12 - Decreased Vitality

Editors: Kane, Robert L.; Ouslander, Joseph G.; Abrass, Itamar B.

Title: Essentials of Clinical Geriatrics, 5th Edition

Copyright 2004 McGraw-Hill

> Table of Contents > Part III - General Management Strategies > Chapter 11 - Cardiovascular Disorders

Chapter 11

Cardiovascular Disorders

In older adults, heart disease is the leading cause of death worldwide and is the most common cause for hospitalization. Physiological changes of the cardiovascular system in aging may modify the presentation of cardiac disease.

PHYSIOLOGICAL CHANGES

In reviewing data on physiological changes of the cardiovascular system, it is important to recognize the selection criteria of the population studied. Because the prevalence of coronary artery disease may be 50 percent in the eighth and ninth decades of life, screening for exclusion of occult cardiovascular disease may modify findings.

In a population screened for occult coronary artery disease, there is no change in cardiac output at rest over the third to eighth decades (Gerstenblith et al., 1987) (Table 11-1). There is a slight decrease in heart rate and a compensatory slight increase in stroke volume. This is in contrast to studies in unscreened individuals, where cardiac output falls from the second to the ninth decades. During maximal exercise, however, other changes are manifest even in the screened population (Table 11-2). Heart rate response to exercise is decreased in older adults, as compared to younger individuals, reflecting a diminished -adrenergic responsiveness in aging. Cardiac output is decreased, slightly. Cardiac output is maintained by increasing cardiac volumes increasing end-diastolic and end-systolic volumes. With this increase in workload and the work of pumping blood against less-compliant arteries and a higher blood pressure, cardiac hypertrophy occurs even in the screened elderly population.

TABLE 11-1 RESTING CARDIAC FUNCTION IN PATIENTS AGED 30 TO 80 YEARS COMPARED WITH THAT IN 30-YEAR-OLDS

  UNSCREENED FOR OCCULT CAD SCREENED FOR OCCULT CAD
Heart rate
Stroke volume - - +
Stroke volume index - - 0
Cardiac output - - 0
Cardiac index - - 0
Peripheral vascular resistance + + 0
Peak systolic blood pressure + + + +
Diastolic pressure 0 0
Key: CAD, coronary artery disease; +, slight increase; ++, increase; -, slight decrease; --, decrease; 0, no difference.

TABLE 11-2 PERFORMANCE AT MAXIMUM EXERCISE IN SAMPLE SCREENED FOR CORONARY ARTERY DISEASE, AGE 30 TO 80 YEARS

  COMPARED WITH 30-YEAR-OLDS
Heart rate - -
End-diastolic volume + +
Stroke volume + +
Cardiac output -
End-systolic volume + +
Ejection fraction - -
Total peripheral vascular resistance 0
Systolic blood pressure 0
Key: + +, increase; -, slight decrease; - -, decrease; 0, no difference.

Because myocardial reserve mechanisms are used to maintain normal function in aging, older persons are more vulnerable to development of dysfunction when disease is superimposed.

Diastolic dysfunction retarded left ventricular filling and higher left ventricular diastolic pressure is present both at rest and during exercise in older persons. Older persons are more dependent on atrial contraction, as opposed to ventricular relaxation, for left ventricular filling, and thus are more likely to develop heart

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failure if atrial fibrillation ensues. Heart failure may occur in the absence of systolic dysfunction or valvular disease.

HYPERTENSION

Hypertension is the major risk factor for stroke, heart failure, and coronary artery disease in older adults; all are important contributors to mortality and functional disability. Because hypertension is remediable and its control may reduce the incidence of coronary heart disease and stroke, increased efforts at detection and treatment of high blood pressure are indicated.

Hypertension is defined as a systolic blood pressure of 140 mmHg or greater and/or a diastolic blood pressure of 90 mmHg or greater. Isolated systolic hypertension is defined as a systolic pressure of 140 mmHg or greater with a diastolic pressure of less than 90 mmHg. With these definitions, as many as 40 to 50 percent of individuals older than age 65 may be hypertensive.

Despite the high prevalence of hypertension in older adults, it should not be considered a normal consequence of aging. Hypertension is the major risk factor for cardiovascular disease in older adults and that risk increases with each decade. Elevation of systolic blood pressure and of pulse pressure are both better predicators of adverse events than diastolic pressure. This is particularly relevant to older individuals who frequently have isolated systolic hypertension.

Evaluation

The diagnosis should be made on serial blood pressures. In patients with labile hypertension, blood pressure should be averaged to make the diagnosis, because these patients are at no less risk than those patients with stable hypertension. The history and physical examination should be directed toward assessing the duration, severity, treatment, and complications of the hypertension (Table 11-3). Atherosclerosis may interfere with occlusion of the brachial artery by a blood pressure cuff, leading to erroneously elevated blood pressure determinations, or pseudohypertension. Such an effect can be determined by the Osler maneuver. The cuff pressure is raised above systolic blood pressure. If the radial artery remains palpable at this pressure, significant atherosclerosis is probably present and may account for a 10- to 15-mmHg pressure error. Standing blood pressure should also be determined. Initial laboratory evaluation should include urinalysis, complete blood cell count; measurements of blood electrolytes, creatinine, fasting glucose, and lipids; and 12-lead electrocardiogram.

