TY - CHAP
T1 - From genes and molecules to organs and organisms
T2 - Heart
AU - Rudy, Y.
N1 - Funding Information:
Writing of this chapter was made possible by support from the NIH-National Heart, Lung and Blood Institute (grants HL-33343 and HL-49054) and from the National Science Foundation (grant 0929633).
PY - 2012
Y1 - 2012
N2 - Mechanical contraction of the heart and its blood-pumping action are activated and synchronized by a wave of electrical excitation. Propagation of the excitation wave involves action potential (AP) generation by cardiac cells and its conduction in the multicellular tissue. AP generation is accomplished through complex, nonlinear interactions between membrane ion channels, transmembrane voltage, and the dynamically changing ionic milieu of the cell. AP propagation is achieved by flow of electrical charge from cell-to-cell through intercellular gap junctions. As described in this chapter, the propagation process involves strong interactions within and across scales between the molecular structure and function of ion channels, the properties of gap junctions, the subcellular organization of the cell, and the tissue architecture. At the whole-heart scale, normal excitation is generated in the right atrium by the sino-atrial (SA) node and transmitted to the ventricles through the atrio-ventricular (AV) node. It then spreads rapidly via the specialized conduction (Purkinje) system to establish broad excitation wavefronts that propagate synchroneously from endocardium to epicardium in both ventricles. Abnormal electrical activity can originate at any scale of this system, possibly leading to cardiac rhythm irregularities that could be fatal (cardiac arrhythmias are one of the most frequent causes of morbidity and mortality in the human population).
AB - Mechanical contraction of the heart and its blood-pumping action are activated and synchronized by a wave of electrical excitation. Propagation of the excitation wave involves action potential (AP) generation by cardiac cells and its conduction in the multicellular tissue. AP generation is accomplished through complex, nonlinear interactions between membrane ion channels, transmembrane voltage, and the dynamically changing ionic milieu of the cell. AP propagation is achieved by flow of electrical charge from cell-to-cell through intercellular gap junctions. As described in this chapter, the propagation process involves strong interactions within and across scales between the molecular structure and function of ion channels, the properties of gap junctions, the subcellular organization of the cell, and the tissue architecture. At the whole-heart scale, normal excitation is generated in the right atrium by the sino-atrial (SA) node and transmitted to the ventricles through the atrio-ventricular (AV) node. It then spreads rapidly via the specialized conduction (Purkinje) system to establish broad excitation wavefronts that propagate synchroneously from endocardium to epicardium in both ventricles. Abnormal electrical activity can originate at any scale of this system, possibly leading to cardiac rhythm irregularities that could be fatal (cardiac arrhythmias are one of the most frequent causes of morbidity and mortality in the human population).
KW - Action potential
KW - Cardiac arrhythmias
KW - Cardiac electrophysiology
KW - Conduction
KW - Electrocardiography
KW - Ion channels
UR - http://www.scopus.com/inward/record.url?scp=84879183660&partnerID=8YFLogxK
U2 - 10.1016/B978-0-12-374920-8.00924-3
DO - 10.1016/B978-0-12-374920-8.00924-3
M3 - Chapter
AN - SCOPUS:84879183660
SN - 9780080957180
VL - 9
SP - 268
EP - 327
BT - Comprehensive Biophysics
PB - Elsevier Inc.
ER -