Recurrent Syncope In Patients Research Articles

Recurrence of syncope after valve replacement in severe aortic stenosis

ObjectiveThe recurrence of syncope after valve intervention in severe aortic stenosis (SAS) and its impact on outcome are unknown. We hypothesised that syncope on exertion will disappear after intervention, whereas...

Clinical controversy: methodology and indications of cardioneuroablation for reflex syncope.

Observational studies and a recent randomized controlled trial have provided some evidence that cardioneuroablation (CNA) may prevent syncope recurrence in patients affected by cardioinhibitory reflex syncope during the first 2 years following the procedure. Nevertheless, many issues concerning clinical indications, methodology, and long-term results remain unresolved. These issues constitute the background of this manuscript in which pioneers in CNA and experts in syncope debated critical aspects aimed at finding agreement or, if not possible, that highlighting the controversies could be addressed in future studies.

Recurrent syncope in patients with a pacemaker and bradyarrhythmia

Background. Pacemakers are used to treat syncope in patients with bradyarrhythmia; however, the risk of recurrent syncope has only been investigated in few and smaller studies. Objective. The aim of this study was to investigate the risk of recurrent syncope after pacemaker implantation in patients with bradyarrhythmia and prior syncope. Methods. This retrospective, population-based cohort study included patients with a prior syncope and implantation of a pacemaker using data from the Danish nationwide registers from 1996 to 2017. Cumulative incidence and cox regression was used to estimate the 5-year incidence and the risk of recurrent syncope, respectively. Results. In total, 11,126 patients (median age: 78 years, interquartile range: 69–85, 56% male) were included and the 5-year cumulative incidence of recurrent syncope was 19.6% (95% confidence interval (CI): 18.8–20.3%). Sinus node dysfunction (hazard ratio [HR]: 1.29, 95%CI: 1.17–1.42) and unspecified type of bradyarrhythmia (HR: 1.32, 95%CI: 1.15–1.52) were associated with an increased risk of syncope compared to advanced atrioventricular (AV) block. Male sex (HR: 1.22, 95%CI: 1.22–1.34), cerebrovascular disease (HR: 1.17, 95%CI: 1.05–1.30), and prior number of syncopes were significantly associated with a higher HR of recurrent syncope. Conclusion. Almost one-in-five patients with bradyarrhythmia and prior syncope who had a pacemaker implanted had a recurrent syncope within five years. A higher risk of syncope was observed among patients with sinus node dysfunction and unspecified type of bradyarrhythmia compared to AV block. Male sex, cerebrovascular disease, and prior number of syncopes were associated risk factors of recurrent syncope.

SGLT2-inhibitors reduce the cardiac autonomic neuropathy dysfunction and vaso-vagal syncope recurrence in patients with type 2 diabetes mellitus: the SCAN study

BackgroundIn patients with type 2 diabetes mellitus (T2DM) the vaso-vagal syncope (VVS) recurrence could be due to the alteration of autonomic system function, evaluated by heart rate variability (HRV), and by 123I-metaiodobenzylguanidine (123I-mIBG) myocardial scintigraphy indexes: Heart to Mediastinum ratio (H/Mlate), and Washout rate (WR). The SGLT2-I could modulate/reduce autonomic dysfunction in T2DM patients with VVS. This effect could reduce the VVS recurrence in T2DM patients. MethodsIn a prospective multicenter study, after propensity score matching, we studied a population of 324 T2DM patients with VVS, divided into 161 SGLT2-I-users vs. 163 Non-SGLT2-I users. In these patients as SGLT2-I-users vs. Non-SGLT2-I users, we investigated the HRV and 123I-MIBG modifications and VVS recurrence at 12 months of follow-up. ResultsAt follow-up end, the SGLT2-I-users vs. Non-SGLT2-I users had best glucose homeostasis and lower values of inflammatory markers, and resting heart rate (p < 0.05). The SGLT2-I-users vs. Non-SGLT2-I users evidenced the lowest low frequency/high frequency ratio (LF/HFr), a significant difference for all the indexes of autonomic dysfunction via ECG Holter analysis, and higher values of H/Mlate (p < 0.05). Finally, comparing SGLT2-I-users vs. Non-SGLT2-I users, we found a higher rate of VVS recurrence events, specifically of the vasodepressor VVS recurrence at 1-year follow-up (p < 0.05). We did not find a significant difference of mixed and cardio-inhibitory VVS recurrence events at 1 year of follow-up in the study cohorts (p > 0.05). At the Cox regression analysis H/Mlate (0.710, [0.481–0.985]), and SGLT2-I therapy (0.550, [0.324–0.934]) predicted all causes of syncope recurrence at 1 year of follow-up. ConclusionsNon-SGLT2-I users vs. SGLT2-I-users had alterations of the autonomic nervous system, with a higher rate of VVS recurrence at 1 year of follow-up. The indexes of cardiac denervation predicted the VVS recurrence, while the SGLT2-I reduced the risk of VVS recurrence.Clinical trial registration number: NCT03717207.

