Biological pacemakers: are we at the dawn of a new treatment era?

摘要

In this issue of the Journal, Boink et al. (1) reported the study of biological pacemaker function in mongrel dogs that underwent radiofrequency ablation of the atrioventricular node and were then treated with gene transfer using the hyperpolarization-activated cyclic nucleotide-gated current channel 2 (HCN2) construct, the skeletal muscle sodium channel {SkMi) construct, or the dual (HCN2/SkMl) construct injected into the left bundle branch (LBB) or the left ventricular (LV) subepicardium. The researchers coex-pressed SkMl with HCN2 on the basis of the hypothesis that when HCN2 generated the inward current that would drive the membrane toward threshold, SkMl would create greater availability of sodium channels during diastole because of a more favorable inactivation curve than the cardiac sodium channel, leading to a more negative threshold potential, improved pacemaker stability, and increased beating rates.