TABLE 11-3 INITIAL EVALUATION OF HYPERTENSION IN OLDER ADULTS

History
   Duration
   Severity
   Treatment
   Complications
   Other risk factors
Physical examination
   Blood pressure, including Osler maneuver and standing determinations
   Weight
   Funduscopic, vascular, and cardiac examination for end-organ damage
   Abdominal bruit
   Neurological examination for focal deficits
Laboratory tests
   Urinalysis
   Electrolytes
   Creatinine
   Calcium
   Chest radiograph
   Electrocardiogram

Secondary forms of hypertension are uncommon in older adults, but should be considered in treatment-resistant patients and in those with diastolic pressures >115 mmHg (Table 11-4). Pheochromocytoma is uncommon in older adults and

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is particularly unusual in those older than age 75. Atherosclerotic renovascular hypertension and primary hyperaldosteronism may occur more frequently in older persons. With the use of automated calcium determinations, the frequency of diagnosis of primary hyperparathyroidism is increasing, particularly in postmenopausal women. Because there is a causal link between this disorder and hypertension, the diagnosis and treatment of hyperparathyroidism may ameliorate the elevated blood pressure.

TABLE 11-4 SECONDARY HYPERTENSION IN OLDER PERSONS

Renovascular disease (atherosclerotic)
Primary hyperaldosteronism
Hyperparathyroidism (calcium)
Estrogen administration
Renal disease (decreased creatinine clearance)

Estrogen therapy in the postmenopausal woman may be associated with hypertension. Such an association can be assessed by withdrawing estrogen therapy for several months and following the blood pressure response.

Treatment

The issue of treatment of systolic/diastolic or isolated systolic hypertension in older individuals has been resolved. Multiple large trials have demonstrated that treating hypertension in older adults decreases morbidity and mortality from coronary artery disease and stroke (reviewed in Joint National Committee, 1997).

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Although there has been concern about the hazard of treating individuals with cerebrovascular disease, the evidence suggests that the presence of cerebrovascular disease is an indication for, rather than a contraindication to, hypertensive therapy.

Some of the treatment trials that have included individuals to age 84 years suggest that there should be no age cutoff above which high blood pressure is not treated. Relatively healthy older persons at any age should be treated unless they have severe comorbid disease that clearly will limit their life expectancy or unless the toxicity of treatment is so great that it outweighs potential benefits. The treatment goal for uncomplicated hypertension is a blood pressure <140/90 mmHg.

Specific Therapy

Lifestyle changes are not easily accomplished but should be attempted, including maintaining ideal body weight, limiting dietary sodium intake, eating fruits and vegetables and low fat dairy products, reducing saturated and total fats, and engaging in aerobic exercise (reviewed in August, 2003). Foods rich in potassium, calcium, and magnesium should be consumed. Other risk factors, such as smoking, dyslipidemia, and diabetes mellitus, should also be modified.

If dietary measures fail to control blood pressure, drug therapy should be considered. Physiological and pathological changes of aging should be considered in individualizing the therapy. Changes in volumes of distribution and hepatic and renal metabolism may alter pharmacokinetics (see Chap. 14). Changes in vessel elasticity and baroreceptor sensitivity may alter responses to posture and drug-induced falls in blood pressure.

Thiazide diuretics are usually the initial step in therapy, especially in older patients with isolated systolic hypertension. They are well tolerated, are relatively inexpensive, and can be given once a day (Table 11-5). Many older hypertensives can be treated with diuretics as the only medication. Low-dose thiazides, for example, 12.5 to 25 mg of chlorthalidone, are efficacious in lowering blood pressure,

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while minimizing metabolic side effects. Higher doses have a minimal additional effect on blood pressure with a more marked effect on hypokalemia. Thiazides are contraindicated in patients with gout. Postural hypotension is uncommon, but serum potassium should be monitored. Diabetics may have increased requirements for insulin or oral hypoglycemic agents.

TABLE 11-5 THIAZIDE DIURETICS FOR ANTIHYPERTENSIVE THERAPY

ADVANTAGES ADVERSE EFFECTS
Well tolerated
No central nervous system side effects
Relatively inexpensive
Infrequent dosing
Good response rate
Orthostatic hypotension uncommon
Can be used in conjunction with other agents
Effective in advanced age
Effective in systolic hypertension
Hypokalemia
Volume depletion
Hyponatremia
Hyperglycemia
Hyperuricemia
Impotence

Although beta blockers are also recommended as initial-step therapy, two meta-analyses have called this into question (Psaty et al., 1997; Messerli et al., 1998). In these analyses beta blockers were shown to reduce stroke and congestive heart failure but not coronary heart disease, cardiovascular mortality, or all-cause mortality in older adults. When compared to each other, thiazides are superior to beta blockers in older adults (MRC Working Party, 1992). In ALLHAT, thiazides were superior to angiotensin-converting enzyme (ACE) inhibitors in reducing cardiovascular disease, stroke, and heart failure (ALLHAT Collaborative Research Group, 2002). However, another trial suggests that ACE inhibitors are superior in older subjects, particularly men, in reducing cardiovascular events and mortality, but not stroke (Wing et al., 2003). Beta-blocking agents may be used as the initial drug when another indication for their use exists, such as coronary heart disease, tachyarrhythmias, or essential tremor.

