Electrocardiography of the Dog and Cat, Diagnosis of Arrhythmias, 2nd Edition

Preface

“It is the theory which decides what we can observe.”

Albert Einstein

The main objective of this book is to give both clinical and theoretical information to interpret simple and complex electrocardiograms in dogs and cats. Detailed description of normal rhythm variations and arrhythmias is provided to meet the readers’ needs whether they are just beginners or experts. Consequently, veterinary students and busy general practitioners will find the information sought to categorize electrocardiograms, while cardiology residents and specialists will discover additional depths for understanding the complexities of the electrophysiology behind the electrocardiogram. For all, the goal of this book is to increase knowledge to meet the challenge of electrocardiographic interpretation. We have made the deliberate choice to use the same terminology and electrocardiographic planes used for the analysis of the human electrocardiogram. We have done so because the main source of information concerning the clinically applicable electrophysiologic studies of arrhythmias is from those performed in people.

In recent years, research to understand the electrophysiological mechanisms behind cardiac arrhythmias in veterinary patients has increased. Although these studies remain limited, the advancements are real and give us a better understanding of the clinical arrhythmias we commonly and uncommonly diagnose. Such information improves not only our ability to make an accurate diagnosis, but to deliver better treatment.

The first three chapters of this book include a detailed description of the anatomy and electrophysiology of the conduction system, the theory behind the formation of the electrocardiographic waveforms, and the recording techniques available to the clinician. The following chapters first focus on the characteristics of normal rhythm in dogs and cats, the impact of cardiac chamber enlargement on electrocardiogram, and then detail the portfolio of atrial and ventricular arrhythmias described in veterinary medicine. Specifically, chapters 7 to 10 are dedicated to ectopies and tachyarrhythmias. Chapters 11 and 12 describe bradyarrhythmias and conduction abnormalities. Chapter 13 is an overview of the effects of systemic diseases and drugs on the electrocardiogram. Finally, chapter 14 describes the electrocardiogram in the presence of an artificial pacemaker, and the signs of device malfunction. We have included at the end this book a series of electrocardiograms that readers can use to test their knowledge.

Initially published in Italian, this publication is now accessible to the English-speaking readership in an expanded and updated version. This project was possible by the addition of two co-authors. Notably this work stems from a common passion for the fascinating complexity of arrhythmias and it is the product of friendship, collaboration and mutual academic respect.

We hope that the readers will find it helpful in their daily clinical activities, and rather than feeling overwhelmed by the intricacies of electrocardiography, will develop their interest in deciphering the tracings they record.

Finally, we would like to thank all the individuals who have directly or indirectly contributed to this book: architect Federica Fare who designed several new figures; architect Federica Fare and Veronica Santilli for the ideation and realisation of the cover; Dr. Lucia Ramera and Dr. Maria Mateos Panero who prepared the material needed to proceed with the first translation from Italian to English; Dr. Gianmario Spadacini and Dr. Paolo Moretti from the Institute Clinico Humanitas Mater Domini Castellanza (Varese) for their guidance and leadership in the field of clinical cardiac electrophysiology; Dr. Alberto Perini for his expertise in anesthesiology and his assistance during electrophysiologic studies and pacemaker implantation procedures; Dr. Silvia Scarso and the Anesthesia Section of Cornell University for consulting on the effects of sedatives and anesthetics on the cardiac rhythm; our colleagues of the Veterinary Clinic Malpensa for their help in the management of our canine and feline patients with arrhythmias; Shari Hemsley for extensive Holter analysis at Cornell University; the cardiology residents at Cornell University; the many veterinarians who continue to refer us cases and help us expand our database of electrocardiograms and Holters by using the cardiology services of the Veterinary Clinic Malpensa and Cornell University; finally, Edra Publishing House for technical support, and Dr Carlo Scotti for believing in this work and supporting its development.

Roberto A. Santilli, N. Sydney Moise, Romain Pariaut, Manuela Perego