Randomized Pragmatic Trial of Pacemaker Versus Implantable Cardiac Monitor in Syncope and Bifascicular Block.

In this study, the authors tested whether a strategy of empiric permanent pacing reduces major composite events more effectively than acting on the results of an implantable cardiac monitor (ICM). Syncope may be caused by intermittent complete heart block in patients with bifascicular heart block, but competing diagnoses coexist. Whether empiric permanent pacing or acting on investigative results provides best care is unknown. This was a multinational, randomized, pragmatic clinical trial of patients≥50 years of age with bifascicular block, preserved left ventricular function, and≥1 syncope in the preceding year. The primary composite outcome measure comprised cardiovascular death, syncope, bradycardia resulting in pacemaker insertion, and device complications. There were 57 and 58 subjects randomized to receive a pacemaker or ICM. A total of 41 patients had left bundle branch block and 74 had right bundle branch block and a left fascicular block. Patients were followed for a median 33months. There were fewer composite primary outcomes in patients randomized to pacemaker compared with ICM, respectively (20 [35%] vs 44 [76%]; chi square P< 0.0001), with lower actuarial probabilities of a primary outcome (0.45 and 1.00; P< 0.001). Syncope was as likely in the groups randomized to receive a pacemaker or ICM (29% vs 26%, chi-square P = 0.95). Empiric permanent pacing compared with ICM reduced major adverse events but not syncope in older patients with bifascicular block and recent syncope. There remains a substantial likelihood of syncope recurrence in patients who receive a permanent pacemaker likely caused by vasodepressor syncope. (Syncope: Pacing or Recording in the Later Years [SPRITELY]; NCT01423994).

B-PO01-027 PERMANENT PACING VERSUS CARDIONEUROABLATION FOR CARDIOINHIBITORY VASOVAGAL SYNCOPE

Permanent cardiac pacing (PM) can reduce syncopal events in patients with refractory cardioinhibitory (CI) vasovagal syncope (VVS). Cardioneuroablation (CNA) has been shown to be effective in reducing syncopal recurrences in patients with CI-VVS. To compare the safety and efficacy of CNA with PM in patients with recurrent CI-VVS. We conducted a 5-center, retrospective study of all patients who underwent CNA or received PM for recurrent, severe, CI-VVS. Clinical diagnosis of CI-VVS was supported by cardiac monitoring or positive cardioinhibitory response to head-up tilt testing. All patients had disabling symptoms with traumatic syncope despite conservative therapies. The primary efficacy endpoint was freedom from syncope during follow up. Any procedure-related adverse events (AE) were also assessed. 162 patients (CNA [n=61], PM [n=101]) with age 36+11 years (64 % female) and syncope frequency of 6.7±3.9/year were included. In patients undergoing CNA, age (35 + 12 vs 36 + 11, p =0.581) and pre-procedure syncope frequency [median 5 (IQR 4-8) vs median 6 (IQR (4-10), p = 0.52) were similar, and proportion of women lesser compared to the PM group (40.9% vs 77.2%, p <0.001). At 1-year, 96.7% (59/61) and 89.1% (90/101) met primary efficacy endpoint in the CNA and PM groups (unadjusted HR=0.30, 95% CI 0.07 - 1.34, p=0.119, p=NS, adjusted HR=0.27, 95% CI 0.06 - 1.24, p=0.09) (Figure 1). Major and minor AE occurred in 5/61 in the CNA and 11/101 in the cardiac pacing groups (p=0.79). In patients with CI-VVS, CNA demonstrated equivalent efficacy in reducing syncopal events when compared to cardiac pacing, with a similar safety profile.

