Usefulness and safety of shortened head-up tilt testing potentiated with sublingual glyceryl trinitrate in older patients with recurrent unexplained syncope

Prevalence of asystole during tilt test-induced vasovagal syncope may depend on test methodology

This review addresses tilt-testing methodology by searching the literature which reports timing of asystole and loss of consciousness (LOC). Despite the Italian protocol being the most widely adopted, its stipulations are not always followed to the letter of the European Society of Cardiology guidelines. The discrepancies permit reassessment of the incidence of asystole when tilt-down is early, impending syncope, compared with late, established LOC. Asystole is uncommon with early tilt down and diminishes with increasing age. However, if LOC is established as test-end, asystole is more common, and it is age-independent. Thus, the implications are that asystole is commonly under-diagnosed by early tilt-down. The prevalence of asystolic responses observed using the Italian protocol with a rigorous tilt down time is numerically close to that observed during spontaneous attacks by electrocardiogram loop recorder. Recently, tilt-testing has been questioned as to its validity but, in selection of pacemaker therapy in older highly symptomatic vasovagal syncope patients, the occurrence of asystole has been shown to be an effective guide for treatment. The use of head-up tilt test as an indication for cardiac pacing therapy requires pursuing the test until complete LOC. This review offers explanations for the findings and their applicability to practice. A novel interpretation is offered to explain why pacing induced earlier may combat vasodepression by raising the heart rate when sufficient blood remains in the heart.

Safety and tolerability of Tilt Testing and Carotid Sinus Massage in the octogenarians

OBJECTIVE

to evaluate the safety and tolerability of Tilt Testing (TT) and Carotid Sinus Massage (CSM) in octogenarians with unexplained syncope.

METHODS

patients consecutively referred for transient loss of consciousness to the 'Syncope Units' of three hospitals were enrolled. TT and CSM were performed according to the European Society of Cardiology guidelines on syncope. Complications were evaluated in each group. An early interruption of TT was defined as 'intolerance' and considered as a non-diagnostic response.

RESULTS

one thousand four hundred and one patients were enrolled (mean age 72 ± 16 years, male 40.8%). Six hundred and ninety-four patients (49.5%) were 80 years old or older (mean age 83 ± 3 years) and 707 (50.5%) were younger (mean age 60 ± 17 years). Complications after TT occurred in 4.5% of older patients and in 2.1% of the younger ones (P = 0.01). All complications were 'minor/moderate', as prolonged hypotension, observed in ∼3% of patients ≥80 years. Major complications such as sustained ventricular tachycardia, ventricular fibrillation, asystole requiring cardiac massage, transient ischaemic attack, stroke and death were not observed in any patient. The presence of orthostatic hypotension and the mean number of syncopal episodes were predictors of TT complications. Intolerance was reported in 2.4% of older patients and 1% of the younger ones (P = 0.08), mainly due to orthostatic intolerance. No complications occurred after CSM.

CONCLUSIONS

TT and CSM appear to be safe and well tolerated in octogenarians, who should not be excluded by age from the diagnostic work-up of syncope.

Multimorbidity in Older Adults with Heart Failure

Multimorbidity is common among older adults with heart failure and creates diagnostic and management challenges. Diagnosis of heart failure may be difficult, as many conditions commonly found in older persons produce dyspnea, exercise intolerance, fatigue, and weakness; no singular pathognomonic finding or diagnostic test differentiates them from one another. Treatment may also be complicated, as multimorbidity creates high potential for drug-disease and drug-drug interactions in settings of polypharmacy. The authors suggest that management of multimorbid older persons with heart failure be patient, rather than disease-focused, to best meet patients' unique health goals and minimize risk from excessive or poorly-coordinated treatments.

The usefulness of the head-up tilt test in patients with suspected epilepsy

PURPOSE

It is estimated that approximately 20-30% of patients diagnosed with epilepsy have been misdiagnosed, and neurocardiogenic syncope (NCS) might frequently be the real cause of transient loss of consciousness (TLOC) episodes. We assessed the role of the head-up tilt test (HUTT) in patients previously diagnosed with refractory epilepsy to evaluate the ability of this test to correctly diagnose patients with NCS.

