Increased Vulnerability to Atrial Fibrillation Is Associated With Increased Susceptibility to Alternans in Old Sheep
| Autor: | Charles M, Pearman, George W P, Madders, Emma J, Radcliffe, Graeme J, Kirkwood, Michael, Lawless, Amy, Watkins, Charlotte E R, Smith, Andrew W, Trafford, David A, Eisner, Katharine M, Dibb |
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| Rok vydání: | 2018 |
| Předmět: |
Muscle Cells
Sheep alternans Myocardial Biology aging Age Factors Action Potentials Correction Atrial Function Calcium Cycling/Excitation-Contraction Coupling Membrane Potentials Electrophysiology action potential Atrial Fibrillation Mechanisms Animals Arrhythmia and Electrophysiology Calcium Female Disease Susceptibility Heart Atria Original Research calcium regulation |
| Zdroj: | Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease |
| ISSN: | 2047-9980 |
| Popis: | Background Atrial fibrillation (AF) is common in the elderly, but rare in the young; however, the changes that occur with age that promote AF are not fully understood. Action potential (AP) alternans may be involved in the initiation of AF. Using a translationally relevant model, we investigated whether age‐associated atrial vulnerability to AF was associated with susceptibility to AP alternans. Methods and Results AF was induced in conscious young and old sheep using 50 Hz burst pacing. Old sheep were more vulnerable to AF. Monophasic and cellular APs were recorded from the right atrium in vivo and from myocytes isolated from the left and right atrial appendages. AP alternans occurred at lower stimulation frequencies in old sheep than young in vivo (old, 3.0±0.1 Hz; young, 3.3±0.1 Hz; P |
| Databáze: | OpenAIRE |
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