MODULE SUPPLEMENT: CARDIOVASCULAR SYSTEM
Clinical Implications

These changes--as discussed on the previous page--also have clinical implications. Changes in the base to apex length of the cardiac chambers (atria, ventricles) can cause the mitral chordae tendineae to become longer than necessary which can cause the posterior leaflet to hood slightly, mimicking mitral valve prolapse. The valves become thicker and sclerosic which contributes to the development of aortic stenosis, which reaches a prevalence of nearly 20% in octogenarians (Bramstedt, 2003).

As the pericardium tends to become stiffer, it can contribute to decreased diastolic function, a problem that is discussed in greater detail when we focus on congestive heart failure. In addition, alterations in the conduction system, including fibrosis, fatty infiltration, and loss of specialized conducting tissue, may, along with changes in responsiveness to norepinephrine (discussed below), affect maximum response to exercise and predispose the older adult to arrhythmias.

In addition to the structural changes that occur, some physiologic processes are altered. The level of Atrial Naturetic Factor (ANF), which is produced by the atrial, usually in response to stretch, tends to increase with age. The clinical importance of ANF relates especially to its impact on the excretion of sodium in the kidney. Also see Changes in Renal Homeostatic Controls (Note: This link will open in a new browser window which you can close to return here).