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a Department of Medicine, North Tyneside Health Care Trust, North Tyneside Hospital, North Shields, Tyne and Wear, United Kingdom
Liesl M. Allcock, Department of Geriatric Medicine, Royal Victoria Infirmary, Newcastle Upon Tyne, NE1 4LP, UK E-mail: d.oshea{at}st-vincents.ie.
Decision Editor: William B. Ershler, MD
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Abstract |
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Methods. A total of 120 consecutive patients over the age of 65 presenting to a single geriatrician were assessed. After a full history and physical examination, patients underwent neurocardiovascular investigation: blood pressure and heart rate response to active stand, carotid sinus massage, and 30-minute head-up tilt.
Results. The 120 patients assessed had a mean age of 78 years (range 66–94 years); in this group, 85 were women. Of these patients, 23% presented with falls, 14% with blackouts, and 30% with dizziness. The remaining 33% had overlap of symptoms. Neurocardiovascular investigations produced a diagnosis in 57% of the patients: 22% had cardioinhibitory carotid sinus syndrome (CSS); 15% had vasodepressor CSS; 29% had orthostatic hypotension; and 3% had vasovagal syncope. Thirteen percent had more than one neurocardiovascular abnormality, and 18% had benign positional vertigo. Five patients had postural instability causing falls. Hyperventilation syndrome, aortic stenosis, dysrhythmia, cervical spondylosis, and epilepsy each accounted for one case. Seventeen percent of the subjects remained undiagnosed after integrated neurocardiovascular assessment.
Conclusion. Management of falls requires access to neurocardiovascular assessment. It is feasible to provide such a service in the district general hospital setting, with a comparable diagnostic yield to tertiary referral centers.
DIZZINESS, syncope, and falls are common complaints among elderly patients. Serious injury requiring hospitalization occurs in up to 5% of those who experience falls in this age group. Of those admitted to hospitals after a fall, only about half are alive 1 year later.
Neurocardiovascular investigation units aim to detect those patients who fall due to disturbances of blood pressure control or cardiac conduction. Orthostatic hypotension, carotid sinus syndrome, and vasovagal syncope are the principal diagnoses. Intervention and treatment of these conditions can reduce the frequency and consequences of a patient's falls.
Retrograde amnesia for loss of consciousness results in confusion between syncope and falls (1). For this reason, patients with dizziness, syncope, and unexplained falls should be assessed in a neurocardiovascular unit.
Neurocardiovascular investigation in the elderly population has, until recently, been a specialist interest of tertiary referral centers. Diagnostic yield from specialist syncope clinics is high (2) but may reflect the expertise of those working in a tertiary referral setting.
North Tyneside Hospital is a district general hospital serving an urban population of 200,000. A neurocardiovascular unit for investigation of elderly people experiencing dizziness, syncope, and falls was established at this hospital in 1996. The unit is run by one consultant geriatrician and junior medical staff. It is equipped with a standard electrocardiograph limb lead recorder, tilt table, and Finapres (Ohmeda, Madison, WI) finger plethysmography device. This study recorded the feasibility of setting up and running a neurocardiovascular investigation unit in a district general hospital.
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Methods |
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Baseline Evaluation of Patients
We obtained a complete history and physical and neurological examinations for all patients. Where available, details of witness accounts of symptoms were recorded. Lying and standing blood pressure measurements were obtained using a standard mercury sphygmomanometer. Baseline laboratory investigations, including full blood count, electrolytes, urea, creatinine, and glucose, were obtained.
Patients attended for investigation between 8 AM and 12 PM, and underwent a series of neurocardiovascular investigations (Fig. 1).
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Carotid Sinus Massage
Patients were tested in the supine and tilted-upright (70°) positions with the neck slightly extended. Massage was applied over the point of maximum carotid impulse, medial to the sternomastoid muscle at the level of the upper border of the thyroid cartilage. Longitudinal massage was applied for 5 seconds. The test was initially performed on the right side and, after 1 minute, on the left. Continuous electrocardiography recorded the heart rate response to massage. Continuous, noninvasive, beat-to-beat blood pressure was measured with a Finapres device.
