+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: not found

      Atrial fibrillation is associated with increased spontaneous calcium release from the sarcoplasmic reticulum in human atrial myocytes.


      metabolism, Aged, Sodium-Calcium Exchanger, secretion, Sarcoplasmic Reticulum, Patch-Clamp Techniques, ultrastructure, physiology, Myocytes, Cardiac, Middle Aged, Microscopy, Confocal, Male, Humans, physiopathology, Heart Atria, Female, Calcium Signaling, Atrial Fibrillation, Atrial Appendage

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          Spontaneous Ca2+ release from the sarcoplasmic reticulum (SR) can generate afterdepolarizations, and these have the potential to initiate arrhythmias. Therefore, an association may exist between spontaneous SR Ca2+ release and initiation of atrial fibrillation (AF), but this has not yet been reported. Spontaneous Ca2+ release from the SR, manifested as Ca2+ sparks and Ca2+ waves, was recorded with confocal microscopy in atrial myocytes isolated from patients with and those without AF. In addition, the spontaneous inward current associated with Ca2+ waves was measured with the use of the perforated patch-clamp technique. The Ca2+ spark frequency was higher in 8 patients with AF than in 16 patients without (6.0+/-1.2 versus 2.8+/-0.8 sparks/mm per second, P<0.05). Similarly, the spontaneous Ca2+ wave frequency was greater in patients with AF (2.8+/-0.5 versus 1.1+/-0.3 waves/mm per second, P<0.01). The spontaneous inward current frequency was also higher in 10 patients with AF than in 13 patients without this arrhythmia (0.101+/-0.028 versus 0.031+/-0.007 per second, P<0.05, at a clamped potential of -80 mV). In contrast, both the Ca2+ released from the SR and the Na+-Ca2+ exchange rate induced by a rapid caffeine application were comparable in patients with and without AF. The observed increase in spontaneous Ca2+ release in patients with AF probably is due to an upregulation of the SR Ca2+ release channel activity, which may contribute to the development of AF.

          Related collections

          Author and article information



          Comment on this article