|
Diseases of the heart and circulation are so common and the laity is so well acquainted with the major symptoms resulting from these disorders that patients, and occasionally physicians, erroneously attribute many noncardiac complaints to cardiovascular disease.(1) It should not be a surprise that this occurs since most patients are aware that cardiovascular disease remains the leading cause of death in the United States. More than 50 percent of patients with ischemic heart disease initially present with acute myocardial infarction, and 50 percent of patients who suffer acute myocardial infarction do not survive.(2)
There are four principle properties of the cardiovascular system that can be evaluated to provide diagnostic, prognostic, and therapeutic management information. These include (1) electrical conduction, (2) pump function, (3) myocardial perfusion, and (4) anatomy.(3)
Ischemia, or inadequate myocardial perfusion, is manifest most frequently as chest discomfort. A cardinal principle is that cardiac function that is adequate at rest may be inadequate during exertion. Thus, a history of chest pain or discomfort only during activity is characteristic of heart disease. Reduction in the pumping ability of the heart frequently manifests as weakness and fatigability, or as the disease process continues and becomes more severe, produces cyanosis, hypotension, syncope, and elevated intravascular pressure behind a failing ventricle. A failing ventricle will also produce the accumulation of fluid (edema) either in the systemic or pulmonary circulation, and may cause dyspnea, and orthopnea. Obstructions to blood flow, such as is found in valvular stenosis, can cause symptoms resembling congestive heart failure. Arrhythmias, or disorders of electrical conduction usually develop suddenly. The accompanying signs and symptoms—palpitations, dyspnea, angina, hypotension, and syncope may disappear as rapidly as they develop.
Patients with cardiovascular disease may also be completely asymptomatic. They may present, however, with elevated arterial pressure, a heart murmur, abnormal chest x-ray or abnormal ECG upon medical evaluation. In cardiovascular disease, the history taking, interview, and physical examination remain the most important elements of patient assessment.(4) While there are many technologically advanced tests available, they are only effective when used in conjunction with a complete history and physical examination. History taking enables the examiner to establish a relationship with the patient, develop an awareness of the patient's perception of problems and quality of life, and an assessment of the problem's acuity and severity.(5) Particular attention should be paid to the family history, as familial clustering is common in many forms of heart disease.
The New York Heart Association has outlined the elements of a complete cardiac diagnosis. They include consideration of:(6)
- The underlying etiology. Is the disease congenital, infectious, hypertensive, or ischemic in origin?
- The anatomic abnormalities. What chambers are involved? Which valves are affected? Is there pericardial involvement? Has there been a myocardial infarction?
- The physiologic disturbances. Is there an arrhythmia present? Is there evidence of congestive heart failure or myocardial ischemia?
- The extent of functional disability. How strenuous is the physical activity required to elicit symptoms? The latter should be evaluated in light of the intensity of therapy.
There are several risk factors for cardiovascular disease that are essentially immutable. These are older age, male gender, and a family history of CVD. Additionally, three major risk factors identified include cigarette smoking, dyslipidemia, and hypertension.(7) Other identified factor
|
