed by intracardiac impedance and by echocardiography in a controlled clinical setting. Methods: The study enrolled 68 patients (mean age, 66 ± 9 years; 74% males) at 12 investigational sites. The patients had an indication for CRT-D implantation, New York Heart Association class II/III symptoms, left ventricular ejection fraction 15%–35%, and a QRS duration ≥150 ms. Two months after a CRT-D implantation, hemodynamic changes were provoked by overdrive pacing. Intracardiac impedance was recorded at rest and at four pacing rates ranging from 10 to 40 beats/min above the resting rate. In parallel, echocardiography measurements were performed. We hypothesized that a mean intra-individual correlation coefficient (rmean) between stroke impedance (difference between end-systolic and end-diastolic intracardiac impedance) measured by CRT-D and the aortic velocity time integral (i.e., stroke volume) determined by echocardiography would be significantly larger than 0.65. Results: The hypothesis was evaluated in 40 patients with complete data sets. The rmean was 0.797, with a lower confidence interval bound of 0.709. The study hypothesis was met (p = 0.007). A stepwise reduction of stroke impedance and stroke volume was observed with increasing heart rate. Conclusions: Intracardiac impedance measured by implanted CRT-Ds correlated well with the aortic velocity time integral (stroke volume) determined by echocardiography. The impedance measurements bear potential and are readily available technically, not requiring implantation of additional material beyond standard CRT-D system.

Published
2021

13. [Ca.sup.2+]/calmodulin-dependent protein kinase II regulates cardiac [Na.sup.+] channels

Author

Wagner, Stefan, Dybkova, Nataliya, Rasenack, Eva C.L., Jacobshagen, Claudius, Fabritz, Larissa, Kirchhof, Paulus, Maier, Sebastian K.G., Zhang, Tong, Hasenfuss, Gerd, Brown, Joan Heller, Bers, Donald M., and Maier, Lars S.

Subjects
Sodium channels -- Research, Calmodulin -- Research, Protein kinases -- Research
Abstract

In heart failure (HF), [Ca.sup.2+]/calmodulin kinase II (CaMKII) expression is increased. Altered [Na.sup.+] channel gating is linked to and may promote ventricular tachyarrhythmias (VTs) in HF. Calmodulin regulates [Na.sup.+] channel [...]

Published
2006

14. An unexpected requirement for brain-type sodium channels for control of heart rate in the mouse sinoatrial node

Author

Maier, Sebastian K.G., Westenbroek, Ruth E., Yamanushi, T.T., Dobrzynski, H., Boyett, Mark R., Catterall, William A., and Scheuer, Todd

Subjects
Sodium channels -- Physiological aspects, Cell research -- Analysis, Immunocytochemistry -- Research, Heart ventricles -- Physiological aspects, Electrocardiogram -- Research, Electrocardiography, Cells -- Physiological aspects, Brain -- Physiological aspects, Science and technology
Abstract

Voltage-gated [Na.sup.+] channels are composed of pore-forming [alpha] and auxiliary [beta] subunits. The majority of [Na.sup.+] channels in the heart contain tetrodotoxin (TTX)-insensitive [Na.sub.v]1.5 [alpha] subunits, but TTX-sensitive brain-type [Na.sup.+] channel [alpha] subunits are present and functionally important in the transverse tubules of ventricular myocytes. Sinoatrial (SA) nodal cells were identified in cardiac tissue sections by staining for connexin 43 (which is expressed in atrial tissue but not in SA node), and [Na.sup.+] channel localization was analyzed by immunocytochemical staining with subtype-specific antibodies and confocal microscopy. Brain-type TTX-sensitive [Na.sub.v]1.1 and [Na.sub.v]1.3 [alpha] subunits and all four [beta] subunits were present in mouse SA node, but [Na.sub.v]1.5 [alpha] subunits were not. [Na.sub.v]1.1 [alpha] subunits were also present in rat SA node. Isolated mouse hearts were retrogradely perfused in a Langendorff preparation, and electrocardiograms were recorded. Spontaneous heart rate and cycle length were constant, and heart rate variability was small under control conditions. In contrast, in the presence of 100 nM TTX to block TTX-sensitive [Na.sup.+] channels specifically, we observed a significant reduction in spontaneous heart rate and markedly greater heart rate variability, similar to sick-sinus syndrome in man. We hypothesize that brain-type [Na.sup.+] channels are required because their more positive voltage dependence of inactivation allows them to function at the depolarized membrane potential of SA nodal cells. Our results demonstrate an important contribution of TTX-sensitive brain-type [Na.sup.+] channels to SA nodal automaticity mouse heart and suggest that they may also contribute to SA nodal in function and dysfunction in human heart.

