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Biomedical subjects

L A Lipsitz

Publications and source records attributed to L A Lipsitz.

104 records · Page 6Linked to original sources
PubMed1987

Impaired heart rate responses to cough and deep breathing in elderly patients with unexplained syncope.

To test the hypothesis that elderly patients with unexplained syncope have impaired autonomic control of heart rate, chronotropic responses to deep breathing and cough were studied in 12 elderly patients (85 +/- 4 years), 14 elderly control subjects (82 +/- 7 years) and 10 young subjects (26 +/- 5 years). There was no difference in resting RR interval between elderly patients with syncope and control subjects. However, the ratio of the maximum RR/minimum RR (an index of heart rate variability) during deep breathing was significantly lower in patients than in control subjects (p less than 0.005). In the minute following cough, there was no difference in initial reflex tachycardia, but subsequent rebound bradycardia was blunted in the elderly patients with syncope. The predominant impairment in elderly patients with unexplained syncope was the bradycardia component of the responses to deep breathing and cough, suggesting that these patients may have impaired parasympathetic modulation of heart rate. Although not likely to be the cause of syncope in these patients, these findings may reflect an underlying autonomic defect.

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PubMed1987

Biomedical research in the nursing home: methodological issues and subject recruitment results.

Although nursing homes are potentially important sites for geriatric research, previous reports have identified impediments to subject recruitment in this setting. We are conducting five simultaneous clinical studies in a 725-bed nursing home. Utilizing a systematic subject recruitment methodology designed to minimize patient and staff burden, we have recruited over 100 subjects. The average recruitment rate over two years from nursing home residents meeting study entry criteria was 43%. The rate was highest (81%) for a study of urinary incontinence offering direct benefit to participants, and lowest (28% and 14% respectively) for physiologic studies of vasopressin regulation and dermal vitamin D production, offering no direct benefit. Studies of syncope and dementia which benefitted groups affected by these problems but not controls, had intermediate recruitment rates (46 and 44%, respectively, P less than .002 compared to incontinence). Thus, clinically relevant projects, sensitive to the needs of the patient and institution, can recruit subjects from the nursing home.

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PubMed1987

The prevalence and prognosis of minimally elevated creatine kinase-myocardial band activity in elderly patients with syncope.

Syncope in elderly patients is often the initial manifestation of myocardial infarction (MI). Small elevations in creatine kinase-myocardial band (CK-MB) activity following syncope may represent MI, transient myocardial hypoperfusion, or insignificant background activity. To determine the prevalence and prognostic significance of minimal CK-MB elevations in elderly patients with syncope, serial serum CK-MB activities and subsequent survival experiences were determined for elderly syncope patients with and without MI, and for age-matched nonsyncopal controls. While all syncope patients with MI by specific clinical criteria had one or more abnormal CK-MB levels (greater than 5 U/L) and died within 31 months, 10% of syncope patients without MI and 10% of controls had abnormal CK-MB with no impact on mortality. Using standard clinical laboratory techniques, minimal elevation in CK-MB was found in 10% of elderly subjects with and without syncope and probably had no prognostic significance.

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PubMed1986

Cardiovascular and norepinephrine responses after meal consumption in elderly (older than 75 years) persons with postprandial hypotension and syncope.

Aging is associated with alterations in cardiovascular homeostasis that impair adaptation to common hypotensive stresses. Postprandial blood pressure (BP) reduction has been described in elderly subjects, but its clinical significance and pathophysiologic mechanisms are unknown. We have identified 8 elderly patients with meal-related syncope and large postprandial BP declines. To evaluate the role of sympathetic nervous system activity and insulin in the development of postprandial BP reduction, mean arterial BP, heart rate, plasma catecholamine and insulin responses to a high carbohydrate meal in these 8 syncope patients were compared with those of 7 young and 12 old nonsyncopal controls. By 60 minutes after the meal, mean arterial BP declined an average of 26 mm Hg (p = 0.001) in old syncope patients, in contrast to a decline of 9 mm Hg (p = 0.1) in elderly controls and no change in young controls. Young and old controls had significant, sustained increases in heart rate or plasma norepinephrine levels, or both, throughout the 90-minute postprandial period. However, elderly syncope patients had no significant change in heart rate and only an initial increase but subsequent sustained decrease in plasma norepinephrine levels that paralleled the marked mean arterial BP reduction. Insulin and glucose responses were not significantly correlated with mean arterial BP reduction. These findings demonstrate that compared with old and young controls, elderly patients with meal-related syncope have marked sustained declines in postprandial mean arterial BP associated with a failure to maintain compensatory norepinephrine levels and cardioacceleratory responses.

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PubMed1986

Syncope in institutionalized elderly: the impact of multiple pathological conditions and situational stress.