METHOD

We retrospectively analysed the clinical records of 107 consecutive patients with a previous diagnosis of refractory epilepsy that were taking antiepileptic drugs and who were referred for HUTT between January 2000 and December 2010. During the subsequent follow-up, we recorded the treatments performed and the recurrence of symptoms.

RESULTS

Complete follow-up data were available for 94 (88%) patients, and the mean follow-up period was 80±36 months. The HUTT was positive in 54% of patients. Thirty-one (33%) patients were misdiagnosed with epilepsy, and 20 (21%) patients had a dual diagnosis of NCS and epilepsy. The recurrence of TLOC was reported in 55% of the patients, but it was significantly lower in the misdiagnosed group (42% versus 64%; P=0.039).

CONCLUSION

NCS is an important cause of epilepsy misdiagnosis. The HUTT is often critical for making an accurate diagnosis and subsequently selecting the appropriate treatment for patients presenting with TLOC. The diagnostic overlap between epilepsy and NCS is not uncommon, suggesting that electroencephalographic monitoring during a HUTT may play an important role in diagnosing patients with recurrent, undiagnosed TLOC episodes.

Neuroautonomic evaluation of patients with unexplained syncope: incidence of complex neurally mediated diagnoses in the elderly

Background

The incidence of syncope increases in individuals over the age of 70 years, but data about this condition in the elderly are limited. Little is known about tilt testing (TT), carotid sinus massage (CSM), or supine and upright blood pressure measurement related to age or about patients with complex diagnoses, for example, those with a double diagnosis, ie, positivity in two of these three tests.

Methods

A total of 873 consecutive patients of mean age 66.5±18 years underwent TT, CSM, and blood pressure measurement in the supine and upright positions according to the European Society of Cardiology guidelines on syncope.1 Neuroautonomic evaluation was performed if the first-line evaluation (clinical history, physical examination, electrocardiogram) was suggestive of neurally mediated syncope, or if the first-line evaluation was suggestive of cardiac syncope but this diagnosis was excluded after specific diagnostic tests according to European Society of Cardiology guidelines on syncope, or if certain or suspected diagnostic criteria were not present after the first-line evaluation.

Results

A diagnosis was reached in 64.3% of cases. TT was diagnostic in 50.4% of cases, CSM was diagnostic in 11.8% of cases, and orthostatic hypotension was present in 19.9% of cases. Predictors of a positive tilt test were prodromal symptoms and typical situational syncope. Increased age and a pathologic electrocardiogram were predictors of carotid sinus syndrome. Varicose veins and alpha-receptor blockers, nitrates, and benzodiazepines were associated with orthostatic hypotension. Twenty-three percent of the patients had a complex diagnosis. The most frequent association was between vasovagal syncope and orthostatic hypotension (15.8%); 42.9% of patients aged 80 years or older had a complex diagnosis, for which age was the strongest predictor.

Conclusion

Neuroautonomic evaluation is useful in older patients with unexplained syncope after the initial evaluation. A complex neurally mediated diagnosis is frequent in older people. Our results suggest that complete neuroautonomic evaluation should be done particularly in older patients.

Poor diagnostic performance of tilt testing in hypertensive patients with unexplained syncope

Syncope is a common condition. Tilt testing with sublingual nitroglycerin (TT-TNT) provides a test with good specificity and positivity rate in young and old patients. Its use in hypertensive patients with unexplained syncope has not been validated. The aims of this study were to evaluate the positivity rate, specificity and tolerability of TT-TNT in hypertensive patients with unexplained syncope. Five hundred and ten subjects (mean age 55 years) were enrolled, 388 patients with unexplained syncope (73 hypertensive and 315 normotensive) and 122 controls (59 hypertensive and 63 normotensive). All subjects underwent TT-TNT. The responses were classified as positive, negative or exaggerated (aspecific). In hypertensive patients, the usual hypotensive therapy was taken on the day of the test. In hypertensive controls, the positive responses were higher than in normotensives (19% vs 6%, P<0.001). The overall specificity was 81% in hypertensives and 94% in normotensives. The positivity rate was significantly lower in hypertensives (55% vs 72%, P<0.03). There was no significant difference between young patients and patients >65 years. TT was well tolerated, and no serious side effects occurred. TT potentiated with TNT has a lower positivity rate and specificity in hypertensive than in normotensive patients with syncope.

