Opinion FRITH & PARRY Tilt-table testing: down but not out 11 Opinion Tilt-table testing: down but not out “The [tilt] test has been used with varying tilt angles and durations, and with various degrees of pharmacological and mechanical stimulation to help induce fainting during blood pressure and heart rate monitoring in susceptible individuals.” Clin. Pract. Keywords: syncope • tilt-table test • vasovagal syncope Syncope is very common, with the overall blood pressure and heart rate monitoring incidence for first syncope being 6.2 per 1000 in susceptible individuals [6]. However, the patient years, increasing to 20 in females aged recent NICE guidance on transient loss of over 80 years [1] . Vasovagal syncope (VVS) is consciousness minimizes the importance of by far the most common cause, explaining tilt table testing while missing the nuances over 20% of cases, with an underlying car- of its benefits to clinicians and patients[7] . diac cause in 10% of cases and up to 37% of Below, we show how tilt-table testing contin- cases remaining unexplained [1] . ues to be a safe, useful addition to the syncope The importance of syncope cannot be diagnosis and management armamentarium. James Frith understated. It can have a negative impact Author for correspondence: upon education, physical activity and leisure, Safety UK NIHR Biomedical Research Centre for Ageing & Age-related Disease, but can also result in loss of employment, Tilt-table testing is arguably one of the saf- Institute for Ageing & Health, driving restrictions, social isolation, falls est, simplest and least restrictive or invasive Newcastle University, Newcastle upon and significant injury. Vasovagal syncope investigations in the evaluation of syncope. Tyne, UK aside, cardiac and unexplained syncope are In 1969 consecutive tilt tests performed in Tel.: +44 191 282 5948 Fax: +44 191 282 5338 also associated with an increased mortality, individuals aged over 60 years, an episode of [email protected] 10.2217/CPR.14.21 necessitating accurate diagnosis [1] . atrial fibrillation, with no cardiovascular or The increase in morbidity and mortal- neurological complication, was the only com- ity is one of the driving forces behind the plication identified [8]. The most commonly development of international guidelines and cited case report relating to the safety of tilt the creation of specialist syncope clinics. testing is that of an 80-year-old female who When the European Society of Cardiology developed (and survived) an episode of ven- 3 Practice Guideline is applied in a specialist tricular fibrillation during an isoproterenol syncope setting the rate of undiagnosed syn- tilt test [9]. She was known to have a history cope decreases from 37 to 10% [2,3]. More- of coronary artery disease and a conduction over, specialist syncope clinics reduce hospi- defect on her ECG, which today would pre- 2014 tal readmission, reduce inappropriate use of clude her from having isoproterenol. Indeed, Steve W Parry investigations and reduce healthcare costs [4]. even a passive tilt test would not be recom- UK NIHR Biomedical Research Centre At the heart of these specialist clinics is the mended in high-risk individuals until a car- for Ageing & Age-related Disease, tilt table. diac cause had been excluded and the history Institute for Ageing & Health, Newcastle University, Newcastle upon was suggestive of VVS. Tyne, UK Tilt-table testing and Tilt-table testing has been used as an adjunct Accuracy Falls & Syncope Service, Newcastle in the diagnosis of vasovagal syncope since One of the principle arguments against tilt upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK 1986 [5]. The test has been used with varying testing is its sensitivity and specificity. This tilt angles and durations, and with various varies widely, depending on inclusion/exclu- degrees of pharmacological and mechanical sion criteria, methodology (e.g., tilt angle, stimulation to help induce fainting during duration and provocation method), interpre- part of 10.2217/CPR.14.21 © 2014 Future Medicine Ltd Clin. Pract. (2014) 11(3), 265–268 ISSN 2044-9038 265 Opinion Frith & Parry tation of result and expertise of the clinician. Perhaps VVS tend to have a dysautonomic pattern of progres- the most widely used method is ‘The Italian Protocol’, sive blood pressure drop prior to sudden collapse with which consists of a 20-min passive upright phase, fol- loss of consciousness, compared with the younger lowed by a 15-min provocation phase (400 μg sub- patient with the classical prodromal symptoms of lingual glyceryl trinitrate) [10] . It may be a surprise VVS who collapses with a rapid fall in blood pressure to sceptics of the tilt test to note that the sensitivity and/or heart rate [15] . To add to the complexity, older (62%) and specificity (92%) of this protocol is high people are more likely to have a history of cardiac dis- and fares very well when compared with other com- ease and an abnormal ECG, but where a cardiac cause monly used clinical investigations, for