Unchanged heat-shock protein 70 expression in myocardium of patients with permanent atrial fibrillation.

AIM

Cardiomyocytes respond to permanent atrial fibrillation (AF) with an increase in mitochondrial heat shock proteins (Hsp). The aim of our study was to test if there is a cytoplasmic response to stress by investigating the expression of Hsp70.

METHODS

Right atrial samples from 18 patients undergoing elective cardiac surgery were excised and immediately frozen in liquid nitrogen. Eight patients had permanent AF (> 3 months) and 10 patients were in sinus rhythm (SR). Hsp70 was determined by SDS-PAGE, Western blot and quantified with optical densitometry.

RESULTS

We found no increase in Hsp70 expression in myocardial samples from patients with permanent AF.

CONCLUSION

The unchanged expression of Hsp70 may indicate that the cytoplasmic stress response in permanent AF is exhausted.