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Congenital long QT syndrome (LQTS) is characterised by heart rate corrected QT interval prolongation and life-threatening arrhythmias, leading to syncope and sudden death. Variations in genes encoding for cardiac ion channels, accessory ion channel subunits or proteins modulating the function of the ion channel have been identified as disease-causing mutations in up to 75% of all LQTS cases. Based on the underlying genetic defect, LQTS has been subdivided into different subtypes. Growing insights into the genetic background and pathophysiology of LQTS has led to the identification of genotype-phenotype relationships for the most common genetic subtypes, the recognition of genetic and non-genetic modifiers of phenotype, optimisation of risk stratification algorithms and the discovery of gene-specific therapies in LQTS. Nevertheless, despite these great advancements in the LQTS field, large gaps in knowledge still exist. For example, up to 25% of LQTS cases still remain genotype elusive, which hampers proper identification of family members at risk, and it is still largely unknown what determines the large variability in disease severity, where even within one family an identical mutation causes malignant arrhythmias in some carriers, while in other carriers, the disease is clinically silent. In this review, we summarise the current evidence available on the diagnosis, clinical management and therapeutic strategies in LQTS. We also discuss new scientific developments and areas of research, which are expected to increase our understanding of the complex genetic architecture in genotype-negative patients, lead to improved risk stratification in asymptomatic mutation carriers and more targeted (gene-specific and even mutation-specific) therapies. [ABSTRACT FROM AUTHOR]

Objective: To develop an ECG-based tool for rapid risk assessment of a cardiac cause of syncope in patients ≥40 years.Methods: In a prospective international multicentre study, 2007 patients ≥40 years presenting with syncope were recruited in the emergency department (ED) of participating centres ranging from large university hospitals to smaller rural hospitals in eight countries from May 2010 to July 2017. 12-Lead ECG recordings were obtained at ED presentation following the syncopal event. The primary diagnostic outcome, a cardiac cause of syncope, was centrally adjudicated by two independent cardiologists using all available clinical information including 12-month follow-up. ECG predictors for a cardiac cause of syncope were identified using penalised backward selection and a continuous-scale likelihood was calculated based on regression analysis coefficients. Findings were validated in an independent US multicentre cohort including 2269 patients.Results: In the derivation cohort, a cardiac cause of syncope was adjudicated in 267 patients (16%). Seven ECG criteria were identified as predictors for this outcome: heart rate and QTc-interval (continuous predictors), rhythm, atrioventricular block, ST-segment depression, bundle branch block and ventricular extrasystole/non-sustained ventricular tachycardia (categorical predictors). Diagnostic accuracy of these combined predictors for a cardiac cause of syncope was high (area under the curve 0.80, 95% CI 0.77 to 0.83). Overall, 138 patients (8%) were rapidly triaged towards rule-out and 181 patients (11%) towards rule-in of a cardiac cause of syncope. External validation showed similar performance.Conclusion: In patients ≥40 years with a syncopal event, a combination of seven ECG criteria enabled rapid assessment of the likelihood that syncope was due to a cardiac cause.Trial Registration Number: NCT01548352 (BASEL IX), NCT01802398 (SRS study). [ABSTRACT FROM AUTHOR]

The review aims to summarise evidence addressing patients' values, preferences and practical issues on deciding between transcatheter aortic valve insertion (TAVI) and surgical aortic valve replacement (SAVR) for aortic stenosis. We searched databases and grey literature until June 2020. We included studies of adults with aortic stenosis eliciting values and preferences about treatment, excluding medical management or palliative care. Qualitative findings were synthesised using thematic analysis, and quantitative findings were narratively described. Evidence certainty was assessed using CERQual (Confidence in the Evidence from Reviews of Qualitative Research) and GRADE (Grading of Recommendations Assessment, Development and Evaluation). We included eight studies. Findings ranged from low to very low certainty. Most studies only addressed TAVI. Studies addressing both TAVI and SAVR reported on factors affecting patients' decision-making along with treatment effectiveness, instead of trade-offs between procedures. Willingness to accept risk varied considerably. To improve their health status, participants were willing to accept higher mortality risk than current evidence suggests for either procedure. No study explicitly addressed valve reintervention, and one study reported variability in willingness to accept shorter duration of known effectiveness of TAVI compared with SAVR. The most common themes were desire for symptom relief and improved function. Participants preferred minimally invasive procedures with shorter hospital stay and recovery. The current body of evidence on patients' values, preferences and practical issues related to aortic stenosis management is of suboptimal rigour and reports widely disparate results regarding patients' perceptions. These findings emphasise the need for higher quality studies to inform clinical practice guidelines and the central importance of shared decision-making to individualise care fitted to each patient. [ABSTRACT FROM AUTHOR]

