Results 51 to 60 of about 972,180 (179)

Mitochondrial dysfunction on sinoatrial node and pulmonary vein electrophysiological activities

Experimental and Therapeutic Medicine, 2017
Atrial fibrillation (AF) is associated with mitochondrial dysfunction. Sinoatrial node (SAN) dysfunction increases arrhythmogenesis of pulmonary veins (PVs), which is the most important trigger of AF; however, it is not clear whether mitochondrial dysfunction differentially regulates electrical activity of SANs and PVs.
Yung-Kuo, Lin, Chen-Chuan, Cheng, Min-Chien, Tsai, Pei-Yu, Wu, Yi-Ann, Chen, Yao-Chang, Chen, Shih-Ann, Chen, Yi-Jen, Chen   +7 more
openaire   +3 more sources

Heart Rate Reserve in Fontan Patients: Chronotropic Incompetence or Hemodynamic Limitation?

Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease, 2019
Background Patients with a Fontan circulation achieve lower peak heart rates (HR) during exercise. Whether this impaired chronotropic response reflects pathology of the sinoatrial node or is a consequence of altered cardiac hemodynamics is uncertain.
Guido Claessen, Andre La Gerche, Alexander Van De Bruaene, Mathias Claeys, Rik Willems, Steven Dymarkowski, Jan Bogaert, Piet Claus, Werner Budts, Hein Heidbuchel, Marc Gewillig   +10 more
doaj   +1 more source

Werner Irnich: Pioneer in the Development of the Dual‐Chamber Pacemaker—An Obituary

Pacing and Clinical Electrophysiology, EarlyView.
ABSTRACT Fifty years ago, Werner Irnich presented the concept of an optimal pacemaker capable of responding appropriately to various cardiac arrhythmias and perceptual disturbances, and intended to be used in 85% of patients. With this concept, Irnich was far ahead of his time. His proposed circuitry for AV block and atrial fibrillation, as well as his
Bernd Lemke
wiley   +1 more source

TMEM16A Ca2+‐activated Cl− channel: Functional interactions with cytoskeletal and membrane‐associated proteins

The Journal of Physiology, EarlyView.
Abstract figure legend The calcium‐activated chloride (ClCa) channel TMEM16A (also known as ANO1) plays critical roles in ion transport, neurotransmission and smooth muscle contraction. Dysregulation of TMEM16A channel activity contributes to the development and progression of various diseases.
Hisao Yamamura, Rubii Kondo, Yoshiaki Suzuki, Yuji Imaizumi, Aya Yamamura   +4 more
wiley   +1 more source

Analisis Numerik Model Sinoatrial Node menggunakan Metode Euler [PDF]

, 2020
The synoatrial node is an important part of the human heart, which functions as a regulator and generator of the frequency of the electrical signals that produce the heart rate.
Maulidiyah, Jauharoh
core  

Mechanisms underlying local Ca2+ signalling differences between right and left atrial myocytes at normal and increased frequencies

The Journal of Physiology, EarlyView.
Abstract figure legend Left atrial myocytes have TAT‐associated faster Ca2+ release but are more prone to maladaptation at higher frequencies due to weaker peripheral SR Ca2+ uptake and smaller trigger Ca2+ current. Abstract Changes in heart rate affect Ca2+ signalling and contractility in ventricular muscle, but the effects on atrial Ca2+ signalling ...
Joon‐Chul Kim, Hieu Trong Huynh, Phuong Kim Luong, Tran Nguyet Trinh, Yixuan Wu, Eleonora Grandi, Sun‐Hee Woo   +6 more
wiley   +1 more source

Energetic microdomains and the vascular control of neuronal and muscle excitability: Toward a unified model

The Journal of Physiology, EarlyView.
Abstract figure legend The capillary–mitochondria–ion channel (CMIC) axis scales structural resources to match functional workload. (Left) In settings of restricted energetic capacity (e.g. cortical neurons), sparse capillary networks and modest mitochondrial pools set a lower energetic ceiling, sufficient to support phasic, low‐workload excitability. (
L. Fernando Santana, Scott Earley
wiley   +1 more source

Role of Ca^<2+> Release from Sarcoplasmic Reticulum in Pacemaker Activity of the Sinoatrial Node

, 2002
2002-12Recent studies using confocal microscopy combined with patch clamping on single sinoatrial (SA) node pacemaker cells suggest that Ca^ release from the sarcoplasmic reticulum (SR) during diastole may play a prominent role in the late phase of ...
MITSUI, Kazuyuki, SHIBATA, Nitaro, HONJO, Haruo, NIWA, Ryoko, KAMIYA, Kaichiro, BOYETT, Mark R., INADA, Shin, KODAMA, Itsuo   +7 more
core   +1 more source

When NCX switches sides: Experimental and computational insights into Ca2+ regulation in the heart

The Journal of Physiology, EarlyView.
Abstract figure legend Due to its presence inside the dyadic cleft, Na+/Ca2+ exchanger (NCX) builds a functional unit together with L‐type calcium channels and ryanodine receptors in the dyadic cleft. NCX acts bidirectionally (forward and reverse mode) dependent on extracellular calcium ([Ca2+]o) and sodium ([Na+]o) concentrations and the membrane ...
Wilhelm Neubert, Judith Hüttemeister, Paulina Sander, Nagaiah Chamakuri, Felix Hohendanner, Martin Falcke, Frank R. Heinzel   +6 more
wiley   +1 more source

An age‐associated decline in the role of the sarcoplasmic reticulum and associated calcium‐handling proteins sets the pace for sinoatrial node function

The Journal of Physiology, EarlyView.
Abstract figure legend Stable, responsive pacemaking in the sinoatrial node is driven by the activity of the funny current (membrane clock), interplay of calcium cycling and release from the sarcoendoplasmic reticulum with depolarising sodium‐calcium exchange current (calcium clock). With increasing age, key proteins associated with calcium cycling are
Sandra A. Jones, Fiona S. Godbeer, Matthew K. Lancaster   +2 more
wiley   +1 more source