Clinical Neurocardiology: Fundamentals and Clinical Cardiology PDF

Preface

The heart and the brain are arguably the most important organs in the human body. The brain is the organ that makes us what we are. The traits that allow others to recognize and characterize each of us as individuals, including our intelligence, personality, ambition, character, and sense of humor, are all determined by our brains. Intact brain function is necessary for us to move, walk, feel, see, hear, speak, read, and communicate.

The heart is the core, the hub, of the body. The heart is absolutely necessary for life to continue; when our heart dies, we die. The heart's pumping action keeps the other body organs alive. The brain, in turn, exerts some control over cardiac function. Both organs have tentacles that reach the periphery of the body—the blood vessels and the spinal cord and peripheral nervous systems— and carry activity and information to and from all the body's vital regions.

The heart and brain are so interdependent and interrelated that it is impossible to practice first-rate neurology or cardiology without a working knowledge of each specialty. Neurological complications of cardiac disease and cardiac procedures and operations—strokes, seizures, coma, paralysis—are probably among the most feared patient outcomes for cardiologists. Cardiologists are often asked to consult on patients with strokes and neurological diseases to determine the presence of heart abnormalities and their relation to the neurological condition.

This book is aimed at cardiologists, internists, and neurologists. We intend the book to serve them as a practical, clinical, and relatively concise source of information for them about the neurological and cardiological abnormalities relevant to their practices. At present there is no other handy reference source that serves this function.

The first three chapters consider neurological findings in patients with heart disease. Chapter 1 explores the neurology of cardiac arrest and circulatory failure. Coma and brain damage guide prognosis and heavily determine the treatment strategies that cardiologists will choose for these patients. Chapter 2 considers brain embolism. Newer diagnostic techniques such as emboli monitoring using transcranial Doppler ultrasound show that an ever-increasing percentage of brain infarcts are due to embolism from the heart, aorta, and proximal cervicocranial arteries. The effects of various toxic and metabolic disorders that cause neurological symptoms in patients with cardiac disease are discussed in Chapter 3, which also includes a discussion of the neurological side effects of drugs commonly given to cardiac patients.

The next two chapters consider neurological complications of cardiac surgery and cardiac procedures. Unfortunately, neurological symptoms and signs often follow cardiac interventions. The causes and outcomes of neurological complications and their prevention and treatment are considered in these chapters.

Finally, Chapters 6 and 7 describe the cardiac and cardiovascular as well as the neurological findings in patients whose primary disorders are neurological. Chapter 6 discusses the management of patients who have both coronary artery and carotid artery disease. Since occlusive vascular disease is one of the most common causes of both brain disease and heart disease, the topic of coexistent coronary and cerebrovascular disease is an important issue for both cardiologists and neurologists. Chapter 7 describes the cardiac lesions and cardiac findings as well as the common neurological findings in patients with primary neurological diseases such as stroke, muscle dystrophy, hereditary ataxias, etc., and the cardiac and cardiovascular findings in patients with disorders that affect both the heart and the nervous system

Central nervous system and muscle diseases often have an associated cardiopathy. Cardiologists are frequently asked to consult on patients with a wide variety of neurological conditions, and neurologists often consult on patients with various systemic and cardiac disorders. Many of the neurological diseases are rare. In some patients, a systemic condition such as an endocrinopathy affects both the heart and nervous system. In other patients, the cardiac and neurological conditions are concurrent but not causally related and are each a part of a genetically mediated condition—e.g., a mitochondrial disorder.

Associated cardiac findings are important and often determine prognosis. There is now no ready source of information available for cardiologists, neurologists, or other physicians to look up the cardiac and neurological findings in these diseases, many of which will be unfamiliar to them. We do not discuss hypertension, cerebrovascular disease, or stroke diagnosis or management in any depth in this book, since excellent texts are available on these vast subjects.

The two principal neurologist authors, Drs. Caplan and Chimowitz, each have had, for a very long time, a major interest in both stroke and heart disease. Dr. Caplan is board-certified in internal medicine as well as neurology. In medical school he was a disciple of Drs. Barney Marriott and Leonard Sherlis. He was fortunate at the Beth Israel Deaconess Medical Center and the New England Medical Center in Boston and at the Michael Reese Hospital in Chicago to have worked closely with many outstanding cardiologists, including Paul Zoll, Stafford Cohen, George Kurland, Ivan D'Cruz, Herb Levine, Deeb Salem, Nat Pandian, Mark Estes, Paul Wang, Earl Silber, and Arnold Pick. Dr. Marc Chimowitz was the director of the stroke service at the University of Michigan and now serves in that capacity at Emory University in Atlanta. He developed an interest in heart– brain interactions when, as an intern, he spent 2 months on Professor Christiaan Barnard's cardiac surgery service at the Groote Schur Hospital in Cape Town, South Africa. During his fellowship in stroke at the Cleveland Clinic, he had extensive experiencewith patientswho had cardiac procedures and cardiac surgery. He was fortunate to have been guided by Drs. Tony Furlan and Cathy Sila, neurologists at the Cleveland Clinic who have written extensively on cardiac neurology.

Drs. Caplan and Chimowitz have had extensive experience in writing about stroke and in writing for cardiologists and internists. They enlisted the help of Dr. J. Willis Hurst of Emory University to write about the cardiac findings in patients with primary neurological diseases. Dr. Hurst has always had a wide interest in general internal medicine, including neurology as well as cardiology. His writings are very well known to cardiologists throughout the world. Dr. Hurst has read and commented on all the chapters in this book, which represents the combined experience of the three authors.

We owe thanks to a great many individuals who helped with this book. In Boston, Pauline Dawley was instrumental in ensuring that the references, permissions, and final drafts were prepared speedily and accurately. Susan Marshall and Carol Miller played similar roles in Atlanta. Dr. Rick Schiefe, a neuropharmacologist, reviewed Chapter 3 and offered sage advise. Dr. Roy Freeman, an expert on the autonomic nervous system, reviewed Chapter 7 and offered a number of suggestions. Dr. Frank Sellke, a cardiac surgeon, critiqued Chapter 4. A number of colleagues from the neurology and cardiac services at the Beth Israel Deaconess Medical Center, the New England Medical Center, and Emory University were very helpful in consulting on aspects of the first three chapters and Chapter 7.