This article aims to give advice on how to identify and manage patients with syncope who are at risk of severe outcomes, that is, at risk of trauma, potentially life-threatening episodes or frequent recurrences reducing quality of life. The first step of syncope diagnostic assessment is to identify patients with cardiac syncope, and once established, these patients must receive the adequate mechanism-specific treatment. If cardiac syncope is unlikely, reflex (neurally mediated) syncope and orthostatic hypotension are the most frequent causes of transient loss of consciousness. For these presentations, efficacy of therapy is largely determined by the mechanism of syncope rather than its aetiology or clinical features. The identified mechanism of syncope should be carefully assessed and assigned either to hypotensive or bradycardic phenotype, which will determine the choice of therapy (counteracting hypotension or counteracting bradycardia). The results of recent trials indicate that 'mechanism-specific therapy' is highly effective in preventing recurrences. Established mechanism-specific treatment strategies include withdrawal of hypotensive drugs, applying fludrocortisone and midodrine for the hypotensive phenotype and cardiac pacing in the bradycardic phenotype. [ABSTRACT FROM AUTHOR]

Objective: Up to 50% of patients with hypertrophic cardiomyopathy (HCM) show no disease-causing variants in genetic studies. TRIM63 has been suggested as a candidate gene for the development of cardiomyopathies, although evidence for a causative role in HCM is limited. We sought to investigate the relationship between rare variants in TRIM63 and the development of HCM.Methods: TRIM63 was sequenced by next generation sequencing in 4867 index cases with a clinical diagnosis of HCM and in 3628 probands with other cardiomyopathies. Additionally, 3136 index cases with familial cardiovascular diseases other than cardiomyopathy (mainly channelopathies and aortic diseases) were used as controls.Results: Sixteen index cases with rare homozygous or compound heterozygous variants in TRIM63 (15 HCM and one restrictive cardiomyopathy) were included. No homozygous or compound heterozygous were identified in the control population. Familial evaluation showed that only homozygous and compound heterozygous had signs of disease, whereas all heterozygous family members were healthy. The mean age at diagnosis was 35 years (range 15-69). Fifty per cent of patients had concentric left ventricular hypertrophy (LVH) and 45% were asymptomatic at the moment of the first examination. Significant degrees of late gadolinium enhancement were detected in 80% of affected individuals, and 20% of patients had left ventricular (LV) systolic dysfunction. Fifty per cent had non-sustained ventricular tachycardia. Twenty per cent of patients suffered an adverse cerebrovascular event (20%).Conclusion: TRIM63 appears to be an uncommon cause of HCM inherited in an autosomal-recessive manner and associated with concentric LVH and a high rate of LV dysfunction. [ABSTRACT FROM AUTHOR]

Objective: Troponin and high signal intensity on T2-weighted (HighT2) cardiovascular magnetic resonance imaging (CMRi) are both markers of myocardial injury in hypertrophic cardiomyopathy (HCM). The interplay between exercise and disease development remains uncertain in HCM. We sought to assess the occurrence of postexercise troponin rises and its determinants.Methods: Multicentre project on patients with HCM and mutation carriers without hypertrophy (controls). Participants performed a symptom limited bicycle test with hs-cTnT assessment pre-exercise and 6 hours postexercise. Pre-exercise CMRi was performed in patients with HCM to assess measures of hypertrophy and myocardial injury. Depending on baseline troponin (< or >13 ng/L), a rise was defined as a >50% or >20% increase, respectively.Results: Troponin rises occurred in 18% (23/127) of patients with HCM and 4% (2/53) in mutation carriers (p=0.01). Comparing patients with HCM with and without a postexercise troponin rise, maximum heart rates (157±19 vs 143±23, p=0.004) and maximal wall thickness (20 mm vs 17 mm, p=0.023) were higher in the former, as was the presence of late gadolinium enhancement (85% vs 57%, p=0.02). HighT2 was seen in 65% (13/20) and 19% (15/79), respectively (p<0.001). HighT2 was the only independent predictor of troponin rise (adjusted odds ratio 7.9; 95% CI 2.7 to 23.3; p<0.001).Conclusions: Postexercise troponin rises were seen in about 20% of patients with HCM, almost five times more frequent than in mutation carriers. HighT2 on CMRi may identify a group of particularly vulnerable patients, supporting the concept that HighT2 reflects an active disease state, prone to additional injury after a short episode of high oxygen demand. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relationship of hospital admissions due to unexplained syncope and orthostatic hypotension (OH) with subsequent cardiovascular events and mortality.Methods: We analysed a population-based prospective cohort of 30 528 middle-aged individuals (age 58±8 years; males, 40%). Adjusted Cox regression models were applied to assess the impact of unexplained syncope/OH hospitalisations on cardiovascular events and mortality, excluding subjects with prevalent cardiovascular disease.Results: After a median follow-up of 15±4 years, 524 (1.7%) and 504 (1.7%) participants were hospitalised for syncope or OH, respectively, yielding 1.2 hospital admissions per 1000 person-years for each diagnosis. Syncope hospitalisations increased with age (HR, per 1 year: 1.07, 95% CI 1.05 to 1.09), higher systolic blood pressure (HR, per 10 mm Hg: 1.06, 95% CI 1.01 to 1.12), antihypertensive treatment (HR: 1.26, 95% CI 1.00 to 1.59), use of diuretics (HR: 1.77, 95% CI 1.31 to 2.38) and prevalent cardiovascular disease (HR: 1.59, 95% CI 1.14 to 2.23), whereas OH hospitalisations increased with age (HR: 1.11, 95% CI 1.08 to 1.12) and prevalent diabetes (HR: 1.82, 95% CI 1.23 to 2.70). After exclusion of 1399 patients with prevalent cardiovascular disease, a total of 473/464 patients were hospitalised for unexplained syncope/OH before any cardiovascular event. Hospitalisation for unexplained syncope predicted coronary events (HR: 1.85, 95% CI 1.49 to 2.30), heart failure (HR: 2.24, 95% CI 1.65 to 3.04), atrial fibrillation (HR: 1.84, 95% CI 1.50 to 2.26), aortic valve stenosis (HR: 2.06, 95% CI 1.28 to 3.32), all-cause mortality (HR: 1.22, 95% CI 1.09 to 1.37) and cardiovascular death (HR: 1.72, 95% CI 1.23 to 2.42). OH-hospitalisation predicted stroke (HR: 1.66, 95% CI 1.24 to 2.23), heart failure (HR: 1.78, 95% CI 1.21 to 2.62), atrial fibrillation (HR: 1.89, 95% CI 1.48 to 2.41) and all-cause mortality (HR: 1.14, 95% CI 1.01 to 1.30).Conclusions: Patients discharged with the diagnosis of unexplained syncope or OH show higher incidence of cardiovascular disease and mortality with only partial overlap between these two conditions. [ABSTRACT FROM AUTHOR]

