Abstract: It is demonstrated that hyperpolarization-activated cyclic nucleotide-gated (HCN)-based biological pacing, especially that achieved by transduction of the HCN2 gene into cardiac cells in vivo, was significantly improved by co-transduction of the skeletal muscle sodium channel 1 (SkMI) gene. Expression of both genes hyperpolarized the action potential (AP) threshold. When viral biological pacemaker constructs carrying genes for HCN2 and SkMI were injected into the heart of dogs in vivo, the pacemaker function was facilitated by the slow depolarizing HCN2 current and the hyperpolarized AP threshold generated by SkMI. This dual gene therapy provided both highly efficient pacing and a brisk autonomic response that is superior to those of previously developed gene- or cell-based approaches.

Abstract: This invention provides a bypass bridge comprising a tract of gap junction-coupled cells having a first end and a second end, both ends capable of being attached to two selected sites in a heart so as to allow the conduction of a pacemaker and/or electrical signal/current across the tract between the two sites, wherein the cells functionally express a sodium channel. The invention also provides related methods of making the bypass bridge, methods of implanting same in a heart, and methods of treating a disorder associated with an impaired conduction in a subject's heart.

Abstract: This invention provides a bypass bridge comprising a tract of gap junction-coupled cells having a first end and a second end, both ends capable of being attached to two selected sites in a heart so as to allow the conduction of a pacemaker and/or electrical signal/current across the tract between the two sites, wherein the cells functionally express a sodium channel. The invention also provides related methods of making the bypass bridge, methods of implanting same in a heart, and methods of treating a disorder associated with an impaired conduction in a subject's heart.

Abstract: A method of creating an atrioventricular bypass tract for a heart comprises growing mesenchymal stem cells into a strip with two ends, attaching one end of the strip onto the atrium of the heart, and attaching the other end of the strip to the ventricle of the heart, to create a tract connecting the atrium to the ventricle to provide a path for electrical signals generated by the sinus node to propagate across the tract and excite the ventricle.

Abstract: A method of creating an atrioventricular bypass tract for a heart comprises growing mesenchymal stem cells into a strip with two ends, attaching one end of the strip onto the atrium of the heart, and attaching the other end of the strip to the ventricle of the heart, to create a tract connecting the atrium to the ventricle to provide a path for electrical signals generated by the sinus node to propagate across the tract and excite the ventricle.

Abstract: The present invention provides compositions and methods of treatment for atrial fibrillation and ventricular tachycardia. The compositions are useful for modifying the conducting properties of heart tissues in which impulses are generating and/or are useful for altering refractoriness without prolonging repolarization.