Persistent atrial fibrillation was associated with reduced L-type calcium channel alpha 1 and sarcoplasmic reticulum Ca(2+)-ATPase mRNA (-57%, p=0.01; -28%, p=0.04) and protein contents.
Case-Control (n=36)
Persistent, but not paroxysmal, atrial fibrillation is associated with reduced gene and protein expression of key calcium handling proteins, suggesting these alterations are secondary to long-term AF rather than a primary cause.
p-value: p=0.01
OBJECTIVE: Persistent atrial fibrillation (AF) results in an impairment of atrial function. In order to elucidate the mechanism behind this phenomenon, we investigated the gene expression of proteins influencing calcium handling. METHODS: Right atrial appendages were obtained from eight patients with paroxysmal AF, ten with persistent AF (> 8 months) and 18 matched controls in sinus rhythm. All controls underwent coronary artery bypass grafting, whereas most AF patients underwent Cox's MAZE surgery (n = 12). All patients had a normal left ventricular function. Total RNA was isolated and reversely transcribed into cDNA. In a semi-quantitative polymerase chain reaction the cDNA of interest and of glyceraldehyde-3-phosphate dehydrogenase were coamplified and separated by ethidium bromide-stained gel electrophoresis. Slot blot analysis was performed to study protein expression. RESULTS: L-type calcium channel alpha 1 and sarcoplasmic reticulum Ca(2+)-ATPase mRNA (-57%, p = 0.01 and -28%, p = 0.04, respectively) and protein contents (-43%, p = 0.02 and -28%, p = 0.04, respectively) were reduced in patients with persistent AF compared to the controls. mRNA contents of phospholamban, ryanodine receptor type 2 and sodium/calcium exchanger were comparable. No changes were observed in patients with paroxysmal AF. CONCLUSIONS: Alterations in gene expression of proteins involved in the calcium homeostasis occur only in patients with long-term persistent AF. In the absence of underlying heart disease, the changes are rather secondary than primary to AF.
B Brundel (1999) conducted a case-control in Atrial fibrillation (n=36). Persistent and paroxysmal atrial fibrillation vs. Sinus rhythm (matched controls) was evaluated on L-type calcium channel alpha 1 and sarcoplasmic reticulum Ca(2+)-ATPase mRNA and protein contents (p=0.01). Persistent atrial fibrillation was associated with reduced L-type calcium channel alpha 1 and sarcoplasmic reticulum Ca(2+)-ATPase mRNA (-57%, p=0.01; -28%, p=0.04) and protein contents.