Although electrical heterogeneity within the ventricular myocardium has been the focus of numerous studies, little attention has been directed to the mechanical correlates. This study examines unloaded cell shortening, Ca(2+) transients, and inward L-type Ca(2+) current (I(Ca,L)) characteristics of epicardial, endocardial, and midmyocardial cells isolated from the canine left ventricle. Unloade...

A voltage clamp for single muscle fibers has been developed. Stability of the system was achieved when an artificial node was created by enclosing a single muscle fiber in a petroleum jelly seal which served as an analogue of the myelin sheath. Typical voltage clamp records were obtained with large inward transient currents followed by a delayed rectification of the outward currents. These curr...

For the first time, a patient with asymptomatic QT interval prolongation was found to carry missense mutation c.277G>A (p.Val93Ile) in KCNJ2 gene, described previously only as cause of familial form atrial fibrillation. The corresponding amino acid substitution introduced into plasmid encoding Kir2.1 channel and mutant gene expressed Chinese hamster ovary cells (CHO-K1) evaluate effect on IK1 c...