Coronary Artery Disease and Dysrhythmias

CAD is a generic designation for many different conditions that involve obstructed blood flow through the coronary arteries. The most prevalent etiologies of CAD are atherosclerosis, coronary vasospasm, and microvascular angina. Microvascular angina results from poor function of the smaller blood vessels that supply the heart. Atherosclerosis is by far the most common cause of CAD and is the focus of this chapter. Both individual risk factors and the presence of concurrent disease states influence the incidence of CAD. Some populations have an increased occurrence of CAD because of definable characteristics or risks. Risk factors are classically categorized as nonmodifiable and modifiable. Nonmodifiable risk factors include age, gender, race, and family history and genetics. Modifiable risk factors include diabetes, hypertension, tobacco use, sedentary lifestyle, obesity, and stress (see Risk Factors box). The American Heart Association (AHA) has not firmly established hyperhomocysteinemia as an independent risk factor; however, it has established guidelines for monitoring homocysteine levels in high-risk individuals. C-reactive protein, another measure of inflammation, is also considered a marker for an increased risk of cardiovascular disease and of adverse outcomes in patients with acute coronary syndrome (ACS). People in a high-risk group have about a C H A P T E R 2 9