Riesgo arrítmico en episodios únicos o recurrentes de síncope inexplicado con bloqueo completo de rama / Arrhythmic risk in single or recurrent episodes of unexplained syncope with complete bundle branch block

Introducción y objetivos: Los pacientes con un episodio sincopal inexplicable único (ESU) y bloqueo completo de rama del haz de His (BcR) con frecuencia se tratan de manera más conservadora que aquellos con episodios recurrentes (ESR). El objetivo fue analizar si existen diferencias entre pacientes con ESU o ESR y BcR en cuanto al riesgo arrítmico, el rendimiento diagnóstico de las pruebas y los resultados clínicos. Métodos: Estudio de cohorte de pacientes consecutivos con seguimiento medio de 3 años. Fueron estudiados mediante un protocolo escalonado basado en un estudio electrofisiológico y seguimiento con un monitor cardiaco implantable (MCI). Resultados: De los 503 pacientes incluidos en el estudio, 238 (47,3%) referían un ESU. El riesgo de síncope arrítmico fue similar en ambos grupos (58,8% ESU frente a 57,0% ESR; p=0,68), también tras ajustar por variables de confusión (HR=1,06; IC95%, 0,81-1,38; p=0,674). No se encontraron diferencias significativas en cuanto a los resultados del estudio electrofisiológico y la rentabilidad diagnóstica del monitor cardiaco implantable. Un total de 141 (59,2%) pacientes con ESU y 154 (58,1%) con ESR requirieron el implante de un dispositivo cardiaco (p=0,797). Tras el tratamiento adecuado, 35 (7%) pacientes presentaron recurrencia del síncope. La tasa de recurrencia y la mortalidad también fueron similares. Conclusiones: Los pacientes con BcR y síncope tienen un alto riesgo de tener una etiología arrítmica, aunque solo hayan presentado un episodio aislado. Los pacientes con ESU y ESR tienen un riesgo arrítmico similar y presentan un pronóstico similar, por lo que no existe una justificación clínica para no tratarlos de la misma manera.(AU)

Introduction and objectives: Patients with a single syncopal episode (SSE) and complete bundle branch block (cBBB) are frequently managed more conservatively than patients with recurrent episodes (RSE). The objective of this study was to analyze if there are differences between patients with single or recurrent unexplained syncope and cBBB in arrhythmic risk, the diagnostic yield of tests, and clinical outcomes. Methods: Cohort study of consecutive patients with unexplained syncope and cBBB with a median follow-up time of 3 years. The patients were evaluated via a stepwise workup protocol based on electrophysiological study (EPS) and long-term follow-up with an implantable cardiac monitor. Results: Of the 503 patients included in the study, 238 (47.3%) had had only 1 syncopal episode. The risk of an arrhythmic syncope was similar in both groups (58.8% in SSE vs 57.0% in RSE; P=.68), also after adjustment for possible confounding variables (HR, 1.06; 95%CI, 0.81-1.38; P=.674). No significant differences between the groups were found in the EPS results and implantable cardiac monitor diagnostic yield. A total of 141 (59.2%) patients with SSE and 154 (58.1%) patients with RSE required cardiac device implantation (P=.797). After appropriate treatment, 35 (7%) patients had recurrence of syncope. The recurrence rate and mortality were also similar in both groups. Conclusions: Patients with cBBB and unexplained syncope are at high risk of an arrhythmic etiology, even after the first syncopal episode. Patients with SSE and RSE have a similar arrhythmic risk and similar outcomes, and therefore there is no clinical justification for not managing them in the same manner.(AU)

Arrhythmic syncope: From diagnosis to management.

Syncope is a concerning symptom that affects a large proportion of patients. It can be related to a heterogeneous group of pathologies ranging from trivial causes to diseases with a high risk of sudden death. However, benign causes are the most frequent, and identifying high-risk patients with potentially severe etiologies is crucial to establish an accurate diagnosis, initiate effective therapy, and alter the prognosis. The term cardiac syncope refers to those episodes where the cause of the cerebral hypoperfusion is directly related to a cardiac disorder, while arrhythmic syncope is cardiac syncope specifically due to rhythm disorders. Indeed, arrhythmias are the most common cause of cardiac syncope. Both bradyarrhythmia and tachyarrhythmia can cause a sudden decrease in cardiac output and produce syncope. In this review, we summarized the main guidelines in the management of patients with syncope of presumed arrhythmic origin. Therefore, we presented a thorough approach to syncope work-up through different tests depending on the clinical characteristics of the patients, risk stratification, and the management of syncope in different scenarios such as structural heart disease and channelopathies.