If thiazides alone do not control blood pressure, a second agent is added (Table 11-6) or a thiazide is added if one of the other agents has failed. The choice should be individualized and usually selected from among beta blockers, calcium-channel antagonists, angiotensin-converting enzyme (ACE) inhibitors, or angiotensin-receptor antagonists (ARBs) (The Medical Letter, 2001). Beta blockers are indicated for treatment of angina, heart failure, previous myocardial infarction, and tachyarrhythmias in association with hypertension. These agents

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are contraindicated in patients with cardiac conduction deficits, bradyarrhythmias, and reactive airways disease. The more water-soluble beta blockers may be well suited for the geriatric population because they enter the central nervous system less readily and thus have fewer of the central nervous system side effects such as somnolence and depression; this would be a particular advantage in the elderly. However, if cardiac output is decreased, renal perfusion and glomerular filtration rate may be affected. One concern with beta blockers is the production of bradycardia with reduced cardiac output. One simple test to monitor for this side effect is the patient's response to mild exercise after each dosage increase; a failure to increase pulse by at least 10 beats per minute is an indication to reduce the dosage. If a patient is to be taken off a beta-blocking agent, withdrawal should be done slowly over a period of several days to avoid rebound of original symptoms.

TABLE 11-6 ANTIHYPERTENSIVE MEDICATIONS

AGENT* ADVANTAGES DISADVANTAGES
Beta-blockers Useful in angina, previous myocardial infraction, heart failure
Water-soluble agents have fewer central nervous system side effects
Must be withdrawn slowly in presence of coronary artery disease
Contraindicated in cardiacconduction defects and reactive airways disease
May cause bronchospasm, bradycardia, impaired peripheral circulation, fatigue, and decreased exercise tolerance
Calcium channel blockers Peripheral vasodilator
Coronary blood flow maintained
Potency increased with age or in systolic hypertension
Headaches
Sodium retention
Negative inotropic effect
Conduction abnormality
Angiotensin-converting enzyme inhibitors Preload and afterload reduction
Use in congestive heart failure, diabetes mellitus, other nephropathy with proteinuria
Hyperkalemia
Hypotension
Decreased renal function
Cough
Angioedema
Angiotensin-receptor antagonists Use in angiotensin converting enzyme inhibitor induced cough, congestive heart failure, diabetes mellitus, other nephropathy with proteinuria Hyperkalemia
Angioedema (rare)
Clonidine Increased renal perfusion Somnolence, depression
Dry mouth, constipation
Rarely, withdrawal hypertensive crisis
Alpha blockers Useful in benignprostatic hypertrophy Orthostatic hypotension
Hydralazine May be useful in systolic hypertension Reflex tachycardia, aggravation of angina
Lupus-like syndrome at high dosage
* With all these agents, initiation with low dosage and careful titration may minimize side effects.

Calcium-channel antagonists are peripheral vasodilators with the advantage of maintaining coronary blood flow. These agents appear to have increased potency with age, possibly as a result of the decreased reflex tachycardia and myocardial contractility in older adults as compared with younger individuals. Headache, sodium retention, negative inotropic effects especially in combination with beta blockers and conduction abnormalities may limit their use. Calcium-channel antagonists are effective in reducing stroke incidence in older patients with isolated systolic hypertension (Staessen et al., 1997). However, these drugs do not significantly reduce the risk of heart failure (Blood Pressure Lowering Treatment Trialists' Collaboration, 2000).

ACE inhibitors are effective and well tolerated for treatment of hypertension. They are both preload and afterload reducers and thus are particularly useful in the face of congestive heart failure. They prolong survival in patients with heart failure or left ventricular dysfunction after a myocardial infarction. Long-acting agents may have an advantage in adherence. Renal function, which may deteriorate on administration of these agents, must be monitored carefully. These agents may also induce hyperkalemia and should generally not be used with a potassium-sparing diuretic. Older adults are also more vulnerable to the hypotensive effects of these drugs.

ARBs are effective in lowering blood pressure without causing cough. They and ACE inhibitors are appropriate initial therapy in patients with diabetes mellitus, renal disease, or congestive heart failure (August, 2003). ARBs are superior to beta blockers in the treatment of patients with isolated systolic hypertension and left ventricular hypertrophy (Kjeldsen et al., 2002).

Clonidine may cause somnolence and depression, but it increases renal perfusion. The clonidine transdermal patch may lessen some of these adverse effects. However, local skin reactions may occur in about 15 percent of users. The once-per-week application of the patch may be an asset in improving adherence.