First Vs Recurrent Syncope In Patients With Structural Heart Disease Or Bundle Branch Block

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Hospital Universitari Vall d"Hebron - Vall d"Hebron Institut de Recerca. CIBERCV BACKGROUND Patients with structural heart disease (SHD) or bundle branch block (BBB) are at high risk of having an arrhythmic syncope (AS). In patients with recurrent syncope episodes (RSE) complete work-up including electrophysiological study (EPS) and/or implantation of a loop recorder (ILR) is recommended, however patients with their first episode may also be at risk of an AS. AIM To determinate if the patients with SHD or BBB with a single syncope episode (SSE) are at high risk of having an AS and compare it with patients with recurrent episodes (RSE). METHODS Cohort study carried out in a tertiary hospital that is a reference centre for syncope. From January 2008 to August 2020 patients with SHD or BBB with syncope of unknown origin after the initial evaluation and without direct indication of an ICD were included. They were managed according the current ESC guidelines. RESULTS 417patients were included (74 ±11 y. o; 39% female). Mean follow up was 2.5 ±1 y. 223 patients were diagnosed from an AS [113 (53%) in SSE group and 110 (54%) in RSE group, p = 0.9], 210 were due to bradyarrhythmia (AV block or sinus arrest). No differences in baseline characteristics where found comparing both groups, except that BBB was slightly more prevalent in patients with RSE (81% vs 90%, p = 0.01) (FIGURE- PANEL A). Risk of AS was 53% in patients with SE and 54% (p = 0.9). RSE were not associated with an increased risk of AS in univariate analyses (OR 1.01 IC95% 0.7-1.5) neither in the multivariate (FIGURE- PANEL B). EPS and ILR diagnostic yield was 45% / 32% respectively in SSE group and 44% / 33% in RSE group (p = 0.8) (FIGURE - PANEL C). After appropriate treatment, recurrence syncope rate was 10% in SSE group and 9% in RSE group (p = 0.8). No significant differences in mortality rate were found. CONCLUSIONS Patients with SHD or BBB and single syncope episode are at a high risk of having AS, and similar to those with RSE. EPS and ILR offer a similar diagnostic yield in both groups. Complete syncope work-up must be recommended in these patients despite having had only a single episode. Abstract Figure

Causes of syncopal recurrences in patients treated with permanent pacing for bradyarrhythmic syncope: Findings from the SYNCOPACED registry

Few studies have examined the causes of syncope/collapse recurrences in patients with a previously implanted pacemaker for bradyarrhythmic syncope. The purpose of this study was to assess the causes of syncope/collapse recurrences after pacemaker implantation for bradyarrhythmic syncope in a large patient population. The SYNCOpal recurrences in patients treated with permanent PACing for bradyarrhythmic syncope (SYNCOPACED) registry was a prospective multicenter observational registry enrolling 1364 consecutive patients undergoing pacemaker implantation for bradyarrhythmic syncope. During follow-up, the time to the first syncope/collapse recurrence was recorded. Patients with syncope/collapse recurrences underwent a predefined diagnostic workup aimed at establishing the mechanism of syncope/collapse. During a median follow-up of 50 months, 213 patients (15.6%) reported at least 1 syncope/collapse recurrence. The risk of syncope/collapse recurrence was highest in patients who underwent implantation for cardioinhibitory vasovagal syncope (26.4%), followed by unexplained syncope and chronic bifascicular block (21.5%), cardioinhibitory carotid sinus syndrome (17.2%), atrial fibrillation needing pacing (15.5%), atrioventricular block (13.6%), and sinus node disease (12.5%) (P = .017). The most frequent cause of syncope/collapse recurrence was reflex syncope (27.7%), followed by orthostatic hypotension (26.3%), pacemaker or lead malfunction (5.6%), structural cardiac disease (5.2%), and atrial and ventricular tachyarrhythmias (4.7% and 3.8%, respectively). In 26.8% of cases, the mechanism of syncope/collapse remained unexplained. In patients receiving a pacemaker for bradyarrhythmic syncope, reflex syncope and orthostatic hypotension are the most frequent mechanisms of syncope/collapse recurrence after implantation. Pacing system malfunction, structural cardiac diseases, and tachyarrhythmias are rare mechanisms. The mechanism remains unexplained in >25% of patients.

