Results 71 to 80 of about 72,302 (222)

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

Chronic atrial and intestinal dysrhythmia: A rare genetic disorder of intestinal pseudo‐obstruction

JPGN Reports, EarlyView.
Abstract Pediatric intestinal pseudo‐obstruction (PIPO) is a rare and severe disorder of gastrointestinal (GI) motility; patients with PIPO display signs and symptoms of intestinal obstruction in the absence of occluding lesions. Chronic atrial and intestinal dysrhythmia (CAID) syndrome is an exceedingly rare autosomal recessive disorder caused by ...
Kanya Ahuja, Shivany Pathania, Nicole Baron, Julie Khlevner, Martin Bialer, Jennifer Mait‐Kaufman   +5 more
wiley   +1 more source

Multiple mechanisms of spiral wave breakup in a model of cardiac electrical activity [PDF]

, 2002
It has become widely accepted that the most dangerous cardiac arrhythmias are due to re- entrant waves, i.e., electrical wave(s) that re-circulate repeatedly throughout the tissue at a higher frequency than the waves produced by the heart's natural pacemaker (sinoatrial node). However, the complicated structure of cardiac tissue, as well as the complex
arxiv   +1 more source

Sinus node dysfunction: current understanding and future directions.

American Journal of Physiology. Heart and Circulatory Physiology, 2022
The sinoatrial node (SAN) is the primary pacemaker of the heart. Normal SAN function is crucial in maintaining proper cardiac rhythm and contraction.
Pavan Manoj, Jitae A Kim, Stephanie Kim, Tingting Li, Maham Sewani, Mihail G. Chelu, Na Li   +6 more
semanticscholar   +1 more source

Cardiac output‐mediated regulation of cerebral blood flow during exercise: Clinical perspectives on the indirect impact of muscle metaboreflex

Experimental Physiology, EarlyView.
Abstract The muscle metaboreflex stimulates the elevation of arterial blood pressure, aiming to rectify the oxygen deficit by enhancing oxygen delivery to support muscle activity. Moreover, activating the muscle metaboreflex significantly increases cardiac output (CO) by increasing factors such as heart rate, ventricular contractility, preload, stroke ...
Shigehiko Ogoh
wiley   +1 more source

Altered microRNA and mRNA profiles during heart failure in the human sinoatrial node

Scientific Reports, 2021
Heart failure (HF) is frequently accompanied with the sinoatrial node (SAN) dysfunction, which causes tachy-brady arrhythmias and increased mortality. MicroRNA (miR) alterations are associated with HF progression.
Ning Li, Esthela Artiga, Anuradha Kalyanasundaram, Brian J. Hansen, Amy Webb, Maciej Pietrzak, Brandon Biesiadecki, Bryan Whitson, Nahush A. Mokadam, Paul M. L. Janssen, John D. Hummel, Peter J. Mohler, Halina Dobrzynski, Vadim V. Fedorov   +13 more
doaj   +1 more source

The Calcium and Voltage Clocks in Sinoatrial Node Automaticity [PDF]

, 2009
Recent evidence indicates that the voltage (cyclic activation and deactivation of membrane ion channels) and Ca2+ clocks (rhythmic spontaneous sarcoplasmic reticulum Ca2+ release) jointly regulate sinoatrial node (SAN) automaticity.
Chen, Peng-Sheng, Joung, Boyoung, Lin, Shien-Fong, Ogawa, Masahiro   +3 more
core   +2 more sources

Disruption of mitochondria–sarcoplasmic reticulum microdomain connectomics contributes to sinus node dysfunction in heart failure

Proceedings of the National Academy of Sciences of the United States of America, 2022
Significance The human heart beats 60 to 80 times a minute, which can amount to more than 3 billion heartbeats in one’s lifetime. Each heartbeat is initiated by the sinoatrial node (SAN). SAN dysfunction is a common feature of heart failure (HF). However,
Lu Ren, R. Gopireddy, G. Perkins, Hao Zhang, V. Timofeyev, Y. Lyu, Daphne A Diloretto, Pauline Trinh, Padmini Sirish, James L Overton, Wilson Xu, N. Grainger, Y. Xiang, E. Dedkova, Xiao-Dong Zhang, E. Yamoah, Manuel F. Navedo, Phung N. Thai, N. Chiamvimonvat   +18 more
semanticscholar   +1 more source

Controlling parasympathetic regulation of heart rate: a gatekeeperrole for RGS proteins in the sinoatrial node

Frontiers in Physiology, 2012
Neurotransmitters released from sympathetic and parasympathetic nerve terminals in the SAN exert their effects via G-protein-coupled receptors. Integration of these different G-protein signals within pacemaker cells of the sinoatrial node (SAN) is ...
Alexandra eMighiu, Scott Patrick Heximer
doaj   +1 more source

Electrophysiological and Molecular Mechanisms of Sinoatrial Node Mechanosensitivity

Frontiers in Cardiovascular Medicine, 2021
The understanding of the electrophysiological mechanisms that underlie mechanosensitivity of the sinoatrial node (SAN), the primary pacemaker of the heart, has been evolving over the past century.
Daniel Turner, Chen Kang, Pietro Mesirca, Juan Hong, Matteo E. Mangoni, Alexey V. Glukhov, Rajan Sah   +6 more
doaj   +1 more source