Carther

Section I
INTR ODUCTION
Chapter 1

The History and Physical Examination . . . . . . . . . 2
Chapter 2

Coronary Atherosclerosis . . . . . . . . . . . . . . . . . . . 18
Chapter 3

Electrocardiography . . . . . . . . . . . . . . . . . . . . . . . 29
Chapter 4

Noninvasive Cardiac Imaging . . . . . . . . . . . . . . . 42
Chapter 5

Diagnostic Coronary Angiography . . . . . . . . . .. 53
Chapter 6

Use of Diagnostic Testing . . . . . . . . . . . . . . . . . . 64

Chapter 1

The History and Physical Examination
Marschall S. Runge and E. Magnus Ohman The ability to determine whether disease is present or absent—and how that patient should be treated— is the ultimate goal for clinicians evaluating patients with suspected heart disease. Despite the number of diagnostictests available, never has the importance of a careful history and physical examination been greater. Selection of the most appropriate test and therapeutic approach for each patient can only result from establishing the prior probability of disease, an assessment based on a skillfully performed history and physical examination. Opportunities for error in this judgment are abundant. Screeningpatients for coronary risk using a broad and unfocused panel of laboratory and noninvasive tests instead of a history and physical examination is inappropriate. While entire texts have been written on cardiac history and physical examination, this chapter specifically focuses on features of the cardiac history and the cardiovascular physical examination that help discern the presence or absence ofheart disease.

THE CONCEPT OF PRIOR PROBABILITY
The history and physical examination should enable the clinician to establish the prior probability of heart disease: that is, the likelihood that the symptoms reported by the patient result from heart disease. A reasonable goal is to establish a patient’s risk of heart disease as “low,” “intermediate,” or “high.” One demonstration of this principlein clinical medicine is the assessment of patients with chest pain, in which the power of exercise stress testing to accurately diagnose coronary heart disease (CHD) depends on the prior probability of disease. In patients with very low risk of CHD based on clinical findings, exercise stress testing resulted in a large number of false-positive test results. Because 15% or less of exercise stresstests produce positive results in individuals without CHD, use of this test in a lowrisk population can result in an adverse ratio of false-positive:true-positive test results and unnecessary cardiac catheterizations. Conversely, in patients with a very high risk of CHD based on clinical findings, exercise stress testing can result in false-negative test results—an equally undesirable outcomebecause patients with significant coronary artery disease (CAD) and their physicians may be falsely reassured that no further evaluation or treatment is necessary.

Emphasis is increasing on quantifying prior probability to an even greater degree using various mathematical models. This is a useful approach in teaching and may be clinically feasible in some diseases. However, for the majority ofpatients with suspected heart disease, categorizing risk as low, intermediate, and high is appropriate, reproducible, and feasible in a busy clinical practice. Therefore, obtaining the history and physical examination represents a key step before any testing, to minimize use of inappropriate diagnostic procedures.

THE HISTORY
A wealth of information is available to clinicians who perform a carefulassessment of the patient’s history. Key components are assessment of the chief complaint; careful questioning for related, often subtle, symptoms that may further define the chief complaint; and determination of other factors that help categorize the likelihood of disease. Major symptoms of heart patients include chest discomfort, dyspnea, palpitations, and syncope or presyncope. Chest...