The major side effect of alpha blockers is orthostatic hypotension; this is especially problematic with initial doses of prazosin. Newer agents with lesser hypotensive effects are now being used to treat symptomatic benign prostatic

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hypertrophy. In ALLHAT, the alpha-blocker arm was stopped early because of a higher incidence of congestive heart failure. Consequently, alpha blockers are not recommended as monotherapy for hypertension.

Although hydralazine is usually a third-step drug, it may occasionally be used as a second-step drug in older adults because reflex tachycardia rarely occurs. If used with diuretics alone, it should be initiated in low dosages, which should be increased slowly. It should not be used in the absence of a beta blocker if coronary artery disease is present.

With the newer, more effective agents, drug-resistant hypertension is unusual. In such cases, drug adherence should be monitored and sodium intake assessed. If such factors are not contributing to drug resistance, secondary causes of hypertension should be considered, especially renovascular disease and primary hyperaldosteronism.

STROKE AND TRANSIENT ISCHEMIC ATTACKS

Although the incidence of stroke is declining, it is still a major medical problem affecting approximately 50,000 individuals in the United States every year. It is the third leading cause of death and is also a major cause of morbidity, long-term disability, and hospital admissions. Stroke is clearly a disease of older adults; approximately 75 percent of strokes occur in those older than age 65 years. The incidence of stroke rises steeply with age, being 10 times greater in the 75- to 84-year-old age group than in the 55- to 64-year-old age group.

Table 11-7 lists the types and outcomes of stroke. In cerebral infarct, thrombosis, usually arteriosclerotic, is the commonest cause, with embolization from an ulcerated plaque or myocardial thrombosis less frequent. Table 11-8 lists outcomes for survivors.

TABLE 11-7 STROKE

CAUSE RELATIVE FREQUENCY % MORTALITY RATE %
Subarachnoid hemorrhage 10 50
Intracerebral hemorrhage 15 80
Cerebral infarction (thrombosis and embolism) 75 40

TABLE 11-8 OUTCOME FOR SURVIVORS OF STROKE

OUTCOME PERCENT
No dysfunction 10
Mild dysfunction 40
Significant dysfunction 40
Institutional care 10

Table 11-9 lists the modifiable risk factors for ischemic stroke. Hypertension is the major risk factor. Systolic hypertension is associated with a three- to fivefold

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increased risk for stroke. Hypertension accelerates the formation of atheromatous plaques and damages the integrity of vessel walls, predisposing to thrombotic occlusion and cerebral infarction. Hypertension also promotes growth of microaneurysms in segments of small intracranial arteries. Those lesions are sites of intracranial hemorrhage and lacunar infarcts.

TABLE 11-9 MODIFIABLE RISK FACTORS FOR ISCHEMIC STROKE

Alcohol consumption (>5 drinks/d)
Asymptomatic carotid stenosis (>50%)
Atrial fibrillation
Elevated total cholesterol level
Hypertension
Obesity
Physical inactivity
Smoking
Modified from Straus et al., 2002.

Whether diabetes mellitus is a modifiable risk factor remains an unresolved issue. Tight glycemic control trials in type 2 diabetes have not shown improved outcomes for stroke.

Patients with a history of transient ischemic attacks (TIAs) are at substantial risk for subsequent stroke, particularly within the first few days. Completed stroke as a sequel of TIA is reported to occur in 12 to 60 percent or more of untreated TIA patients. In retrospective studies of patients with completed stroke, previous TIA is reported to have occurred in 50 to 75 percent of patients.

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The keystone to the diagnosis of stroke is a clear history of sudden, acute neurological deficit. When the history is not clear, especially if the deficit could have had a gradual onset, consideration should be given to a mass lesion. In such cases, brain scanning with computed tomography is indicated. Electroencephalography is only occasionally helpful in the differential diagnosis. Lumbar puncture is indicated in stroke patients if hemorrhage is suspected, but not if there is evidence of increased intracranial pressure. An electrocardiogram should be performed routinely in cases of TIA or stroke because it may relate the episode to myocardial infarction or cardiac arrhythmia. Invasive techniques are usually unnecessary in stroke patients.

In older adults, symptoms acceptable as evidence of cerebral ischemia are often misinterpreted. Table 11-10 lists the presenting symptoms for TIA in the carotid and vertebral basilar systems.

TABLE 11-10 TIA: PRESENTING SYMPTOMS

SYMPTOM CAROTID VERTEBROBASILAR
Paresis + + + + +
Paresthesia + + + + + +
Binocular vision 0 + + +
Vertigo 0 + + +
Diplopia 0 + +
Ataxia 0 + +
Dizziness 0 + +
Monocular vision + + 0
Headache + +
Dysphasia + 0
Dysarthria + +
Nausea and vomiting 0 +
Loss of consciousness 0 0
Visual hallucinations 0 0
Tinnitus 0 0
Mental change 0 0
Drop attacks 0 0
Drowsiness 0 0
Light-headedness 0 0
Hyperacusia 0 0
Weakness (generalized) 0 0
Convulsion 0 0
Key: + + +, most frequent; 0, least frequent.