Recurrent syncope in patients with a pacemaker and bradyarrhythmia

Abstract Objectives To investigate the risk of recurrent syncope and all-cause mortality after implantation of a pacemaker in patients with bradyarrhythmia. Background A pacemaker is generally recommended when syncope is caused by bradyarrhythmias to prevent a new syncope. However, the occurrence and risk of recurrent syncope in patients with bradyarrhythmia after pacemakerimplantation are still unknown. Methods Patients with a prior syncope and an implantation of pacemaker were identified. Cumulative incidences of 5-years were estimated for the outcomes stratified into groups according to the type of bradyarrhythmia; and type of pacemaker. The risk of recurrent syncope and all-cause mortality were estimated using adjusted cox proportional hazard regressions. Results We identified 8,663 patients with a prior syncope and pacemaker implantation (median age of 78,1 years (SD 69,1–84,8) and 55,1% males). The 5-year cumulative incidence of recurrent syncope was 19,3% (95% confidence intervals (CI) 18,4–20,2). Factors associated with a significant increased risk of recurrent syncope were male sex, age 80 years and above, alcohol related disease, bleeding, chronic obstructive pulmonary disease, chronic kidney disease, stroke, and malignancy. Atrial fibrillation was associated with a significantly decreased risk of recurrent syncope. Patients with an advanced AV conduction abnormality had a lower associated risk of syncope compared to patients with sinus node dysfunction (HR 0,85, 95% CI 0,76–0,94, p=0,003). Conclusions One fifth of the cohort had a recurrence syncope after five years. Besides older age and male sex, several comorbidities were found to be associated with a higher risk of recurrence of syncope. Clinicians need to be attentive that a large proportion of patients with bradyarrhythmia suffer from syncope even when treated with a pacemaker. Funding Acknowledgement Type of funding source: None

Risk of syncopal recurrences in patients treated with permanent pacing for bradyarrhythmic syncope: role of correlation between symptoms and electrocardiogram findings.

To evaluate the risk of syncopal recurrences after pacemaker implantation in a population of patients with syncope of suspected bradyarrhythmic aetiology. Prospective, multicentre, observational registry enrolling 1364 consecutive patients undergoing pacemaker implantation for syncope of bradyarrhythmic aetiology (proven or presumed). Before pacemaker implantation, all patients underwent a cardiac work-up in order to establish the bradyarrhythmic aetiology of syncope. According to the results of the diagnostic work-up, patients were divided into three groups: Group A, patients in whom a syncope-electrocardiogram (ECG) correlation was established (n = 329, 24.1%); Group B, those in whom clinically significant bradyarrhythmias were detected without a documented syncope-ECG correlation (n = 877, 64.3%); and Group C, those in whom bradyarrhythmias were not detected and the bradyarrhythmic origin of syncope remained presumptive (n = 158, 11.6%). During a median follow-up of 50 months, 213 patients (15.6%) reported at least one syncopal recurrence. Patients in Groups B and C showed a significantly higher risk of syncopal recurrences than those in Group A [hazard ratios (HRs): 1.60 and 2.66, respectively, P < 0.05]. Failure to establish a syncope-ECG correlation during diagnostic work-up before pacemaker implantation was an independent predictor of syncopal recurrence on multivariate analysis (HR: 1.90; P = 0.002). In selecting patients with syncope of suspected bradyarrhythmic aetiology for pacemaker implantation, establishing a correlation between syncope and bradyarrhythmias maximizes the efficacy of pacing and reduces the risk of syncopal recurrences.

Usefulness of post-procedural heart rate response to predict syncope recurrence or positive head up tilt table testing after cardioneuroablation.

