Recurrencia y mortalidad a largo plazo de los pacientes con síncope no cardiogénico / Long-term recurrences and mortality in patients with noncardiac syncope

Introducción y objetivos: La evolución a largo plazo de los pacientes que padecen síncope, una vez descartada su etiología cardiaca, no se ha descrito en profundidad. Se describe la evolución a largo plazo de esta población. Métodos: Durante 147 meses, se estudió a todos los pacientes remitidos a nuestra unidad de síncope tras haberse descartado una causa cardiaca. Resultados: Se incluyó a 589 pacientes consecutivos, 313 de ellos mujeres (53,1%), con una mediana de 52 [34-66] años. A 405 (68,8%) se les diagnosticó síncope vasovagal (SVV); a 65 (11%), síncope por hipotensión ortostática (SHO), y a 119 (20,2%), síncope de etiología desconocida (SED). Durante una mediana de 52 [28-89] meses de seguimiento, 220 (37,4%) tuvieron recurrencias (el 21,7%, 2 o más recurrencias) y se produjeron 39 muertes (6,6%). La recurrencia del síncope se produjo en el 41% de los pacientes con SVV, el 35,4% del grupo con SHO y el 25,2% del de SED (p=0,006). La recurrencia se correlacionó en el análisis multivariado con la edad (p=0,002), el sexo femenino (p<0,0001) y el número de episodios previos (< 5 frente a ≥ 5; p <0,0001). Fallecieron 15 pacientes (3,5%) con SVV, 11 (16,9%) con SHO y 13 (10,9%) con SED (p=0,001), El análisis multivariado asoció edad (p=0,0001), diabetes (p=0,007) y diagnóstico de SHO (p=0,026) y SED (p=0,020) con la muerte. Conclusiones: En los pacientes con síncope de origen no cardiaco, a los 52 meses de seguimiento, la tasa de recurrencias es del 37,4% y la de mortalidad, del 6,6%. Hay más recurrencias en los pacientes con perfil neuromediado y más mortalidad en los pacientes con perfil no neuromediado (AU)

Introduction and objectives: There are no in-depth studies of the long-term outcome of patients with syncope after exclusion of cardiac etiology. We therefore analyzed the long-term outcome of this population. Methods: For 147 months, we included all patients with syncope referred to our syncope unit after exclusion of a cardiac cause. Results: We included 589 consecutive patients. There were 313 (53.1%) women, and the median age was 52 [34-66] years. Of these, 405 (68.8%) were diagnosed with vasovagal syncope (VVS), 65 (11%) with orthostatic hypotension syncope (OHS), and 119 (20.2%) with syncope of unknown etiology (SUE). During a median follow-up of 52 [28-89] months, 220 (37.4%) had recurrences (21.7% ≥ 2 recurrences), and 39 died (6.6%). Syncope recurred in 41% of patients with VVS, 35.4% with OHS, and 25.2% with SUE (P=.006). In the Cox multivariate analysis, recurrence was correlated with age (P=.002), female sex (P <.0001), and the number of previous episodes (< 5 vs ≥ 5; P <.0001). Death occurred in 15 (3.5%) patients with VVS, 11 (16.9%) with OHS, and 13 (10.9%) with SUE (P=.001). In the multivariate analysis, death was associated with age (P=.0001), diabetes (P=.007), and diagnosis of OHS (P=.026) and SUE (P=.020). Conclusions: In patients with noncardiac syncope, the recurrence rate after 52 months of follow-up was 37.4% and mortality was 6.6% per year. Recurrence was higher in patients with a neuromedial profile and mortality was higher in patients with a nonneuromedial profile (AU)

Right anterior ganglionated plexus: The primary target of cardioneuroablation?