A hybrid clinical and electrocardiographic score to predict the origin of outflow tract ventricular arrhythmias.

BACKGROUND: To predict the outflow tract ventricular arrhythmias (OTVA) site of origin (SOO) before the ablation procedure has important practical implications. The present study sought to prospectively evaluate the accuracy of a clinical and electrocardiographic hybrid algorithm (HA) for the prediction of OTVAs-SOO, and at the same time to develop and to prospectively validate a new score with improved discriminatory capacity. METHODS: In this multicenter study, we prospectively enrolled consecutive patients referred for OTVA ablation (N = 202), and we divided them in a derivation sample and a validation cohort. Surface ECGs during OTVA were analyzed to compare previous published ECG-only criteria and to develop a new score. RESULTS: In the derivation sample (N = 105), the correct prediction rate of HA and ECG-only criteria ranged from 74 to 89%. R-wave amplitude in V3 was the best ECG parameter for discriminating LVOT origin in V3 precordial transition (V3PT) patients, and was incorporated to the novel weighted hybrid score (WHS). WHS correctly classified 99 (94.2%) patients, presenting 90% sensitivity and 96% specificity (AUC 0.97) in the entire population; WHS mantained a 87% sensitivity and 91% specificity (AUC 0.95) in patients with V3PT subgroup. The high discriminatory capacity was confirmed in the validation sample (N = 97): the WHS exhibited an AUC (0.93), and a WHS ≥ 2 allowed a correct prediction of LVOT origin in 87 (90.0%) cases, yielding a sensitivity of 87% and specificity of 90%; moreover, the V3PT subgroup showed an AUC of 0.92, and a punctuation ≥ 2 predicted an LVOT origin with a sensitivity of 94% and specificity of 78%. CONCLUSIONS: The novel hybrid score has proved to accurately anticipate the OTVA's origin, even in those with a V3 precordial transition. A Weighted hybrid score. B Typical examples of the use of the weighted hybrid score. C ROC analysis of WHS and previous ECG criteria for prediction of LVOT origin in the derivation cohort. D ROC analysis of WHS and previous ECG criteria for prediction of LVOT origin in the V3 precordial transition OTVA subgroup.

Arrhythmic risk in single or recurrent episodes of unexplained syncope with complete bundle branch block.

INTRODUCTION AND OBJECTIVES: Patients with a single syncopal episode (SSE) and complete bundle branch block (cBBB) are frequently managed more conservatively than patients with recurrent episodes (RSE). The objective of this study was to analyze if there are differences between patients with single or recurrent unexplained syncope and cBBB in arrhythmic risk, the diagnostic yield of tests, and clinical outcomes. METHODS: Cohort study of consecutive patients with unexplained syncope and cBBB with a median follow-up time of 3 years. The patients were evaluated via a stepwise workup protocol based on electrophysiological study (EPS) and long-term follow-up with an implantable cardiac monitor. RESULTS: Of the 503 patients included in the study, 238 (47.3%) had had only 1 syncopal episode. The risk of an arrhythmic syncope was similar in both groups (58.8% in SSE vs 57.0% in RSE; P=.68), also after adjustment for possible confounding variables (HR, 1.06; 95%CI, 0.81-1.38; P=.674). No significant differences between the groups were found in the EPS results and implantable cardiac monitor diagnostic yield. A total of 141 (59.2%) patients with SSE and 154 (58.1%) patients with RSE required cardiac device implantation (P=.797). After appropriate treatment, 35 (7%) patients had recurrence of syncope. The recurrence rate and mortality were also similar in both groups. CONCLUSIONS: Patients with cBBB and unexplained syncope are at high risk of an arrhythmic etiology, even after the first syncopal episode. Patients with SSE and RSE have a similar arrhythmic risk and similar outcomes, and therefore there is no clinical justification for not managing them in the same manner.

Sex-Related Differences in Patients With Unexplained Syncope and Bundle Branch Block: Lower Risk of AV Block and Lesser Need for Cardiac Pacing in Women.