Previous reports have suggested that cardioneuroablation (CNA) can be effective in reducing syncopal recurrences in patients with vasovagal syncope (VVS). This study assessed the efficacy of CNA in preventing a positive response to head-up tilt testing (HUT). This is a single-centre retrospective study reviewing prospectively collected data. Fifty-one consecutive patients with VVS were included in the study. After confirmation of >3 s asystole on HUT, all patients underwent CNA. Head-up tilt testing was repeated 1 month after CNA. The main outcome measures were recurrence of syncope episode and positive response on HUT. During a median follow-up period of 11 months (interquartile range 3-27 months), all but 3 (5.8%) of 51 patients were free of syncope. Repeated HUTs were negative in 44 (86.2%) patients. When patients with recurrent syncope were excluded, vasodepressor response was seen in three cases and cardioinhibitory response in one case, respectively. Cardioneuroablation caused significant and durable shortening of RR interval in all cases. This effect was significantly higher in patients without positive HUT responses. This pilot study shows that CNA can effectively prevent recurrent syncopal episodes in patients with refractory VVS. Head-up tilt testing seems as a valuable diagnostic tool not only to select suitable candidates and but also to evaluate success of CNA.

The evolving picture of SARS-CoV-2 and COVID-19 in children: critical knowledge gaps.

<h3>Background</h3> 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. <h3>Method sand results</h3> 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. <h3>Conclusions</h3> 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.

ELectrophysiological mechanisms underlying the Inhibitory CArdiac syncope without asystolic significant pause: Therapeutic and prognostic implications. The ELICA randomized trial.

Background:The aim of this study was to investigate syncope recurrence in patients with a 2A cardioinhibitory response to the head up tilt testing (HUT).Methods:In this study, we enrolled 72 consecutive patients affected by syncope with cardioinhibitory response without asystolic significant pause to HUT (2A type). In these patients, we randomly performed electrophysiological study (ES). In case of sino-atrial node, atrio-ventricular node dysfunction, and sustained arrhythmias induction, the ES resulted positive. ES was positive in 9 patients (group A), then treated by catheter ablation, and/or by devices implants. Otherwise, ES resulted negative (group B), and these patients did not receive an interventional treatment. However, after ES, we evaluated syncope recurrence during 360 days follow-up.Results:There was a lower statistical significant syncope recurrence at follow-up, comparing group A to group B of patients [n of events 9 (40.9%) vs 8 (57.1%), P < .05]. At multivariate analysis, ES result was the only factor predicting syncope recurrence at follow-up (hazard ratio = 27.63, 95% confidence interval = 1.02–54.24, P < .005).Conclusion:The positivity to ES study, and successful interventional therapies may reduce the burden of syncope recurrence at 360 days follow-up in 2A HUT subjects.Clinical trial number: NCT02861274.

Incidence and predictors of syncope recurrence after cardiac pacing in patients with carotid sinus syndrome

BackgroundCardiac pacing is the treatment of choice for cardioinhibitory carotid sinus syndrome (CSS), but syncope recurrence occurs in up to 20% of patients within 3 years. The present study aims at assessing incidence and identifying predictors of syncope recurrence in patients receiving pacing therapy for CSS. MethodsThe Syncope Clinics of two large regional hospitals in Northern Italy, both following European Syncope Guidelines, combined to perform this study. Retrospective analysis of 3127 consecutive patients undergoing carotid sinus massage (CSM) was performed 2004–2014. Ten-second supine and standing CSM was systematically assessed in patients aged >40 years with suspected reflex syncope as part of the initial evaluation. Syncope recurrence was investigated in those paced for CSS having >6 months' available follow-up. Data were collected from clinical records and patient interviews. ResultsCSS was diagnosed in 261 patients (8.3%). Pacemakers were implanted in 158, with follow-up data available in 112: 19 (17%) experienced 73 syncope recurrences during a mean follow-up of 89 ± 42 months, yielding an incidence of 0.5 episodes per patient/year. Prodrome, predisposing situations preceding syncope and chronic nitrate therapy were more frequent in patients reporting recurrence. Prodrome and predisposing situations remained independent predictors of post-implantation recurrence on multivariable analysis. ConclusionsCSS is a frequent cause of syncope, if CSM is performed during the initial evaluation. Most patients treated by pacing remain asymptomatic during long-term follow-up. In those who have recurrence, its incidence is very low. Prodrome and predisposing situations are predictors of post-implantation recurrence, suggesting presence of hypotensive susceptibility.

