SAFE PACE 2: Syncope and Falls in the Elderly--Pacing and Carotid Sinus Evaluation: a randomized controlled trial of cardiac pacing in older patients with falls and carotid sinus hypersensitivity.

SAFE PACE is a multicentre randomized controlled trial to assess the efficacy of dual-chamber pacing in older patients with carotid sinus hypersensitivity and recurrent unexplained falls. Patients are eligible if they have had two or more unexplained falls (+/- up to one syncope) and if they have a cardio-inhibitory response (>3 s asystole) to carotid sinus massage. Patients will be randomized to receive either a Medtronic Kappa 700(Europe)/Kappa 400(North America) pacemaker or an implantable loop recorder (ILR)(control group). Patients will be required to complete weekly fall diaries. The primary outcome measure is the number of patients who fall in the 24-month follow-up period. Recruitment began in October 1998 and continues for 12 months; the follow-up is for 24 months.     

Prevalence and One-year Outcome of Carotid Sinus Hypersensitivity in Unexplained Syncope: A Prospective Cohort Study from South India

Background

Carotid sinus syndrome accounts for one third of patients who presents with unexplained syncope. Prevalence of carotid sinus hypersensitivity (CSH) in Indians has not been studied till now.

Syncope-related falls in the elderly

Age-related physiological impairments of heart rate, blood pressure and cerebral blood flow, in combination with comorbid conditions and concurrent medications, account for an increased susceptibility to syncope in older adults. Common causes of syncope are orthostatic hypotension, neurally-mediated syncope (including carotid sinus syndrome) and cardiac arrhythmias. A high proportion of older patients with cardiovascular syncope present with falls and deny loss of consciousness. Patients who are cognitively normal and have unexplained falls should have a detailed cardiovascular assessment. (J Geriatr Cardiol 2005; 2 (2): 74-83).     

Clinical spectrum of neurally mediated reflex syncopes.

AIMS: The clinical features of the various types of neurally mediated reflex syncope have not been systematically investigated and compared. We sought to assess and compare the clinical spectrum of neurally mediated reflex syncopes. METHODS AND RESULTS: Four hundred sixty-one patients with syncope were prospectively evaluated and 280 had neurally mediated reflex syncope. Each patient was interviewed using a standard questionnaire. A cause of syncope was assigned using standardized diagnostic criteria. Typical vasovagal syncope was diagnosed in 39 patients, situational syncope in 34, carotid sinus syncope in 34, tilt-induced syncope in 142 and complex neurally mediated syncope (positive response to both carotid sinus massage and tilt test) in 31. The clinical features of situational, carotid sinus, tilt-induced and complex neurally mediated syncope were very similar. By contrast, typical vasovagal syncope differed from other neurally mediated syncopes not only in terms of its precipitating factors (fear, strong emotion, etc.), which constituted predefined diagnostic criteria, but also in the variety of its clinical features (lower age and prevalence of organic heart disease, higher prevalence of prodromal symptoms, and of autonomic prodromes, longer duration of prodromes, higher prevalence of symptoms during the recovery phase and lower prevalence of trauma). CONCLUSION: The clinical spectrum of neurally mediated reflex syncopes demonstrates much overlap between them. However, when the afferent neural signals are localized in cortical sites, as in typical vasovagal syncope, symptoms are more frequent and of longer duration.     

CAROTID SINUS HYPERSENSITIVITY IN ELDERLY NURSING HOME PATIENTS

Abstract Fourteen of 100 geriatric nursing home patients were shown to have evidence of carotid sinus hypersensitivity. The incidence of syncope and falls was noted in prospective follow-up over 33 months. Falls were classified as either simple or complicated by laceration or fracture. Patients experienced simple falls at similar rates whether carotid sinus hypersensitivity was present or absent. For patients with carotid sinus hypersensitivity, the risk of a laceration was increased more than twofold, that of fracture more than threefold, and that of syncope tenfold. Carotid sinus hypersensitivity warrants greater attention as a contributory factor to serious falls and syncope in the elderly, and its importance may have been underestimated in the past.     