Head-up Tilt
In 88 patients for whom syncope remained undiagnosed or whose history suggested vasovagal syncope, prolonged head-up tilt to 70° for 30 minutes was performed with simultaneous, continuous heart rate and noninvasive blood pressure monitoring.
Diagnostic Criteria
The following are the diagnostic criteria as defined at the beginning of the study. Assignment of a cause was based on strict adherence to these criteria. Definitions of diagnoses were based on previously published data (3)(4)(5).
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Results |
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Presenting symptoms were dizziness alone in 30% of the patients, falls in 23%, and syncope in 14%. The remainder had an overlap of symptoms (Fig. 2).
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In 7 patients, the cardioinhibitory response was thought to be exacerbated or caused by medications: oral beta adrenergic blockers, timolol eye drops, and digoxin. Repeat of carotid sinus massage after the patients had stopped the culprit medications resulted in a normal response in two subjects. Three subjects had a persistent cardioinhibitory response but reduction in carotid sinus massage–induced pause. One subject was lost to follow-up, and one who was unable to discontinue medications was referred for dual-chamber cardiac pacing.
Thirteen patients with cardioinhibitory carotid sinus hypersensitivity were referred to a regional cardiology service for consideration for pacing. Eleven were paced as a result of these referrals, one patient refused a pacemaker, and for another, a change in medication was felt to be more appropriate therapy.
For those with a predominantly vasodepressor response, the response was right-sided in 8, left-sided in 1, and bilateral in 9 of the patients. The mean vasodepressor response was 77 mmHg (SD = 19). In 4 cases the vasodepressor response was attributed to medications: timolol eye drops, calcium antagonists, diuretics, nitrates, angiotensin-converting enzyme inhibitors, and tricyclic antidepressants. One patient was taking three medications that might have exacerbated the problem.
Thirty-five patients had orthostatic hypotension that was idiopathic in 17, drug-related in 8, and associated with diabetes mellitus in 1. Diuretics were the most common exacerbating medications.
Eighty-eight of 120 patients underwent head-up tilt. Four patients had evidence of vasovagal sensitivity. The mean time to presyncope was 21 minutes (SD = 14.1). The mean heart rate change was +3.3 beats per minute. None of our patients had vasovagal syncope with bradycardia.
Eighteen patients had benign positional vertigo. This group had reduction of symptoms after treatment with betahistidine or cinnarizine.
Of the 35 patients without diagnostic tilt room findings or benign positional vertigo, 14 had 24-hour ambulatory electrocardiogram (ECG) recordings. Only one of these showed any abnormality that accounted for symptoms.
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Discussion |
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Carotid sinus syndrome was the most frequent diagnosis. Twenty-six patients had cardioinhibitory carotid sinus syndrome; 11 of these were paced during the study period. The North American Society for Pacing and Electrophysiology, or NASPE, (8) and the British Pacing and Electrophysiology Group, or BPEG, (9), both recognize carotid sinus syndrome as an indication for pacemaker insertion. Atrioventricular sequential pacing is regarded by most as the treatment of choice in patients with symptomatic cardioinhibition. Atrial pacing is largely contraindicated in view of the high incidence of atrioventricular block in patients with the syndrome (10). Ventricular pacing abolishes cardioinhibition but fails to alleviate symptoms in many patients. Retrograde conduction through intact ventriculo-atrial pathways allows exacerbation of the vasodepressor component of the carotid sinus syndrome (11), presumably mediated by atrial baroreceptors. Dual-chamber pacing results in significantly less vasodepression than does ventricular pacing during both supine and upright carotid sinus massage (12). With appropriate pacing, syncope is abolished in 85%–90% of patients with cardioinhibition (10)(13), but dizziness persists in up to 20%.
The role of pacemakers in treating patients with unexplained falls and cardioinhibitory carotid sinus hypersensitivity, who may have retrograde amnesia for syncopal episodes, is unknown. A randomized control study to assess benefits from pacemaker intervention in these patients is under way.
Eighteen subjects in this study had a pure vasodepressor response to carotid sinus massage. The pathophysiology of the vasodepressor response is incompletely understood, and the medical treatment is unsatisfactory. Alpha-adrenergic agonists (14) and fludrocortisone (15) have been used, but adverse effects limit the long-term usefulness of these drugs.