Relationship Between Phosphate and Sodium Nitrite Ingestion and Vascular Hardness of Longevity Elderly Population in Okinawa Prefecture

Cardiac pacing is the treatment of choice for cardioinhibitory carotid sinus syndrome (CSS), but syncope recurrence occurs in up to 20% of patients within 3 years. The present study aims at assessing incidence and identifying predictors of syncope recurrence in patients receiving pacing therapy for CSS.The Syncope Clinics of two large regional hospitals in Northern Italy, both following European Syncope Guidelines, combined to perform this study. Retrospective analysis of 3127 consecutive patients undergoing carotid sinus massage (CSM) was performed 2004–2014. Ten-second supine and standing CSM was systematically assessed in patients aged >40 years with suspected reflex syncope as part of the initial evaluation. Syncope recurrence was investigated in those paced for CSS having >6 months' available follow-up. Data were collected from clinical records and patient interviews.CSS was diagnosed in 261 patients (8.3%). Pacemakers were implanted in 158, with follow-up data available in 112: 19 (17%) experienced 73 syncope recurrences during a mean follow-up of 89 ± 42 months, yielding an incidence of 0.5 episodes per patient/year. Prodrome, predisposing situations preceding syncope and chronic nitrate therapy were more frequent in patients reporting recurrence. Prodrome and predisposing situations remained independent predictors of post-implantation recurrence on multivariable analysis.CSS is a frequent cause of syncope, if CSM is performed during the initial evaluation. Most patients treated by pacing remain asymptomatic during long-term follow-up. In those who have recurrence, its incidence is very low. Prodrome and predisposing situations are predictors of post-implantation recurrence, suggesting presence of hypotensive susceptibility.

Vasovagal syncope with asystole: the role of cardiac pacing.

Whereas cardiac pacing has a very limited role overall in patients with vasovagal syncope (VVS), there are three reasons which support pacing efficacy in tilt-induced asystolic VVS. These are: (1) contrary to mixed and vasodepressor forms, an asystolic tilt response is specific, i.e., diagnostic, of VVS and is unlikely to occur in control patients without history of syncope and in patients with cardiac syncope; (2) contrary to mixed and vasodepressor forms, an asystolic tilt response predicts a similar asystolic event during prolonged ECG monitoring with a positive predictive value of 86%; (3) the available evidence from trials supports the efficacy of dual-chamber pacing with a low recurrence rate of syncope after pacing ranging from 6% up to 23% during 3years of follow-up. The latter results should be confirmed by an ongoing double-blind randomized controlled trial before cardiac pacing becomes an established indication. It is commonly believed that the most frequent cause of recurrence of syncope in patients treated with a pacemaker is an associated hypotensive reflex. In these cases additional measures should be used to counteract hypotension. Recognizing prodromal symptoms, avoiding triggers, and performing counterpressure maneuvers are the well-known first steps. There are two additional useful measures when these fail: stopping/reducing hypotensive drugs and (in selected cases) adding fludrocortisone.

P1605Low QRS voltage in limb leads may predict recurrent syncope in patients with syncope of unknown origin

P1605Low QRS voltage in limb leads may predict recurrent syncope in patients with syncope of unknown origin

Tilt-table testing of patients with pacemaker and recurrent syncope

The diagnosis of recurrent syncope in patients with pacemakers (PM) is quite challenging and the etiology of syncope is often multifactorial. To portray the mechanism of syncope in PM patients, we report the results of head-up tilt table testing (HUT) in a series of patients with PM, originally implanted for reasons other than neurally mediated syncope, referred due to syncope or pre-syncope (aborted syncope, vertigo, suspected orthostatic hypotension).Forty-one patients with PM undergoing a HUT in our syncope unit between January 1st, 2007 and December 31st 2011 were included. A standard HUT protocol with nitroglycerine provocation was used and the test results were classified according to current guidelines. Baseline data were retrieved from the medical records.Overall, 54% of patients had a positive response to HUT. Vasodepressor or orthostatic hypotensive response were the most prevalent responses accounting for 72% of patients with a positive test. There were no differences between groups with positive or negative test result regarding age, gender, resting blood pressure and heart rate, daily fluid intake, pacing mode, pacing indication or pacing rhythm at rest.HUT in patients with pacemakers has a high diagnostic yield. Although, the majority of patients had a vasodepressor or orthostatic hypotensive response, cardioinhibitory response leading to syncope was also seen.