Epidemiology of syncope in hospitalized patients

OBJECTIVE: To describe the etiologies of syncope in hospitalized patients and determine the factors that influence survival after discharge. DESIGN: Observational retrospective cohort. SETTING: Department of Veterans Affairs hospital, group-model HMO, and Medicare population in Oregon. PATIENTS: Hospitalized individuals (n = 1,516; mean age +/- SD, 73.0 +/- 13.4 years) with an admission or discharge diagnosis of syncope (ICD-9-CM 780.2) during 1992, 1993, or 1994. MEASUREMENTS AND MAIN RESULTS: During a median hospital stay of 3 days, most individuals received an electrocardiogram (97%) and prolonged electrocardiographic monitoring (90%), but few underwent electrophysiology testing (2%) or tilt-table testing (0. 7%). The treating clinicians identified cardiovascular causes of syncope in 19% of individuals and noncardiovascular causes in 40%. The remaining 42% of individuals were discharged with unexplained syncope. Complete heart block (2.4%) and ventricular tachycardia (2. 3%) were rarely identified as the cause of syncope. Pacemakers were implanted in 28% of the patients with cardiovascular syncope and 0. 4% of the others. No patient received an implantable defibrillator. All-cause mortality +/- SE was 1.1% +/- 0.3% during the admission, 13% +/- 1% at 1 year, and 41% +/- 2% at 4 years. The adjusted relative risk (RR) of dying for individuals with cardiovascular syncope (RR 1.18; 95% confidence interval [CI] 0.92, 1.50) did not differ from that for unexplained syncope (RR 1.0) and noncardiovascular syncope (RR 0.94; 95% CI 0.77, 1.16). CONCLUSIONS: Among these elderly patients hospitalized with syncope, noncardiovascular causes were twice as common as cardiovascular causes. Because survival was not related to the cause of syncope, clinicians cannot be reassured that hospitalized elderly patients with noncardiovascular and unexplained syncope will have excellent outcomes.     

Diagnosis of carotid sinus hypersensitivity in older adults: carotid sinus massage in the upright position is essential

OBJECTIVE—To assess the diagnostic value of supine and upright carotid sinus massage in elderly patients.
DESIGN—Prospective controlled cohort study.
SETTING—Three inner city accident and emergency departments and a dedicated syncope facility.
PATIENTS—1375 consecutive patients aged > 55 years presenting with unexplained syncope and drop attacks; 25 healthy controls.
INTERVENTIONS—Bilateral supine carotid sinus massage, repeated in the 70° head up tilt position if the initial supine test was not diagnostic of cardioinhibitory and mixed carotid sinus hypersensitivity.
MAIN OUTCOME MEASURES—Diagnosis of cardioinhibitory or mixed carotid sinus hypersensitivity; clinical characteristics of supine v upright positive groups.
RESULTS—226 patients were excluded for contraindications to carotid sinus massage. Of 1149 patients undergoing massage, 223 (19%) had cardioinhibitory or mixed carotid sinus hypersensitivity; 70 (31%) of these had a positive response to massage with head up tilt following negative supine massage (95% confidence interval, 25.3% to 37.5%). None of the healthy controls showed carotid sinus hypersensitivity on erect or supine massage. The initially positive supine test had 74% specificity and 100% sensitivity; these were both 100% for the upright positive test. The clinical characteristics of the supine v upright positive subgroups were similar.
CONCLUSIONS—The diagnosis of carotid sinus hypersensitivity amenable to treatment by pacing may be missed in one third of cases if only supine massage is performed. Massage should be done routinely in the head up tilt position if the initial supine test is negative.


Keywords: carotid sinus; tilt table testing; syncope; elderly patients     

The use of an implantable loop recorder in the investigation of unexplained syncope in older people

