A Multicenter External Validation of a Score Model to Predict Risk of Events in Patients With Brugada Syndrome.

A multivariate risk score model was proposed by Sieira et al in 2017 for sudden death in Brugada syndrome; their validation in 150 patients was highly encouraging, with a C-index of 0.81; however, this score is yet to be validated by an independent group. A total of 192 records of patients with Brugada syndrome were collected from 2 centers in the United Kingdom and retrospectively scored according to a score model by Sieira et al. Data were compiled summatively over follow-up to mimic regular risk re-evaluation as per current guidelines. Sudden cardiac death survivor data were considered perievent to ascertain the utility of the score before cardiac arrest. Scores were compared with actual outcomes. Sensitivity in our cohort was 22.7%, specificity was 57.6%, and C-index was 0.58. In conclusion, up to 75% of cardiac arrest survivors in this cohort would not have been offered a defibrillator if evaluated before their event. This casts doubt on the utility of the score model for primary prevention of sudden death. Inherent issues with modern risk scoring strategies decrease the likelihood of success even in robustly designed tools such as the Sieira score model.

Analysis of Conduction Intervals in Normal Electrophysiological Studies: Establishment of Reference Values the Brazilian Population

Abstract Background In the investigation of cardiac rhythm disorders, a normal electrophysiological (EPS) study is associated with a favorable prognosis. One of the normality criteria is established by conduction intervals within expected range. Objective To establish reference values in EPS for the intracavitary conduction intervals (PA, AH and HV) in a Brazilian population. Methods A retrospective cohort study of the first 1,500 patients submitted to EPS ablation was performed at Instituto de Cardiologia do Rio Grande do Sul, Brazil. The EPS was considered normal if the test was performed for diagnostic purpose; absence of induced arrhythmias; and conduction intervals within the expected range. The REDCap software was used for data collection and management, and the SPSS Statistics 22.0 used for data analysis. Continuous variables were compared with Student's t-test for independent samples and categorical variables with the chi-square test (X 2 ). Values of p ≤ 0.05 were considered significant. Results A total of 124 (8.3%) with EPS considered normal were included; mean age was 52 ± 21 years, and 63 were male. The mean values in milliseconds of PA, AH and HV were 23 ± 9, 88 ± 25 and 44 ± 7, respectively. The PA, AH, and HV percentile ranges were 13 - 25, 81-107 and 40 - 52, respectively. When the patients were divided into three age groups (1 to 18 years, 19 to 64 years and 65 or more), we observed that the group of older patients had significantly higher values of PA, AH and HV compared with younger patients. Conclusion This study showed that intracavitary conduction intervals in a sample of the Brazilian population were similar to previously published studies. Elderly patients tend to have higher values of intracavitary conduction intervals in EPS. Future studies including broader age ranges could enable the acquisition of more reliable and reproducible reference values. (Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0)

Flecainide Versus Procainamide in Electrophysiological Study in Patients With Syncope and Wide QRS Duration.

OBJECTIVES: This study sought to compare the differences between procainamide and flecainide to stress the His-Purkinje system during electrophysiological study (EPS) in patients with syncope and bundle branch block (BBB). BACKGROUND: Patients with syncope and BBB are at risk of developing atrioventricular block. EPS is recommended including class I drug challenge to unmask His-Purkinje disease in cases with baseline normal His-ventricular interval. There is little data on differences between different class I drugs. METHODS: This was a prospective study of all consecutive patients undergoing EPS for syncope and BBB at a single center (January 1, 2012 to June 30, 2017). Of those patients with negative baseline EPS, 2 cohorts were compared: group A (historical cohort: procainamide) and group B (flecainide). RESULTS: During the study, 271 patients (age 73.9 ± 12.1 years, 64.9% male, QRS duration: 139.4 ± 13.9 ms) underwent EPS. In 166, baseline EPS was negative and class I drug challenge was performed (90 procainamide, 76 flecainide). The final value and percentage increase in the His-ventricular interval (76 ± 16 ms vs. 64 ± 10 ms and 22.5 ± 6.2% vs. 11.8 ± 5.3%; p < 0.001) and diagnostic yield (14.5% vs. 7.8%, p = 0.04) were higher with flecainide. No differences were found in baseline characteristics. During follow-up (25.8 ± 6.3 months), 39 patients (24.8%) with negative EPS (19.2% with flecainide vs. 30.1% with procainamide: relative risk: 5.1; 95% confidence interval: 2.6 to 10.2; p < 0. 001) received a pacemaker. CONCLUSIONS: Flecainide has a higher diagnostic yield than does procainamide in patients with BBB, syncope, and negative baseline EPS due to a greater increase of the His-ventricular interval. Additionally, there is a lesser need for pacemaker implantation in patients in whom the class I drug test using flecainide was negative.