Midodrine for orthostatic hypotension and recurrent reflex syncope: A systematic review.

Symptomatic orthostatic hypotension (SOH) and recurrent reflex syncope (RRS) can be disabling. Midodrine has been proposed in the management of patients with these conditions but its impact on patient important outcomes remains uncertain. We performed a systematic review to evaluate the efficacy and safety of midodrine in patients with SOH and RRS. We searched multiple electronic databases without language restriction from their inception to June 2013. We included randomized controlled trials of patients with SOH or RRS that compared treatment with midodrine against a control and reported data on patient important outcomes. We graded the quality of evidence according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Eleven trials involving 593 patients were included in this review. Three studies addressed health-related quality of life in patients with RRS, showing improvement with midodrine: risk difference 14% (95% confidence interval [CI] -3.5 to 31.6), very low confidence. Seven studies addressed symptom improvement and provided poolable data showing improvement with midodrine in patients with SOH: risk difference 32.8% (95% CI 13.5-48), low confidence; and RRS: risk difference 63.3% (95% CI 47.6-68.2), very low confidence. Five studies reported syncope recurrence in patients with RRS showing improvement with midodrine: risk difference 37% (95% CI 20.8%-47.4%), moderate confidence. The most frequent side effects in the midodrine arm were pilomotor reactions (33.6%, risk ratio 4.58 [95% CI 2.03-10.37]). Evidence warranting low/moderate confidence suggests that midodrine improves clinical important outcomes in patients with SOH and RRS.

Cardiac pacing in patients with neurally mediated syncope and documented asystole: effectiveness analysis from the Third International Study on Syncope of Uncertain Etiology (ISSUE-3) Registry

The randomized, double-blind Third International Study on Syncope of Uncertain Etiology (ISSUE-3) showed that dual-chamber permanent pacing was effective in reducing the recurrence of syncope in patients ≥ 40 years with severe asystolic, probably neurally mediated syncope (NMS), documented by implantable loop recorder (ILR). Analysis in ISSUE-3 was performed according to the intention-to-treat principle. In the present study, we performed an on-treatment analysis, which included additionally those non-randomized patients followed up in the ISSUE registry to evaluate in a better manner the effectiveness of cardiac pacing therapy. Initially, 504 patients received an ILR, 162 (32%) patients had a diagnosis consistent with NMS within a mean observation period of 15 ± 11 months: 99 (19%) patients had documentation of syncope with ≥ 3 s asystole or ≥ 6 s asystole without syncope. Sixty patients affected by asystolic NMS received cardiac pacing therapy and 86 (33 asystolic and 53 non-asystolic NMS) were untreated; 16 patients were lost to follow-up. Paced and unpaced groups had similar clinical characteristics. During subsequent follow-up, syncope recurred in 10 paced (17%) and in 40 non-paced (46%) patients. At 21 months, the estimated product-limit syncope recurrence rates were 27% [95% confidence interval (CI) 15-47] and 54% (95% CI 43-67), respectively (P = 0.01). With cardiac pacing, the risk of recurrence was reduced by 57% (hazard ratio = 0.43, 95% CI = 0.2-0.8). Complications of pacemaker therapy were haemothorax at implantation in one patient and lead dislodgement that required correction in two patients. Permanent cardiac pacing is effective in reducing recurrence of syncope in patients ≥ 40 years with severe asystolic possible NMS with a few complications. The study shows that 61% of patients with a diagnosis of NMS made by ILR received a pacemaker but 5.1 ILRs had to be implanted to find one patient who finally had a pacemaker implanted.