INTRODUCTION: Reveal is a patient activated implantable loop recorder device with an 18 month battery life now available to assist in the diagnosis of suspected syncope or arrhythmias. We present our experience using this device in older subjects referred to a dedicated falls and syncope clinic in whom usual clinical assessment had not satisfactorily identified an attributable diagnosis but where we still suspected a cardiovascular cause for syncope or falls. METHODS AND RESULTS: during the past 3 years 15 subjects (mean age 73 years, range 61-89 years) had Reveal implanted for symptoms of syncope alone (n=6; 40%) and unexplained falls (n=3; 20%) or symptoms of syncope and unexplained falls (n=6; 40%). Symptom duration was long (mean 48 months; range 4-200 months). Subjects had experienced significant morbidity, 6 subjects (40%) required A&E attendance or hospital admission and 4 (27%) experienced a fracture. Despite extensive and repeated investigations, which included 12-lead ECG, echocardiogram, 24-h ambulatory heart rate monitor, 24-h ambulatory blood pressure monitor, orthostatic blood pressure measurement, supine and erect carotid sinus massage, electroencephalogram, and passive and GTN head up tilt testing, the attributable diagnosis remained unexplained. Of the 15 subjects, 7 have activated the device at 4 (range 0-14) months after implantation. Bradycardia was identified in 3 and ventricular tachycardia in 1 subject. Two subjects did not activate the device during the 18 months it was in-situ. Four people had problems with device activation. This is comparable to rates noted using Reveal in younger subjects. CONCLUSION: Reveal offers additional diagnostic yield in complex elderly subjects with suspected cardiovascular causes of syncope or unexplained falls which have not been previously satisfactorily diagnosed despite extensive investigations.     

The diagnostic value of ATP testing in patients with unexplained syncope.

A minority of patients with unexplained syncope has an increased susceptibility to adenosine triphosphate (ATP) injection. In these 'hypersensitive' patients, owing to its powerful cardiac and hypotensive effects, endogenous adenosine released under physiological and pathological conditions could trigger bradycardia and/or hypotension and cause syncope. This hypothesis still needs to be proven. However, there is some evidence that the ATP test identifies a group of patients with otherwise unexplained syncope with definite clinical features, absence of structural heart disease and benign prognosis. The mechanism of syncope is heterogeneous; indeed, in cases of electrocardiographic documentation of spontaneous syncope, either a long ventricular pause (mainly due to paroxysmal atrioventricular (AV) block) or no rhythm variations or even tachycardia were documented. ATP-positive patients have clinical features and mechanisms of syncope which are different from tilt-positive patients. Owing to its low positive predictive value, the ATP test is of little value in selecting treatment. A favourable outcome suggests a strategy of postponing treatment, in particular pacemaker therapy, until a definite diagnosis can be made by documenting a spontaneous syncopal relapse.     

Clinical characteristics of patients with vasovagal reactions presenting as unexplained syncope.

OBJECTIVE: To describe the clinical characteristics of vasovagal syncope (VVS) in patients presenting to a tertiary referral centre with unexplained syncope, in whom the diagnosis of VVS was confirmed by tilt table testing (HUT) and in whom other causes of syncope excluded. DESIGN: Prospective study of 62 consecutive patients with more than two episodes of syncope in the past year. SETTING: A regional tertiary referral centre for patients with unexplained syncope. PATIENTS: Sixty-two patients, mean age 50 +/- 21 years, 39 female, were studied. Mean duration of symptoms was 5 years. Average frequency of attacks was one episode per week. INTERVENTIONS: Detailed semi-structured questionnaires were completed regarding presenting symptoms. RESULTS: In over one-third of patients, episodes occurred suddenly, with no prodromal features. In those with prodrome, 71% had autonomic symptoms, but 27% had palpitations or dyspnoea and 21% had chest pain. Eleven percent of patients denied known provocative features. In the remainder, the most common were prolonged standing (37%), hot weather (27%) and lack of food (23%). One-fifth had symptoms sitting and 5% whilst driving. Seventy-five percent of patients suffered after effects, the most common being severe fatigue. Over half sustained an injury during syncope, and 13% sustained a fracture. Unwitnessed episodes occurred in 25%. Pallor was reported in half the cases, sweating in 13% and myoclonus in 5%. CONCLUSIONS: Atypical presentations of VVS occur in many patients referred to a tertiary referral centre. Knowledge of the clinical characteristics of unexplained syncope for which VVS is the attributable diagnosis should assist in appropriate management of such patients.     

Clinical experience of a new rate drop response algorithm in the treatment of vasovagal and carotid sinus syncope.