Objective: To analyze if there are sex-related differences in patients with unexplained syncope and bundle branch block (BBB). Background: Despite increasing awareness that sex is a major determinant of the incidence, etiology, and the outcomes of different arrhythmias, no studies have examined differences in presentation and outcomes between men and women with syncope and BBB. Methods: Cohort study of consecutive patients with unexplained syncope and BBB was included from January 2010 to January 2021 with a median follow-up time of 3.4 years [interquartile range (IQR) 1.7-6.0 years]. They were evaluated by a stepwise workup protocol based on electrophysiological study (EPS) and long-term follow-up with an implantable cardiac monitor (ICM). Results: Of the 443 patients included in the study, 165 (37.2%) were women. Compared with men, women had less diabetes (25.5 vs. 39.9%, p = 0.002) and less history of ischemic heart disease (IHD; 13.3 vs. 25.9%, p = 0.002). Left bundle branch block (LBBB) was more frequent in women (55.2 vs. 27.7%, p < 0.001) while right bundle branch block (RBBB) was more frequent in men (41.5 vs. 67.7%, p < 0.001). His to ventricle (HV) interval in the EPS was shorter in women (58 ms [IQR 52-71] vs. 60 ms [IQR 52-73], p = 0.035) and less women had an HV interval longer than 70 ms (28.5 vs. 38.1%, p = 0.039), however, EPS and ICM offered a similar diagnostic yield in both sexes (40.6 vs. 48.9% and 48.4% vs. 51.1%, respectively). Women had a lower risk of developing atrioventricular block (AVB) (adjusted odds ratio [OR] 0.44-95% CI 0.26-0.74, p = 0.002) and of requiring permanent pacemaker implantation (adjusted hazard ratio [HR] 0.72-95% CI: 0.52-0.99, p = 0.046). The mortality rate was lower in women (4.5 per 100 person-years [95% CI 3.1-6.4 per 100 person-years] vs. 7.3 per 100 person-years [95% CI 5.9-9.1 per 100 person-years]). Conclusions: Compared to men, women with unexplained syncope and BBB have a lower risk of AVB and of requiring cardiac pacing. A stepwise diagnostic approach has a similar diagnostic yield in both sexes, and it seems appropriate to guide the treatment and avoid unnecessary pacemaker implantation, especially in women.

Remote heart failure management using the HeartLogic algorithm. RE-HEART registry.

INTRODUCTION AND OBJECTIVES: HeartLogic is a multiparametric algorithm incorporated into implantable cardioverter-defibrillators (ICD). The associated alerts predict impending heart failure (HF) decompensations. Our objective was to analyze the association between alerts and clinical events and to describe the implementation of a protocol for remote management in a multicenter registry. METHODS: We evaluated study phase 1 (the investigators were blinded to the alert state) and phases 2 and 3 (after HeartLogic activation, managed as per local practice and with a standardized protocol, respectively). RESULTS: We included 288 patients from 15 centers. In phase 1, the median observation period was 10 months and there were 73 alerts (0.72 alerts/patient-y), with 8 hospitalizations and 2 emergency room admissions for HF (0.10 events/patient-y). There were no HF hospitalizations outside the alert period. In the active phases, the median follow-up was 16 (95%CI, 15-22) months and there were 277 alerts (0.89 alerts/patient-y); 33 were associated with HF hospitalizations or HF death (n=6), 46 with minor decompensations, and 78 with other events. The unexplained alert rate was 0.39 alerts/patient-y. Outside the alert state, there was only 1 HF hospitalization and 1 minor HF decompensation. Most alerts (82% in phase 2 and 81% in phase 3; P=.861) were remotely managed. The median NT-proBNP value was higher within than outside the alert state (7378 vs 1210 pg/mL; P <.001). CONCLUSIONS: The HeartLogic index was frequently associated with HF-related events and other clinically relevant situations, with a low rate of unexplained events. A standardized protocol allowed alerts to be safely and remotely detected and appropriate action to be taken on them.

Cardiac monitoring for patients with palpitations.

Palpitations are one of the most common reasons for medical consultation. They tend to worry patients and can affect their quality of life. They are often a symptom associated with cardiac rhythm disorders, although there are other etiologies. For diagnosis, it is essential to be able to reliably correlate the symptoms with an electrocardiographic record allowing the identification or ruling out of a possible rhythm disorder. However, reaching a diagnosis is not always simple, given that they tend to be transitory symptoms and the patient is frequently asymptomatic at the time of assessment. In recent years, electrocardiographic monitoring systems have incorporated many technical improvements that solve several of the 24-h Holter monitor limitations. The objective of this review is to provide an update on the different monitoring methods currently available, remarking their indications and limitations, to help healthcare professionals to appropriately select and use them in the work-up of patients with palpitations.

Right ventricular resynchronization in a patient with repaired tetralogy of Fallot and severe ventricular dysfunction.

Right ventricular (RV) resynchronization therapy (CRT) with stimulation electrode implantation in the latest activation area guided by a high-density electroanatomic activation map was successfully performed in a patient with repaired tetralogy of Fallot (rToF), severe pulmonary regurgitation (PR), and severe dysfunction and dilatation of the right ventricle. An improvement in his clinical condition and intraventricular synchrony was achieved. There is a mechanical-electrical interaction in the right ventricle of patients with rToF; therefore, RV CRT in selected cases may be beneficial. Electroanatomic activation mapping can help achieve maximum clinical benefit by identifying the optimal stimulation site.

