Lesson 1, Topic 1
In Progress

Changes in Anatomy, Physiology, and Diseases of the Cardiovascular and Pulmonary Systems

April 11, 2024

Learning Objective: Examine the changes in anatomy, physiology, and diseases of the cardiovascular and pulmonary systems.
      The aging process brings about changes in all of the body’s systems. TABLE 30.1 summarizes the changes to the cardiovascular and pulmonary systems and what can be done to promote healthy aging. The following sections provide more detail about the changes to those systems.

Cardiovascular System
Learning Objective: Explain the changes in the anatomy and physiology of the cardiovascular system caused by aging.
      Cardiovascular disease is the most frequent cause of illness and disability in the aging population, and congestive heart failure (CHF) (see Chapter 25) is the most common reason for hospitalization. Age-related changes can occur in the cardiovascular system. Disease and lifestyle habits such as lack of exercise, poor diet, and stress can greatly contribute to these changes. Heart disease is ranked as the leading cause of death among men and women. Proper management of cardiovascular disease can help maintain the health of an aging population and reduce mortality rates.
      The aging process causes structural changes in the heart. Myocardial cells enlarge, and deposits of fat and connective tissue increase. These combine to make the myocardial wall stiffer and increase the time needed for the relaxation phase of the cardiac cycle. As a result, cardiac output declines, making aging people more susceptible to CHF. The reduction in cardiac output leads to pooling of blood in the legs, cold extremities, and edema. In addition, the heart cannot respond as quickly or forcefully to an increased workload. Exercise, sudden movements, and changes in position can result in dizziness and loss of balance. Aging typically brings with it an increase in blood pressure, requiring the heart to work harder to pump blood into the systemic circulation. Hypertension increases the workload of the left ventricle, which may result in hypertrophy of the chamber and weakening of the myocardial wall. The valves of the heart tend to thicken and become more rigid, making it more difficult for blood to circulate through the cardiopulmonary vessels. With these cardiovascular problems, arrhythmias become more common.
      Aging causes the walls of the veins to weaken and stretch. This damages the valves, especially in the veins of the legs, where the walls are subject to greater pressure as blood struggles to return to the heart against the force of gravity. As a result, edema and varicose veins of the lower extremities are common in older adults, increasing the risk of phlebitis and the formation of thrombi in the deep veins, or deep vein thrombosis (DVT).
Arteriosclerosis is considered part of the aging process. The vessel walls thicken and become less elastic because of the calcification and buildup of connective tissue. In addition, the artery’s ability to dilate and contract diminishes. The heart must work harder to overcome the resistance caused by stiffened vessels to maintain an adequate blood supply throughout the body. Older adults have a higher incidence of orthostatic hypotension. The clinical criterion for alterations in blood pressure from sitting to standing is as follows:

                • A drop of 20 mm Hg or more in the systolic pressure, or
                • 10 mm Hg or more in the diastolic pressure, or
                • Experiencing lightheadedness or dizziness
      When a person with orthostatic hypotension stands, gravity causes blood to pool in the legs, resulting in a drop in the amount of blood returning to the heart for circulation. This decrease in circulating blood volume causes a sudden drop in blood pressure. The provider may have the medical assistant take orthostatic blood pressures as part of the routine intake protocol for aging patients. To perform this procedure, have the patient lie down for 5 minutes, apply a blood pressure cuff, and take the individual’s blood pressure and pulse while the patient is lying down. Leave the cuff in place, have the patient stand, take the blood pressure and pulse after 1 minute of standing, and then again after 3 minutes. Record the blood pressure immediately, including the position for each of the readings.

Pulmonary System
Learning Objective: Explain the changes in the anatomy and physiology of the pulmonary system caused by aging.
      Maximum lung function decreases with age. The rate of airflow through the bronchi slowly declines after age 30, and the maximum force one can achieve on inspiration and expiration declines. The lungs lose their elasticity because of changes in elastin and collagen. They become smaller and flabbier. The alveoli enlarge, their walls become thinner, and the number of capillaries is reduced. As a result, the area for gas exchange in the lungs is reduced. The chest wall may stiffen from osteoporosis of the ribs and vertebrae and calcification of the costal cartilage. The respiratory muscles become weaker, making it harder to move air into and out of the lungs. To compensate, older adults rely more on accessory muscles, such as the diaphragm. Weakening of the respiratory muscles and stiffening of the chest wall make it harder to cough deeply enough to clear mucus from the lungs. Pulmonary function tests reveal a decrease in vital capacity and an increase in residual volume. The incidence of sleep apnea and sleep disorders increases, causing a potential problem with nocturnal hypoxemia. All these factors combine to put the older adult at greater risk for pneumonia and aspiration and reactivation of tuberculosis.
      The larynx also changes with aging, causing a change in the pitch and quality of the voice. The voice sounds quieter and slightly hoarse. The individual’s voice may sound weaker, but it should not interfere with the ability to communicate effectively.