Objective: Syncope is sudden transient loss of consciousness and postural tone with spontaneous recovery; the most common form is vasovagal syncope (VVS). We previously demonstrated impaired post-synaptic adrenergic responsiveness in young VVS patients was reversed by blocking nitric oxide synthase (NOS). We hypothesised that nitric oxide may account for reduced orthostatic tolerance in young recurrent VVS patients.Methods: We recorded haemodynamics in supine VVS and healthy volunteers (aged 15-27 years), challenged with graded lower body negative pressure (LBNP) (-15, -30, -45 mm Hg each for 5 min, then -60 mm Hg for a maximum of 50 min) with and without NOS inhibitor NG-monomethyl-L-arginine acetate (L-NMMA). Saline plus phenylephrine (Saline+PE) was used as volume and pressor control for L-NMMA.Results: Controls endured 25.9±4.0 min of LBNP during Saline+PE compared with 11.6±1.4 min for fainters (p<0.001). After L-NMMA, control subjects endured 24.8±3.2 min compared with 22.6±1.6 min for fainters. Mean arterial pressure decreased more in VVS patients during LBNP with Saline+PE (p<0.001) which was reversed by L-NMMA; cardiac output decreased similarly in controls and VVS patients and was unaffected by L-NMMA. Total peripheral resistance increased for controls but decreased for VVS during Saline+PE (p<0.001) but was similar following L-NMMA. Splanchnic vascular resistance increased during LBNP in controls, but decreased in VVS patients following Saline+PE which L-NMMA restored.Conclusions: We conclude that arterial vasoconstriction is impaired in young VVS patients, which is corrected by NOS inhibition. The data suggest that both pre- and post-synaptic arterial vasoconstriction may be affected by nitric oxide. [ABSTRACT FROM AUTHOR]

Objectives: Most elderly patients affected by reflex vasodepressor syncope take one or more hypotensive drugs. The role of these drugs in causing syncope has not yet been established. We hypothesised that recurrence of syncope and presyncope can be reduced by discontinuing/reducing vasoactive therapy without increasing the risk of cardiovascular and neurological events.Methods: This randomised, parallel, prospective, trial was conducted from January 2014 to March 2016 in four general hospitals. Of 328 initially screened participants, 58 patients (mean (SD) age 74±11 years) affected by vasodepressor reflex syncope, which was reproduced by tilt testing (n=54) or carotid sinus massage (n=4), were randomised to stop/reduce vasoactive therapy or to continue it. Primary end point was recurrence of syncope, presyncope or adverse events (defined as stroke, cerebral transient ischaemic attacks, worsening heart failure, myocardial infarction).Results: Of 58 patients who were randomised, 55 completed the trial. After 1 month, systolic blood pressure was significantly higher in the 'stop/reduce' group than in the 'continue' group, in both supine (141±13 mm Hg vs 128±14 mm Hg; p=0.004) and standing (133±13 mm Hg vs 122±15 mm Hg; p=0.02) positions. During a mean follow-up of 13±7 months, the primary combined end point occurred in seven 'stop/reduce' patients (23%): three had syncope, three had presyncope and one had heart failure. Conversely, it occurred in 13 'continue' patients (54%): 10 had syncope, 2 had presyncope and 1 had cerebral transient ischaemic attack. The log-rank p value was 0.02 and the HR was 0.37 (95% CI 0.15 to 0.91).Conclusions: Recurrence of syncope and presyncope can be reduced by discontinuing/reducing vasoactive therapy in most elderly patients affected by reflex vasodepressor syncope.Trial Registration Number: NCT01509534; EudraCT2013-004364-63; Results. [ABSTRACT FROM AUTHOR]