Dual chamber pacing has proven beneficial in patients with sudden drops in heart rate as seen in vasovagal syncope and carotid sinus syndrome. Newer algorithms for faster detection of an insidious drop in heart rate and short lasting intervention pacing at a high rate, as in the rate drop response algorithm in the Medtronic Kappa series of pacemakers, might improve the effect of pacing. Two case reports, that demonstrate the use of these rate drop response algorithms, are presented. A 24-year-old woman with recurrent episodes of syncope and repeated tilt-table tests with vasovagal cardioinhibitory outcomes had a Medtronic Kappa 400 pacemaker implanted. Syncope was abolished during repeat tilt-table testing following pacemaker implantation and proper functioning of the rate drop response algorithm. The patient has been free of syncope during follow-up apart from a single episode that occurred due to neglect of vasovagal warning symptoms. A 52-year-old man with coronary artery disease developed recurrent blackouts. Carotid sinus massage resulted in 5.5 s of asystole and presyncope. A Medtronic Kappa 700 pacemaker with a rate drop response algorithm was implanted and the patient became asymptomatic. The rate drop response algorithm is discussed in detail based upon the case reports, and recommendations are given for the use of this algorithm in patients with vasovagal syncope and carotid sinus syndrome.     

Diagnosis and characteristics of syncope in older patients referred to geriatric departments

OBJECTIVES: To test the applicability and safety of a standardized diagnostic algorithm in geriatric departments and to define the prevalence of different causes of syncope in older patients. DESIGN: Multicenter cross-sectional observational study. SETTING: In-hospital geriatric acute care departments and outpatient clinics. PARTICIPANTS: Two hundred forty-two patients (aged>or=65, mean+/-standard deviation=79+/-7, range 65-98) consecutively referred for evaluation of transient loss of consciousness to any of six clinical centers participating in the study. Of these, 11 had a syncope-like condition (5 transient ischemic attack; 6 seizures), and 231 had syncope (aged 65-74, n=71; aged>or=75, n=160). MEASUREMENTS: Protocol designed to define etiology and clinical characteristics of syncope derived from European Society of Cardiology Guidelines on syncope. RESULTS: No major complication occurred with use of the protocol. Neurally mediated was the more prevalent form of syncope in this population (66.6%). Cardiac causes accounted for 14.7% of all cases. The neuroreflex form of syncope (vasovagal, situational, and carotid sinus syndrome) was more common in younger than in older patients (62.3% vs 36.2%; P=.001), whereas orthostatic syncope was more frequent in the older than in the younger group (30.5% vs 4.2%; P<.001). In only 10.4% of cases, syncope remained of unexplained origin. After initial evaluation, a definite diagnosis was possible in 40.1% of the cases, and a suspected diagnosis was obtained in 57.9%. Syncope of suspected cardiac origin after initial evaluation was confirmed in 43.7% of cases, and neuromediated causes were confirmed in 83.5% of the cases. CONCLUSION: The protocol is applicable even beyond the age of 90 in geriatric departments. The standardized protocol is associated with a reduction in the frequency of unexplained syncope to about 10%.     

Clinical predictors for bradycardia and supraventricular tachycardia necessitating therapy in patients with unexplained syncope monitored by insertable cardiac monitor

BackgroundInsertable cardiac monitors (ICMs) improve diagnostic yield in patients with unexplained syncope. The most of cardiac syncope is arrhythmic causes include paroxysmal bradycardia and supraventricular tachycardia (SVT) in patients with unexplained syncope receiving ICM. Predictors for bradycardia and SVT that necessitate therapy in patients with unexplained syncope are not well known.HypothesisThis study aimed to investigate predictors of bradycardia and SVT necessitating therapy in patients with unexplained syncope receiving ICMs.MethodsWe retrospectively reviewed medical records of consecutive patients who received ICMs to monitor unexplained syncope. We performed Cox''s stepwise logistic regression analysis to identify significant independent predictors for bradycardia and SVT.ResultsOne hundred thirty‐two patients received ICMs to monitor unexplained syncope. During the 17‐month follow‐up period, 19 patients (14%) needed pacemaker therapy for bradycardia; 8 patients (6%) received catheter ablation for SVT. The total estimated diagnostic rates were 34% and 48% at 1 and 2 years, respectively. Stepwise logistic regression analysis indicated that syncope during effort (odds ratio [OR] = 3.41; 95% confidence interval [CI], 1.21 to 9.6; p = .02) was an independent predictor for bradycardia. Palpitation before syncope (OR = 9.46; 95% CI, 1.78 to 50.10; p = .008) and history of atrial fibrillation (OR = 10.1; 95% CI, 1.96 to 52.45; p = .006) were identified as significant independent predictors for SVT.ConclusionSyncope during effort, and palpitations or history of atrial fibrillation were independent predictors for bradycardia and for SVT. ICMs are useful devices for diagnosing unexplained syncope.     

