Syncope in older persons

Association between invasively measured aortic pulse pressure and orthostatic hypotension in patients undergoing invasive coronary angiography

OBJECTIVE

Underlying pathophysiology of orthostatic hypotension has been poorly understood. We hypothesized that aortic pulse pressure (APP) reflecting aortic stiffness may be involved in the development of orthostatic hypotension.

METHODS

A total of 200 patients (age 64.3 ± 10.9 years, 62.5% men) who underwent invasive coronary angiography (ICA) were prospectively recruited. Orthostatic hypotension was defined as SBP drop at least 20 mmHg or DBP drop at least 10 mmHg within 3 min of the standing position compared with the supine position. Hemodynamic parameters were measured at the ascending aorta using a pig-tail catheter immediately before ICA. APP was calculated as a difference between the aortic peak systolic pressure and the end-diastolic pressure.

RESULTS

A total of 156 patients (78.0%) had obstructive coronary artery disease on ICA. Orthostatic hypotension was present in 58 patients (29.0%). Diabetes mellitus was more prevalent in patients with orthostatic hypotension than those without (48.3% vs. 23.2%; P < 0.001). Other clinical parameters including age, cardiovascular risk factors, laboratory findings and concomitant medications were not different between patients with and without orthostatic hypotension (P > 0.05 for each). In hemodynamic parameters, APP was higher in patients with orthostatic hypotension than those without (78.4 ± 25.8 vs. 68.3 ± 21.3 mmHg; P = 0.005). Higher APP was significantly associated with the presence of orthostatic hypotension even after controlling for potential confounders (odds ratio, 2.99; 95% confidence interval 1.15-7.78; P = 0.025).

CONCLUSION

In patients undergoing ICA, APP was associated with increased risk of orthostatic hypotension. Central aortic stiffness may play a role in the development of orthostatic hypotension.

Incorporation of Novel Vascular Measures into Clinical Management: Recent Insights from the Framingham Heart Study

PURPOSE OF REVIEW

The review discusses evidence from the Framingham Heart Study that supports the assessment and utility of novel vascular and blood pressure measures to inform clinical management of blood pressure-related cardiovascular disease.

RECENT FINDINGS

Recent Framingham Heart Study investigations provide new insights into the associations of novel and traditional vascular and blood pressure measures, such as measures of aortic stiffness, components of blood pressure waves, and orthostatic change in blood pressure, with cardiovascular disease events and brain structure and function. Novel vascular measures provide opportunities for additional investigation and potential development of new interventions that are more precisely targeted at underlying pathophysiology. Inclusion of novel vascular measures should be considered in clinical practice to screen for early, subclinical disease and to stratify high-risk individuals for targeted therapies.

Inter-Relations of Orthostatic Blood Pressure Change, Aortic Stiffness, and Brain Structure and Function in Young Adults

BACKGROUND

Relations of orthostatic change in blood pressure with brain structure and function have not been studied thoroughly, particularly in younger, healthier individuals. Elucidation of factors that contribute to early changes in brain integrity may lead to development of interventions that delay or prevent cognitive impairment.

METHODS AND RESULTS

In a sample of the Framingham Heart Study Third Generation (N=2119; 53% women; mean age±SD, 47±8 years), we assessed orthostatic change in mean arterial pressure (MAP), aortic stiffness (carotid-femoral pulse wave velocity), neuropsychological function, and markers of subclinical brain injury on magnetic resonance imaging. Multivariable regression analyses were used to assess relations between orthostatic change in MAP and brain structural and neuropsychological outcomes. Greater orthostatic increase in MAP on standing was related to better Trails B-A performance among participants aged <49 years (β±SE, 0.062±0.029; P=0.031) and among participants with carotid-femoral pulse wave velocity <6.9 m/s (β±SE, 0.063±0.026; P=0.016). This relation was not significant among participants who were older or had stiffer aortas. Conversely, greater orthostatic increase in MAP was related to larger total brain volume among older participants (β±SE, 0.065±0.029; P=0.023) and among participants with carotid-femoral pulse wave velocity ≥6.9 m/s (β±SE, 0.078±0.031; P=0.011).

CONCLUSIONS

Blunted orthostatic increase in MAP was associated with smaller brain volume among participants who were older or had stiffer aortas and with poorer executive function among persons who were younger or who had more-elastic aortas. Our findings suggest that the brain is sensitive to orthostatic change in MAP, with results dependent on age and aortic stiffness.

The prevalence and prognostic significance of near syncope and syncope: a prospective study of 395 cases in an emergency department (the SPEED study)

BACKGROUND

The prognostic significance of near-syncope has not yet been adequately characterized.

METHOD

We collected prospective data on a consecutive series of patients seen in an emergency department with syncope (brief loss of consciousness, usually with loss of muscle tone) or near-syncope (a feeling that syncope is about to occur, but without actual loss of consciousness or muscle tone). We report on the prevalence, etiology, and prognosis of such events (the SPEED study). Patients were followed up at 30 days and at 6 months after the event.