example, the has been excluded, tilt testing provides a safe and chest x-ray diagnosis of the pneumothorax (sensitiv- rapid diagnostic method. The combination of these ity 52% and specificity 99%) or the ECG in diagnos- factors makes the diagnosis of VVS more challenging ing an ST elevation myocardial infarction (sensitivity in older people and emphasizes the value of tilt testing 56% and specificity 94%) [11,12]. in complex cases. Diagnosis Epilepsy While it is not suggested that all cases of suspected Epilepsy is a life-changing diagnosis, with implica- VVS should undergo tilt-table testing, it is an tions for driving, employment, life-long medication, extremely useful tool for those in whom the diagnosis stigma and family planning issues. The history is is in doubt, where there are driving or employment characteristic for many patients with seizure disorders, restrictions or for guiding the treatment strategy. with prolonged loss of consciousness and postevent confusion, muscle aching and lateral tongue biting “While it is not suggested that all cases of being very suggestive of seizure rather than syncope. suspected vasovagal syncope should undergo [16] . However, convulsions can occur in up to 80% of tilt-table testing, it is an extremely useful tool people with a syncopal episode [17] and history alone for those in whom the diagnosis is in doubt, may not be adequate when attempting to distinguish where there are driving or employment VVS from epilepsy; clinical history has a specificity restrictions or for guiding the treatment of only 50% in suspected temporal lobe epilepsy [18]. strategy. One retrospective study revealed that 27% of cases ” of epilepsy were misdiagnosed when in fact they had The majority of syncopal episodes can be confi- VVS [19] . Tilt testing has much to offer in terms of dently diagnosed as VVS in the context of a struc- improving the precision of diagnosis, indeed, it has turally normal heart, normal surface ECG and an the highest diagnostic yield for cases of unexplained appropriate clinical history [2,6] with no further inves- seizures in apparent treatment-resistant epilepsy [19] . tigation. However, in the absence of these features, tilt testing can provide a valuable diagnostic and edu- Further benefits cational tool. Although there are no trials assessing Driving the accuracy of the diagnosis based on simple clinical The UK Driver and Vehicle Licencing Agency has evaluation, there are scoring tools based on features strict regulations that often result in driving restric- from the history, examination and ECG findings. tions following syncope. For example, for a single However, with a sensitivity of 87% and specificity of episode of unexplained syncope, a bus or lorry driver 32% these tools provide little support for their use in would be prevented from driving for 3 months after the diagnosis of VVS [13] . the event, even if the probability of VVS were high. The restrictions may be longer in the presence of Unexplained syncope high-risk features, such as an abnormal ECG or injury The diagnosis of VVS is often complex; a classic sustained during the episode, but if the cause is iden- example of this being the older person who presents tified and treated the restrictions are shorter. In such with unheralded syncope, recurrent unexplained falls circumstances syncope has huge implications for an or drop attacks. Older people with VVS are less likely individual who may lose their income. Timely tilt to report dizziness, palpitations and syncope, and less testing in this situation is crucial. likely to associate the event with change in posture, hot environments or prolonged standing [14] . This Employment may be partly explained by the differing patterns of Rapid diagnosis and initiation of treatment is equally hypotension and bradycardia associated with fainting important for those who are unable to work in high- in older and younger age groups. Older people with risk employment (e.g., at height, with dangerous 266 Clin. Pract. (2014) 11(3) future science group Tilt-table testing: down but not out Opinion machinery/chemicals), until diagnosis is ascertained spontaneous events. Without the tilt test such patients and treatment started. would be denied definitive management [20]. Education Conclusion For those individuals who have short-lived premoni- Tilt testing is safe, accurate and noninvasive. It tory symptoms, or those who do not recognize the increases diagnostic rates in unexplained syncope presyncopal warning a tilt test is a valuable tool to and can help reduce misdiagnosis in some patients educate individuals how to recognize presyncope, with apparent treatment-resistant epilepsy. It should when to begin abortive measures, and to demonstrate be used early when there are driving or employment how effective and simple abortive measures are. restrictions but also in older people with unheralded syncope, unexplained falls and drop attacks where a Treatment strategy cardiac or alternative cause has been excluded.