Preface

Cardiovascular disease (CVD) continues to be the leading cause of morbidity and mortality in both developed and developing countries. Early diagnosis and management are key to reducing the number of deaths attributed to CVD. Electrocardiogram (ECG) plays a major role in diagnosing both ischemic heart disease and arrhythmia disorders. Within the context of the current COVID-19 pandemic, related cardiac diseases place additional stress on the health system. Fortunately, CVDs can be diagnosed early via noninvasive techniques. Hence, accurate interpretation of ECG results is vital in cardiology.

This book is divided into two sections on "Practical Applications of ECG in Arrhythmias" and "Clinical Use of ECG." In cardiac electrophysiology, one of the basic and most important procedures is an electrophysiology study that provides a great amount of information about the electrical system of the heart. In the first section, a chapter is dedicated to the interpretation of intra-cardiac ECG during an electrophysiology study. By obtaining intra-cardiac ECGs, medical professionals can accurately identify and locate arrhythmias, determine the effectiveness of treatments, and guide catheter-based interventions. Two additional chapters in this section discuss the classic ECG features of narrow QRS complex tachycardia and wide QRS complex tachycardia, respectively. It is important to note that differentiating between narrow and wide QRS tachycardia based solely on ECG criteria can sometimes be challenging, and clinical context, patient presentation, and additional diagnostic tests may be required for accurate identification and appropriate management of the tachycardia.

In the second section, one chapter describes the practical applications of ECG in cattle. Another chapter addresses the relationship between COVID-19 infection and acute coronary syndromes, such as myocardial infarction, which can cause direct injury to the heart muscle, leading to myocarditis and myocardial injury. These conditions can result in reduced heart function and an increased risk of developing or exacerbating coronary artery disease (CAD). As such, this section also includes a chapter describing the use of unshielded magnetocardiography in the detection of myocardial damage in patients who are recovering from COVID-19.

I gratefully acknowledge the invaluable organizational skills of the staff at IntechOpen, especially Author Service Manager Ms. Sara Debeuc for her timely and invaluable assistance. I am also thankful to the book's designer, information technology staff, and marketing representatives who are working to promote the book on various platforms. I sincerely appreciate and applaud all the contributing authors for their excellence, hard work, and commitment to advancing and spreading their knowledge of ECG. They have taken time from their personal and professional life to complete this task. I thank them profusely for that.

This book is dedicated to my little Master Shawn who continues to inspire me and make my life blissful.

We hope that this book will serve as a useful reference for clinical providers interested in comprehensive electrophysiology using intra-cardiac ECGs.

> **Umashankar Lakshmanadoss, MD, FACC, FHRS** Division of Cardiac Electrophysiology, The Jewish Hospital of Cincinnati-Mercy Heart Institute, Cincinnati, OH, USA

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Section 1

Practical Applications

of ECG in Arrhythmias

Section 1