RESULTS

From 17 July to 31 October 2011, 395 patients were seen in the emergency department for a chief complaint of syncope or near-syncope (3% of all emergency patients). Their median age was 70 years, and 55% were men. 62% had experienced syncope, and 38% near-syncope. The patients with near-syncope were younger than those with syncope ( 63 vs. 72 years, p < 0.014) and were also more commonly male (63% vs. 49%, p = 0.006). The two patient groups did not differ significantly with respect to their measured laboratory values and vital parameters or their accompanying medical conditions. Hospitalizations were more common for syncope than for near-syncope (86% vs. 70%, p < 0.001). Etiologies were similarly distributed in the two patient groups, with the main ones being reflex syncope, orthostatic syncope, cardiac syncope, and syncope of uncertain origin. In all, 123 of 379 patients (32%) had further undesired events within 30 days of the event. Multivariable logistic regression revealed that age, heart rate, and renal dysfunction were independent predictors of undesired events, while the type of syncope was not.

CONCLUSION

Patients with near-syncope do not differ to any large extent from patients with syncope with respect to the features studied. The diagnostic evaluation should be similar for patients in the two groups.

Diagnostic and prognostic value of high-sensitivity cardiac troponin T in patients with syncope

OBJECTIVE

We examined the diagnostic and predictive value of high-sensitivity cardiac troponin T (cTnThs) in patients with syncope.

METHODS

We performed an analysis of consecutive patients with syncope presenting to the emergency department. The primary end point was the accuracy to diagnose a cardiac syncope. In addition, the study explored the prognostic relevance of cTnThs in patients with cardiac and noncardiac syncope.

RESULTS

A total of 360 patients were enrolled (median age, 70.5 years; male, 55.8%; 23.9% aged >80 years). Cardiac syncope was present in 22% of patients, reflex syncope was present in 40% of patients, syncope due to orthostatic hypotension was present in 20% of patients, and unexplained syncope was present in 17.5% of patients. A total of 148 patients (41%) had cTnThs levels above the 99% confidence interval (CI) (cutoff point). The diagnostic accuracy for cTnThs levels to determine the diagnosis of cardiac syncope was quantified by the area under the curve (0.77; CI, 0.72-0.83; P < .001). A comparable area under the curve (0.78; CI, 0.73-0.83; P < .001) was obtained for the predictive value of cTnThs levels within 30 days: Patients with increased cTnThs levels had a 52% likelihood for adverse events, patients with cTnThs levels below the cutoff point had a low risk (negative predictive value, 83.5%). Increased cTnThs levels indicate adverse prognosis in patients with noncardiac causes of syncope, but not in patients with cardiac syncope being a risk factor for adverse outcome by itself.

CONCLUSIONS

Patients with syncope presenting to the emergency department have a high proportion of life-threatening conditions. cTnThs levels show a limited diagnostic and predictive accuracy for the identification of patients with syncope at high risk.

Validation of the San Francisco Syncope Rule in two hospital emergency departments in an Asian population

OBJECTIVES

The objective was to externally validate the ability of the San Francisco Syncope Rule (SFSR) to accurately identify patients who will experience a 7-day serious clinical event in an Asian population.

METHODS

This was a prospective cohort study, with a sample of adult patients with syncope and near-syncope enrolled. Patients 12 years old and below and patients with loss of consciousness after head trauma, a witnessed seizure, with known alcohol or illicit drug ingestion, and altered level of consciousness or persistent new neurologic deficits were excluded. The patients were evaluated for the presence of one or more of the five SFSR variables: shortness of breath, history of heart failure, hematocrit <30%, systolic blood pressure <90 mm Hg, and abnormal electrocardiogram (ECG). The patients were followed up by medical record review or telephone interview. Seven-day outcomes were death, arrhythmia, myocardial infarction, acute pulmonary edema, significant structural heart disease, pulmonary embolism, major cardiac procedure, stroke, subarachnoid hemorrhage, major bleeding, and anemia.

RESULTS

A total of 1,250 patients from two centers were recruited. Fifty-six patients were excluded from primary analysis because of incomplete data (n = 55) and/or they were noncontactable for follow-up (n = 32). Of the 1,194 patients analyzed, 138 patients (11.6%) experienced adverse outcomes at 7 days. The rule performed with a sensitivity of 94.2% (95% confidence interval [CI] = 89.0% to 97.0%) and a specificity of 50.8% (95% CI = 47.7% to 53.8%).

CONCLUSIONS

In this study, SFSR rule had a sensitivity of 94.2%. This suggests caution on the strict application of the rule to all patients presenting with syncope. It should only be used as an aide in clinical decision-making in this population.

Cardiovascular assessment of falls in older people

Falls in older people can be caused by underlying cardiovascular disorders, either because of balance instability in persons with background gait and balance disorders, or because of amnesia for loss of consciousness during unwitnessed syncope. Pertinent investigations include a detailed history, 12-lead electrocardiography, lying and standing blood pressure, carotid sinus massage (CSM), head-up tilt, cardiac electrophysiological tests, and ambulatory blood pressure and heart rate monitoring, which includes external and internal cardiac monitoring. The presence of structural heart disease predicts an underlying cardiac cause. Conversely, the absence of either indicates that neurally mediated etiology is likely. CSM and tilt-table testing should be considered in patients with unexplained and recurrent falls. Holter monitoring over 24 hours has a low diagnostic yield. Early use of an implantable loop recorder may be more cost-effective. A dedicated investigation unit increases the likelihood of achieving positive diagnoses and significantly reduces hospital stay and health expenditure.