We conducted a prospective study to identify clinical factors which predispose institutionalized elderly to syncope. Over 3 years, 97 patients (mean age = 87 +/- 6 y) developed syncope. On clinical evaluation, diagnoses fell into two categories: specific diseases including myocardial infarction (6%) and aortic stenosis (5%); and situational stresses including drug-induced hypotension (11%), postprandial syncope (8%), defecation syncope (7%) and postural hypotension (6%). Clinical variables derived from the history, physical examination, and laboratory evaluation of these patients were compared to those of 118 non-syncopal age-matched subjects evaluated in similar fashion. Multivariate analysis identified five independent statistically significant correlates of syncope: coronary artery disease (p = 0.0003), functional impairment (p = 0.006), postural blood pressure reduction (p = 0.003), aortic stenosis (p = 0.008), and insulin therapy (p = 0.03). Syncope patients were more likely than controls to have two or more coexistent factors (p = 0.0001). Syncope in institutionalized elderly is often due to the interaction of multiple coexistent clinical abnormalities which impair cardiovascular compensation for common situational stresses.

Age Factors↗
PubMed1986

Postprandial blood pressure reduction in healthy elderly.

Previous studies have identified postprandial systolic blood pressure reductions in old, frail institutionalized subjects, which do not occur in healthy, young subjects, after a morning meal. To evaluate the relative contributions of state of health and time of day to this potentially dangerous abnormality in cardiovascular homeostasis, we measured sitting systolic blood pressure and heart rate before and at intervals after a noon meal, and in identical fashion without a meal, in 21 healthy, community-dwelling elderly subjects (73 +/- 6 years of age) attending a nutrition program. Systolic blood pressure changed a maximum of -11 +/- 9 (SD) mmHg (P = .006, analysis of variance) by 60 minutes after the meal, in contrast to 1 +/- 7 mmHg (NS) by 60 minutes, when no meal was given (P less than .0001, meal versus control studies). There was a highly significant inverse correlation between postprandial and basal sitting systolic blood pressure changes (R = -0.60, P = .004). Healthy community-dwelling elderly demonstrate postprandial reductions in systolic blood pressure which correlate with basal sitting systolic blood pressure. This is consistent with age- and hypertension-related impairment in baroreflex compensation for the hypotensive stress of eating.

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PubMed1985

Intra-individual variability in postural blood pressure in the elderly.

Orthostatic hypotension, an age-related phenomenon, has been associated with hypertension and body weight variability. To evaluate the relative contributions of blood pressure elevation and abnormalities in extracellular volume regulation to orthostatic hypotension, elderly institutionalized subjects (mean age = 87 +/- 7 years), taking no cardiovascular medications, underwent measurement of body weight (n = 15) and first morning supine and standing blood pressures (n = 19), 12-13 times per subject over a 2-4 week period. There was a wide day-to-day variability in postural systolic blood pressure change (coefficient of variation = 533%) and a strong negative correlation between each day's postural change in systolic blood pressure and basal supine blood pressure (r = -0.55, P less than 0.0001). There was no association between postural blood pressure change and heart rate response or body weight changes, which were very small over the duration of the study (coefficient of variation = 0.6%). Elderly individuals have intact homeostatic mechanisms for the control of standing pressure when basal blood pressure is normal. Postural hypotension in the elderly is a variable phenomenon related to elevations in basal blood pressure.

Age Factors↗
PubMed1985

Abnormalities in blood pressure homeostasis that contribute to falls in the elderly.

Aging is associated with abnormalities in blood pressure homeostasis and may precipitate falls through transient underperfusion of the brain. Age-related declines in baro-reflex sensitivity, cerebral blood flow, and renal sodium conservation threaten normal blood pressure regulation and cerebral perfusion. Common clinical conditions associated with abnormal blood pressure homeostasis and falls in the elderly include postural hypotension, postprandial hypotension, carotid sinus hypersensitivity, and cardiac arrhythmias, all of which are exacerbated by hypertension. Further research is needed to understand the physiologic basis of abnormal blood pressure homeostasis, to explore the potential relationship between hypertension and falling, and to design new therapeutic approaches to this important cause of falls in the elderly.

Accidents↗
PubMed1985

Syncope in an elderly, institutionalised population: prevalence, incidence, and associated risk.

Although syncope is common in the elderly, little is known of its epidemiology and prognosis. A retrospective analysis of syncope in 711 very old (mean age 87 years) institutionalised patients revealed a 10 year prevalence of 23 per cent and one year incidence of 7 per cent. A two-year prospective follow-up of this population revealed a yearly incidence of 6 per cent and recurrence rate of 30 per cent. Of 67 patients who developed syncope during follow-up, a cause was established in 46; 14 (21 per cent) had cardiac and 32 (48 per cent) had non-cardiac aetiologies. Twenty-one cases (31 per cent) remained unexplained. Patients who developed syncope were initially more functionally disabled (p = 0.003) and subsequently changed function more frequently (p = 0.03) than those without the development of syncope, but two year rates of hospitalisation and death were not different between the two groups. Life-table survival analysis showed no difference in the mortality of subgroups with cardiac, non-cardiac, and unknown aetiologies of syncope. Syncope is common in multiply impaired elders and is likely a manifestation of co-morbid disease rather than an independent contributor to mortality.

