This may cause a slightly slower rate of exchange of nutrients and wastes.
This causes dizziness because there is less blood flow to the brain. This may explain why many older people have orthostatic hypotension, a condition in which the blood pressure falls when a person goes from lying or sitting to standing. The baroreceptors become less sensitive with aging. Receptors called baroreceptors monitor the blood pressure and make changes to help maintain a fairly constant blood pressure when a person changes positions or is doing other activities.A heart murmur caused by valve stiffness is fairly common in older people. The valves inside the heart, which control the direction of blood flow, thicken and become stiffer. The heart muscle cells degenerate slightly.
Normal changes in the heart include deposits of the "aging pigment," lipofuscin.They may be caused by several types of heart disease. Abnormal rhythms ( arrhythmias), such as atrial fibrillation, are more common in older people. Heart changes often cause the electrocardiogram ( ECG) of a normal, healthy older person to be slightly different than the ECG of a healthy younger adult.The heart wall thickens, so the amount of blood that the chamber can hold may actually decrease despite the increased overall heart size. A slight increase in the size of the heart, especially the left ventricle occurs in some people.These changes may result in a slightly slower heart rate. The natural pacemaker (the sinoatrial or SA node) loses some of its cells. Some of the pathways of this system may develop fibrous tissue and fat deposits. The heart has a natural pacemaker system that controls the heartbeat.
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