The molecular basis for atrial fibrillation continues to be largely unknown, and therapy remains unchanged, aimed at controlling the heart rate and preventing systemic emboli with anticoagulation. Familial atrial fibrillation is more common than previously suspected. While atrial fibrillation is commonly associated with acquired heart disease, a significant proportion of individuals have early onset without other forms of heart disease, referred to as "lone" atrial fibrillators. It is also well recognized that atrial fibrillation occurs on a reversible or functional basis, without associated structural heart disease, such as with hyperthyroidism or of atrial fibrillation following surgery. It remains to be determined what percentage in these individuals is familial or due to a genetic predisposition. Mapping the locus for familial atrial fibrillation is the first step towards the identification of the gene. Isolation of the gene and subsequent identification of the responsible molecular genetic defect should provide a point of entry into the mechanism responsible for the familial form and the common acquired forms of the disease and eventually provide more effective therapy. We know that the ionic currents responsible for the action potential of the atrium is due to multiple channel proteins as is electrical conduction throughout the atria. Analogous to the ongoing genetic studies in patients with familial long QT syndrome, it is highly likely that defects in each of these channel proteins will be manifested in familial atrial fibrillation.

1. Overview: Genetics of Cardiac Electrophysiology.- Section I. Experimental Investigation of Inherited Electrophysiological Disorders.- 2. Single-Cell Electrophysiology & Ion Channelopathies.- 3. Animal Models of Inherited Electrophysiologic Diseases.- 4. Optical Mapping of Arrhythmias.- 5. Connexins and Conduction.- Section II. Hereditary Arrhythmias.- 6. Hereditary Supraventricular Tachycardias.- 7. Familial Atrial Fibrillation.- 8. The Molecular Cardiology of Heart Block.- Section III. Ion Channel Mutations with Clinical Electrophysiologic Consequences.- 9. Congenital Long QT Syndromes.- 10. Molecular Genetics of the Acquired Long QT Syndrome.- 11. Brugada Syndrome Genetics.- Section IV. Inherited Cardiomyopathies with Arrhythmias.- 12. Familial Hypertrophic Cardiomyopathy Genetics.- 13. Familial Dilated Cardiomyopathy.- 14. Glycogen Storage Diseases.- 15. Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy.- 16. Cardiac Disease in Duchenne & Becker Muscular Dystrophies: The Dystrophinopathies.- 17. Myotonic Muscular Dystrophy Genetics and Cardiac Sequelae.- Section V. Inherited Structural Heart Diseases Associated with Arrhythmias.- 18. Genetic Causes of Atrial Septal Defects.- 19. Holt-Oram Syndrome and the TBX5 Transcription Factor in Cardiogenesis.- 20. Inherited Structural Heart Diseases Associated With Arrhythmias: Defects in Laterality.- 21. Marfan Syndrome and Related Disorders Fibrillin.- 22. The Molecular Genetics of Conotruncal Defects.