Published
2003

15. An unexpected role for brain-type sodium channels in coupling of cell surface depolarization to contraction in the heart

Author

Maier, Sebastian K.G., Westenbroek, Ruth E., Schenkman, Kenneth A., Feigl, Eric O., Scheuer, Todd, and Catterall, William A.

Subjects
Sodium channels -- Physiological aspects, Brain -- Physiological aspects, Heart -- Physiological aspects, Immunocytochemistry -- Research, Muscle contraction -- Physiological aspects, Electrophysiology -- Research, Cell membranes -- Research, Science and technology
Abstract

Voltage-gated sodium channels composed of pore-forming a and auxiliary [beta] subunits are responsible for the rising phase of the action potential in cardiac muscle, but the functional roles of distinct sodium channel subtypes have not been clearly defined. Immunocytochemical studies show that the principal cardiac poreforming a subunit isoform [Na.sub.v]1.5 is preferentially localized in intercalated disks, whereas the brain e subunit isoforms [Na.sub.v]1.1, [Na.sub.v]1.3, and [Na.sub.v]1.6 are localized in the transverse tubules. Sodium currents due to the highly tetrodotoxin (TTX)-sensitive brain isoforms in the transverse tubules are small and are detectable only after activation with [beta] scorpion toxin. Nevertheless, they play an important role in coupling depolarization of the cell surface membrane to contraction, because low TTX concentrations reduce left ventricular function. Our results suggest that the principal cardiac isoform in the intercalated disks is primarily responsible for action potential conduction between cells and reveal an unexpected role for brain sodium channel isoforms in the transverse tubules in coupling electrical excitation to contraction in cardiac muscle.

Published
2002

16. Intraaortic balloon counterpulsation in acute myocardial infarction complicated by cardiogenic shock: Design and rationale of the Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) trial

Author

Thiele, Holger, Schuler, Gerhard, Neumann, Franz-Josef, Hausleiter, Jörg, Olbrich, Hans-Georg, Schwarz, Bettina, Hennersdorf, Marcus, Empen, Klaus, Fuernau, Georg, Desch, Steffen, de Waha, Suzanne, Eitel, Ingo, Hambrecht, Rainer, Böhm, Michael, Kurowski, Volkhard, Lauer, Bernward, Minden, Hans-Heinrich, Figulla, Hans-Reiner, Braun-Dullaeus, Rüdiger C., Strasser, Ruth H., Rochor, Kristin, Maier, Sebastian K.G., Möllmann, Helge, Schneider, Steffen, Ebelt, Henning, Werdan, Karl, and Zeymer, Uwe

Published
2012
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18. Autonomic modulation and antiarrhythmic therapy in a model of long QT syndrome type 3

Author

Fabritz, Larissa, Damke, Dierk, Emmerich, Markus, Kaufmann, Susann G., Theis, Kathrin, Blana, Andreas, Fortmüller, Lisa, Laakmann, Sandra, Hermann, Sven, Aleynichenko, Elena, Steinfurt, Johannes, Volkery, Daniela, Riemann, Burkhard, Kirchhefer, Uwe, Franz, Michael R., Breithardt, Günter, Carmeliet, Edward, Schäfers, Michael, Maier, Sebastian K.G., Carmeliet, Peter, and Kirchhof, Paulus