Aims: Unexplained falls account for 20% of falls in older cohorts. The role of the implantable loop recorder (ILR) in the detection of arrhythmias in patients with unexplained falls is unknown. We aimed to examine the diagnostic utility of the ILR in detection of arrhythmogenic causes of unexplained falls in older patients.Methods: A single centre, prospective, observational cohort study of recurrent fallers over the age of 50 years with two or more unexplained falls presenting to an emergency department. Insertion of an ILR (Reveal, Medtronic, Minnesota, USA) was used to detect arrhythmia. The primary outcome was detection of cardiac arrhythmia associated with a fall or syncope. The secondary outcome was detection of cardiac arrhythmia independent of falls or syncope, and falls or syncope without associated arrhythmia.Results: Seventy patients, mean age 70 years (51-85 years) received an ILR. In 70% of patients cardiac arrhythmias were detected at a mean time of 47.3 days (SD 48.25). In 20%, falls were attributable to a modifiable cardiac arrhythmia; 10 (14%) received a cardiac pacemaker, 4 (6%) had treatment for supraventricular tachycardia. Patients who had a cardiac arrhythmia detected were more likely to experience a further fall.Conclusions: 14 (20%) patients demonstrated an arrhythmia which was attributable as the cause of their fall. Patients who have cardiac arrhythmia are significantly more likely to experience future falls. Further research is important to investigate if early detection of arrhythmogenic causes of falls using the ILR prevents future falls in older patients. [ABSTRACT FROM AUTHOR]

The article focuses on the differential diagnosis and management of syncope. Topics discussed include syncope being the transient loss of consciousness due to global cerebral hypoperfusion; classification of syncope based on pathophysiological cause of hypoperfusion; and occurrence of orthostatic syncope due to insufficient vasoconstriction in response to orthostatic stress.

For some decades, after the introduction of the head-up tilt test into clinical practice, the clinical presentation of vasovagal syncope (VVS) has been classified as typical (or classical) and atypical (or non-classical). Some clinical features and recent data suggest that even unexplained falls and syncope during sleeping hours may be possible clinical presentations of VVS. In recent studies, tilt testing and carotid sinus massage by means of the 'method of symptoms' were performed in one group of patients with unexplained falls and in another group with unexplained syncope (presence of prodromal symptoms). Overall, tilt testing and carotid sinus massage displayed a high positivity rate in the group of patients with unexplained falls (about 60%), which was similar to that of the unexplained syncope group. These new data seem to indicate that some unexplained falls could be cases of atypical VVS/carotid sinus syncope with retrograde amnesia. Some clinical features suggest that syncope during sleeping hours is a form of VVS with a different clinical presentation: high prevalence of autonomic prodromes, of diurnal episodes of typical VVS and specific phobias, and of positive tilt testing with severe cardioinhibition. [ABSTRACT FROM AUTHOR]

Objectives: Syncope is a cause of significant morbidity in sick sinus syndrome (SSS) which may not be resolved with permanent pacemaker therapy. We aimed to determine the incidence, predictors and prognostic implication of syncope in paced patients with SSS. Methods: We studied 1415 patients (mean age 72.9 years, SD 11.1) with SSS who were randomised in the DANPACE study to either rate-responsive single chamber pacing (n=707) or rate-responsive dual chamber pacing (n=708). Main outcome measures were patient-reported syncope after pacemaker implantation and mortality. Results: Mean follow-up was 5.4 years (SD 2.6). A total of 247 (17.5%) patients experienced syncope after pacemaker implantation (135 (19%) from the rateresponsive single chamber pacing group, and 112 (15.8%) from the rate-responsive dual chamber pacing group. Predictors of syncope post pacemaker implantation included: age 0-39 years (HR 2.9, 95% CI 1.4 to 6.3, p=0.01; reference range 60-79 years), age ≥80 years (HR 1.4, 95% CI 1.0 to 1.8, p=0.03), syncope prior to pacemaker implant (HR 1.8, 95% CI 1.4 to 2.3, p<0.001), previous myocardial infarction (HR 1.5, 95% CI 1.1 to 2.1, p=0.03), heart failure (HR 1.4, 95% CI 1.0 to 1.9, p=0.046), and high Charlson comorbidity index (HR 1.6, 95% CI 1.1 to 2.2, p=0.01). Patients who experienced syncope post pacemaker implant had higher mortality compared with patients who did not (adjusted HR 1.6, 95% CI 1.3 to 2.1, p<0.001). Conclusions: Syncope in paced patients with SSS is common, and is associated with higher mortality. The predictors identified in this study suggest a multifactorial aetiology of syncope. [ABSTRACT FROM AUTHOR]

