Ultrastructure of Sarcolemma, Immunofluorescence of Calcium Handling Proteins and Mitochondrial Function in Atrial Myocytes of Patients in Sinus Rhythm and With Atrial Fibrillation

The aim of this work is to study the prevalence of T-tubular system in left and right myocytes from patients in sinus rhythm and whether this is altered in paroxysmal and permanent atrial fibrillation. Furthermore, since current information is lacking on the key Ca2+-handling proteins RyR, NCX, and SERCA-2a from patients in Atrial Fibrillation (AF), it will be investigated whether a regulation of these proteins could be an underlying cause of the disease. Mitochondrial function will also studied.

1. The investigators hypothesize that both structure of sarcolemma and localization of key Ca2+-handling proteins are altered in patients with atrial fibrillation compared with patients in sinus rhythm.
2. The investigators hypothesize that mitochondrial function is altered in patients with atrial fibrillation compared with patients in sinus rhythm.