Unfortunately, no single therapeutic breakthrough alone is likely to mitigate the rising burden of AF. Although all AF is characterized by chaotic atrial electrical activity, the arrhythmia is a final common pathway of multiple heterogeneous conditions, including electrical triggers (especially in the pulmonary veins), underlying structural heart disease, long-standing hypertension, genetic disorders, cardiomyopathies, and, almost certainly, other conditions we do not yet understand. Currently, guideline-based treatment strategies for AF begin with assessment and appropriate reduction of stroke risk (with aspirin, warfarin, or other anticoagulants) followed by treatment of AF-associated symptoms beginning first with control of the ventricular response to AF. If a rate control strategy fails or is otherwise unacceptable to the patient, efforts to achieve and maintain normal sinus rhythm can include cardioversion, antiarrhythmic drugs, and/or ablation by either catheter-based or surgical approaches. Unfortunately, patients continue to be hospitalized with poor ventricular rate control despite the use of rate controlling drugs. Furthermore, even when control of the rhythm is desired, antiarrhythmic drugs have both incomplete efficacy and substantive toxicities. Although promising in some, catheter ablation in the best candidates has both nontrivial procedural risk and a likelihood of success for a first procedure on the order of 60% to 85%, even with concomitant antiarrhythmic drug therapy.10 At a fundamental level, all of these treatments address a condition that has already afflicted the heart without addressing the upstream causes.