Twenty-nine percent of our subjects had orthostatic hypotension. Previous investigators have demonstrated a prevalence of orthostatic hypotension in 20% of medical outpatients over 65 years old and in 30% of those over 75 years old (16). In healthy elderly people, the prevalence is less than 7% (17). The presence of postural symptoms is not always correlated with blood pressure fall (18). Epidemiological data suggest that a decrease of more than 20 mmHg is associated with an increased risk of falls (19), syncope (20), and mortality (21). Although the nadir blood pressure may be more relevant to causation of these risks than the degree of fall, establishing a causal association is difficult and requires further studies.
Orthostatic hypotension is a clinical finding rather than a disease entity. It may be secondary to medications that hamper the homeostatic mechanisms of blood pressure control or to disorders affecting the autonomic nervous system such as diabetes and amyloid (22). Some elderly subjects have orthostatic hypotension without any obvious comorbid conditions; they are said to have age-related orthostatic hypotension. The pathophysiological basis for age-related orthostatic hypotension is unclear: some authors suggest dysfunction in the afferent limb of the baroreflex arc (23); others suggest reduced vascular wall compliance (24), possibly due to association between orthostatic hypotension and supine hypertension (25).
The treatment of orthostatic hypotension is initially nonpharmacological. Fludrocortisone (25) and midodrine (26) (a peripheral alpha-adrenoceptor agonist) have both been used with some effect but have side effects that limit their general use.
Vasovagal syncope was uncommon in our study, affecting only 4% of patients. Our findings, however, conflict with others who have reported incidences of vasovagal syncope as high as 37% (27)(28)(29) for those over the age of 65 years and 23% for those over the age of 80 years (27). There are a number of reasons for this apparent discrepancy. None of our patients had an intravenous cannula inserted. This has been shown to alter the specificity of head-up tilt testing for vasovagal syncope in elderly patients (30). We did not use isoprenaline or glyceryl trinitrate as provocative agents. Both of these agents increase the diagnostic yield of the head-up tilt test in the elderly patient (27)(28). In 1992, Grubb and colleagues demonstrated that in a group of 25 patients over the age of 65 years, the use of isoprenaline after a drug-free, passive, head-up tilt resulted in an additional 7 patients testing positive, increasing the diagnostic yield to 64%. Glyceryl trinitrate has similarly been shown to increase diagnostic yield while maintaining a high degree of specificity (31).
We were not surprised by the low diagnostic yield of 24-hour ambulatory ECG recording in our study: only one subject with symptomatic dysrhythmia was detected. Previous investigators have shown a similarly low yield (32). Although increasing the time of recording up to 72 hours may increase the diagnostic potential of the test (33), the principal reason for the low yield is thought to be the preponderance of neurogenically mediated syncope in subjects with intermittent bradyarrhythmias.
In summary, we have demonstrated the feasibility of setting up and running a neurocardiovascular unit for investigation of syncope and falls in a district general hospital. Assessment of the first consecutive 120 patients over the age of 65 reveals a high diagnostic yield after a preordained investigation program. Outcome following treatment intervention was not recorded; thus, although we have attributed our subjects' symptoms to the cardiovascular abnormalities found, a definite association cannot be proven from this study. Previous investigators have demonstrated significant symptom reduction following interventions tailored to abnormal tilt room findings (2); revalidation of this finding was not an aim of this study.
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Acknowledgments |
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Footnotes |
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Received July 7, 1999
Accepted December 1, 1999
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This article has been cited by other articles:
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  R A Kenny, F E Shaw, J T O'Brien, P H Scheltens, R Kalaria, and C Ballard Carotid sinus syndrome is common in dementia with Lewy bodies and correlates with deep white matter lesions J. Neurol. Neurosurg. Psychiatry, July 1, 2004; 75(7): 966 - 971. [Abstract] [Full Text] [PDF]
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 J. E. Morley Editorial: A Fall Is a Major Event in the Life of an Older Person J. Gerontol. A Biol. Sci. Med. Sci., August 1, 2002; 57(8): M492 - 495. [Full Text] [PDF]
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