BACKGROUND: Catheter ablation of ganglionated plexus (GP) as cardioneuroablation in the left atrium (LA) has been used to treat vasovagal syncope (VVS). OBJECTIVE: The purpose of this study was to assess the effects of ablation of GPs on heart rate and to observe the acute, short-term, and long-term effects after cardioneuroablation. METHODS: A total of 115 consecutive patients with VVS who underwent cardioneuroablation were enrolled. GPs of the LA were identified by high-frequency stimulation and/or anatomic landmarks being targeted by radiofrequency catheter ablation. RESULTS: During ablation of right anterior ganglionated plexus (RAGP), heart rate increased from 61.3 ± 12.2 bpm to 82.4 ± 14.7 bpm (P <.001), whereas during ablation of other GPs only vagal responses were observed. During follow-up of 21.4 ± 13.1 months (median 18 months), 106 participants (92.2%) had no recurrence of syncope or presyncope. Holter data showed that minimal heart rate significantly increased at all follow-up time points (all P<.05), and mean heart rate remained higher than baseline 12 months after ablation (P = .001). CONCLUSION: Cardioneuroablation via GP ablation in the LA effectively inhibited the recurrence of VVS. Ablation of RAGP could increase heart rate immediately and for the long term. This unique phenomenon may provide a new potential approach for treatment of neural reflex syncope or bradyarrhythmias.

Electroanatomic-mapping-guided cardioneuroablation versus combined approach for vasovagal syncope: a cross-sectional observational study.

PURPOSE: This study was designed to assess the efficacy of electroanatomic-mapping (EAM)-guided cardioneuroablation (CNA) vs combined approach for vasovagal syncope (VVS). METHODS: Twenty patients with VVS refractory to conventional treatments who underwent CNA in our institution were enrolled in the study. Twelve of these patients underwent recently introduced EAM-guided CNA using signal-based approach while 8 patients underwent combined CNA using a combination of high-frequency stimulation and spectral analysis. Both atria and coronary sinus were divided into seven segments to categorize distribution of ganglionated plexi in ablation sites. Clinical responses were evaluated and compared in terms of prodromal symptoms and syncope recurrence rates. Electrophysiological parameters and heart rate variability (HRV) analysis were used to evaluate procedural response. RESULTS: Procedural endpoints were achieved in all cases without any serious adverse events. Compared with the combined approach group, EAM-guided CNA was related to a shorter procedure and fluoroscopy times (p < 0.001). The mean number of ablation points in each anatomical segment was comparable between groups. The prodromal symptoms demonstrated a significant and comparable decrease after CNA. Median event-free survival was comparable between groups (χ2 = 0.03, p = 0.87). There was no new syncopal episode in any case at the end of 6-month follow-up. In the combined approach group, new syncope episodes occurred in two cases after 12-month follow-up. HRV parameters indicating parasympathetic activity were comparably decreased after ablation in both groups. CONCLUSION: This pilot study shows that EAM-guided CNA strategy is feasible and safe in VVS patients resistant to conventional therapies.

Prognostic analysis of orthostatic intolerance using survival model in children.

BACKGROUND: Orthostatic intolerance (OI) is a common disease at pediatric period which has a serious impact on physical and mental health of children. The purpose of this study was to investigate the effect of related factors on the prognosis of children with OI. METHODS: The subjects were 170 children with OI, including 71 males (41.8%) and 99 females (58.2%) with age from 6 to 17 (12.0±2.6) years. The effect of related factors on the prognosis of children was studied by using univariate analysis. Then, the impact of children's age, symptom score, duration, disease subtype, and treatment on patient's prognosis was studied via analysis of COX proportional conversion model. RESULTS: Among 170 cases, 48 were diagnosed with vasovagal syncope, including 28 cases of vasoinhibitory type, 16 cases of mixed type, and 4 cases of cardioinhibitory type; 115 cases were diagnosed with postural tachycardia syndrome and 7 cases with orthostatic hypotension. By using univariate analysis of Cox regression, the results showed that symptom score had a marked impact on the time of symptoms improvement of children after taking medication (P < 0.05), while other univariates had no impact (P > 0.05). Multivariate analysis using Cox proportional hazards regression model showed that the symptom score at diagnosis had a significant effect on holding time of symptoms improvement of children after taking medication (P < 0.05). Kaplan-Meier curve showed that symptom-free survival was higher in children with symptom score equal to 1 than children with symptom score equal to or greater than 2 during follow-up (P < 0.05). CONCLUSION: Symptom score is an important factor affecting the time of symptom improvement after treatment for children with OI.