Outcomes of Unexplained Syncope in the Elderly

The objective of this study was to determine whether syncope of unknown etiology (SUE) influences mortality in the elderly. Patients with SUE at 65 years or older were identified retrospectively and their outcomes were compared with an age-, sex-, and comorbidity-matched group of patients drawn from the same population. All-cause 3-year mortality was analyzed using the Kaplan-Meier method and the log-rank test. SUE was identified in 150 of 304 patients (49%) with syncope. Patients with SUE and controls experienced mortality rates (1/1000 person-years [95% confidence interval]) of 147.8 (112.6-193.9) and 153.4 (117.5-200.3), P=.7, respectively. Of all the recorded characteristics of SUE, only the inpatient status was associated with higher all-cause mortality (Cox model adjusted hazard ratio [95% confidence interval] of inpatients vs outpatients with SUE: 2.2 [1.1-4.1], P=.017). New-onset SUE is not an independent predictor of mortality in elderly patients.

Swallow syncope in a patient with esophageal stenosis caused by an ascending aorta aneurysm: differential diagnosis from postprandial hypotension: a case report

Swallow syncope is usually caused by organic or functional disorders of the esophagus due to abnormal vasovagal reflex. In elderly patients this situation could be confused with postprandial hypotension. We present a case of an elderly patient who presented with swallow syncope that was caused by a waist in the midportion of esophagus induced by an ascending aorta aneurysm.

Transient overdrive pacing upon standing prevents orthostatic hypotension in elderly pacemaker patients with chronotropic incompetence

BACKGROUND

Elderly pacemaker patients with chronotropic incompetence (CI) may experience orthostatic hypotension (OH) upon standing. The objective of this study was to determine whether a transient increase in heart rate (HR) by overdrive pacing upon standing prevents OH in elderly pacemaker patients.

METHODS

We studied the effect of transient overdrive pacing upon standing in mitigating the drop in blood pressure (BP) in 62 pacemaker patients (77 +/- 6 years, 32 F) implanted with DDD pacemaker for sick sinus syndrome (n = 40) or atrioventricular block (n = 22). All patients underwent two standing procedures in random order: a control, with backup (60 bpm) pacing and another with overdrive DDD pacing (at 35 bpm above their baseline rate) for 2 minutes upon standing. Systolic (SBP) and diastolic blood pressure (DBP) and HR were measured while supine (baseline) and 1, 2, and 3 minutes after standing. OH was defined as a drop in SBP > or = 20 mmHg or DBP > or = 10 mmHg during standing. Chronotropic incompetence (CI) was defined as an absence of HR increase of > or = 10 bpm during standing.

RESULTS

A total of 17 (27%) patients developed OH upon standing during backup pacing. Baseline clinical characteristics (age, sex, prevalence of diabetes, use of vasoactive medications, and sick sinus syndrome) were similar between patients with or without OH. In patients with or without OH, transient overdrive pacing upon standing increased HR and DBP as compared with baseline (P < 0.05). However, in patients with OH, transient overdrive pacing did not prevent decrease in SBP upon standing and avoided the development of OH in only 10/17 patients (59%). Among those patients with OH, 10/17 (59%) patients had CI. In OH patients with CI, transient overdrive pacing upon standing maintained SBP and DBP as compared to baseline and prevented OH in the majority of patients (80%). By contrast, transient overdrive pacing in OH patients without CI had no significant effect on the decrease in SBP upon standing and prevented OH in only 20% of patients.

CONCLUSIONS

OH is common (27%) in the elderly pacemaker population. In a subgroup of these patients, CI may be responsible for the occurrence of OH, and OH can be prevented by transient overdrive pacing upon standing.

When the report is dizziness

The complaint of "I'm dizzy," is a familiar one heard from those over age 60 by nurses in any health care setting. This complaint requires assessing subjective reports and determining potential causes to assist in obtaining appropriate interventions. Specialized testing may be required, as well as review of the person's activity, medications, diagnoses, and potential environmental and emotional situation. The end goal in nursing care is to prevent injury and promote physical and psychosocial well-being.

Arterial stiffness as the candidate underlying mechanism for postural blood pressure changes and orthostatic hypotension in older adults: the Rotterdam Study

OBJECTIVE

To investigate whether arterial stiffening, one of the characteristics of the aging vascular system, is associated with orthostatic hypotension.

DESIGN

Cross-sectional data of a cohort study in elderly men and women.

PARTICIPANTS

We investigated the relationship between arterial stiffness and orthostatic hypotension within the framework of the Rotterdam Study, a population-based study in individuals aged 55 and older. The present study included 3362 subjects participating in the third examination phase. The carotid-femoral pulse wave velocity was used as measure of arterial stiffness. Orthostatic hypotension was assessed with blood pressure measurements in supine and standing position.

