Understanding Atrial Fibrillation

Preface ix

Acknowledgments xiii

Part I: Building blocks of fibrillation 1

Excitation and propagation 1

Source-sink relationships 2

What determines source-sink balance? 3

Propagation and reentry 4

Requirements for reentry 4

What makes a circuit? 6

Source-sink balance and rotors 6

Wave length 8

Wave length, path length, and reentry 9

Restitution 10

Initiating reentry 11

Part II: Atrial fibrillation mechanisms 21

The evolution of current concepts 21

The mass hypothesis of atrial fibrillation 30

Principles of propagation: Implications for fibrillation 32

Focal rotors 52

Micro-reentry 55

Fibrillatory conduction or multi-wavelet reentry? 66

Location of atrial fibrillation drivers 76

Principles of propagation: Driver interactions in fibrillation 87

Part III: Working with incomplete information 93

Cardiac mapping 93

Sample density and atrial fibrillation 115

What should we do with the patient who comes to the lab tomorrow? Putting it all together (without "it all") 128

Putting it all together: Atrial fibrillation in three questions 132

Appendix A: Calculating probability in a random walk 135

Appendix B: Dominant frequency analysis 137

Appendix C: A stupid idea, but a learning opportunity 143

References 149

Index 161

"This book on atrial fibrillation is a must-read for any physician and/or investigator interested in studying the condition or caring for an AF patient. Dr. Spector takes a critical scientific approach to AF and its mechanisms. This book is a very welcome addition to the field."
--Hugh Calkins, MD, Professor of Medicine, Director of Electrophysiology, Johns Hopkins Medical Institutions, Baltimore, MD, USA

"Understanding Atrial Fibrillation is a gem. In less than 150 pages, I learned enough basic science about atrial fibrillation and its physiology to allow me to feel competent reviewing different approaches to its mapping and ablation. Peter Spector has an amazing knack for explaining complex physiology. This little book will be sit on the top of my bookshelf."
--Kenneth A. Ellenbogen, MD, Kimmerling Professor of Cardiology, VCU School of Medicine, Richmond, VA, USA

"Dr. Spector frames atrial fibrillation as a compelling scientific mystery, his text flowing smoothly between sequences of questions and answers that read like detective story that one cannot put down."
--Omer Berenfeld, PhD, Professor of Internal Medicine, Professor of Biomedical Engineering, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, USA

"The excellent book Understanding Atrial Fibrillation by Dr. Peter Spector refreshingly explains atrial fibrillation as a scientific mystery; the text flows smoothly with sequences of questions and answers that read like a detective story that cannot be put down. From time to time, the reader is led to think that the culprit is found, only to discover in the following chapter that the evidence is not convincing enough and the investigation must continue. The book is a must-read for everyone, novice or expert, interested in developing a deeper understanding of atrial fibrillation."
--Omer Berenfeld, PhD, Professor of Internal Medicine, Professor of Biomedical Engineering, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, USA

Peter Spector, MD, is Professor of Medicine, Professor of Electrical and Biomedical Engineering, and Director of Cardiac Electrophysiology and the Cardiac Electrophysiology Laboratory at the University of Vermont Medical Center, Burlington, VT, USA.

P. Spector, Professor of Medicine, Director, Cardiac Electrophysiology and Cardiac Electrophysiology Laboratory, University of Vermo