Head-up tilt testing for diagnosing vasovagal syncope: a meta-analysis

BACKGROUND

A systematic evaluation focused on sensitivity and specificity of head-up tilt testing (HUT) for diagnosing vasovagal syncope has not been previously performed. We conducted a meta-analysis of studies comparing HUT outcome between patients with syncope of unknown origin and control subjects without previous syncope.

METHODS

We searched Pubmed and Embase databases for all English-only articles concerning case-control studies estimating the diagnostic yield of HUT, and selected 55 articles, published before March 2012, including 4361 patients and 1791 controls. The influence of age, test duration, tilt angle, and nitroglycerine or isoproterenol stimulation on tilt testing outcome was analyzed.

RESULTS

Head-up tilt testing demonstrated to have a good overall ability to discriminate between symptomatic patients and asymptomatic controls with an area under the summary receiver-operating characteristics curve of 0.84 and an adjusted diagnostic odds ratio of 12.15 (p<0.001). A significant inverse relationship between sensitivity and specificity of tilt testing for each study was observed (p<0.001). At multivariate analysis, advancing age and a 60° tilt angle showed a significant effect in reducing sensitivity and increasing specificity of the test. Nitroglycerine significantly raised tilt testing sensitivity by maintaining a similar specificity in comparison to isoproterenol.

CONCLUSIONS

The results from this meta-analysis show the high overall performance of HUT for diagnosing vasovagal syncope. Our findings provide useful information for evaluating clinical and instrumental parameters together with pharmacological stressors influencing HUT accuracy. This could allow the drawing of tilt testing protocols tailored on the diagnostic needs of each patient with unexplained syncope.

Head-up tilt testing with different nitroglycerin dosages: experience in elderly patients with unexplained syncope

AIMS

Protocols using sublingual nitrates have been increasingly used to improve diagnostic accuracy of head-up tilt testing (HUT). Nevertheless, exaggerated responses to nitrates have been frequently described, particularly in elderly patients. The aim of this article is to evaluate, in an elderly population with unexplained syncope, whether the impact of sublingual nitroglycerin (NTG) used as a provocative agent is dose-dependent.

METHODS AND RESULTS

One hundred and twenty consecutive elderly patients submitted to HUT using NTG after an asymptomatic drug-free phase were studied. Patients were divided into three groups according to the NTG dosage: 500, 375 and 250 microg. The test was considered positive when there was reproduction of symptoms with bradycardia and/or arterial hypotension. A gradual decrease in the blood pressure after NTG was considered an exaggerated response to nitrates. There were no differences in the clinical characteristics of the different subgroups. A positive test was obtained in 50% of the patients in each group. The rate of exaggerated responses was identical in all groups and ranged between 15 and 17%.

CONCLUSION

In an elderly population with syncope of unknown origin submitted to HUT, the response to NTG is not dose-dependent, and no difference was found in the rate of exaggerated responses to nitrates with different NTG dosages.

Tilt table testing in patients with suspected epilepsy

BACKGROUND

Approximately 20-30% of patients with epilepsy are misdiagnosed and syncope often seems to be the mistaken cause. We re-evaluated patients referred to an epilepsy clinic where suspicion of neurally mediated (reflex) syncope were raised using tilt table testing (HUT).

METHODS

HUT laboratory results and medical records of 120 consecutive patients were reviewed retrospectively over a period of 27 months.