RESULTS

Odds ratios for orthostatic hypotension increased through quartiles of pulse wave velocity; the age, gender and mean arterial pressure adjusted odds ratio in the last quartile of pulse wave velocity was 1.45 (95% confidence interval, 1.09-1.93) when compared with the first quartile (reference). In fully adjusted models estimates remained statistically significant. In subjects with higher stiffness we observed a higher drop in blood pressure but no significant change of heart rate.

CONCLUSIONS

Arterial stiffness is independently associated with orthostatic hypotension. The drop in blood pressure levels and the contemporary attenuated response of heart rate to orthostatic challenge in subjects with stiffer arteries support the hypothesis that arterial stiffness may explain, at least in part, the reduced baroreflex observed in older adults.

Epidemiology of reflex syncope

Cost-effective diagnostic approaches to reflex syncope require knowledge of its frequency and causes in different age groups. For this purpose we reviewed the available literature dealing with the epidemiology of reflex syncope. The incidence pattern of reflex syncope in the general population and general practice is bimodal with peaks in teenagers and in the elderly. In the young almost all cases of transient loss of consciousness are due to reflex syncope. The life-time cumulative incidence in young females ( congruent with 50 %) is about twice as high as in males ( congruent with 25 %). In the elderly, cardiac causes, orthostatic and postprandial hypotension, and the effects of medications are common, whereas typical vasovagal syncope is less frequent. In emergency departments, cardiac causes and orthostatic hypotension are more frequent especially in elderly subjects. Reflex syncope, however, remains the most common cause of syncope, but all-cause mortality in subjects with reflex syncope is not higher than in the general population. This knowledge about the epidemiology of reflex syncope can serve as a benchmark to develop cost-effective diagnostic approaches.

[Iatrogenic syncopes and malaises]

Syncope or presyncope related to adverse drug reactions are well-known. On the other hand, little is known about the specific role of different drugs. Over one six year period, 1611 patients were referred in our hospital for syncope or presyncope, including 688 in the cardiology department. Among these patients, 420 were 70 years old or more. The search for an adverse drug reaction was systematic, with the help of the French method for causality of adverse drug reaction: knowledge of "extrinsic" criteria (bibliographical data relating to the drug involved); moreover, score on the basis of "intrinsic", chronological and symptomatic criteria. Seventy five patients (11% of the group with syncope leading to admission in cardiology department) were thus retained: score = I2, "possible adverse drug reaction", for 28 patients (37%); score = I3, "probable adverse drug reaction", for 47 patients (63%). Score I4, "definite adverse drug reaction" was not used since it required the readministration of the drug to prove the iatrogenic effect. Average age was 78 years, with a female majority of 69%. Seventy two patients (96%) had previous cardiovascular disease, 37 (50%) previously experienced syncope or presyncope. In addition to the basic assessment, a Holter recording was performed among 56 patients, finding a drug-induced arrhythmia in three cases. In the majority of the patients (59 patients, 79%), the adverse drug reaction consisted of hypotension, clinically obvious in 49 cases. In ten cases, vasovagal syndrome facilitated by the drugs was diagnosed by a tilt-test. The other side effects were eight rhythm disorders and eight severe metabolic disorders. The treatments were always multiple. The involved drug was a cardiovascular therapy in 66% of the cases. The other drug classes were primarily represented by uroselective alpha 1-adrenergic blocking drugs (12%) and psychotropic ones (22%). Among the cardiovascular treatments, ACE inhibitors and diuretics, generally in association, were involved (59%). This study confirms the role for antihypertensive drugs in iatrogenic syncope, its great frequency in elderly patients but also the responsibility of another drug class less often reported, the uroselective alpha 1-adrenergic blocking drugs.

The management of patients with carotid sinus syndrome: is pacing the answer?

Carotid sinus syndrome (CSS) is an under recognized cause of recurrent unexplained syncope and potentially of recurrent falls in the elderly. The mechanisms that lead to syncope in patients with CSS remain debated. However, evidence for both peripheral and central alterations have been recently reported. The diagnosis of CSS is challenging and a high clinical suspicion is usually needed to make the diagnosis. Clinical presentation may be typical and characterized by a clear association between accidental manipulation of the carotid sinus and the presentation of syncope. On the other hand, recurrent unexplained syncope and unexplained falls may be the clinical presentation of patients with CSS without a specific trigger. Carotid sinus hypersensitivity documented by carotid sinus massage (CSM) may be the only finding indicating the possibility of CSS as the cause of syncope. In older patients with recurrent unexplained syncope and a negative diagnostic work-up, carotid sinus massage both in the supine and upright positions is recommended. CSS may present primarily as a cardioinhibitory response or a true vasodepressor response. Therapy should address any underlying pathology if present, and be directed to either prevent cardioinhibition, vasodepression or both alterations. A variety of medical therapies have been used with unclear effects. No appropriately designed controlled clinical trials have been performed comparing pacing with medical therapy. Nonetheless, available information indicates that pacing may have a strong beneficial effect and prevents recurrence of syncope in patients with CSS. The present paper critically reviews the latest insights in the pathophysiology, diagnosis and management of CSS.

Arterial Stiffness Is Associated with Orthostatic Hypotension in Elderly Subjects with History of Falls

OBJECTIVES

To test the hypothesis that impaired hemodynamic orthostatic changes commonly observed in the elderly may be related to age-related increase in arterial wall stiffness.