Nitrate-potentiated head-up tilt testing (HUT) has a low diagnostic yield in patients with likely vasovagal syncope.

BACKGROUND: Vasovagal syncope (VVS) is characterized by a wide spectrum of clinical presentations, but the relationship between clinical presentation and response to head-up tilt testing (HUT) has not yet been evaluated in detail. The aim of this study was to assess the relationship between the clinical presentation of VVS and HUT and clinical outcome at long-term follow-up. METHODS: Out of 671 consecutive subjects undergoing nitroglycerin-potentiated HUT for suspected VVS, 369 patients with normal electrocardiogram and no structural heart disease were included in our study. RESULTS: A history suggestive of typical or atypical VVS was obtained in 198 and 171 patients, respectively. The positivity rate of HUT was 65% and 36% in patients with established and likely VVS, respectively (P < 0.0001). In patients with established VVS, a time interval of ≤28 days between the last syncope and HUT was the only independent predictor of a positive test. In patients with likely VVS, no variable was predictive of a positive HUT. At a mean follow-up of 43 ± 27 months, the rate of adverse events (all-cause mortality, syncope recurrence, and major diagnostic and/or therapeutic procedures) was similar in patients of both groups, independent of HUT results. CONCLUSION: In patients with likely VVS, HUT has a low-diagnostic yield and may be inadequate to establish a reliable diagnosis. Similar long-term outcomes were observed in patients with positive or negative test results, suggesting that HUT is of limited value in the management of patients with suspected neurally mediated syncope.

Vasovagal syncope related to emotional stress predicts coronary events in later life.

BACKGROUND: The aim of the study was to assess whether history of vasovagal syncope (VVS) mediated by emotional (emotional VVS) or orthostatic stress (orthostatic VVS) is associated with an increased risk of cardiovascular (CV) events in later life. METHODS: Retrospective analysis based on medical records of the consecutive 3,288 cardiologic outpatients (mean age, 61 ± 12 years; 43% men). RESULTS: A total of 254 patients (7.7%) reported emotional VVS, whereas 294 (9.0%) had history of orthostatic VVS. First-ever syncopal episode was reported at a median age of 16 years (interquartile range [IQR], 12 years to 28 years), and the median total number of episodes was two (IQR, 1 to 5). There were 779 patients (23.7%) with at least one CV event, and the median age for the first CV event was 59 years (IQR, 52 years to 67 years). In the fully adjusted model, history of emotional VVS was predictive of CV event (hazard ratio [95% confidence interval]: 1.63, [1.27-2.09]; P < 0.001), myocardial infarction (1.99, [1.49-2.66]; P < 0.001), and percutaneous coronary intervention (1.84, [1.31-2.60]; P = 0.001). There was one significant interaction (P = 0.07) between history of emotional VVS and gender. Emotional VVS was predictive of CV event in men (1.89 [1.41-2.53]; P < 0.001) but not in women (1.24 [0.79-1.94]; P = 0.35). CONCLUSIONS: History of emotional but not orthostatic VVS is independently associated with increased risk of coronary events in later life. The relationship between predisposition to emotional VVS in adolescence and development of cardiovascular disease requires further studies.

Tilt-induced cardioinhibitory syncope: a follow-up study in 16 patients.

INTRODUCTION: The exact clinical and prognostic significance and the therapeutic implications of asystole induced by head-up tilt test are still a matter of debate. METHODS: We assessed, by means of a semi-structured interview, the long-term outcome of cardioinhibitory syncope in all the patients who presented a tilt-induced sinus arrest of more than 3 s in our Autonomic Unit between 1996 and 2010. CONCLUSIONS: Although syncopal recurrences were common, tilt-induced asystole did not imply a poor prognosis in terms of death or major therapeutic procedures.

Syncope and structural heart disease: historical criteria for vasovagal syncope and ventricular tachycardia.