Bundle branch reentrant ventricular tachycardia: review and case presentation.

Bundle branch reentrant ventricular tachycardia (BBRVT) is characterized by a unique, fast (200-300 beats/min), monomorphic wide complex tachycardia (WCT) associated with syncope, hemodynamic compromise, and cardiac arrest. It is challenging to diagnose, requiring a His bundle recording and specific pacing maneuvers. The overall incidence has been reported to be up to 20% among patients with non-ischemic cardiomyopathy (NICM) undergoing electrophysiologic studies. We report a case of BBRVT in a patient with ischemic cardiomyopathy (ICM) presenting as a WCT with recurrent implantable-cardioverter-defibrillator (ICD) shocks. We describe all the characteristic features of BBRVT and discuss its differential. We also discuss the role of ablation for this condition.

Dangerous mistake: an accidental caffeine overdose.

Caffeine (1,3,7-trimethylxanthine) is a natural product commonly presented in food's composition, beverages and medicinal products. Generally, it is thought to be safe under normal dosage, yet it can be fatal in case of severe intoxication. We report a case of a healthy 32-year-old woman who went to the local emergency department (ED) 30 min after ingesting, accidentally, 5000 mg of anhydrous caffeine for a preworkout supplement. At the ED, she presented an episode of presyncope followed by agitation. ECG showed polymorphic broad complex QRS tachycardia and arterial blood gas revealed metabolic acidaemia with severe hypokalemia. The dysrhythmia was successfully treated with intravenous propranolol. Acid-base and hydroelectrolytic disorders were also corrected. A persistent sinus tachycardia was observed in the first 2 days in the ward and 5 days later she was discharged asymptomatic with internal medicine follow-up.

Permanent pacemaker implantation in octogenarians with unexplained syncope and positive electrophysiologic testing.

BACKGROUND: Syncope is a common problem in the elderly, and a permanent pacemaker is a therapeutic option when a bradycardic etiology is revealed. However, the benefit of pacing when no association of symptoms to bradycardia has been shown is not clear, especially in the elderly. OBJECTIVE: The aim of this study was to evaluate the effect of pacing on syncope-free mortality in patients aged 80 years or older with unexplained syncope and "positive" invasive electrophysiologic testing (EPT). METHODS: This was an observational study. A positive EPT for the purposes of this study was defined by at least 1 of the following: a corrected sinus node recovery time of >525 ms, a basic HV interval of >55 ms, detection of infra-Hisian block, or appearance of second-degree atrioventricular block on atrial decremental pacing at a paced cycle length of >400 ms. RESULTS: Among the 2435 screened patients, 228 eligible patients were identified, 145 of whom were implanted with a pacemaker. Kaplan-Meier analysis determined that time to event (syncope or death) was 50.1 months (95% confidence interval 45.4-54.8 months) with a pacemaker vs 37.8 months (95% confidence interval 31.3-44.4 months) without a pacemaker (log-rank test, P = .001). The 4-year time-dependent estimate of the rate of syncope was 12% vs 44% (P < .001) and that of any-cause death was 41% vs 56% (P = .023), respectively. The multivariable odds ratio was 0.25 (95% confidence interval 0.15-0.40) after adjustment for potential confounders. CONCLUSION: In patients with unexplained syncope and signs of sinus node dysfunction or impaired atrioventricular conduction on invasive EPT, pacemaker implantation was independently associated with longer syncope-free survival. Significant differences were also shown in the individual components of the primary outcome measure (syncope and death from any cause).