Background The closed-loop stimulation (CLS) pacemaker algorithm is a system that permanently monitors the contractile state of the myocardium and converts the intrinsic information into rate regulation. The role that the CLS algorithm plays in the prevention of syncope recurrences still remains unclear. The aim of our prospective, randomised, single-blind, crossover study was to evaluate the effect of dual-chamber CLS in the prevention of syncope recurrence in patients with refractory vasovagal syncope (VVS) and a cardioinhibitory response to head-up tilt test (HUT) during a 36 months follow-up. Method sand results We studied 50 patients (mean age 53±5.1; 33 male) with the indication for permanent dual-chamber cardiac pacing for HUT-induced vasovagal cardioinhibitory syncope. They were randomised after 1 month of stabilisation period to CLS algorithm features programmed OFF or ON for 18 months each, using a crossover design. The number of syncopal and presyncopal episodes during active treatment was lower than those registered during no treatment (n syncopal episodes: 2 vs 15; p=0.007; n presincopal episodes: 5 vs 30; p = 0.004). Lead parameters remained stable over time, and there were no lead-related complications. Conclusions Based on these 36 months follow-up data, it is concluded that dual-chamber CLS is an effective algorithm for preventing syncope recurrences in healthy patients with tilt-induced vasovagal cardioinhibitory syncope. [ABSTRACT FROM AUTHOR]

Objective To assess the cost-effectiveness of implantable loop recorders (ILRs) and tilt testing (TT) to direct pacing therapy in people with recurrent episodes of transient loss of consciousness that are adversely affecting their quality of life or represent a high risk of injury and are suspected to be vasovagal. Design Decision analytical modelling was used to estimate the costs and benefits of diagnostic testing including the costs and benefits of treatment for several clinically important arrhythmias following diagnosis. Setting A UK National Health Service and personal social services perspective was taken. Patients People with recurrent episodes of transient loss of consciousness that are adversely affecting their quality of life or represent a high risk of injury and which are suspected to be vasovagal. Interventions The diagnostic test strategies compared were TT alone, TT followed by ILR (if TT 'negative'), ILR alone and no further testing. Main outcome measures Benefits measured using quality-adjusted life years and incremental costeffectiveness ratios (ICER) are reported. Results The ICERs for TT alone, ILR alone and TT followed by ILR were £5960, £24 620 and £19 110, respectively, compared with no testing. ILR alone was extendedly dominated by the other strategies, meaning that it is never the most cost-effective option. Sensitivity analysis found that the cost-effectiveness estimates were robust despite the areas of uncertainty identified in the evidence and assumptions used to inform the model. Conclusions TT alone is likely to be the most costeffective strategy in this population. [ABSTRACT FROM AUTHOR]

Objectives The purpose of this study was to investigate the hypothesis that responses to the ATP test and head-up tilt test (HUT) may be correlated with different purinergic profiles. Design and setting The ATP and HUT identify distinct subsets of patients with neurally mediated syncope (NMS). Adenosine and its A2A receptors (A2AR) may be implicated in the pathophysiology of NMS in patients with positive HUT. Nothing is known about the purinergic profile of patients with positive ATP. Patients and measures This prospective study includes a consecutive series of patients with suspected NMS. All patients underwent both HUT and ATP. Before testing, samples were collected for measurement of baseline adenosine plasma level (APL) and expression. Results A total of 46 patients (25 men and 21 women) with a mean age of 57618 years were enrolled. The HUT test was positive in 27 patients and the ATP test in 20. Both tests were positive in 9 and negative in 8. High APL was associated with high probability of positive HUT while low APL was associated with high probability of positive ATP. Expression of A2AR was lower in patients with positive ATP than in those with positive HUT. Conclusion These findings indicate that patients with NMS present different purinergic profiles and that responses to HUT and ATP are correlated with these profiles. [ABSTRACT FROM AUTHOR]

Since its introduction 15 years ago, the implantable loop recorder (ILR) has become the investigative tool of choice in recurrent unexplained syncope following negative initial investigations. This is based on very few randomised controlled clinical trials and modestly sized observational studies. Further controlled data are required to inform clinical practice with attention focused on empowering ILR-guided diagnosis, establishing the optimal timing of ILR use in syncope and embracing new technological advancements. [ABSTRACT FROM AUTHOR]

Objective To examine whether a history of stressful life events and prolonged mental stress are associated with arrhythmic events in inherited long QT syndrome (LQTS). Methods Participants who had a molecularly established mutation of KCNQ1, KCNH2 or SCN5A channel and were thus diagnosed as patients with LQT1, LQT2 and LQT3 (n=566), accordingly. The control group consisted of their 614 non-affected relatives. A history of stressful life events was indexed by the major stressful life events. Prolonged mental stress was indexed by vital exhaustion (VE), which was measured with the Maastricht Questionnaire. Results Multinomial logistic regression analysis including patients with LQTS with and without arrhythmic events and the control subjects showed an age- and sex-adjusted association of stressful life events OR=1.15 (95% CI 1.08 to 1.22) and VE (OR=3.33 (95% CI 1.63 to 6.78)) with symptomatic status of LQTS. Symptomatic patients with LQTS had experienced more stressful life events (OR=1.16 (95% CI 1.08 to 1.24)) and the level of VE (OR=3.40 (95% CI 1.44 to 8.03)) was more than three times higher among patients with LQTS with arrhythmic events than in asymptomatic LQTS mutation carriers. The association between stressful life events and arrhythmic events was independent of age, sex, specifically focused medication and LQTS subtype. Conclusions A history of stressful life events and prolonged mental stress are associated with arrhythmic events in LQTS in this large sample of molecularly defined patients with LQTS. It is important for future studies to assess how strong these predisposing factors are for arrhythmic events in LQTS. [ABSTRACT FROM AUTHOR]