INTRODUCTION: to develop evidence-based criteria that distinguish syncope due to ventricular tachycardia (VT) from vasovagal syncope (VVS) in patients with structural heart disease (SHD). METHODS AND RESULTS: one hundred and thirty-four patients with syncope and SHD completed a 118-item questionnaire and underwent noninvasive and invasive diagnostic assessments in a prospective cohort study. The contributions of symptoms to diagnoses were estimated with logistic regression and a point score was developed and then tested using receiver-operator characteristic analysis. The effectiveness of the decision rule was evaluated with long-term outcome. There were 21 patients with tilt-positive VVS, 78 with clinically declared or inducible VT, and 35 with no identified cause of syncope. Six features were significant predictors. Factors that predicted VT included male sex and age at onset >35 years; factors predicting VVS included prolonged sitting or standing; developing presyncope preceded by stress; recurrent headaches; and experiencing fatigue, which lasts longer than 1 minute after syncope. The point score correctly classified 92% of patients, diagnosing VT with 99% sensitivity and 68% specificity. The negative predictive value is ≥ 96%. Fully 67% of patients with undiagnosed syncope were classified as having VT based upon their symptoms. The decision rule predicted 9-year arrhythmia-free survival (VVS 84%, VT 39%, hazard ratio 4.32) and 9-year overall survival (VVS 66%, VT 37%, hazard ratio 2.87). CONCLUSIONS: the causes of syncope in patients with SHD, and their clinical outcomes, can be estimated accurately based on the clinical history. The history safely screens out the possibility of VT as a cause of syncope.

Syncope while driving: clinical characteristics, causes, and prognosis.

BACKGROUND: The risk of syncope occurring while driving has obvious implications for personal and public safety. We aimed to define the clinical characteristics, causes, and prognosis of syncope while driving. METHODS AND RESULTS: In this case-control study of consecutive patients evaluated for syncope from 1996 through 1998 at an academic medical center, we documented causes, clinical characteristics, and recurrence of syncope while driving. Of 3877 patients identified, 381 (9.8%) had syncope while driving (driving group). Compared with the 3496 patients (90.2%) who did not have syncope while driving, the driving group was younger (P=0.01) and had higher percentages of male patients (P<0.001) and patients with a history of any cardiovascular disease (P=0.01) and stroke (P=0.02). Syncope while driving was commonly caused by neurally mediated syncope (37.3%) and cardiac arrhythmias (11.8%). Long-term survival in the driving group was comparable to that of an age- and sex-matched cohort from the Minnesota population (P=0.15). Among the driving group, syncope recurred in 72 patients, 35 of whom (48.6%) had recurrence >6 months after the initial evaluation. Recurrences during driving happened in 10 patients in the driving group, 7 of which (70%) were >12 months after the initial evaluation. CONCLUSIONS: In our study, neurally mediated syncope was the most common type of syncope while driving. The causes of syncope, the late recurrences of syncope (during > or =6 months of follow-up), and the overall low incidence of recurrent syncope while driving provide useful information to supplement current recommendations on driving for these patients.

Pacing to prevent vasovagal syncope.

Patients with frequent vasovagal syncope have markedly poor quality of life and are often resistant to treatment with standard pharmacologic approaches. Vasovagal syncope is due to combinations of bradycardia and hypotension. There is accumulating evidence that many of these patients may respond to permanent cardiac pacing. Several controlled open-label studies suggest that about half of paced patients no longer faint, and most of the rest are improved. At this point, we do not know the role of placebo, and specific pacing modes in this improvement are not known. Ongoing trials will clarify how to select patients and how best to pace them.

[It is not easy to examine the causes of fainting. Vasovagal syncope is mostly not dangerous, cardiac syncope is potentially life-threatening]. / Inte helt lätt att utreda orsakerna till svimning. Vasovagal svimning oftast ofarlig, kardiell potentiellt livshotande.

Of the approximately 30 per cent of the population who are afflicted with syncope at some time of life, 30 per cent will relapse. Despite extensive investigation, no specific cause is identified in about one third of cases. Although some episodes of syncope, e.g. cardiovascular syncope, are benign and self-limiting, others such as mechanical cardiac syncope and arrhythmogenic syncope are associated with considerable mortality. The article consists in a review of available data on differential diagnostic evaluation and treatment with special emphasis on case history.