Preface

The diagnosis of endocarditis has evolved substantially over the years, and there are many reasons for this. Advances in medical imaging technologies, including echocardiography, computed tomography (CT), and magnetic resonance imaging (MRI) combined with greater utilization of these modalities for the serial diagnosis and management of patients have allowed for improved diagnosis and understanding of various disease conditions. In addition, greater awareness of the problem, especially some of the contributing risk factors such as implantable cardiac devices, intravenous drug/substance abuse, and more advanced chronically ill and immunosuppressed patients, has contributed to a significant increase in the overall incidence of infections involving heart valves and other cardiac structures.

While the diagnosis of endocarditis has remained somewhat consistent over the years, the tools used to evaluate and manage patients have become more widely available, more accurate, and more precise. Because of the increased utilization of advanced imaging technologies on patients at all stages of life, many more patients are being diagnosed with potential infectious complications of their cardiac structures. This has resulted in a growing incidence of unusual, complex, and poorly understood problems, all of which are discussed in this book.

It is also becoming clear that the global increase in substance abuse, especially intravenous drugs and the use of 'dirty' needles or 'contaminated' drugs, has also increased the incidence of infectious problems. While the ethical implications of managing patients with long-standing substance abuse have been previously discussed, various chapters in this book address some of the practical aspects of management of infectious complications associated with 'right-sided problems. Historically, the established international guidelines have focused on the management of 'left-sided disease, namely, involving the aortic and/or mitral valves. However, with the increased incidence of 'right-sided pathology, mainly the tricuspid valve and less commonly the pulmonic valve, the technical aspects of management continued to evolve. Likewise, decision-making regarding indications, medical therapy, and goals of care continue to evolve and become incorporated into professional society guidelines.

With the growing understanding of the incidence, risk factors, management, and overall pathophysiology of endocarditis, there is also the increasing recognition of a potential impact on a broader range of the patient population. For example, with advanced in-cancer therapies and the potential impact on the heart, there is also growing interest in the potential role that oncologic treatment has on the heart, either as a primary impact or a secondary process, such as an increased risk for structural abnormalities including infectious endocarditis, and the ability to distinguish between normal, abnormal, and abnormal from infectious complications versus non-infectious complications. Chapters in this text lend some insights and guidance into these evolving multi-disciplinary areas of cardio-oncologic care.

While the topic of endocarditis is extensive and a comprehensive review is far beyond the scope of a single project, it is the goal of this text to highlight some evolving areas in both the diagnosis and management of infectious complications. Even though the focus is on the pathophysiology of endocarditis, it is also important to recognize that the same advanced diagnostic tools that are being used to identify various pathologic states are also being more widely utilized to better help understand the natural history and evolution from normal structure and function to a pathologic disease state. In other words, a primary goal of this text is to provide some greater insights into the rapidly evolving themes regarding the diagnosis and management of endocarditis with the recognition that to understand abnormal appropriately, we also must be proficient in our understanding of normal.

The editors greatly appreciate the authors for their hard work and thoughtful contributions.

> **Michael S. Firstenberg** St. Elizabeth Medical Center, Appleton, Wisconsin, USA

> > **1**

**Chapter 1**

Endocarditis

*Michael S. Firstenberg*

**1. Introduction**

Introductory Chapter:

based approach to the diagnosis and management.

might be greater than historically believed [2].

epidemiology, and management options of endocarditis.

Endocarditis a very complex and diverse set of problems and can include infectious and non-infectious diseases of the heart. The spectrum of problems includes vegetations on valves, fistulas and abscess cavities, and infections that develop on prosthetic materials such as pacemaker and defibrillator leads, prosthetic valves, intra-cardiac catheters, heart pumps, and any other type of intracardiac foreign material. The diagnosis and management of these problems can be quite challenging and will typically require an integrated multi-disciplinary team. Nevertheless, with advances in the therapies that are being offered to older and sicker patients, offset by advances in both the medical and surgical management of infectious cardiac problems, the number of cases continue to grow with still major risks for morbidity and mortality. In addition, the global concerns for substance abuse and the risks for the use of contaminated needles has led to a significant increase in associated infectious complications. Without a doubt, endocarditis in the setting of substance abuse is not only a significant medical and surgical problem – but a difficult social problem as well. The financial and ethical implications of endocarditis further highlight the emphasis of a team-

Unfortunately, even minor invasive procedures have been shown to increase to risk of infections of native or prosthetic valves [1]. Typically, endocarditis was associated with blood-stream infections in the setting of dental procedures, but it is becoming more recognized that even minor procedures, such as gastrointestinal endoscopy, can increase risk for cardiac infections and might prompt a broader reevaluation of the role of prophylactic antibiotics prior to such procedures.

Evidence, especially in higher-risk patients such as those with bicuspid aortic valves and mitral valve prolapse, is suggesting that the risk for bloodstream infection

The growing incidence of endocarditis also parallels the growing social problems of modern society as is seen in the evolving epidemiology of patients presenting with infections of their heart, heart valves, and intra-cardiac devices and structures. As mentioned, the global drug abuse epidemic – combined with the increasing utilization of cardiac procedures in older and sicker patients with advanced co-morbidities, reflects the need for a more wide-spread recognition of this problem. Fortunately, advances in diagnostic –especially imaging technology and microbiology serology testing – and surgical techniques can improve outcomes in those who present with even advanced disease. As such, the goal of this book is to emphasize and review some of the evolving concepts in the diagnosis, presentation,

**Umashankar Lakshmanadoss MD, FACC, FHRS, CCCDS** Mercy Heart Institute, Cincinnati, OH, USA
