ABSTRACT
PURPOSE: Gelsolin (gsn) is involved in the reorganization of the cytoskeleton, thereby modulating cardiomyocytal L-type Ca(2+) channels. We investigated global cardiac electrophysiological characteristics in a gsn-deficient (gsn(-/-)) mouse strain. METHODS: Using transvenous catheterization, atrial and ventricular stimulation were performed in 15 male mice [eight gsn(-/-), seven wild-type (gsn(+/+))]. Surface ECG, standard electrophysiological parameters, and inducibility of atrial fibrillation (AF) were evaluated. RESULTS: The surface ECG showed shorter PQ (37.8 +/- 4.6 versus 42.9 +/- 2.7 ms; P = 0.02), but longer QRS (16.5 +/- 1.8 versus 13.9 +/- 1.2 ms; P = 0.005) and QT intervals (38.5 +/- 2.2 versus 35.6 +/- 2.4 ms, P = 0.03) in gsn(-/-). Gsn(-/-) exhibited significantly higher susceptibility to induction of prolonged AF episodes > or =60 s [six of eight gsn(-/-) versus one of seven gsn(+/+); P = 0.04]. Sustained AF episodes > or =10 min were observed in 50% of the gsn-deficient animals. CONCLUSIONS: Gsn deficiency results in perpetuation of inducible episodes of atrial fibrillation. Altered L-type Ca(2+) currents and disturbed Ca(2+) handling known to be associated to gsn deficiency likely contribute to this effect.