Background Cardioinhibitory carotid sinus hypersensitivity (CICSH) is highly prevalent among older people with falls. Objective To assess the efficacy of dual-chamber pacing in older patients with CICSH and unexplained falls. Design A multicentre, double blind, randomised controlled trial. Setting Selection from emergency room, geriatric medicine and orthopaedic departments. Patients Patients aged >50 years, with two unexplained falls and/or one syncopal event in the previous 12 months for which no other cause is evident apart from CICSH. Interventions Patients randomised to either a 700/400 ?, rate responsive pacemaker or implantable loop recorder (Medtronic Reveal thera RDR, Medtronic, Minneapolis, Minnesota, USA). Main outcome measures The primary outcome was the number falls after implantation. Secondary outcomes were time to fall event, presyncope, quality of life and cognitive function. Results 141 patients were recruited from 22 centres. Mean age was 78 years and mean follow-up 24 months. The overall relative risk of falling after device implantation compared with before was 0.23 (0.15 to 0.32). No significant reduction in falls was seen between paced and loop recorder groups (RR=0.79; 95% CI 0.41 to 1.50). Data were also consistent in both groups for syncope, quality of life and cognitive function. Conclusions These results question the use of pacing in CICSH. However, the study was underpowered and also patient characteristics differed from those in Safepace 1-participants were physically and cognitively frailer. Further work is necessary to assess cardiac pacing in this setting. [ABSTRACT FROM AUTHOR]

OBJECTIVES: While carotid sinus syndrome (CSS) is traditionally defined by the association of carotid sinus hypersensitivity (CSH) with syncope, uncertainty remains over the role, if any, of complex pacing in patients with CSH and unexplained or recurrent falls. We sought to clarify the role of dual chamber pacing in this patient group in the first placebo-controlled study in CSH. DESIGN: Randomised, double-blind, crossover, placebo-controlled trial. SETTING: Specialist falls and syncope facility. PATIENTS: Consecutive subjects aged over 55 years with CSH as the sole attributable cause of three or more unexplained falls in the 6 months preceding enrolment. INTERVENTION: Dual-chamber permanent pacing with rate-drop response programming. The pacemaker was switched on (DDD/RDR) or off (ODO (placebo)) for 6 months, then crossed over to the alternate mode for a further 6 months, in randomised, double-blind fashion. MAIN OUTCOME MEASURE: The primary outcome measure was number of falls in paced and non-paced modes. RESULTS: Twenty-five of 34 subjects (mean 76.8 years (SD 9.0), 27 (79%) female) recruited completed the study. Pacing intervention had no effect on number of falls (4.04 (9.54) in DDD/RDR mode, 3.48 (7.22) in ODO; relative risk of falling in ODO mode 0.82, 95% CI 0.62 to 1.10). CONCLUSION: Permanent pacing intervention had no effect on fall rates in older patients with CSH. Further work is urgently needed to clarify the role, if any, of complex pacing in this patient group. [ABSTRACT FROM AUTHOR]

Objective: To develop, in patients referred for syncope to an emergency department (ED), a diagnostic score to identify those patients likely to have a cardiac cause. Design: Prospective cohort study. Setting: ED of 14 general hospitals. Patients: 516 consecutive patients with unexplained syncope. Interventions: Subjects underwent a diagnostic evaluation on adherence to Guidelines of the European Society of Cardiology. The clinical features of syncope were analysed using a standard 52-item form. In a validation cohort of 260 patients the predictive value of symptoms! signs was evaluated, a point score was developed and then validated in a cohort of 256 other patients. Main outcome measurements: Diagnosis of cardiac syncope, mortality. Results: Abnormal ECG and/or heart disease, palpitations before syncope, syncope during effort or in supine position, absence of autonomic prodromes and absence of predisposing and/or precipitating factors were found to be predictors of cardiac syncope. To each variable a score from +4 to -1 was assigned to the magnitude of regression coefficient. A score ~3 identified cardiac syncope with a sensitivity of 95%/92% and a specificity of 61%/69% in the derivation and validation cohorts, respectively. During follow-up (mean (SD) 614 (73) days) patients with score ⩾3 had a higher total mortality than patients with a score <3 both in the derivation (17% vs 3%; p<0.001) and in the validation cohort (21% vs 2%; p<0.001). Conclusions: A simple score derived from clinical history can be usefully employed for the triage and management of patients with syncope in an ED. [ABSTRACT FROM AUTHOR]