DESIGN

Convenience sample of consecutive patients admitted for falls.

SETTING

Acute- and intermediate-care geriatric ward of a French hospital.

PARTICIPANTS

Fifty-seven elderly patients (46 women) consecutively admitted to a geriatric ward with a history of recent falls.

MEASUREMENTS

Orthostatic hypotension (OH) was assessed using blood pressure measurements in the supine position and 1, 2, and 3 minutes after standing. Arterial wall stiffness was assessed using upper-limb and aortic pulse-wave velocities, measured with an external pressure transducer connected to a computer.

RESULTS

OH was present in 18 patients with a mean age+/-standard deviation of 85.4+/-7.6 (5 men, 13 women) and absent in 39 patients aged 83.7+/-6.2 (6 men, 33 women). Upper-limb pulse-wave velocity was significantly higher, by 16%, in patients with OH than those without (9.91 vs 8.53 m/s; P<.02). Significant correlations were found between upper-limb pulse-wave velocity and systolic blood pressure changes after 1 minute of standing (r=0.263, P<.05) and maximal diastolic blood pressure change after standing (r=0.351, P<.01).

CONCLUSION

Upper-limb arterial wall stiffness was significantly greater in elderly patients with OH than in patients without OH and was significantly related to blood pressure changes after standing. These results highlight the possible role of age-related changes in the arterial tree in the hemodynamic response to orthostatic challenges.

Prevalence and clinical outcomes of patients with multiple potential causes of syncope

OBJECTIVE

To determine the prevalence, predictors, and prognosis of patients with multiple potential causes of syncope.

PATIENTS AND METHODS

This is a retrospective cohort study with prospective follow-up of consecutive patients with syncope of uncertain cause who were referred to the electrophysiology service for syncope evaluation from January 1, 1996, through December 31, 1998. The main outcome measures were prevalence of multiple potential causes of syncope, survival of patients with multiple potential causes of syncope compared with survival of patients with a single cause, and clinical predictors of multiple potential causes of syncope.

RESULTS

A total of 987 patients were studied (mean +/- SD age, 58.0 +/- 21.4 years; male, 550 [55.7%]). Multiple potential causes were present in 182 patients (18.4%). Patients with multiple potential causes of syncope had a lower survival rate at 4 years, 73.1% (95% confidence interval, 64.6%-82.8%), vs those with a single cause, 89.3% (95% confidence interval, 86.4%-92.2%) (P < .001). Multivariate predictors of multiple potential causes were older age, atrial fibrillation, use of cardiac medications, and New York Heart Association classification II, III, and IV.

CONCLUSION

Of the patients evaluated for syncope, 18.4% had multiple potential causes. The presence of multiple potential causes was an independent predictor of increased mortality among patients with syncope.

Evaluating elderly patients with syncope

Age-related physiologic changes together with high prevalence of chronic illness and the use of multiple medications predispose older adults to syncope. The causes of many of these patients' syncope are unexplained and most remained symptomatic. A thoughtful diagnostic strategy is essential to pinpoint the cause in each patient. The initial assessment includes a comprehensive medical history, preferably with an eye witness account, and a thorough physical examination. The decision for further diagnostic tests often depends on whether there is evidence of underlying structural heart disease. In the absence of heart disease, tilt table testing and the related autonomic function testing are usually most productive. Various cardiac studies will be more appropriate for those with suspected structural heart disease. A cause of syncope can only be concluded if there is a sufficiently strong correlation between syncopal symptoms and the detected abnormalities on investigations. A strategic evaluation of syncope of the elderly subjects should allow a correct diagnosis and appropriate management.

Setting up a falls and syncope service for the elderly

Establishing a neurocardiovascular investigation unit for the investigation of falls and syncope in the elderly is feasible. With the increasing growth in the elderly population, these units will be required to play an equally increasing role in both the clinical management of patients and the ongoing clinical research into the conditions that cause falls and blackouts in the elderly.

Prevention of carotid angioplasty-induced bradycardia and hypotension with temporary venous pacemakers

OBJECTIVE

Carotid angioplasty with stent placement is becoming an established treatment modality for patients with high-risk carotid stenosis. Unlike carotid endarterectomy, angioplasty causes direct mechanical dilation of the stenotic carotid artery and bulb. Stimulation of the sinus baroreceptors induces a reflexive response that consists of increased parasympathetic discharge and inhibition of sympathetic tone, which results in bradycardia and subsequent cardiogenic hypotension.

METHODS

At a single institution, the experience with 43 patients treated from November 1994 to January 2000 with 47 angioplasty and stent procedures for occlusive carotid artery disease was retrospectively reviewed. Prophylactic temporary venous pacemakers were used to prevent hypotension from possible angioplasty-induced bradycardia. Pacemakers were set to capture a heart rate decrease below 60 beats per minute. Variables analyzed included demographics, etiology of disease, side of the lesion, the presence of symptoms, history of coronary artery disease, percent stenosis, type of stent used, number of dilations, pressure of dilation, and angioplasty balloon diameter.

