By the time a person reaches 65, his or her heart has done an astounding amount of work. The adult heart beats more than 100,000 times a day, pumping roughly 2,000 gallons of blood through 60,000 miles of blood vessels every 24 hours. The strongest muscle in the body, the heart at 65 still has the capacity for many more years of service. Nevertheless, natural physiologic changes in old age will somewhat lessen its efficiency.
Physiological changes
As we age, like any other organ in the body the heart also undergoes age-related subtle changes even in the absence of disease.
The muscles of the aged heart may relax less completely between beats; as a result, the pumping chambers (ventricles) become stiffer and may work less efficiently, especially if specific cardiac diseases are present. In old age, the heart also may not pump as vigorously or as effectively as it once did. The older heart also becomes less responsive to adrenaline and cannot increase the strength or rate of its contractions during exercise to the same extent it could in youth. We all come to realize that although a 50- or 100-yard dash was easy when we were 20, it is extremely difficult as we get older—the heart just can’t get enough blood out to muscles to supply them with adequate oxygen.
Blood vessels
The vascular system, too, experiences gradual changes over the decades. The walls of the arteries tend to lose their elasticity and stiffen, even without internal blockage from fatty deposits (atherosclerosis). Commonly, this may lead to a specific kind of high blood pressure among older people called isolated systolic hypertension.
High blood pressure
High blood pressure is more common with advancing age, and so are its associated complications, of stroke, kidney disease, heart attack, and heart failure. Elderly people should have blood pressure measured at least twice a year, and high levels (generally defined as 160/90 mm Hg and above) should be treated. The notion has long persisted that a certain degree of high blood pressure is a normal part of the aging process, and may even be necessary to pump sufficient blood to vital organs. More recently, however, convincing evidence has been gathered that high blood pressure in the elderly is not benign. Even in old age, lowering elevated blood pressure can save lives.
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Control of high blood pressure may not be achieved as readily as in younger patients, but even so, partial treatment can lower the rate of potentially serious complications, a conclusion backed up by well-documented evidence from several long-term research studies. How aggressively should high blood pressure in the elderly be treated?
In general, lowering even mildly elevated blood pressure is potentially beneficial, and perhaps of greatest benefit for people with other kinds of cardiovascular disease. For those with no other heart disease, a trial of diet modification, moderate exercise, and (if indicated) smoking cessation and weight loss may be sufficient to lower blood pressure and reduce other concomitant risks.
Coronary artery disease and heart attacks
Coronary heart disease is the leading killer of older people; half of all heart attack victims are over 65. While men have markedly higher rates of coronary heart disease in middle age than do women, women’s rates of coronary disease begin to rise sharply after menopause; ultimately their rates are about equal to those of men.
Coronary heart disease may be manifested as reversible episodes of myocardial ischemia, characterized by chest pain (angina) or shortness of breath, on exertion or when severe, even at rest.
A heart attack, occurs when inadequate blood flow to part of the heart leads to the death of heart muscle and scar formation ( Myocardial infarction). So-called silent heart attacks can occur without the classic symptoms of chest pain—and are more likely in old age, especially in diabetic individuals.
Instead of causing the typical crushing chest pain or pressure, a heart attack may announce itself with a symptom such as “heartburn,” shortness of breath, fainting, or confusion; in some cases, the symptoms are few or none. The elderly, and those who care for them, should be aware of these atypical warning signs of a heart attack and seek prompt evaluation. Evidence of heart damage may be detected on an electrocardiogram or echocardiogram.
Heart valve disease
Certain types of valve disorders are far more common among the elderly. Some can be treated effectively with medications, regardless of age; others will not respond to medication but can be treated surgically, an option that may merit consideration if symptoms interfere with the activities of daily life.
The most common valvular problem in old age is aortic valve disease. The aortic valve is the gateway for blood pumped from the left ventricle to the rest of the body. Aortic sclerosis refers to the process of thickening and stiffening (fibrosis, or scarring) in the valve. It affects up to a third of all elderly people.
Severe aortic valve stenosis ( narrowing) can cause fainting (because of impaired blood flow to the brain across the narrowed valve); heart failure (when the heart’s muscle becomes unable to pump blood in a forward direction through the too-small opening); and chest pain (because of increased work and a lack of sufficient oxygen reaching heart muscles).
Rhythm disorders
Problems with the heart’s rhythm and the electrical system that governs it can occur at any age, but are more common in old age. Rhythm abnormalities, or arrhythmias, may cause no symptoms, or they may be sensed as slow or missed beats, “flutters," palpitations, light-headedness, dizziness, or fainting. The heart’s rhythm may be too slow (bradycardia) or too fast (tachycardia).
Slow rhythm- Can occur due to age related degenerative changes in the heart’s electrical activity generation. As a result, the heartbeat may slow down—in some cases, to a rate below 35 or 40 beats a minute, which will cause the blood pressure to fall to very low levels. Fatigue, confusion, malaise, and fainting may follow.
Fast rhythm- Excessively rapid and irregular rhythm called atrial fibrillation also can occur with ageing. This condition, which affects up to 5 percent of the older population, is generally not dangerous and can be controlled with medication.
Although life-style changes made in old age may no longer have the same impact on reducing the risk of heart disease, some—such as regular exercise and smoking cessation—can positively affect the quality of life. Maintaining an appropriate body weight is important. Control of high blood pressure, whether by life-style changes, medication, or both, is also important in maintaining health.
(The writer is a Consultant Physician)
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