Sinus tachyarrhythmias and the specific bradycardic agents: a marriage made in heaven?

A relatively novel group of drugs that inhibit the funny current in the sinus node pacemaker cells, the so-called specific bradycardic agents, are likely to play a significant role in the management of a wide range of cardiovascular disorders, including the sinus tachyarrhythmias. This comprehensive review initially provides an insight into these agents, their historical background, and their mechanism of action. It then discusses the differential diagnosis of the sinus tachyarrhythmias (normal sinus tachycardia, inappropriate sinus tachycardia, postural orthostatic tachycardia syndrome, and sinus node reentry tachycardia), elaborates on their pathophysiologic basis, and provides up-to-date evidence-based information on their optimum management. The specific bradycardic agents, by the very nature of their mode of action, may prove ideal therapies for the management of the sinus tachyarrhythmias, and this is explored at every stage.