The Clinical Spectrum of Neurocardiogenic Syncope

Neurocardiogenic Syncope. Neurocardiogenic syncope is a collective term used to describe the clinical syndromes of syncope that result from inappropriate, and often excessive, autonomic reflex activity, and manifest as abnormalities in the control of vascular tone and heart rate. These include carotid sinus syndrome, vasovagal syncope, and the syndromes of cough, deglutition, and micturition syncope. Orthostatic hypotension, which, in contrast, results from a failure of autonomic reflexes, is not considered part of this family of closely related syndromes. This review will focus on vasovagal and carotid sinus syndromes.     

Orthostatic Versus Electrophysiologic Testing in Unexplained Syncope in Children and Adolescents

Orthostatic vs EP Testing in Pediatric Unexplained Syncope. Introduction: Unexplained syncope in the pediatric age group is a common problem that often requires cardiac evaluation. This work-up is expensive and frequently unrevealing. Electrophysiologic and, more recently, tilt table or orthostatic testing have been used in the evaluation of unexplained syncope. Methods and Results: We undertook to compare the results of these two forms of evaluation in a group of 26 young patients less than 19 years of age with episodes of unexplained syncope. Sixteen of the 26 patients (62%) had an abnormal electrophysiologic study with the majority having either mild sinus node dysfunction or inducible atrial flutter. Four of the 26 patients (16%) were thought to have an abnormality found that was clinically significant (sustained ventricular tachycardia [2], nonsustained ventricular tachycardia/polymorphic premature ventricular contractions [1], and high-degree atrioventricular block [1]). An abnormal response to orthostatic testing was found in 14 of 26 patients (56%) with 13 of 14 developing syncope at an average standing time of 6.5 minutes. Sixteen patients underwent treatment based on the study findings and follow-up with an average time of 1.6 years is available on 13 of 16 patients who underwent treatment. Of the nine patients treated for neurally mediated syncope (fludrocortisone [7], beta blocker [1], theophylline [1]), all are asymptomatic. The four patients with an arrhythmic cause of syncope found by electrophysiologic testing are asymptomatic on treatment (antiarrhythmic drug [3], permanent pacing [1]). Conclusion: Orthostatic testing has a higher positive yield than electrophysiologic testing in the evaluation of unexplained syncope in young patients. Orthostatic or tilt table testing should be considered early on in the cardiovascular evaluations of these patients. (J Cardiovasc Electrophysiol, Vol. 3, pp. 418–422, October 1992)     

Monitoring devices for falls and syncope

Monitoring devices are an important adjunct to the clinical assessment of patients who experience falls. The use of these devices should be guided by the clinical history, a physical assessment, and routine investigations. Quantitative measures of postural sway should be used in conjunction with clinical measures to provide a more accurate assessment of gait and balance. Assessment of blood pressure changes during the investigation of neurocardiovascular causes of syncope and falls in older adults should be performed with noninvasive digital photoplethysmographic devices, so long as their appropriate use and limitations are applied and understood. Only minimal information can be gained from short-term heart rate and rhythm monitoring in patients with infrequent symptoms. The usefulness of long-term ECG monitoring (with both external and implantable recorders) is well established for the diagnosis of unexplained syncope but requires further assessment in older individuals who experience falls. Twenty-four-hour measurements of ambulatory blood pressure generally are not diagnostically helpful in patients who experience falls or syncope but do have a role in the monitoring of therapeutic interventions.     