RESULTS

Ten patients were excluded because pacemakers were not used during their angioplasty procedures, and these included three emergencies and a lesion that was unrelated anatomically to the carotid sinus (petrous carotid). The remaining 37 procedures were performed in 33 patients with a mean age of 67 years, and consisted of 17 men, 16 women, 20 right and 17 left-sided lesions. The pacemakers maintained a cardiac rhythm in 23 (62%) of the 37 procedures and in no case did the pacemaker fail to respond when activated. Recurrent (56%; 10 of 18), radiation-induced (78%; 7 of 9), and medically refractory carotid stenosis (67%; 6 of 9) required intraprocedural pacing. Two patients with recurrent stenosis became hypotensive despite the aid of the pacing device but were not symptomatic. Seventy-nine percent (15 of 19) of symptomatic lesions and 57% (8 of 14) of nonsymptomatic lesions required pacing, which was statistically significant (P = 0.049). No patient experienced an operative morbidity or mortality as a consequence of the temporary pacing devices.

CONCLUSION

Angioplasty-induced bradycardia is a common condition, and it is more prevalent in radiation-induced stenosis and with symptomatic lesions. Temporary venous demand pacing is a safe procedure and may prevent life-threatening, baroreceptor-induced hypotension.

[Usefulness of the implantable subcutaneous recorder in the diagnosis of recurrent syncope of unknown etiology in patients without structural heart disease and negative tilt test and electrophysiological study]

BACKGROUND AND OBJECTIVES

In up to 38% of the cases, the etiology of syncope difficult to determine. The main obstacle for diagnosis of the causes of syncope lies in the unpredictable frequency of episodes. Development of implantable loop recorders allows long term electrocardiographic monitoring. The aim of this study was to evaluate the usefulness of the implantable loop recorder for the diagnosis of recurrent syncope of unknown origin.

PATIENTS AND METHODS

From May 1991 to April 1999, a cohort of 176 patients with recurrent syncope was prospectively assessed. Investigations, including Holter monitoring, Tilt Test and electrophysiological study, allowed the determination of the etiology in 161 patients. The remaining 15 patients, without structural cardiac disease were selected for continuous electrocardiographic monitoring using an implantable loop recorder.

RESULTS

During follow up after implant, 15 +/- 2 months (X- +/- SEM), 9 patients showed recurrence of symptoms concordant with prior episodes (time: 105 +/- 30 days). In 7 cases records during symptoms were diagnostic (0.47; CI 95%: 0.21-0.73), in 3 cases a diagnosis with documented arrhythmia was achieved, and in 4 other cases a presumptive clinical diagnosis of non-arrhythmic cause was made. In 8 patients, 6 with no recurrences, diagnosis was not possible. There were no complications related to the use of the device.

CONCLUSIONS

The strategy of long term monitoring with the implantable loop recorder is safe and effective in patients with recurrent syncope of unknown etiology.

Ambulatory blood pressure monitoring and postprandial hypotension in elderly persons with falls or syncopes

BACKGROUND

Postprandial hypotension (PPH) is increasingly recognized as a common cause of falls and syncope in elderly persons. Noninvasive ambulatory blood pressure monitoring (ABPM) has been recommended for detecting PPH. This study investigates postprandial blood pressure (BP) changes by means of ABPM in elderly patients experiencing falls or syncopes.

METHODS

Twenty-four-hour ABPM was performed in 156 inpatients (111 women, mean age 80.4 +/- 8.1 years). Among them, 45 had been admitted for falls and 75 for syncope; 36 with no history of falls or syncope served as controls. Postprandial change in systolic blood pressure (deltaSBP) was calculated by subtracting the mean SBP within the 2 hours following the meal from the mean SBP within the 2 hours preceding the meal. PPH was defined by a deltaSBP > or = 20 mm Hg.

RESULTS

For the entire group, mean SBP decreased after the three meals. On average, the decline in SBP was greater after breakfast than after lunch or dinner, and the number of patients experiencing PPH was greater after breakfast. Average maximal deltaSBP was significantly larger in the syncope group than in the other groups ( p < .05). Moreover, the number of patients experiencing PPH was significantly higher in the syncope/fall group than in the control group (23% vs 9%; p = .03). Compared with patients without PPH, patients with PPH were more likely to have a history of diabetes mellitus (p < .01) or to use more than three different drugs daily ( p = .04), and they showed greater daytime SBP variability (p < .0001). Furthermore, there was a strong positive correlation between preprandial SBP and deltaSBP after breakfast.

CONCLUSIONS

About one out of four elderly patients with falls or syncope experiences PPH, usually after breakfast. Postprandial decline in BP contributes to BP variability. deltaSBP and preprandial SBP are positively correlated.

Assessment of unexplained falls and gait unsteadiness: the impact of age

When a patient with a balance disorder reports rotational vertigo, the clinician rightly focuses his or her attention on the vestibular system. This article reviews the possible diagnoses in the many patients who primarily report falls or gait disorder. Falls can be caused by predisposing neurologic conditions impairing gait, cardiovascular conditions, or epileptic episodes. The proportion of idiopathic falls, however, remains high. In the elderly, environmental circumstances, visual defects, psychotropic medication, and poor general health are additional risk factors. Clinical assessment of gait is more revealing and less expensive than computerized posture/ gait systems. The diagnosis of orthostatic tremor, however, requires either Fourier analysis of sway platform signals or electromyography.

