Drug effects on the sinus node. A clinical perspective.

The direct and indirect effects of drugs on the sinoatrial (SA) node are described in relation to basic cellular mechanisms and clinical applications. The effects of the different classes of antiarrhythmic agents are considered in terms of their direct depressant and excitatory actions. Indirect actions, particularly autonomic effects, are also discussed. Clinical aspects of the pharmacologic management of disorders of sinus node function such as the bradycardia-tachycardia syndrome, inappropriate sinus tachycardia, sinus bradycardia, and the identification of sinus node dysfunction by drug effects are considered in detail.