Objective: To analyse the influence of breathing activity on cerebrovascular dynamics during presyncope. Design: Retrospective study. Setting: University hospital. Patients: 38 subjects developing neurocardiogenic syncope (syncope group), and 61 age-matched control subjects with negative tilt. Interventions: Middle cerebral artery mean blood flow velocity (MCFV), continuous non-invasive blood pressure (BP), end-tidal CO2 (CO2-et) and minute ventilation were measured before and during 45' 60° tilting. Main outcome measures: Respiratory and cerebrovascular variability, cerebrovascular resistance (CVR)-absolute and corrected for CO2-et at 40 mm Hg (CVR-40)-and dynamic cerebrovascular regulation (CVR-dyn: transfer function phase analysis between MCFV and BP), obtained during supine rest (baseline), first 5 minutes of tilt (early tilt), early- and late presyncope (first and second half, respectively, of 4 minutes preceding syncope in syncope group, and equivalent time in controls). Results: Tilting induced a mean (SE) CVR decrease in controls (baseline 1.20 (0.04); late presyncope 1.12 (0.06) mm Hg x s/cm, p<0.05) but not in the syncope group (baseline 1.09(0.04); late presyncope 1.09 (0.06) mm Hg x s/cm, p = NS). However, CVR-40 showed similar reduction in both groups (controls: from 1.15 (0.04) to 0.96 (0.04) mm Hg x s/cm; syncope group: from 1.01(0.04) to 0.83 (0.04) mm Hg x s/cm, p = NS). CVR-dyn of the two groups was also similar (p = NS). Respiratory variability increased in the syncope group, from early tilt to late presyncope (p<0.05 or better), preceding hyperventilation and being significantly correlated with an increase in MCFV and BP variability (p<0.01). Conclusions: During presyncope, the development of respiratory instability and hypocapnia impairs MCFV, thus facilitating the onset of syncope despite preserved cerebrovascular regulation. [ABSTRACT FROM AUTHOR]

Symptoms of impaired consciousness (syncope and presyncope) occur in 15-25% of patients with hypertrophic cardiomyopathy (HCM).1 In young patients a history of recurrent syncope is associated with an increased risk of sudden death.25 Syncope usually occurs without warning or symptoms suggestive of the cause. Detailed investigations identify a probable mechanism in a minority, usually paroxysmal atrial fibrillation or ventricular tachycardia. In the majority however no likely mechanism is found despite repeated 24-hour ambulatory echocardiography (ECG) or patient-activated monitoring, exercise testing and invasive electrophysiological studies. 6 Empirical treatment with amiodarone, a pacemaker or an implantable cardioverter-defibrillator is commonly employed, but is often unsuccessful in relieving the symptoms. We have previously observed that approximately 30% of patients with HCM have abnormal blood pressure response during maximal upright exercise.7 8 This was due in the majority of patients to an exaggerated fall in systemic vascular resistance, possibly arising from abnormal activation of stretch-sensitive left ventricular mechanoreceptors,9 10 by a mechanism similar to that described in aortic stenosis.1 However, in some patients an inadequate cardiac output response to exercise may be responsible.12 We hypothesised that abnormal vasodepressor-mediated hypotension may also occur during daily life in patients with HCM, and that this may be an important mechanism of syncope when conventional investigations fail to reveal a cause. [ABSTRACT FROM AUTHOR]

Objective: To evaluate use of the implantable loop recorder in children. Setting: Royal Hospital for Sick Children, Glasgow, UK. Method: Retrospective study of children who had an implantable loop recorder between September 1998 and October 2005. Results: 38 devices were implanted in 34 children. Median age at implantation 11.3 years (range 1.8-17.6); median follow-up period 15 months (range 2-58). The main presenting complaint was syncope in 26 (76.5%), seizures in 6 (17.6%) and palpitations in 2(5.9%). After implantation, 19 (55.9%) patients had symptom recurrence. Of these, 11 were shown to have sinus rhythm during symptoms and 8 had an abnormal ECG. Four patients had asystole >3 seconds and were diagnosed with reflex asystolic syncope; 2 had polymorphic ventricular tachycardia. One patient who already had a diagnosis of long QT syndrome was shown to have ventricular ectopy during symptoms and 3-blockers were increased. One patient had transient complete heart block during symptoms but refused a pacemaker. In almost half the patients (44.1%), symptoms resolved after implantation. Complications requiring removal of the device occurred in 6(15.8%) implants. Conclusions: In children with syncope and palpitations, the implantable loop recorder appears to be an excellent method of effecting a "cure" in almost 50% of subjects. For those who remain symptomatic, it is successful in determining cardiac rhythm during symptoms, but the complication rate in children may be higher than that of adults. [ABSTRACT FROM AUTHOR]

The article presents the diagnosis and treatment of syncope in general cardiology. It discusses the critical first step in evaluating patients with syncope. The diagnostic strategy will be based on the initial evaluation and will determine the appropriate diagnostic pathways and risk evaluation. The whole process is discussed.