Treatment

The FDA has approved and committees of the American Heart Association and the American Academy of Neurology have published guidelines endorsing the use of tissue plasminogen activator within 3 hours of onset of ischemic stroke. Thrombolytic therapy increases the risk for early death and intracranial hemorrhage but decreases the combined end point of death or dependency at 3 to 6 months. Despite the use of thrombolytics, treatment of stroke leads to little improvement in outcomes. Thus, intervention is directed toward prevention of stroke.

For primary prevention of stroke, adequate blood pressure reduction, and treatment of hyperlipidemia, use of antithrombotic therapy in patients with atrial fibrillation, and of antiplatelet therapy in patients with myocardial infarction are effective and supported by evidence from several randomized trials (Straus et al., 2002). These same strategies are effective in secondary prevention of stroke, as is carotid endarterectomy in patients with severe carotid artery stenosis.

Lowering blood pressure in hypertensive individuals is effective in the prevention of hemorrhagic and ischemic stroke. The benefits of antihypertensive treatment extends to patients older than age 80 years (Gueyffier et al., 1999). Thiazide diuretics, beta blockers, ACE inhibitors, and long-acting calcium channel blockers reduce the incidence of stroke. Selection of a specific class of drugs is discussed earlier in this chapter.

Patients with atrial fibrillation have a mortality rate double that of age- and sex-matched controls without atrial fibrillation. The risk of stroke with nonrheumatic atrial fibrillation is approximately 5 percent a year. Adjusted-dose warfarin and aspirin reduce stroke in patients with atrial fibrillation, and warfarin is substantially more efficacious than aspirin (Hart et al., 1999; Segal et al., 2000). Major extracranial hemorrhage is minimally increased in warfarin-treated patients. Excess bleeding risk with warfarin in elderly patients can be similar to the low

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rates achieved in the randomized trials (Caro et al., 1999). Strokes that occur in patients receiving warfarin or aspirin are not more severe than those occurring in placebo-treated patients. Stroke risks and benefits of antithrombotic therapy are similar for patients with paroxysmal or chronic atrial fibrillation (Hart et al., 2000).

Although aspirin may be beneficial in the primary prevention of myocardial infarction, it is not efficacious for the primary prevention of stroke. The risk of ischemic stroke is increased after a myocardial infarction, particularly in the first

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month. Aspirin reduces the risk of nonfatal stroke in patients who have experienced a myocardial infarction (Antiplatelet Trialists' Collaboration, 2002). Aspirin decreases the risk of stroke in patients with previous TIA or stroke, and there appears to be no dose-response relationship in doses of 50 to 1500 mg/d. Clopidogrel and ticlopidine are modestly more effective than aspirin in decreasing risk of the combined endpoint of stroke myocardial infarction or vascular death (Straus et al., 2002).

Carotid endarterectomy decreases the risk of stroke or death in patients with symptomatic carotid disease and severe carotid artery stenosis (70 to 99 percent). In patients with symptomatic moderate carotid artery stenosis (50 to 69 percent) benefits were more marginal. Patients with lesser degrees of stenosis (<50 percent) may be harmed by surgery. For people with asymptomatic carotid disease, the optimal therapy is unclear. However, identifying carotid artery stenosis in asymptomatic individuals can involve expensive and invasive diagnostic procedures. The costs of screening large numbers of asymptomatic people outweighs the benefits to the number of individuals screening would identify.

Stroke Rehabilitation

Table 11-11 presents factors in the prognosis for rehabilitation of elderly stroke patients. Although the benefit of stroke rehabilitation is controversial, it should be initiated early in the course if it is to be of benefit. Stroke patients fare better in rehabilitative facilities than in skilled nursing facilities (Kane et al., 1996; Schlenker et al., 1997). Generally, most neurologic return occurs during the first month after the stroke. By the end of the third month, little if any further return can be expected. Not all dysfunctions result in the same level of disability. Motor loss is often the least disabling. Perceptual and/or sensory loss, aphasia, loss of balance, hemicorporal neglect, hemianopsia, and/or cognitive damage may cause more severe and often untreatable disabilities.

TABLE 11-11 FACTORS IN PROGNOSIS FOR REHABILITATION

Availability and implementation of sound program
Mentation
Motivation
Prognosis for neurological return
Vigor

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In the immediate rehabilitation stage, treatment is directed toward avoiding complications such as pressure sores, contractures, phlebitis, pulmonary embolism, aspiration pneumonia, and fecal impaction.

In the next stage of rehabilitation, treatment is directed toward reeducating muscles (affected areas) and enhancing remaining capabilities (unaffected areas). Table 11-12 describes measures to be taken during this phase.

TABLE 11-12 STROKE REHABILITATION

Acute phase
    Change of patient's position at least every 2 h
    Positioning of patient's joints to prevent contractures
    Positioning of patient to prevent aspiration pneumonia
    Range-of-motion exercises
Later phase
    Activities of daily living training
    Ambulation training
    Functional activities for affected side
    Muscle reeducation exercises
    Perceptual training
    Training in transfer technique

When the patient stops making progress after intensive therapy, the goal of rehabilitation shifts to finding ways for the patient to cope with the dysfunction. At this stage, the patient is assessed for the need for braces and assistive devices for both ambulation and performance of activities of daily living. With a sound program of rehabilitation, the older patient who survives a stroke can return to the community.