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PubMed1983

Postprandial reduction in blood pressure in the elderly.

We evaluated the effects of a meal on systolic blood pressure and heart rate in elderly institutionalized subjects (mean age +/- S.E.M., 87 +/- 1) with and without histories of syncope and in young normal subjects. Pulse and blood pressure were measured before the test meal and at intervals for up to 60 minutes afterward. By 35 minutes mean systolic blood pressure had declined a maximum of 25 +/- 5 mm Hg in 10 elderly subjects with syncope and 24 +/- 9 mm Hg in 10 elderly subjects without syncope (P less than 0.03); the level then stabilized without further change until 60 minutes. There were no changes in blood pressure in 11 young subjects or in elderly subjects not given a meal. The postprandial change in systolic pressure was not related to medications or diagnoses. Compensatory cardioacceleration was minimal in the elderly, suggesting impaired baroreflexes. Our observations show that postprandial reductions in blood pressure may predispose the elderly to symptomatic hypotension.

Adolescent↗
PubMed1983

The drop attack: a common geriatric symptom.

While the "drop attack" has been described in the British literature as a classic geriatric syndrome accounting for as many as one-quarter of all falls in their elderly population, it is rarely acknowledged in discussions of falls by physicians in the United States. Is the drop attack a distinct entity that has been overlooked and under-investigated in this country, or is it perhaps a symptom of a spectrum of diseases? This paper reviews the original descriptions of the drop attack for its characteristic features, and focuses on the epidemiology, etiology and clinical management of this common, but infrequently recognized, event.

Accidents↗
PubMed1983

Syncope in the elderly.

Syncope is a common, potentially dangerous manifestation of transient cerebral dysfunction that often remains unexplained despite medical evaluation. In elderly persons the cause of syncope depends on the accumulation of several age- and disease-related abnormalities that impair adaptation to minor physiologic stresses not ordinarily expected to produce syncope. The evaluation of syncope requires a careful history and physical examination to identify common conditions and physiologic stresses that may present atypically as syncope, as well as conditions such as postural hypotension, aortic stenosis, and carotid hypersensitivity that are often overlooked on routine examination. Laboratory studies have a low sensitivity and specificity in the elderly patient and should be ordered selectively. Therapy should be directed toward preventing recurrent episodes by minimizing risks for syncope and treating symptomatic abnormalities regardless of the age of the patient, but with attention to age-related changes in drug metabolism and action.

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PubMedDate not supplied

Patterns of orthostatic blood pressure change and their clinical correlates in a frail, elderly population.

OBJECTIVES: To determine patterns of within-day orthostatic blood pressure (BP) changes and clinical factors correlated with them in frail, elderly nursing home residents. DESIGN: Prevalence study of orthostatic BP change. SETTING: Sample of 45 nursing homes. PARTICIPANTS: A total of 911 long-stay residents, aged 60 years or older, able to stand for at least 1 minute. MAIN OUTCOME MEASURES: Supine and 1-minute and 3-minute standing BP measurements and heart rates, taken by a random-zero sphygmomanometer before and after breakfast and before and after lunch, symptoms upon standing, medication use, and clinical and functional assessments. RESULTS: Four orthostatic hypotension (OH) groups were defined based on the frequency of a 20 mm Hg or greater orthostatic BP decline during any of 8 postural change measures: no OH group (48.5%); isolated OH group (only once, 18.3%); variable OH group (2-3 times, 19.9%); and persistent OH group (> or =4 times, 13.3%). Orthostatic hypotension was most prevalent before breakfast, especially 1 minute after standing (21.3%), and least prevalent after lunch after 3 minutes of standing (4.9%) (P=.001). A regression approach to repeated measures analysis (method of general estimating equations) showed the following to be significantly associated with OH (P< or =.05): elevated supine systolic BP before breakfast, dizziness/light-headedness on standing, male sex, medication for Parkinson disease, time of day (particularly before breakfast), greater independence in activities of daily living, and low body mass index. CONCLUSIONS: Orthostatic hypotension occurs in more than half of frail, elderly nursing home residents, but is highly variable over time. It is most prevalent in the morning when subjects first arise and when supine BP is highest. The relationship of OH with elevated BP, but not antihypertensive medication use, suggests that the treatment of hypertension may improve postural BP regulation.

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