This article focuses on aortic stenosis. Aortic stenosis (AS) has become the most frequent valvar heart disease and the most frequent cardiovascular disease after hypertension and coronary artery disease in Europe and North America. It primarily presents as calcific AS in adults of advanced age. During a long latent period with increasing outflow tract obstruction, which results in increasing left ventricular pressure load, patients remain asymptomatic and acute complications are rare. However, as soon as symptoms such as exertional dyspnoea, angina, or dizziness and syncope occur, outcome becomes dismal.

This article will address the epidemiology of reflex syncope in children and adolescents, its clinical characteristics and syndromes, the approach to diagnosis, and finally treatment. Syncope can be defined as a temporary loss of consciousness and postural tone secondary to a lack of adequate cerebral blood perfusion. The incidence of syncope coming to medical attention appears to be clearly increased in two age groups-that is, in the young and in the old. The incidence of syncope in young subjects coming to medical attention varies from approximately 0.5 to 3 cases per 1000. Syncopal events which do not reach medical attention occur much more frequently. In fact, the recently published results of a survey of students averaging 20 years of age demonstrated that about 20% of males and 50% of females report to have experienced at least one syncopal episode.

OBJECTIVES: To assess the efficacy of a protocol designed to improve the diagnosis and management of syncope. DESIGN: Prospective outcome analysis of all patients presenting with syncope for the 12 month period from 1 November 2000 to 31 October 2001, compared with a retrospective study of all patients presenting with syncope during the calendar year 1998. Use of the protocol commenced in September 2000. SETTING: Eastbourne District General Hospital, serving a population of approximately 250 000; 25% are older than 65 years. SUBJECTS: 421 consecutive patients presenting with syncope, investigated prospectively in January 2000 and compared with 660 patients retrospectively analysed for the calendar year 1998. RESULTS: In 1998, 71% of patients with syncope received a diagnostic classification. In January 2000 there was an appropriate diagnostic hypothesis for every patient. Ultimately a diagnosis was made for 78% of patients according to accepted criteria (p = 0.003). Use of tests with the highest diagnostic effectiveness, such as tilt tests, increased in 2001 and many tests were used more appropriately (such as echocardiography). However, non-diagnostic tests were still frequently used (such as chest radiography, electroencephalography, and carotid Doppler studies). Costs of investigation and hospital stay rose from pound 611 to pound 1384 (euro;874 to euro;1980) per patient (p < 0.001), with cost per diagnosis increasing from pound 870 (euro;1245) in 1998 to pound 1949 (euro;2790) (p < 0.001). CONCLUSION: The syncope protocol improved diagnosis and the use of appropriate investigations. However, significant inappropriate investigation and hospital admission still occurred. The protocol allowed reliable triage of syncopal patients into high and low risk groups. [ABSTRACT FROM AUTHOR]

Discusses the relationship between cardiovascular causes of syncope with seizure disorders. Creation of differential diagnostic problem against seizure; Mortality risk of some cardiac causes of syncope; Psychosocial consequences of the diagnosis of epilepsy.

Studies the role of echocardiography in the stepwise evaluation of syncope. Assignment of the causes of syncope using published diagnostic criteria; Usefulness of echocardiography in assessing the severity of the underlying cardiac disease and risk stratification in patients with unexplained syncope but with a positive cardiac history; Implications on cardiology.

Objective: To determine the role of the cerebral cortex in neurally mediated syncope, the electroencephalograms (EEG) of patients recorded during head up tilt table test were analysed.Design: Retrospective study.Setting: University hospital.Patients: 18 patients with syncope or near syncope underwent head up tilt table test with simultaneous ECG and EEG monitoring.Methods: Standard 70 degrees tilt table test was done with simultaneous ECG and EEG monitoring. EEG waveforms were analysed by both visual inspection and spectral analysis.Results: 6 of 18 patients (33%) had a positive tilt table test. Before syncope slow waves increased in patients with a positive test. In addition, five of six tilt positive patients (83%) had slow wave activity that lateralised to the left side of the brain (mean (SD) 822 (724) v 172 (215) micro V(2), p < 0.05), while none of the tilt negative patients exhibited lateralisation (24 (15) v 26 (19) micro V(2), NS). Spectral analysis showed that the lateralisation occurred in the delta frequency. The lateralisation preceded the event by 5-56 seconds (18 (21) seconds).Conclusions: EEG activity lateralises to the left hemisphere of the brain before syncope. The lateralisation precedes syncope and is associated with the onset of bradycardia, hypotension, and clinical symptoms. These findings suggest that the central nervous system may have a role in neurally mediated syncope. [ABSTRACT FROM AUTHOR]

The article presents information on syncope in adolescence. Syncope is considered as a common problem in adolescence and causes extreme anxiety. Neurally mediated syncope is the most common form of syncope. Among the factors that must be considered in the diagnosis of syncope are family history, altered consciousness and abnormal movements. Treatment options include biofeedback techniques and fludrocortisone.

The article discusses new indications for cardiac pacemakers other than primary bradycardia as of October 2013. Such indications include sick sinus syndrome, congestive heart failure, and hypertrophic cardiomyopathy. Information is also presented on pacing issues in sick sinus syndrome patients and in congestive heart failure patients.