CORONARY ARTERY DISEASE

The frequency of both coronary artery disease and myocardial infarction (MI) increase with age. Elderly patients have more severe disease than younger patients, and mortality rate is higher after acute MI.

Hypertension is the major risk factor for coronary artery disease in older adults. Hypercholesterolemia and cigarette smoking become less-important risk factors in this age group, although they are still significant. Risk factor reduction should include treatment of hypertension and dyslipidemia, and smoking cessation.

Angina pectoris has a similar presentation in both older adults and in younger patients, with familiar pain characteristics and radiation. Pharmacologically,

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acute episodes of angina pectoris can be treated with sublingual nitroglycerin, which should be taken in the sitting position to avoid severe orthostatic hypotension. Primary therapy for chronic stable angina is aspirin and beta blockers. Both are underused in the elderly, especially after acute MI. Secondary therapy includes long-acting nitrates and calcium-channel blockers, but their use may be limited by orthostatic hypotension in older patients.

Younger patients with chronic symptomatic coronary artery disease benefit from revascularization. Procedure-related mortality increases with age both after coronary artery bypass graft (Alexander et al., 2000) and after percutaneous coronary intervention (Batchelor et al., 2000). In those without significant comorbidity, mortality approaches that seen in younger patients. One-year outcomes in elderly patients with chronic angina are similar with regard to symptoms, quality of life, and death or nonfatal infarction with invasive versus optimized medical strategies (Pfisterer et al., 2003). Elderly patients with angina refractory to standard drug therapy have a choice between an early invasive strategy that carries a certain early intervention risk and an optimized medical strategy that carries a chance of late hospitalization and revascularization. After 1 year, quality of life outcome and survival will be similar.

The elderly patient with acute MI may present with symptoms other than chest pain (Table 11-13). Treatment of the older patient with acute myocardial infarction is similar to that of the young patient. Particular attention should be paid to avoiding drug toxicity and to beginning early mobilization when possible. Early mobilization may decrease deconditioning, orthostatic hypotension, and thrombophlebitis. No specific trials in the elderly have assessed percutaneous coronary intervention versus thrombolysis for treatment of acute MI. However, subgroup analyses indicate better outcomes with percutaneous coronary intervention. Coronary artery surgery can be performed with excellent symptomatic results in older patients, but with increased morbidity and mortality. The strongest indication for surgery is angina pectoris refractory to medical management. In patients with left main coronary artery disease, surgery significantly improves

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survival over medical therapy. Patients with three-vessel disease may also have improved survival. In older adults, however, improved survival must be considered in the light of the patient's projected survival and the higher operative risk.

TABLE 11-13 PRESENTING SYMPTOMS OF MYOCARDIAL INFARCTION

Chest pain
Confusion
Dyspnea
Rapid deterioration of health
Syncope
Worsening congestive heart failure

Long-term administration of beta blockers to patients after myocardial infarction improves survival. Despite these data, physicians are reluctant to administer beta blockers to many patients, such as older patients (Krumholz et al., 1998) and those with chronic pulmonary disease, left ventricular dysfunction, or non Q-wave myocardial infarction. However, all these subgroups benefit from beta-blocker therapy after myocardial infarction (Gottlieb et al., 1998). Given the higher mortality rates in these subgroups, the absolute reduction in mortality was similar to or greater than that among patients with no specific risk factors. Other secondary prevention interventions should include aspirin, ACE inhibitors, lipid-lowering agents, and smoking cessation.

VALVULAR HEART DISEASE

Calcific Aortic Stenosis

Pathologically, degenerative calcification of the aortic and mitral valves is common among older adults; it is found at autopsy in approximately one-third of individuals older than age 75 years. Aortic valve sclerosis is common in the elderly (29 percent in the Cardiovascular Health Study) and is associated with an increase in the risk of death from cardiovascular causes and the risk of myocardial infarction, even in the absence of hemodynamically significant obstruction of left ventricular outflow (Otto, 1999). The frequency of aortic stenosis increases with age, appearing at autopsy in approximately 4 to 6 percent of those older than age 65. Isolated aortic stenosis is more common among men than women except in those older than age 80, where women predominate. Aortic insufficiency may coexist with calcific aortic stenosis, although regurgitation is usually mild and a regurgitant murmur usually not heard.

The usual clinical presentation of aortic stenosis in older adults consists of fatigue, syncope, angina pectoris, and congestive heart failure. Because systolic murmurs are a frequent finding in older adults, differentiation of mitral regurgitation, aortic sclerosis, or aortic stenosis by auscultation is a challenge. The location of the murmur is usually along the lower left sternal border and apex and often does not radiate to the axilla or carotids. It is characteristically a crescendo-decrescendo systolic murmur ending before the second heart sound. Table 11-14 describes aspects that may help differentiate mitral regurgitation from aortic murmurs.