RESULTS

HUT was positive in 59 (49%) patients. Seventeen of 38 (45%) patients previously diagnosed with epilepsy and taking antiepileptic drugs were found to be misdiagnosed. Four of 21 patients with epilepsy (19%) had dual diagnoses of reflex syncope and epilepsy.

CONCLUSION

HUT is an informative investigation when suspicions of reflex syncope are raised in patients referred to an epilepsy clinic. Reflex syncope is an important and common differential diagnosis of epilepsy.

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.

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%.

Causes of syncope in patients with Alzheimer's disease treated with donepezil

INTRODUCTION

Treatment of Alzheimer's disease (AD) with cholinesterase inhibitors carries a theoretical risk of precipitating bradycardia. Though syncope occurs in patients with AD, its aetiology is unclear. The aim of this study was to determine the causes of syncope in patients with AD who were treated with donepezil and hospitalised for evaluation of syncope.

METHODS

We studied 16 consecutive patients (12 women, 4 men) with AD aged 80 +/- 4 years who were hospitalised for evaluation of syncope. All patients underwent staged evaluation, ranging from physical examination to electrophysiological testing.

RESULTS

The mean dose of donepezil administered was 7.8 mg/day, and the mean duration of donepezil treatment at the time of syncope was 12 +/- 8 months. A cause of syncope was identified in 69% of patients. Carotid sinus syndrome was observed in three patients, complete atrioventricular block in two patients, sinus node dysfunction in two patients, severe orthostatic hypotension in two patients and paroxysmal atrial fibrillation in one patient. A brain tumour was discovered in one patient. No cause of syncope was found in 31% of patients despite comprehensive investigation. Repetition of the investigations after discontinuation of donepezil was noncontributory.

CONCLUSION

In patients with AD treated with donepezil, a noninvasive evaluation identified a probable cause of syncope in over two-thirds of patients. Cardiovascular abnormalities were predominant. Noninvasive evaluation is recommended before discontinuing treatment with cholinesterase inhibitors in patients with AD and unexplained syncope.

Relation of clinical presentation of syncope to the age of patients

The aim of the study was to evaluate the effect of patient age on the clinical presentation of syncope and to establish the diagnostic value of clinical history in older patients. A total of 485 consecutive patients with unexplained syncope referred to secondary and tertiary hospitals were divided into 2 predefined age groups: 224 patients <65 years and 261 patients > or =65 years. The diagnostic criteria for the cause of syncope were developed before the beginning of the study. The clinical features of syncope were analyzed using a standard 46-item form. A cardiac cause of syncope was established in 27 younger (12%) and 89 older (34%) patients. A neurally mediated cause was established in 154 younger (68%) and 142 older (54%) patients. In patients > or =65 years, the clinical features of cardiac and neurally mediated syncope were very similar. The diagnosis of the cause of syncope was possible on the basis of the history alone in 26% younger and 5% older patients (p <0.0001). Myoclonic movements, effort syncope, and supine position during loss of consciousness were the most specific (97%, 99%, and 99%, respectively) diagnostic criteria for a cardiac cause of syncope in older patients, but, all together, they accounted for only 14% of patients. In conclusion, compared with younger patients, the medical history has a limited value in the diagnosis of the cause of syncope in older patients. The specificity of some features is high but these can be observed in only a minority of patients.

[Clinical characteristics and head-up tilt test results with three protocols in 1661 patients with syncope]

Because of the absence of a uniform protocol for the head-up tilt table test (HUT), we compared 1,661 consecutive patients with syncope referred for HUT. The influence of age and gender on the results (positive response rate and patterns) obtained with three different protocols, Westminster, isoprenaline and nitroglycerin (groups A, B and C) was analyzed. The proportion of women was larger in the youngest age group. A positive response to HUT was observed in 592 patients. The positive response rate to the HUT was higher in groups B and C than in group A, and the rate diminished with age in groups A and C, because of the decrease in mixed-positive responses, but not in group B. The rate of positive responses was similar in groups A and C, but different in group B; no influence of gender on these results was observed. The results with the Westminster and nitroglycerin protocols were similar, but the rate of positive responses was higher in the latter.