Cardiovascular diseases comprise the most prevalent serious disorders in industrialized nations and are a rapidly growing problem in developing nations (Chap. 225). Age-adjusted death rates for coronary heart disease have declined by two-thirds in the last 4 decades in the United States, reflecting the identification and reduction of risk factors as well as improved treatments and interventions for the management of coronary artery disease, arrhythmias, and heart failure. Nonetheless, cardiovascular diseases remain the most common causes of death, responsible for 35% of all deaths, almost 1 million deaths each year. Approximately one-fourth of these deaths are sudden. In addition, cardiovascular diseases are highly prevalent, diagnosed in 80 million adults, or ~35% of the adult population. The growing prevalence of obesity (Chap. 77), type 2 diabetes mellitus (Chap. 344), and metabolic syndrome (Chap. 242), which are important risk factors for atherosclerosis, now threatens to reverse the progress that has been made in the age-adjusted reduction in the mortality rate of coronary heart disease.
For many years cardiovascular disease was considered to be more common in men than in women. In fact, the percentage of all deaths secondary to cardiovascular disease is higher among women (43%) than among men (37%) (Chap. 6). In addition, although the absolute number of deaths secondary to cardiovascular disease has declined over the past decades in men, this number has actually risen in women. Inflammation, obesity, type 2 diabetes mellitus, and the metabolic syndrome appear to play more prominent roles in the development of coronary atherosclerosis in women than in men. Coronary artery disease (CAD) is more frequently associated with dysfunction of the coronary microcirculation in women than in men. Exercise electrocardiography has a lower diagnostic accuracy in the prediction of epicardial obstruction in women than in men.
The symptoms caused by heart disease result most commonly from myocardial ischemia, disturbance of the contraction and/or relaxation of the myocardium, obstruction to blood flow, or an abnormal cardiac rhythm or rate. Ischemia, which is caused by an imbalance between the heart's oxygen supply and demand, is manifest most frequently as chest discomfort (Chap. 12), whereas reduction of the pumping ability of the heart commonly leads to fatigue and elevated intravascular pressure upstream of the failing ventricle. The latter results in abnormal fluid accumulation, with peripheral edema (Chap. 36) or pulmonary congestion and dyspnea (Chap. 33). Obstruction to blood flow, as occurs in valvular stenosis, can cause symptoms resembling those of myocardial failure (Chap. 234). Cardiac arrhythmias often develop suddenly, and the resulting symptoms and signs—palpitations (Chap. 37), dyspnea, hypotension, and syncope (Chap. 20)—generally occur abruptly and may disappear as rapidly as they develop.
Although dyspnea, chest discomfort, edema, and syncope are cardinal manifestations of cardiac disease, they occur in other conditions as well. Thus, dyspnea is observed in disorders as diverse as pulmonary disease, marked obesity, and anxiety (Chap. 33). Similarly, chest discomfort may result from a variety of noncardiac and cardiac causes other than myocardial ischemia (ch12). Edema, an important finding in untreated or inadequately treated heart failure, also may occur with primary renal disease and in hepatic cirrhosis (Chap. 36). Syncope occurs not only with serious cardiac arrhythmias but in a number of neurologic conditions as well (Chap. 20). Whether heart disease is responsible for these symptoms frequently can be determined by carrying out a careful clinical examination (Chap. 227), supplemented by noninvasive testing using electrocardiography at rest and during exercise (Chap. 228), echocardiography, roentgenography, and other forms of myocardial imaging (Chap. 229).
Myocardial or coronary function that may be adequate at rest may be insufficient during exertion. Thus, dyspnea and/or chest discomfort that appear during activity are characteristic of patients with heart disease, whereas the opposite pattern, i.e., the appearance of these symptoms at rest and their remission during exertion, is rarely observed in such patients. It is important, therefore, to question the patient carefully about the relation of symptoms to exertion.
Many patients with cardiovascular disease may be asymptomatic both at rest and during exertion but may present with an abnormal physical finding such as a heart murmur, elevated arterial pressure, or an abnormality of the electrocardiogram (ECG) or the cardiac silhouette on the chest roentgenogram or other imaging test. It is important to assess the global risk of CAD in asymptomatic individuals, using a combination of clinical assessment and measurement of cholesterol and its fractions, as well as other biomarkers, such as C-reactive protein, in some patients (Chap. 241). Since the first clinical manifestation of CAD may be catastrophic—sudden cardiac death, acute myocardial infarction, or stroke in previous asymptomatic persons—it is mandatory to identify those at high risk of such events and institute further testing and preventive measures.
As outlined by the New York Heart Association (NYHA), the elements of a complete cardiac diagnosis include the systematic consideration of the following:
The underlying etiology. Is the disease congenital, hypertensive, ischemic, or inflammatory in origin?
The anatomical abnormalities. Which chambers are involved? Are they hypertrophied, dilated, or both? Which valves are affected? Are they regurgitant and/or stenotic? Is there pericardial involvement? Has there been a myocardial infarction?
The physiological disturbances. Is an arrhythmia present? Is there evidence of congestive heart failure or myocardial ischemia?
Functional disability. How strenuous is the physical activity required to elicit symptoms? The classification provided by the NYHA has been found to be useful in describing functional disability (Table 226-1).
Table 226–1. New York Heart Association Functional Classification
| Save Table
Table 226–1. New York Heart Association Functional Classification
|Class I||Class III|
|No limitation of physical ...|
Log In to View More
If you don't have a subscription, please view our individual subscription options
below to find out how you can gain access to this content.
Want access to your institution's subscription?
Sign in to your MyAccess Account while you are actively authenticated on this website
via your institution (you will be able to tell by looking in the top right corner
of any page – if you see your institution’s name, you are authenticated). You will
then be able to access your institute’s content/subscription for 90 days from any
location, after which you must repeat this process for continued access.
If your institution subscribes to this resource, and you don't have a MyAccess account,
please contact your library's reference desk for information on how to gain access
to this resource from off-campus.
AccessMedicine Full Site: One-Year Subscription
Connect to the full suite of AccessMedicine content and resources including more than 250 examination and procedural videos, patient safety modules, an extensive drug database, Q&A, Case Files, and more.
Pay Per View: Timed Access to all of AccessMedicine
48 Hour Subscription
Pop-up div Successfully Displayed
This div only appears when the trigger link is hovered over.
Otherwise it is hidden from view.