Published
2010
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23. Knock-Out of the Potassium Channel TASK-1 Leads to a Prolonged QT Interval and a Disturbed QRS Complex

Author

Decher, Niels, primary, Wemhöner, Konstantin, additional, Rinné, Susanne, additional, Netter, Michael F., additional, Zuzarte, Marylou, additional, Aller, Maria I., additional, Kaufmann, Susann G., additional, Li, Xian Tao, additional, Meuth, Sven G., additional, Daut, Jürgen, additional, Sachse, Frank B., additional, and Maier, Sebastian K.G., additional

Published
2011
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24. Calcium/Calmodulin-Dependent Protein Kinase II Contributes to Cardiac Arrhythmogenesis in Heart Failure

Author

Sag, Can M., primary, Wadsack, Daniel P., additional, Khabbazzadeh, Sepideh, additional, Abesser, Marco, additional, Grefe, Clemens, additional, Neumann, Kay, additional, Opiela, Marie-Kristin, additional, Backs, Johannes, additional, Olson, Eric N., additional, Brown, Joan Heller, additional, Neef, Stefan, additional, Maier, Sebastian K.G., additional, and Maier, Lars S., additional

Published
2009
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25. Conditional Neuronal Nitric Oxide Synthase Overexpression Impairs Myocardial Contractility

Author

Burkard, Natalie, primary, Rokita, Adam G., additional, Kaufmann, Susann G., additional, Hallhuber, Matthias, additional, Wu, Rongxue, additional, Hu, Kai, additional, Hofmann, Ulrich, additional, Bonz, Andreas, additional, Frantz, Stefan, additional, Cartwright, Elizabeth J., additional, Neyses, Ludwig, additional, Maier, Lars S., additional, Maier, Sebastian K.G., additional, Renné, Thomas, additional, Schuh, Kai, additional, and Ritter, Oliver, additional

Published
2007
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26. Aging Reduces the Efficacy of Estrogen Substitution to Attenuate Cardiac Hypertrophy in Female Spontaneously Hypertensive Rats

Author

Jazbutyte, Virginija, primary, Hu, Kai, additional, Kruchten, Patricia, additional, Bey, Emmanuel, additional, Maier, Sebastian K.G., additional, Fritzemeier, Karl-Heinrich, additional, Prelle, Katja, additional, Hegele-Hartung, Christa, additional, Hartmann, Rolf W., additional, Neyses, Ludwig, additional, Ertl, Georg, additional, and Pelzer, Theo, additional

Published
2006
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32. Reduction in Treatment Times Through Formalized Data Feedback Results From a Prospective Multicenter Study of ST-Segment Elevation Myocardial Infarction

Author

Scholz, Karl Heinrich, Maier, Sebastian K.G., Jung, Jens, Fleischmann, Claus, Werner, Gerald S., Olbrich, Hans G., Ahlersmann, Dorothe, Keating, Friederike K., Jacobshagen, Claudius, Moehlis, Hiller, Hilgers, Reinhard, and Maier, Lars S.

Subjects
myocardial infarction, ST-segment elevation myocardial infarction systems, feedback, mortality, reperfusion times
Abstract

ObjectivesThis study sought to evaluate the effect of systematic data analysis and standardized feedback on treatment times and outcome in a prospective multicenter trial.BackgroundFormalized data feedback may reduce treatment times in ST-segment elevation myocardial infarction (STEMI).MethodsOver a 15-month period, 1,183 patients presenting with STEMI were enrolled. Six primary percutaneous coronary intervention hospitals in Germany and 29 associated nonpercutaneous coronary intervention hospitals participated. Data from patient contact to balloon inflation were collected and analyzed. Pre-defined quality indicators, including the percentage of patients with pre-announced STEMI, direct handoff in the catheterization laboratory, contact-to-balloon time

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