Substrate characterization of the right ventricle in repaired tetralogy of Fallot using late enhancement cardiac magnetic resonance.

BACKGROUND: Three-dimensional (3D) substrate characterization by high-resolution late gadolinium enhancement cardiac magnetic resonance (LE-CMR) is useful for guiding ventricular tachycardia ablation of the left ventricle in ischemic heart disease. OBJECTIVE: The purpose of this study was to validate the substrate characterization and 3D reconstruction of LE-CMR images of the right ventricle (RV) in patients with repaired tetralogy of Fallot (rTOF) and to identify the algorithm that best fits with electroanatomic mapping (EAM). METHODS: RV LE-CMR images were compared with RV EAM in 10 patients with rTOF. RV LE-CMR images were postprocessed and analyzed to identify fibrotic tissue on 3D color maps. The 3D RV substrate reconstructions were created using an adjustable percentage of the maximum voxel signal intensity (MSI) of the scar region to define the threshold between core, transitional zone (TZ), and healthy tissue. Extensions of the core and TZ areas were compared with the scar (<0.5 mV) and low-voltage (0.5-1.5 mV) areas obtained by RV EAM. Agreement on anatomic isthmi identification was quantified. RESULTS: The best match between core and scar was obtained at 65% MSI cutoff (mean areas 17.4 ± 9.9 cm2 vs 16.9 ± 10.0 cm2, respectively; r = 0.954; P <.001). Agreement on anatomic isthmi identification was best at 60% MSI cutoff, which identified 95% of isthmi and achieved a total fit in 90% of patients. CONCLUSION: This study demonstrates that characterization of the RV substrate by postprocessing LE-CMR images in rTOF patients is feasible and validates the technique against RV EAM, which could help in planning target ablation.

Cardiac biometric variables and arrhythmic events during COVID-19 pandemic lockdown in patients with an implantable cardiac monitor for syncope work-up

Aim: To assess the changes induced by the COVID-19 lockdown on cardiac biometric variables recorded using an implantable cardiac monitor (ICM) in a patient population monitored for syncope work-up, as well to assess whether there has been an effect on arrhythmic events among the patients.MethodsLongitudinal cohort study. We included 245 adult patients monitored with an ICM indicated for the investigation of syncope. The records from days 1 to 12 March 2020 (prior to the institution of lockdown by the state government) with days 16 to 28 March 2020 were compared.ResultsDaily physical exercise reduced markedly after the imposition of lockdown (132 [55–233] minutes vs. 78 [21–154] minutes). The mean daytime HR prior to lockdown was 77 [69–85] bpm, whereas during lockdown it was 74 [66–81] bpm. During the lockdown period, a drop in the variability in heart rate (114 [94–136] ms vs. 111 [92–133] ms) was observed. Although the incidence of AF was similar over both periods, the daily AF burden was significantly higher post-lockdown (405 [391–425] minutes vs. 423 [423–537] minutes). No differences in the number of other arrhythmias were found.ConclusionsThe establishment of mandatory lockdown has led to a marked drop in daily physical activity in this population which probably explains changes observed in other cardiac biometric variables. Although, in the short term, we have not documented an increased risk of arrhythmia, we cannot rule out an effect in the medium to long term or in other populations of at-risk patients. (AU)

Objetivo: Evaluar los cambios inducidos por el confinamiento durante la pandemia de COVID-19 en las variables biométricas cardiacas registradas, utilizando un monitor cardíaco implantable (ICM) en una población de pacientes monitorizada para el diagnóstico de síncope, así como evaluar si ha habido un efecto sobre los eventos arrítmicos.MétodosEstudio de cohorte prospectivo. Se incluyeron 245 pacientes adultos monitorizados con un ICM indicado para la investigación del síncope. Se compararon los registros de los días uno al 12 de marzo del 2020 (antes del establecimiento del confinamiento por parte del gobierno estatal) con los días 16 al 28 de marzo del 2020.ResultadosEl ejercicio físico diario se redujo notablemente después de la imposición del confinamiento (132 [55 a 233] vs. 78 [21 a 154] min). La frecuencia cardiaca diurna media antes del confinamiento fue de 77 (69 a 85) lpm, mientras que durante el mismo fue de 74 (66 a 81) lpm. Durante el período de confinamiento, se observó una disminución de la variabilidad de la frecuencia cardiaca (114 [94 a 136] vs. 111 [92 a 133] ms). Aunque la incidencia de fibrilación auricular (FA) fue similar en ambos períodos, la carga diaria de FA fue significativamente mayor después del bloqueo (405 [391 a 425] vs. 423 [423 a 537] min). No se encontraron diferencias en el número de otras arritmias.ConclusionesEl establecimiento de un confinamiento obligatorio ha provocado un marcado descenso de la actividad física diaria en esta población, lo que probablemente explica los cambios observados en otras variables biométricas cardiacas. Si bien, a corto plazo, no se ha documentado un aumento del riesgo de arritmia, no podemos descartar un efecto a medio-largo plazo o en otras poblaciones de pacientes de riesgo. (AU)

