Orthostatic hypotension. I. Functional and neurogenic causes.

The maintenance of adequate upright BP requires both a baroreceptor-mediated feedback loop and an effective circulating blood volume. Although functional disruptions of these mechanisms are reversible and common, several permanent and often progressive neurologic disorders exist that interfere with necessary reflexes and orthostatic BP control. Multiple system atrophy affects diffuse neurologic systems; autonomic dysfunction causes a failure of peripheral vasoconstriction from defective sympathetic stimulation. Idiopathic orthostatic hypotension is a selective disorder of autonomic nerves; postganglionic neurons cannot release norepinephrine properly and are supersensitive to exogenous pressors. Conversely, excessive sympathetic discharge occurs in sympathicotonic orthostatic hypotension, the pathogenesis and incidence of which are unclear. Any peripheral neuropathy may interfere with sympathetic vasoconstrictor activity and is most commonly seen in diabetes mellitus.

Orthostatic hypotension. II. Clinical diagnosis, testing, and treatment.

The clinical diagnosis of orthostatic hypotension (OH) is straightforward and usually does not require extensive laboratory testing. Symptoms of cerebral hypoxia may not occur even with low BP because of compensatory cerebral vascular autoregulation. Autonomic function tests may pinpoint the lesion in OH, but they should be selected carefully. Heart rate response to standing, the valsalva maneuver, the cold pressor test, and plasma norepinephrine levels are the most useful. General measures in management, eg, nocturnal head up tilt and use of a pressure-support garment, often will provide major relief of symptoms. The mainstay of drug therapy is fludrocortisone acetate, but edema, supine hypertension, and heart failure occur frequently. Other agents (eg, vasopressors, prostaglandin inhibitors, and beta-adrenergic blockers) may enhance effectiveness of therapy when combined with fludrocortisone acetate.

Invasive treatment for coronary artery disease in the elderly.

The widespread availability of coronary artery bypass grafting and percutaneous transluminal coronary angioplasty presents important treatment options for the older patient. The findings from a number of surgical series of coronary artery bypass grafting and percutaneous transluminal coronary angioplasty are summarized. Certain trends are evident. Perioperative mortality, cardiovascular morbidity, and other complications, while declining, remain somewhat higher in elderly patients. However, the impact of age alone is slight. In both coronary artery bypass grafting and percutaneous transluminal coronary angioplasty, complications are more closely correlated with the presence of serious concomitant disease. Long-term survival and pain relief after coronary artery bypass grafting are excellent in older patients, and percutaneous transluminal coronary angioplasty may be the treatment of choice in some elderly patients with coronary artery disease. As in younger patients, prolongation of survival should not be the exclusive goal. Rather, a focus on quality of life and freedom from dependency should be seriously considered.

Blood platelet response to plasma from patients with ischemic heart disease.

Blood platelets change shape (from small round spheres to larger spread forms) as they participate in thrombosis. Using an electron microscopic technique, we surveyed 14 patients with both acute and chronic ischemic heart disease; each had increased spread platelet forms (69 plus and minus 22.2 [standard deviation] percent) when compared with 14 asymptomatic control subjects (P less than 0.001). When platelets from these 14 control subjects were exposed to plasma from the patients with ischemic heart disease, spread forms increased from 13.4 plus and minus 9.1 to 44.5 plus and minus 15.5 percent (P less than 0.001). There was no significant increase in spread platelets in these control subjects when their blood was mixed with plasma from another control group. Similar studies were performed in seriously ill noncardiac patients: 9 of 13 had increased spread platelet forms when compared with control subjects, but plasma from only 5 of these 9 subjects caused increased spread forms when mixed with platelets from normal subjects (P less than 0.05). Thus a factor existed in the plasma of these patients with ischemic heart disease that caused normal platelets to become spread. Similarly the plasma of some patients with serious noncardiac disease had a comparable effect on normal platelets. Although the identity of this factor is unknown, it is probably unrelated to hormonal or therapeutic influences occurring either during acute infarction or during the stress of serious illness because (1) the effect of the plasma from patients with acute ischemic heart disease was identical to that of patients with chronic ischemic heart disease, and (2) the effect was not present in all patients with serious noncardiac disease.

Ankle/brachial blood pressure in men >70 years of age and the risk of coronary heart disease.

Low ankle/brachial blood pressure index (ABI) is a marker of generalized atherosclerosis in the elderly, although its association with coronary heart disease (CHD) has not been well established. The purpose of this report is to examine the relation between ABI and the risk of CHD in a sample of elderly men. Findings are based on the ABI that was measured in 2,863 Japanese-American men aged 71 to 93 years at an examination that occurred from 1991 to 1993 in the Honolulu Heart Program. All men were free of total CHD at that time and followed for nonfatal myocardial infarction and death from CHD over a 3- to 6-year period. During follow-up, 186 had a coronary event. Age-adjusted incidence declined significantly from 15.3% in men with an ABI <0.8 to 5.4% in men with an ABI >/=1.0 (p <0.001). The effect of ABI on disease was similar across a variety of risk factor strata, although it seemed strongest in the presence of hypertension and in past and current cigarette smokers. Adjustment for other risk factors failed to diminish the relation between ABI and CHD. We conclude that a low ABI increases the risk of CHD in elderly men. If findings can be extended to other elderly population segments, simple measurement of ABI in an outpatient setting could be an important tool for assessing the risk of CHD in the elderly.