Elevated skin and core temperatures both contribute to reductions in tolerance to a simulated haemorrhagic challenge.

NEW FINDINGS: What is the central question of this study? Combined increases in skin and core temperatures reduce tolerance to a simulated haemorrhagic challenge. The aim of this study was to examine the separate and combined influences of increased skin and core temperatures upon tolerance to a simulated haemorrhagic challenge. What is the main finding and its importance? Skin and core temperatures increase during many occupational settings, including military procedures, in hot environments. The study findings demonstrate that both increased skin temperature and increased core temperature can impair tolerance to a simulated haemorrhagic challenge; therefore, a soldier's tolerance to haemorrhagic injury is likely to be impaired during any military activity that results in increased skin and/or core temperatures. Tolerance to a simulated haemorrhagic insult, such as lower-body negative pressure (LBNP), is profoundly reduced when accompanied by whole-body heat stress. The aim of this study was to investigate the separate and combined influence of elevated skin (Tskin ) and core temperatures (Tcore ) on LBNP tolerance. We hypothesized that elevations in Tskin as well as Tcore would both contribute to reductions in LBNP tolerance and that the reduction in LBNP tolerance would be greatest when both Tskin and Tcore were elevated. Nine participants underwent progressive LBNP to presyncope on four occasions, as follows: (i) control, with neutral Tskin (34.3 ± 0.5°C) and Tcore (36.8 ± 0.2°C); (ii) primarily skin hyperthermia, with high Tskin (37.6 ± 0.2°C) and neutral Tcore (37.1 ± 0.2°C); (iii) primarily core hyperthermia, with neutral Tskin (35.0 ± 0.5°C) and high Tcore (38.3 ± 0.2°C); and (iv) combined skin and core hyperthermia, with high Tskin (38.8 ± 0.6°C) and high Tcore (38.1 ± 0.2°C). The LBNP tolerance was quantified via the cumulative stress index (in millimetres of mercury × minutes). The LBNP tolerance was reduced during the skin hyperthermia (569 ± 151 mmHg min) and core hyperthermia trials (563 ± 194 mmHg min) relative to control conditions (1010 ± 246 mmHg min; both P < 0.05). However, LBNP tolerance did not differ between skin hyperthermia and core hyperthermia trials (P = 0.92). The lowest LBNP tolerance was observed during combined skin and core hyperthermia (257 ± 106 mmHg min; P < 0.05 relative to all other trials). These data indicate that elevated skin temperature, as well as elevated core temperature, can both contribute to reductions in LBNP tolerance in heat-stressed individuals. However, heat stress-induced reductions in LBNP tolerance are greatest in conditions when both skin and core temperatures are elevated.

Syncopation affects free body-movement in musical groove.

One of the most immediate and overt ways in which people respond to music is by moving their bodies to the beat. However, the extent to which the rhythmic complexity of groove-specifically its syncopation-contributes to how people spontaneously move to music is largely unexplored. Here, we measured free movements in hand and torso while participants listened to drum-breaks with various degrees of syncopation. We found that drum-breaks with medium degrees of syncopation were associated with the same amount of acceleration and synchronisation as low degrees of syncopation. Participants who enjoyed dancing made more complex movements than those who did not enjoy dancing. While for all participants hand movements accelerated more and were more complex, torso movements were more synchronised to the beat. Overall, movements were mostly synchronised to the main beat and half-beat level, depending on the body-part. We demonstrate that while people do not move or synchronise much to rhythms with high syncopation when dancing spontaneously to music, the relationship between rhythmic complexity and synchronisation is less linear than in simple finger-tapping studies.

"Cardio-Neuromodulation" With a Multielectrode Irrigated Catheter: A Potential New Approach for Patients With Cardio-Inhibitory Syncope.