TABLE 11-14 DIFFERENTIATION OF SYSTOLIC MURMURS

  POSTPER-CUTANEOUS CORONARY ANGIOPLASTY* AMYL NITRATE VALSALVA SQUATTING
Aortic sclerosis
Aortic stenosis
Idiopathic
hypertrophic
subaortic stenosis
Mitral regurgitation
* Best following a premature ventricular contraction.
Effect of maneuver on intensity of murmur.

Differentiation of aortic stenosis from aortic sclerosis can be difficult in the elderly. The typical murmur and pulse of aortic stenosis may be modified in older

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adults. Systemic hypertension may shorten the systolic murmur of stenosis, giving it the characteristic of an aortic sclerosis murmur. Loss of vascular elasticity may modify the pulse pressure, so that the typical pulse contour of aortic stenosis is absent. Therefore, the physical examination alone is not reliable in diagnosing aortic stenosis in older adults. The addition of Doppler flow studies to echocardiography has improved the diagnostic accuracy of noninvasive procedures for aortic stenosis. Left ventricular catheterization remains the most reliable method of assessing aortic stenosis in older adults but should be reserved for patients who are symptomatic (angina, syncope, or dyspnea) and in whom surgery is contemplated.

Surgical mortality for valve replacement is higher in older individuals, but results have improved. Significant coexistent coronary artery disease should be treated with bypass surgery at the time of valve replacement. In general, a biological prosthetic valve is preferred.

Calcified Mitral Annulus

Mitral ring calcification is a disease of older adults and is most frequently found in patients older than age 70. It is reported in 9 percent of autopsies in individuals older than age 50 and has a striking increase with advancing age, particularly in women, in whom it rises from 3.2 percent in women younger than age 70 to 44 percent in women older than age 90.

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This lesion often results in mitral insufficiency or conduction abnormalities and rarely in stenosis. It is an important contributing factor to congestive heart failure in older adults and is a site for endocarditis. As many as two-thirds of patients with mitral annulus calcification present with an apical systolic murmur of mitral regurgitation.

Echocardiography is the best technique for diagnosing mitral annulus calcification. Regurgitation is usually mild to moderate, and surgery is usually indicated only if endocarditis is superimposed. Recommendations for the prevention of bacterial endocarditis have been made by the American Heart Association (Dajani et al., 1997). There is a higher incidence of cerebral embolism in this disorder, and thus anticoagulation with Coumadin may be indicated.

Mitral Valve Prolapse

Mucoid degeneration affects mainly the mitral valve. This process allows stretching of the mitral valve leaflet under normal intracardiac pressure, with subsequent prolapse into the left atrium during systole.

Although the classic murmur is late systolic, the murmur can occur any time in systole. Mucoid degeneration of the mitral valve has been described in approximately 1 percent of autopsies on patients older than age 65 years. It is associated with mitral insufficiency; left atrial dilatation and regurgitant murmurs are common. Mitral insufficiency caused by this disorder is usually well tolerated and rarely requires surgery. Some patients with this syndrome have abnormal electrocardiograms and chest pain suggestive of coronary artery disease; sudden death has been reported.

Death directly from the valve disease is usually related to rupture of the chordae tendineae. Mucoid degeneration also predisposes to infective endocarditis. Prophylaxis for subacute bacterial endocarditis is indicated, and recommendations of the American Heart Association should be followed (Dajani et al., 1997).

Idiopathic Hypertrophic Subaortic Stenosis

In older adults, idiopathic hypertrophic subaortic stenosis (IHSS) may be misdiagnosed as aortic valve stenosis or mitral regurgitation. Presenting symptoms are similar to those of aortic stenosis or coronary artery disease. The presence of a bisferious arterial pulse in the presence of a systolic ejection murmur and in the absence of an aortic regurgitation murmur should suggest IHSS. The IHSS murmur usually does not radiate to the carotids. Squatting, which increases left ventricular filling, usually decreases the murmur of IHSS. Factors that decrease left ventricular volume (Valsalva maneuver, standing) increase the intensity of the murmur.

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Documentation of IHSS is accomplished by echocardiography.

Therapy usually relies on -adrenergic antagonists. Symptoms may be worsened by cardiac glycosides, which increase myocardial contractility, and diuretics, which create volume depletion. Atrial fibrillation is poorly tolerated and may require cardioversion in the rapidly deteriorating patient. In patients refractory to medical therapy, surgery should be considered after cardiac catheterization to assess severity of outflow obstruction and state of coronary artery flow.

ARRHYTHMIAS

Although the prevalence of arrhythmias increases with age, most older patients without clinical heart disease are in normal sinus rhythm.

Atrial fibrillation occurs in 5 to 10 percent of asymptomatic ambulatory older adults and more frequently in hospitalized patients. It is usually associated with underlying heart disease; the causes are the same as in younger individuals. Atrial fibrillation does, however, occur more frequently in older patients with thyrotoxicosis.