At the heart of the arterial baroreflex: a physiological basis for a new classification of carotid sinus hypersensitivity

The aim of this review is to provide an update of the current knowledge of the physiological mechanisms underlying reflex syncope. Carotid sinus syncope will be used as the classical example of an autonomic reflex with relatively well‐established afferent, central and efferent pathways. These pathways, as well as the pathophysiology of carotid sinus hypersensitivity (CSH) and the haemodynamic effects of cardiac standstill and vasodilatation will be discussed. We will demonstrate that continuous recordings of arterial pressure provide a better understanding of the cardiovascular mechanisms mediating arterial hypotension and cerebral hypoperfusion in patients with reflex syncope. Finally we will demonstrate that the current criteria to diagnose CSH are too lenient and that the conventional classification of carotid sinus syncope as cardioinhibitory, mixed and vasodepressor subtypes should be revised because isolated cardioinhibitory CSH (asystole without a fall in arterial pressure) does not occur. Instead, we suggest that all patients with CSH should be thought of as being ‘mixed’, between cardioinhibition and vasodepression. The proposed stricter set of criteria for CSH should be evaluated in future studies.     

Cardiac causes for falls and their treatment

Cardiovascular disorders are a common cause of falls and syncope in older adults. The most common cardiac disorders linked to falls and syncope are carotid sinus syndrome, postprandial hypotension, orthostatic hypotension, vasovagal syncope, and bradyarrhythmias. It is important to recognize these conditions, because they may be associated with an increased mortality. Most are easily treatable.     

The application of a standardized strategy of evaluation in patients with syncope referred to three syncope units.

BACKGROUND: The appropriate diagnostic work-up of patients with syncope is not well defined. We applied the guidelines of Italian 'Associazione Nazionale Medici Cardiologi Ospedalieri' to a group of consecutive patients with syncope referred to three Syncope Units. The aim of the study was to evaluate the applicability of those guidelines in the 'real world' and their impact on the use of the tests. METHODS: We evaluated 308 consecutive patients with syncope (mean age 61 +/- 20 years; median of three syncopal episodes per patient). The hierarchy and appropriateness of diagnostic tests and the definitions of the final diagnosis followed standardized predefined criteria. In brief, all patients underwent initial evaluation consisting of history, physical examination, supine and upright blood pressure measurement and standard electrocardiogram (ECG) (only in patients > 45 years or with history of heart disease). Any subsequent investigations were based on the findings of the initial evaluation. Priority was given to cardiological tests (prolonged ECG monitoring, exercise test, electrophysiological study), or to neurally mediated tests (carotid sinus massage, tilt test, ATP test), or to neuro-psychiatric tests, as appropriate. FINDINGS: The initial evaluation alone was diagnostic in 72 patients (23%). One further test was necessary for diagnosis in 65 patients (21%), > or = 2 tests in 64 (21%) and > or = 3 tests in 50 (16%). The diagnostic yield was 10% for ECG, 3% for echocardiogram, 16% for Holter, 5% for exercise test, 27% for electrophysiological study, 57% for carotid sinus massage, 52% for tilt testing and 15% for ATP test. At the end of the work-up the mechanism of syncope remained unexplained in 57 patients (18%). CONCLUSIONS: When standardized criteria based on the appropriateness of indications are used, few simple tests are usually needed for diagnosis of syncope.     

Psychiatric conditions in patients with recurrent unexplained syncope.

AIMS: The relationship between syncope and psychiatric disorders is little investigated. This study evaluated the prevalence of psychiatric diseases and prognostic outcome in patients with recurrent unexplained syncope. METHODS AND RESULTS: After an inconclusive standard diagnostic work-up for syncope, including head-up tilt testing, a psychiatric evaluation was offered to 50 consecutive patients with recurrent syncope. The evaluation was accepted by 26 patients (77% females, 36 +/- 16 years) and refused by 24 (63% females, 50 +/- 19 years). A psychiatric disorder was diagnosed in 21 (81%) patients: 12 had depression, four panic attacks, two general anxiety, and three a somatization disorder. Only five patients showed normal psychosocial function. Of the patients with psychiatric disorders four accepted psychiatric care, such as psychotherapy and/or pharmacotherapy; 17 patients refused treatment. During 6 months of follow-up no patient under psychiatric care had syncope, while all patients without psycho- or pharmacotherapy had recurrent syncopal events. In these patients the median of syncopal episodes was three in a 6 months interval before and after clinical assessment. Patients who refused both psychiatric evaluation and therapy continued to experience syncope as before. CONCLUSIONS: In patients with recurrent unexplained syncope psychiatric alteration is common. However, patients seldom accepted a psychiatric evaluation and treatment.