Prolonged QTc interval, impaired pulmonary function, and a very lean body mass jointly predict all-cause mortality in elderly men.

PURPOSE: Assess the joint impact of prolonged QTc interval (QT interval corrected for heart rate), impaired lung function, and low body weight on all-cause mortality. METHODS: This is a population-based, prospective study of the Honolulu Heart Program cohort, performed in Oahu Island, Hawaii, during the 1991-1993 fourth examination of cohort survivors. The participants were 3056 Japanese-American men, 71 to 93 years of age. The measurement consisted of: 1) instrument calculated, heart rate corrected QT interval; 2) one second forced expiratory volume (FEV1) as a percentage of age- and height-predicted FEV1; and 3) body mass index (BMI, kg/m2). Relations of subsequent 3 1/2 year, on average, mortality rates with high risk states of these variables are determined. High risk states are QTc > 440 msec, percent predicted FEV1 < or = 80%, and BMI < or = 21 kg/m2. RESULTS: Mortality rates synergistically increase among groups with one, two, or three high risk states. Men having all three high risk states are seven times more likely to die in the follow-up period than men with no high risk conditions. Very thin men having one other high risk state, pulmonary impairment or prolonged QTc, are four times more likely to die. Excluding diabetics, active smokers, or men taking drugs affecting QT interval does not alter findings. Excluding prevalent coronary heart disease decreases mortality rates among joint high risk groups. CONCLUSION: Results are consistent with clinical studies identifying an autonomic neuropathy associated with wasting chronic lung disease, prolonged QTc, and mortality. Aging populations in developed nations will increase the prevalence of diseases associated with these conditions in decades to come.

Ankle-brachial blood pressure in elderly men and the risk of stroke: the Honolulu Heart Program.

Although low ankle/brachial blood pressure index (ABI) is a marker of generalized atherosclerosis in the elderly, it has not been identified as a risk factor for stroke. The purpose of this report is to examine the relation between ABI and stroke in elderly men. ABI was measured from 1991 to 1993 in 2767 men aged 71 to 93 years in the Honolulu Heart Program without a history of stroke and coronary heart disease. Subjects were followed for 3 to 6 years for fatal and nonfatal thromboembolic and hemorrhagic stroke. During follow-up, there were 91 strokes. There was an age-adjusted 2-fold excess in men with an ABI < 0.9 (6.0%) versus men with an ABI > or = 0.9 (2.9%, P < 0.01). Thromboembolic events occurred in 4.6% of men with an ABI < 0.9 and in 2.0% in those with an ABI > or = 0.9 (P < 0.01). Hemorrhagic stroke was also more frequent in men with a low ABI (< 0.9) versus a higher ABI (1.9 vs. 0.8%, respectively). After adjusting for other factors, the risk of total and thromboembolic strokes increased with declining ABI (P = 0.019 and P = 0.004, respectively). The relation between ABI and stroke was similar and statistically significant in the presence and absence of diabetes and hypertension (P < 0.05). Findings suggest that ABI is inversely related to the incidence of stroke. Simple measurement of ABI in an outpatient setting could be an important tool for assessing the risk of stroke in the elderly.

Family practice, internal medicine, and pediatrics as partners in the education of generalists.

The generalist of the future will play an integral role in the health care delivery system, yet the three recognized generalist specialties have developed and functioned along largely separate tracks. No matter what form of generalism evolves, family practice, internal medicine, and pediatrics must begin to cooperate and collaborate in developing new graduate medical education programs that are sufficiently flexible to meet whatever emerges in the future. They must devote their energies to working together, rather than competing; to emphasizing those parts of their programs that have similarities; and to sharing their knowledge, skills, attitudes, and perspectives about the care of patients. They must develop training experiences in which residents will obtain maximum contact with a wide variety of problems and patients in many different settings; a substantial portion of such training should be generic and virtually interchangeable among the three specialties. As the health care system evolves, so should these disciplines; they must begin to "train physicians to provide continuing, comprehensive and coordinated medical care to a population undifferentiated by gender, disease or organ system," as urged by the American Boards of Family Practice and Internal Medicine.

Empathy and medical education.

Spiro has said, "computed tomographic scans offer no compassion and magnetic resonance imaging has no human face. Only men and women are capable of empathy." Empathy is an essential and required part of our roles as caregivers. We must enhance this natural emotion that exists in each of us; we can do so by carefully designing a curriculum, much as we would for learning about the physiology of the liver. The roots of our need for detachment and equanimity go back to Sir William Osler, but the pendulum has swung too far, and the need for retention of millions of data bits overwhelms our souls. Although excessive emotion is destructive and counter-productive, we must not suppress our passion--but control it. The best physician both feels with the patient and prescribes for the patient at the same time. To do one without the other is inadequate care. As medical educators our task is clear.