Syncope is frequently neurally mediated and can seriously affect quality of life. Different ablation strategies have been successfully performed. These approaches have not gained wide acceptance and are quite extensive and complex, exposing patients to significant risks. This article reports the case of a 16-year-old girl who was severely affected by frequent and prolonged episodes of syncope and was treated by tailored ablation of the anterior right ganglionated plexus with a multielectrode irrigated catheter. She had fainted >30 times in the 5 years preceding treatment, experiencing approximately 10 severe episodes of syncope in the previous 12 months. After 3 minutes of ablation, the P-P interval was reduced by >400 milliseconds. Syncope disappeared and the patient has remained completely asymptomatic over a follow-up of 22 months. The "reset" basal P-P interval has remained unchanged (follow-up electrocardiogram at 16 months). At 6 months, there was no residual heart rate activity <50 bpm. On 24-hour rhythm registration, P-P intervals ≥1,000 milliseconds (corresponding to a heart rate of ≤60 bpm) were reduced by >16,000 beats. We believe that this case report is original for several reasons: the unusual clinical presentation; the unique structure targeted; the very limited ablation, implying much lower risks for the patient; the anatomical approach; and the different endpoint. This new "cardio-neuromodulation" approach could be useful for the treatment of patients with neurally mediated syncope.

Insight into specific pro-arrhythmic triggers in Brugada and early repolarization syndromes: results of long-term follow-up.

The pro-arrhythmic triggers in Brugada and early repolarization syndromes (BrS, ERS) have not been analyzed systematically except for case reports. We clinically investigated the circumstances which precede/predispose to arrhythmic events in these syndromes during long-term follow-up. A detailed history from the patients/witnesses was taken to investigate the antecedent events in the last few hours that preceded syncope/ventricular fibrillation (VF); medical records, ECG and blood test from the emergency room (ER) were reviewed. 19 patients that fulfilled the investigation criteria were followed up for 71 ± 49 months (34-190 months). Prior to the event (syncope/VF), the patients were partaking different activities in the following decreasing order; drinking alcoholic beverage, having meal, and getting up from sleep, exercise. 3 patients reported mental/physical stress prior to the event and 2 patients developed VF several days after starting oral steroid for treatment of bronchial asthma. In the ER, elevated J-wave amplitude (0.27 ± 0.15 mV) was found with 58 % of the patients having hypokalemia. After electrolyte correction and cessation of steroids, the following day plasma K+ (4.2 ± 0.3 mEq/L, P < 0.001) was significantly increased and J-wave amplitude (0.13 ± 0.1 mV, P < 0.001) was remarkably reduced. Three patients were kept on oral spironolactone/potassium supplements. During follow-up for 71 ± 49 (34-190) months, among 4 patients with VF recurrence, one patient developed VF after taking oral steroid. In ERS and BrS, hypokalemia and corticosteroid therapy add substantial pro-arrhythmic effects, but potentially treatable. Stopping steroid therapy and avoiding hypokalemia had excellent long-term outcome.

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

OBJECTIVE: to evaluate the safety and tolerability of Tilt Testing (TT) and Carotid Sinus Massage (CSM) in octogenarians with unexplained syncope. METHODS: patients consecutively referred for transient loss of consciousness to the 'Syncope Units' of three hospitals were enrolled. TT and CSM were performed according to the European Society of Cardiology guidelines on syncope. Complications were evaluated in each group. An early interruption of TT was defined as 'intolerance' and considered as a non-diagnostic response. RESULTS: one thousand four hundred and one patients were enrolled (mean age 72 ± 16 years, male 40.8%). Six hundred and ninety-four patients (49.5%) were 80 years old or older (mean age 83 ± 3 years) and 707 (50.5%) were younger (mean age 60 ± 17 years). Complications after TT occurred in 4.5% of older patients and in 2.1% of the younger ones (P = 0.01). All complications were 'minor/moderate', as prolonged hypotension, observed in ∼3% of patients ≥80 years. Major complications such as sustained ventricular tachycardia, ventricular fibrillation, asystole requiring cardiac massage, transient ischaemic attack, stroke and death were not observed in any patient. The presence of orthostatic hypotension and the mean number of syncopal episodes were predictors of TT complications. Intolerance was reported in 2.4% of older patients and 1% of the younger ones (P = 0.08), mainly due to orthostatic intolerance. No complications occurred after CSM. CONCLUSIONS: TT and CSM appear to be safe and well tolerated in octogenarians, who should not be excluded by age from the diagnostic work-up of syncope.

