Cardiac electrical stunning is a common feature of cardiac arrhythmias.
There are many published papers focused on the topic of atrial electrical remodeling, which defined as the shortening and dispersion of effective refractory period (ERP) in patients with paroxysmal or persistent tachyarrhythmias or in animals with long-term rapid atrial pacing. Heart failure could produce the electrical remodeling of sinus node, manifesting the prolongation of corrected sinus node recovery time and sinus cycle length. It might be attributed to decreased hyperpolarization-activated cyclic nucleotide expression of sinus node. Rapid atrial pacing for only 10-15 min, simulating transient atrial tachyarrhythmias, alters sinus node function in human. Termination of atrial flutter by ablation induces reversible changes in sinus node function. After atrial fibrillation (AF) ablation, there was a significant improvement of sinus node function, with an increase in the mean heart rate, maximal heart rate and heart rate range significantly. Reverse electrical remodeling of the ERP occurs at different rates in different regions of the atrium. Previous experiments showed that electrical remodeling of atrial myocardium could be induced by autonomic nervous transmitters and suggested that autonomic nerve activity was an important factor to promote AF episodes. We postulated that electrical remodeling and reverse electrical remodeling are common features of the heart, including atrium, ventricle, sinus node, and conductive system. Inappropriate very rapid or slow electrical depolarization may cause electrical remodeling of the heart, but appropriate rates of electrical depolarization and cessation of rapid stimulation may contribute to the reverse electrical remodeling. So, we forward that a concept defined as cardiac electrical stunning, including electrical remodeling and reverse electrical remodeling, should be a common characteristic and mechanism of cardiac arrhythmias.
Li
Guangping
G
Department of Cardiology, Second Hospital of Tianjin Medical University, No. 23, Pingjiang Road, Hexi District, Tianjin 300211, PR China. gp_limail@yahoo.com.cn
Liu
Tong
T
Liu
Enzhao
E
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000628:therapy; D001282:Atrial Flutter / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D004554:Electric Countershock; D022062:Electrophysiologic Techniques, Cardiac; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008955:Models, Cardiovascular; D012032:Refractory Period, Electrophysiological; D012849:Sinoatrial Node / Q000503:physiopathology; D013610:Tachycardia / Q000503:physiopathology; D013997:Time Factors