Anesthesia Student Survival Guide.pdf - Index of

PhysioloGy And AnesthesiA for elderly PAtients ● 371
Conduction system abnormalities are often seen in the elderly because
of a decrease in the number and function of atrial pacemaker cells. The most
commonly seen abnormalities are right bundle branch block (RBBB) and first
degree heart block. The responsiveness of b-adrenergic receptors is also diminished,
rendering the elderly unable to initiate compensatory increases in heart
rate in response to hypovolemia. Therefore, the elderly are likely to develop
orthostatic hypotension. Although cardiac output may remain unchanged,
systolic blood pressure increases with age, whereas diastolic blood pressure
increases until age 60–65 years and then plateaus or decreases (see Fig. 23.2).
Valvular abnormalities are more common due to sclerosis and calcification,
and more than 70% percent of the elderly have an audible heart murmur.
Pulmonary Changes
The major changes that occur with aging can be broadly attributed to the
following factors:
Figure 23.2 Changes in blood pressure with age.