BACKGROUND: Atrial fibrillation (AF) shortens the atrial effective refractory period (ERP) and predisposes to further episodes of AF. The acute changes in atrial refractoriness may be related to tachycardia-induced intracellular calcium overload. The purpose of this study was to determine whether digoxin, which increases intracellular calcium, potentiates the acute effects of AF on atrial refractoriness in humans. METHODS AND RESULTS: In 38 healthy adults, atrial ERP was measured at basic drive cycle lengths (BDCLs) of 350 and 500 ms after autonomic blockade. Nineteen patients had been treated with digoxin for 2 weeks. After a several-minute episode of AF, atrial ERP was measured serially at alternating BDCLs. Compared with pre-AF ERPs, the first post-AF ERPs were significantly shorter in both the digoxin and the control groups (P:<0.001). The post-AF ERP at a BDCL of 350 ms shortened to a greater degree in the digoxin group (37+/-16 ms) than in the control group (20+/-13 ms, P:<0.001); similar changes occurred at a BDCL of 500 ms. During post-AF determinations of the atrial ERP, secondary AF episodes occurred significantly more often in the digoxin group (32% versus 16%; P:<0. 04). CONCLUSIONS: After a brief episode of AF, digoxin augments the shortening that occurs in atrial refractoriness and predisposes to the reinduction of AF. These effects occur in the setting of autonomic blockade and therefore are more likely to be due to the effects of digoxin on intracellular calcium than to its vagotonic effects.
BACKGROUND:Atrial fibrillation (AF) shortens the atrial effective refractory period (ERP) and predisposes to further episodes of AF. The acute changes in atrial refractoriness may be related to tachycardia-induced intracellular calcium overload. The purpose of this study was to determine whether digoxin, which increases intracellular calcium, potentiates the acute effects of AF on atrial refractoriness in humans. METHODS AND RESULTS: In 38 healthy adults, atrial ERP was measured at basic drive cycle lengths (BDCLs) of 350 and 500 ms after autonomic blockade. Nineteen patients had been treated with digoxin for 2 weeks. After a several-minute episode of AF, atrial ERP was measured serially at alternating BDCLs. Compared with pre-AF ERPs, the first post-AF ERPs were significantly shorter in both the digoxin and the control groups (P:<0.001). The post-AF ERP at a BDCL of 350 ms shortened to a greater degree in the digoxin group (37+/-16 ms) than in the control group (20+/-13 ms, P:<0.001); similar changes occurred at a BDCL of 500 ms. During post-AF determinations of the atrial ERP, secondary AF episodes occurred significantly more often in the digoxin group (32% versus 16%; P:<0. 04). CONCLUSIONS: After a brief episode of AF, digoxin augments the shortening that occurs in atrial refractoriness and predisposes to the reinduction of AF. These effects occur in the setting of autonomic blockade and therefore are more likely to be due to the effects of digoxin on intracellular calcium than to its vagotonic effects.
Authors: Bulent Gorenek; Antonio Pelliccia; Emelia J Benjamin; Giuseppe Boriani; Harry J Crijns; Richard I Fogel; Isabelle C Van Gelder; Martin Halle; Gulmira Kudaiberdieva; Deirdre A Lane; Torben Bjerregaard Larsen; Gregory Y H Lip; Maja-Lisa Løchen; Francisco Marin; Josef Niebauer; Prashanthan Sanders; Lale Tokgozoglu; Marc A Vos; David R Van Wagoner; Laurent Fauchier; Irina Savelieva; Andreas Goette; Stefan Agewall; Chern-En Chiang; Márcio Figueiredo; Martin Stiles; Timm Dickfeld; Kristen Patton; Massimo Piepoli; Ugo Corra; Pedro Manuel Marques-Vidal; Pompilio Faggiano; Jean-Paul Schmid; Ana Abreu Journal: Eur J Prev Cardiol Date: 2016-11-04 Impact factor: 7.804
Authors: Bulent Gorenek; Antonio Pelliccia; Emelia J Benjamin; Giuseppe Boriani; Harry J Crijns; Richard I Fogel; Isabelle C Van Gelder; Martin Halle; Gulmira Kudaiberdieva; Deirdre A Lane; Torben Bjerregaard Larsen; Gregory Y H Lip; Maja-Lisa Løchen; Francisco Marín; Josef Niebauer; Prashanthan Sanders; Lale Tokgozoglu; Marc A Vos; David R Van Wagoner; Laurent Fauchier; Irina Savelieva; Andreas Goette; Stefan Agewall; Chern-En Chiang; Márcio Figueiredo; Martin Stiles; Timm Dickfeld; Kristen Patton; Massimo Piepoli; Ugo Corra; Pedro Manuel Marques-Vidal; Pompilio Faggiano; Jean-Paul Schmid; Ana Abreu Journal: Europace Date: 2017-02-01 Impact factor: 5.214
Authors: C-J A Lindholm; O Fredholm; S-J Möller; N Edvardsson; T Kronvall; T Pettersson; V Firsovaite; A Roijer; C J Meurling; P G Platonov; S B Olsson Journal: Heart Date: 2004-05 Impact factor: 5.994
Authors: Michalis Efremidis; Ioannis P Alexanian; Dimitrios Oikonomou; Dimitrios Manolatos; Konstantinos P Letsas; Loukas K Pappas; Gerasimos Gavrielatos; Maria Vadiaka; Constantinos C Mihas; Gerasimos S Filippatos; Antonios Sideris; Fotios Kardaras Journal: Can J Cardiol Date: 2009-04 Impact factor: 5.223