Electrophysiological study generally is negative in patients <40 years suspected of supraventricular tachycardia but also complaining of chest pain and/or syncope.

BACKGROUND: The diagnosis of paroxysmal supraventricular tachycardia (SVT) frequently is a dilemma. Electrophysiological study (EPS) is the only means to evaluate the nature of symptoms when noninvasive studies remain negative. Our objectives were to determine the clinical factors of negativity or positivity of (EPS) in patients suspected of SVT. METHODS: EPS was performed in 2650 patients complaining of tachycardia and suspected of SVT. Transesophageal EPS consisted of programmed atrial stimulation in control state and after isoproterenol. Patients were followed from 1 month to 18 years (2.93 ± 4 years). RESULTS: SVT was induced in 1944 patients, age 48 ± 19.5. EPS remained negative in 706 patients, age 34 ± 17 (p<0.0001). Age <40 years, feeling of dizziness/syncope or chest pain associated with tachycardia, the absence of heart disease or short PR interval was more frequent in patients with negative EPS (respectively 64, 42, 26, 96, 88.5%) than in patients with induced SVT (34, 14, 4, 88, 59%) (p<0.0001).The positive predictive value for the prediction of a negative EPS of age <40, chest pain, syncope or their association was 63.5, 42, 26.5, 11% and negative predictive value was 66, 86, 94.5, 99.5%. At multivariate analysis, age <40 (0.000, OR 2.79), the presence of syncope associated with tachycardia (0.000, OR 5.075) or chest pain (0.000, OR 17.923) was an independent factor of negative EPS. CONCLUSIONS: Among patients complaining of nondocumented tachycardia, suspected of SVT, the association of tachycardia with chest pain and/or syncope and age <40 years generally was correlated with a negative EPS and did not indicate initially invasive studies. In the remaining patients transesophageal EPS is indicated.

An 88-year-old man with syncope and an alternating axis.

CLINICAL INTRODUCTION: An 88-year-old man, admitted to the emergency room (ER) after three episodes of syncope within 1 day, reported a precursory of syndrome of light-headedness with rapid palpitations that led to an abrupt loss of consciousness. After undergoing percutaneous and surgical revascularisation, he started complaining of chest and back discomfort for the past 20 years and searching for help from Chinese medicine, Fuzi. He had history of chronic renal failure and heart failure, but denied neither taking digitalis nor having family history related to sudden death.On arrival, heart rate was 150 bpm and blood pressure (BP) by cuff was 91/81 mm Hg (non-invasive BP could not be accurately obtained during tachycardia) plus oedema on both lower extremities. There were diffuse crackles and indistinct heart sounds on auscultation.The admission ECG was performed in the ER (figure 1). His serum creatinine was 139.7 mmol/L, serum K(+) was 4.7 mmol/L, N-terminal of the prohormone brain natriuretic peptide was highly elevated (12 000 pg/mL) and troponin I was negative. QUESTION: What is the most likely diagnosis suggested based on the patient's ECG and history? Aconite poisoningDigitalis toxicityCatecholaminergic polymorphic ventricular tachycardia (CPVT)Andersen-Tawil syndrome (ATS).

Síncope por risa: descripción de un caso y revisión de la literatura / Laughter-induced syncope: description of a case and review of the literature

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Value of EP Study and Other Cardiac Investigations.