Patients with recent onset atrial fibrillation and hemodynamic instability or angina should undergo urgent cardioversion (Falk, 2001). If the patient's condition is stable, heart rate should be controlled with intravenous diltiazem, beta blocker, or digoxin. If atrial fibrillation persists and onset is 48 hours, cardioversion may be attempted after initiation of heparin therapy. If onset is >48 hours, treatment should include 3 weeks of anticoagulation prior to cardioversion, unless a transesophageal echocardiogram reveals no atrial thrombus at presentation. Anticoagulation for persistent and intermittent atrial fibrillation was discussed in the treatment of stroke and transient ischemic attacks section of this chapter. For long-term rate control, verapamil, diltiazem, and beta blockers should be the initial drugs of choice. -adrenergic blockers are especially effective in the presence of thyrotoxicosis and increased sympathetic tone. Digoxin should be considered as first-line treatment only in patients with congestive heart failure secondary to impaired systolic ventricular function. In some patients, combinations of these drugs may be needed to control ventricular response. The maintenance dose of digoxin is usually lower in older adults because of decreased muscular mass and decreased renal clearance. In patients with recurrence of persistent atrial fibrillation after electrical cardioversion, rate control is not inferior to rhythm control (repeated cardioversion or antiarrhythmics) for prevention of death and morbidity from cardiovascular causes (Van Gelder et al., 2002). In drug-refractory atrial fibrillation and systolic dysfunction, ablation of the atrioventricular node and implantation of a pacemaker is a highly effective treatment. Implantable pacing/cardioversion devices can significantly decrease the incidence of atrial fibrillation and improve quality of life (Cooper et al., 2002). These devices may have an increasing role in the future.

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The incidence of premature ventricular contractions increases with age and occurs in approximately 10 percent of electrocardiograms and in 30 to 40 percent of Holter monitorings. The decision to treat with antiarrhythmic therapy is difficult except in the immediate postmyocardial infarction period, when it is recommended. Criteria for therapy in older patients are the same as for therapy in younger patients. The half-life of antiarrhythmic drugs is prolonged in the elderly. Therapy should be initiated at lower doses, and blood levels should be monitored (see Chap. 14).

The sick sinus syndrome is particularly common among older patients. Diagnosis is made by Holter monitor. Table 11-15 lists the symptoms of sick sinus syndrome, which are usually related to decreased organ perfusion. There is no satisfactory medical therapy. Symptomatic patients may require pacemakers, which do not seem to decrease mortality in this syndrome but can alleviate symptoms. A pacemaker may be indicated in patients with cardiac side effects from drugs used to control tachycardias in the bradycardia-tachycardia syndrome.

TABLE 11-15 MANIFESTATIONS OF SICK SINUS SYNDROME

Angina pectoris
Congestive heart failure
Dizziness
Insomnia
Memory loss
Palpitations
Syncope

CONGESTIVE HEART FAILURE

Although congestive heart failure is prevalent in older adults, it is often overdiagnosed. Pedal and pretibial edema is not sufficient to warrant the diagnosis. Venous stasis may produce a similar picture. Care is needed to establish the presence of other signs of congestive heart failure (e.g., cardiac enlargement, S3 heart sound, basilar crackles, jugular venous distention, enlarged liver). Determination of ejection fraction by two-dimensional echocardiography may assist in the diagnosis.

Greater than 75 percent of cases of overt heart failure in older patients are associated with hypertension or coronary heart disease. Diastolic dysfunction, not systolic dysfunction, is the primary cause of heart failure in older patients, and is associated with marked increases in all-cause mortality (Redfield et al., 2003).

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Diuretics should be used to treat pulmonary congestion or peripheral edema. In the absence of randomized controlled trials, ACE inhibitors, beta blockers, or calcium-channel blockers are recommended with reservation (Ahmed, 2003).

The mainstays of therapy for congestive heart failure as a result of systolic dysfunction in older patients, as in younger patients, are diuretics for fluid overload, ACE inhibitors, beta blockers, spironolactone, and digoxin. To improve function and survival, all patients with chronic symptomatic congestive heart failure that is associated with reduced systolic ejection or left ventricular remodeling should be treated with ACE inhibitors. Beta blockers also improve symptoms and survival (Hjalmarson et al., 2000). Low doses of spironolactone decrease mortality in severe heart failure (The Medical Letter, 1999).

The use of digitalis preparations must be approached with caution. Patients once begun on digoxin tend to remain on it long after the indications have ceased. Subtle signs of toxicity may be missed, as the drug accumulates in the presence of decreased renal function. Because of decreases in lean body mass and glomerular filtration rate, lower doses of digoxin are generally required in the elderly. Initial maintenance doses should be lower; blood levels should be monitored to avoid toxic levels. Because the therapeutic window is narrowed in older adults, patients who have been on digoxin therapy for long periods of time after an acute episode of cardiac decompensation not related to arrhythmias should be considered for discontinuation of digoxin. Weight should be monitored closely so that digoxin can be reinstated before congestive symptoms occur. With such evaluation and monitoring, some older patients on chronic digoxin therapy for other than antiarrhythmic treatment may not require digoxin therapy.

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Essentials of Clinical Geriatrics
Understanding Thin Client/Server Computing (Strategic Technology Series)
ISBN: 71498222
EAN: 2147483647
Year: 2002
Pages: 23
Authors: Joel P Kanter

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