Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android. Learn more here!

KNOWLEDGE COMPETENCIES

  1. Describe the etiology, pathophysiology, clinical presentation, and patient needs in:

    • Cardiomyopathy

    • Valvular disease

    • Pericarditis

    • Aortic aneurysm

    • Cardiac transplantation

  2. Compare and contrast the principles of management of:

    • Cardiomyopathy

    • Valvular disease

    • Pericarditis

    • Aortic aneurysm

    • Cardiac transplantation

  3. Identify indications for, complications of, and nursing management of patients receiving intra-aortic balloon pump (IABP) and ventricular assist device (VAD) therapy.

PATHOLOGIC CONDITIONS

Cardiomyopathy

Cardiomyopathy is a disease involving destruction of the cardiac muscle fibers, causing impairment of myocardial function and decreased cardiac output (CO). The body responds to this with initiation of several neuroendocrine responses including activation of the sympathetic nervous system and renin-angiotensin-aldosterone chain. The prevailing result is marked vasoconstriction, retention of sodium and water, and further myocyte injury. This process contributes to remodeling of ventricular myocytes and the downward spiral of cardiomyopathy. The cause of cardiomyopathy is often unknown. Cardiomyopathies are commonly classified into three types: dilated, hypertrophic, and restrictive (Figure 19-1).

Figure 19-1.

Types of cardiomyopathies. (A) Dilated (cardiac dilation and impaired contractility). (B) Hypertrophic (decreased size of ventricular chambers and increased ventricular muscle mass). (C) Restrictive (decreased ventricular compliance).

Dilated cardiomyopathy, the most common type of cardiomyopathy, is commonly caused by coronary artery disease and is associated with impaired myocardial contractility and increased ventricular filling pressures. Coronary artery disease contributes to ventricular remodeling, thereby reducing ejection fraction. The two case studies presented later in this chapter involve patients with dilated cardiomyopathy.

Hypertrophic cardiomyopathy may occur in both the young and the older adults. Hypertrophic cardiomyopathy is often categorized as obstructive or nonobstructive. Ventricular hypertrophy occurs in both types. The diagnosis of obstructive hypertrophic cardiomyopathy is made if hypertrophy of the intraventricular septum is also present. This is the congenital form and is often referred to as hypertrophic obstructive cardiomyopathy (HOCM). In the past, other terms used to describe this type of cardiomyopathy were idiopathic hypertrophic subaortic stenosis (IHSS) and asymmetric septal hypertrophy (ASH). The hypertrophied septum obstructs the left ventricular outflow tract just below the aortic valve, thereby limiting ejection. Blood volume is “trapped” within the left ventricular chamber.

Restrictive cardiomyopathy is the least common of the three types. A classic finding for this type of cardiomyopathy is ventricular fibrosis, often caused by infiltration of the cardiac myocytes with abnormal tissue such as sarcoid or amyloid disease. The fibrotic muscle tissue becomes very rigid with decreased compliance thus limiting distention during diastole.

Etiology and Pathophysiology

A variety of conditions may cause or contribute to the development of cardiomyopathy (Table 19-1). As noted previously, coronary artery disease is the most common cause of dilated cardiomyopathy in the United States.

TABLE 19-1ETIOLOGY OF CARDIOMYOPATHY

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.