Risk factors for syncope in a community-based sample (the Framingham Heart Study)

The epidemiology of syncope has not been well described. Prior studies have examined risk factors for syncope in hospital-based or other acute or long-term care settings. To determine risk factors for syncope in a community-based sample, we performed a nested case-control study. We examined reports of syncope in Framingham Heart Study participants who underwent routine clinic visits from 1971 to 1990. For each syncope case (n = 543) 2 controls were matched for age, sex, and examination period. Mean age of subjects was 67 years (range 25 to 95); 59% were women. History of stroke or transient ischemic attack, history of myocardial infarction, high blood pressure, use of antihypertensive medication, use of other cardiac medication, smoking, alcohol intake, body mass index, systolic blood pressure, diastolic blood pressure, heart rate, atrial fibrillation, PR interval prolongation, interventricular block, and diabetes or elevated glucose level were examined as potential predictors. Using conditional logistic regression analysis, the predictors of syncope included a history of stroke or transient ischemic attack (odds ratio [OR] 2.56, 95% confidence interval [CI] 1.62 to 4.04), use of cardiac medication (OR 1.67, 95% CI 1.21 to 2. 30), and high blood pressure (OR 1.46, 95% CI 1.14 to 1.88). Lower body mass index was marginally associated with syncope (OR per 4 kg/m(2) decrement 1.10, 95% CI 0.99 to 1.22), as were increased alcohol intake (OR per 5 oz/week 1.11, 95% CI 0.99 to 1.26), and diabetes or an elevated glucose level (OR 1.29, 95% CI 0.96 to 1.75). To our knowledge, this study represents the first community-based study of risk factors for syncope.

Intraindividual variability in orthostatic blood pressure changes among older adults: the influence of meals

OBJECTIVES

To examine the influence of time of day and of meals on postural blood pressure (BP) changes in older adults.

DESIGN

Prevalence study of BP changes in response to orthostasis.

SETTING

A geriatric short-stay department

PARTICIPANTS

A total of 126 inpatients (91 women and 35 men; mean age: 81.4+/-7.9, range 61-95 years) were included in the study.

MEASUREMENTS

Two sets of BP and heart rate measurements were obtained for each subject by one examiner using a standard mercury manometer: (1) in mid-morning (between 10:00 and 10:30 a.m.) and (2) within 30 to 60 minutes after lunch (between 1:00 and 1:30 p.m.). Orthostatic hypotension (OH) was defined as a systolic blood pressure (SBP) decline > or = 20 mm Hg within 3 minutes after standing.

RESULTS

Sixty-one participants (48%) experienced significant orthostatic BP decline on at least one reading. Among them, 46 (37%) had OH in the mid-morning, and 32 (25%) had OH after lunch (P = .05). Only 17 (13%) had OH on both readings (persistent OH). Forty-four patients (35%) had variable OH. Patients with persistent OH were more likely to exhibit symptoms of dizziness and had a lower body mass index and a higher mean basal supine SBP. There was a positive correlation between basal supine SBP and postural SBP decline.

CONCLUSIONS

Because of the variability of postural BP changes, the diagnosis of OH should not be based on a single orthostatic BP measurement but requires repeated testing, at best under circumstances similar to those in which the symptoms occurred. The postprandial period is not particularly favorable to OH, suggesting that the ingestion of a meal does not worsen orthostatic BP changes in most aged patients.

Evaluation of syncope in the emergency department

Although most cases of syncope are benign, an adequate evaluation, which begins in the emergency department, is required to exclude life-threatening disorders. In addition, life-threatening disorders such as QT prolongation as well as confounding alternative diagnoses (e.g., seizure disorder) are also discussed.

Effects of long-term vasodilator therapy in patients with carotid sinus hypersensitivity

BACKGROUND

In patients affected by carotid sinus hypersensitivity, long-term vasodilator therapy might increase the risk of syncopal episodes by reducing systolic blood pressure and venous return to the heart.

METHODS AND RESULTS

Thirty-two patients (mean age 73 +/- 9 years; 20 men) who met all the following criteria were included: (1) one or more episodes of syncope occurring during long-term (>6 months) treatment with angiotensin-converting enzyme inhibitors, long-acting nitrates, calcium antagonists, or a combination of these; (2) a positive response to carotid sinus massage, defined as the reproduction of spontaneous syncope in the presence of ventricular asystole > or =3 seconds or a fall in systolic blood pressure > or =50 mm Hg; (3) negative workup for other causes of syncope. The patients were randomly assigned to continue or to discontinue use of vasodilators; carotid sinus massage was repeated 2 weeks after randomization. By the end of the study period, the baseline values of systolic blood pressure were significantly different between the 2 groups of patients both in supine (P=.01) and upright (P=.03) positions. Syncope had been induced by carotid sinus massage in 81% of patients in the "on-vasodilator" group and in 62% of patients in the "off-vasodilator" group (P=.21). The cardioinhibitory reflex was of similar magnitude in the 2 groups, being found in 50% of the patients in each group, with a maximum ventricular pause of 7.1 +/- 2.7 and 6.7 +/- 1.8 seconds, respectively. The percentage decrease of blood pressure did not differ between the 2 groups, even if, in absolute values, the baseline difference of blood pressure roughly persisted for the duration of the test. In consequence of that, the rise of blood pressure to similar values was delayed approximately 30 seconds in the "on-vasodilator" group and took more than 2 minutes to return to baseline values.