With the advent of implantable loop recorders capable of prolonged electrocardiographic monitoring, and following studies demonstrating the benefit of implantable cardioverter-defibrillator therapy in subgroups of patients with structural heart disease and depressed left ventricular function, the role of invasive cardiac electrophysiologic (EP) studies in patients with unexplained syncope has been substantially reduced. Nonetheless, in select high-risk patients presenting with unexplained syncope, EP studies still play an important role in identifying a diagnosis in these patients and assessing long-term risk of mortality.

[The role of cardiac pacing therapy in the management of carotid sinus syndrome].

INTRODUCTION: Carotid sinus syndrome is characterized by a hypersensitive carotid sinus and syncope. Although we have clear guidelines for the diagnosis and treatment of carotid sinus syndrome, the efficacy of pacing therapy with this indication has not been the subject of many studies. OBJECTIVE: This study aimed to assess the efficacy and safety of pacing therapy in the treatment of patients with carotid sinus syndrome and to determine the factors contributing to symp- toms recurrence after pacemaker implantation. METHODS: This study was retrospective and included 32 patients in whom a pacemaker was implanted due to carotid sinus syn- drome at the Pacemaker Center, Clinical Center of Serbia, be- tween April 2005 and April 2012. Carotid sinus massage and head-up tilt test (HUTT) were performed to select patients with cardioinhibitory and mixed type carotid sinus syndrome, who were enrolled to the study. RESULTS: The mean age of patients was 65.6 ± 11.5 years and 20 (62.5%) were men. The mean follow-up period was 4.3 ± 1.9 years. HUTT was performed in 3 (9.4%) patients. Twenty-seven (84.4%) patients presented with cardioinhibitory and 5 (15.6%) with mixed type of carotid sinus syndrome. After pacemaker implantation, 22 (68.7%) patients had no further symptoms, 8 (25.0%) had syncope and 2 (6.3%) presyncope.The mixed type of the disease (HR 3.1; 95% CI 1.4-5.1; p = 0.021) and implanta- tion of pacemaker in WI mode (HR 1.8; 95% CI 1.1-3.2; p = 0.034) were independent predictors of symptoms recurrence. There were 3 (9.4%) perioperative surgical complications. CONCLUSION: Pacemaker therapy is an effective and safe treat- ment for patients with carotid sinus syndrome. As predictors of symptoms persistence after pacemaker implantation in our population, we identified the implantation of pacemaker in WI mode and the mixed type of carotid sinus syndrome.

Differences in the yield of the implantable loop recorder between secondary and tertiary centers.

BACKGROUND: The implantable loop recorder (ILR) is a useful tool for diagnosis of syncope or palpitations. Its easy use and safety have extended its use to secondary hospitals (those without an Electrophysiology Lab). The aim of the study was to compare results between secondary and tertiary hospitals. METHODS: National prospective and multicenter registry of patients with an ILR inserted for clinical reasons. Data were collected in an online database. The follow-up ended when the first diagnostic clinical event occurred, or 1 year after implantation. Data were analyzed according to the center of reference; hospitals with Electrophysiology Lab were considered Tertiary Hospitals, while those hospitals without a lab were considered Secondary Hospitals. RESULTS: Seven hundred and forty-three patients (413 [55.6%] men; 65 ± 16 year-old): 655 (88.2%) from Tertiary Centers (TC) and 88 (11.8%) from Secondary Centers (SC). No differences in clinical characteristics between both groups were found. The electrophysiologic study and the tilt table test were conducted more frequently in Tertiary Centers. Follow-up was conducted for 680 (91.5%) patients: 91% in TC and 94% in SC. There was a higher rate of final diagnosis among SC patients (55.4% vs. 30.8%; p < 0.001). Tertiary Hospital patients showed a trend towards a higher rate of neurally mediated events (20% vs. 4%), while bradyarrhythmias were more frequent in SC (74% vs. 60%; p = 0.055). The rate of deaths and adverse events was similar in both populations. CONCLUSIONS: Patients with an ILR in SC and TC have differences in terms of the use of complementary tests, but not in clinical characteristics. There was a higher rate of diagnosis in Secondary Hospital patients.