CONCLUSIONS

In patients affected by carotid sinus hypersensitivity, chronic vasodilator therapy does not have a direct effect on carotid sinus reflexivity, although the delayed recovery of pretest blood pressure values could indirectly potentiate the severity of the clinical manifestations of the syndrome. The persistence of hypotension for a longer time after the end of the massage suggests that vasodilators cause an impairment of compensatory mechanisms.

Effects of chronic vasodilator therapy to enhance susceptibility to vasovagal syncope during upright tilt testing

To evaluate the effect of chronic vasodilator therapy on susceptibility to vasovagal syncope, 45 patients with syncope and a positive response to tilt testing were randomly assigned to continue or to discontinue vasodilators. The study result demonstrated that chronic vasodilator therapy enhances susceptibility to vasovagal reaction during upright tilt testing.

Spells. Differential diagnosis and management strategies

In summary, when approaching the patient who has had a spell of unknown cause, the most important differentiation to make is between a syncopal episode and a seizure. The history and physical examination will provide the diagnosis in approximately 85% of cases. Once the physician has some idea of which path to pursue, it is important to order the tests in a directed fashion tailored to the patient's presentation. A shotgun approach is neither warranted nor beneficial and is best avoided when possible. Some patients will remain without a diagnosis despite a complete workup, thus it is important for the emergency physician to rule out the life-threatening possibilities and to arrange the appropriate long-term follow-up for the patient with their primary care provider.

Permanent cardiac pacing in elderly patients with recurrent falls, dizziness and syncope, and a hypersensitive cardioinhibitory reflex

The study was designed to assess the outcome of treatment with permanent dual-chamber pacing of elderly patients with falls, dizziness and syncope associated with the demonstration of a hypersensitive cardioinhibitory reflex. Questionnaires were sent to patients (and their general practitioners) who had been referred to a regional pacing centre with recurrent falls, dizziness or syncope diagnosed as likely to be secondary to cardioinhibitory carotid sinus syndrome or predominantly cardioinhibitory vasovagal syndrome. After pacemaker insertion, 84% of patients had no further syncope over a mean follow-up period of 10 (range 1.5 to 30) months. Minor symptoms persisted in only 40% of all patients. Symptoms were unchanged in 22%. It was concluded that permanent dual-chamber pacing is an effective treatment for elderly patients with recurrent falls, dizziness and syncope in whom a hypersensitive cardioinhibitory reflex is found. Good results were obtained in this group with a simple diagnostic work-up.

Syncope in the elderly

Age-related physiologic changes and disease-related abnormalities predispose older adults to syncope. It is important to know the physiologic changes that occur with normal aging to understand better their interaction with disease processes and to facilitate better evaluation and treatment of syncope when it occurs. Attention to situational stresses, such as posture changes, meals, or medications, is also likely to increase the diagnostic yield and improve therapeutic strategies that can reduce morbidity and potential mortality of recurrent episodes. Therapy should be directed toward minimizing multiple factors that contribute to syncope, avoiding iatrogenic medication effects, and treating specific contributory diseases.

Pathophysiology of carotid sinus hypersensitivity in elderly patients

Carotid sinus hypersensitivity (CSH) is recognised in up to 45% of elderly patients with syncope, falls, and dizziness that may not be attributed to specific myocardial sinus node dysfunction, various diseases that affect pacemaker activity, cardiac output and blood supply to the brain. The pathophysiology of CSH is unclear but it is associated with ageing, hypertension, and ischaemic heart disease. CSH is potentially treatable with dual chamber pacing for prolonged sinus arrest (cardio-inhibitory CSH) but therapy for the more prevalent hypotension (vasodepressor CSH) is unsatisfactory. However, hypersensitivity of the carotid sinus is not consistent with the known blunting effects of senescence and hypertension on baroreflex sensitivity. The present hypothesis proposes that CSH in elderly patients results from up-regulation of brainstem postsynaptic alpha-2 adrenoceptors. Reduced carotid sinus compliance in elderly arteriosclerotic hypertensive patients will reduce afferent impulse traffic in the baroreflex pathway. Such relative deafferentation may be expected to cause baroreflex postsynaptic hypersensitivity, mediated by up-regulation of the dominant postsynaptic receptor population in the baroreflex pathway, ie, alpha-2 adrenoceptors. Vigorous carotid sinus stimulation, eg, massage, could thus cause an overshoot baroreflex efferent response, resulting in profound hypotension and bradycardia. Hypotension and bradycardia are compounded by the effects of age, hypertension, ischaemic heart disease and arteriosclerosis on rapid cardiovascular compensation, resulting in cerebral hypoperfusion and syncope. Thus CSH in elderly patients should be considered as a clinical marker of widespread arteriosclerotic disease, rather than as a distinct disease entity. If correct, this hypothesis has potentially important implications for the pharmacotherapy of hypotension-related symptoms in elderly arteriosclerotic patients.