[Cardiac biometric variables and arrhythmic events during COVID-19 pandemic lockdown in patients with an implantable cardiac monitor for syncope work-up]. / Variables biométricas cardiacas y eventos arrítmicos durante el confinamiento por la pandemia de COVID-19 en pacientes portadores de un monitor cardiaco implantable para el diagnóstico de síncope.

AIM: To assess the changes induced by the COVID-19 lockdown on cardiac biometric variables recorded using an implantable cardiac monitor (ICM) in a patient population monitored for syncope work-up, as well to assess whether there has been an effect on arrhythmic events among the patients. METHODS: Longitudinal cohort study. We included 245 adult patients monitored with an ICM indicated for the investigation of syncope. The records from days 1 to 12 March 2020 (prior to the institution of lockdown by the state government) with days 16 to 28 March 2020 were compared. RESULTS: Daily physical exercise reduced markedly after the imposition of lockdown (132 [55-233] minutes vs. 78 [21-154] minutes). The mean daytime HR prior to lockdown was 77 [69-85] bpm, whereas during lockdown it was 74 [66-81] bpm. During the lockdown period, a drop in the variability in heart rate (114 [94-136] ms vs. 111 [92-133] ms) was observed. Although the incidence of AF was similar over both periods, the daily AF burden was significantly higher post-lockdown (405 [391-425] minutes vs. 423 [423-537] minutes). No differences in the number of other arrhythmias were found. CONCLUSIONS: The establishment of mandatory lockdown has led to a marked drop in daily physical activity in this population which probably explains changes observed in other cardiac biometric variables. Although, in the short term, we have not documented an increased risk of arrhythmia, we cannot rule out an effect in the medium to long term or in other populations of at-risk patients.

Reduction in new cardiac electronic device implantations in Catalonia during COVID-19.

AIMS: During the COVID-19 pandemic, concern regarding its effect on the management of non-communicable diseases has been raised. However, there are no data on the impact on cardiac implantable electronic devices (CIED) implantation rates. We aimed to determine the impact of SARS-CoV2 on the monthly incidence rates and type of pacemaker (PM) and implantable cardiac defibrillator (ICD) implantations in Catalonia before and after the declaration of the state of alarm in Spain on 14 March 2020. METHODS AND RESULTS: Data on new CIED implantations for 2017-20 were prospectively collected by nine hospitals in Catalonia. A mixed model with random intercepts corrected for time was used to estimate the change in monthly CIED implantations. Compared to the pre-COVID-19 period, an absolute decrease of 56.5% was observed (54.7% in PM and 63.7% in ICD) in CIED implantation rates. Total CIED implantations for 2017-19 and January and February 2020 was 250/month (>195 PM and >55 ICD), decreasing to 207 (161 PM and 46 ICD) in March and 131 (108 PM and 23 ICD) in April 2020. In April 2020, there was a significant fall of 185.25 CIED implantations compared to 2018 [95% confidence interval (CI) 129.6-240.9; P < 0.001] and of 188 CIED compared to 2019 (95% CI 132.3-243.7; P < 0.001). No significant differences in the type of PM or ICD were observed, nor in the indication for primary or secondary prevention. CONCLUSIONS: During the first wave of the COVID-19 pandemic, a substantial decrease in CIED implantations was observed in Catalonia. Our findings call for measures to avoid long-term social impact.

Risk stratification of ventricular arrhythmias in repaired tetralogy of Fallot.

INTRODUCTION AND OBJECTIVES: Risk stratification of ventricular arrhythmias in patients with repaired tetralogy of Fallot (rTOF) remains unresolved. We aimed to identify right ventricular (RV) electrophysiological parameters potentially associated with a higher risk of ventricular arrhythmias in patients with rTOF. METHODS: We included all consecutive patients with rTOF who underwent RV electroanatomical mapping at a single tertiary center. We used logistic regression modeling to identify those variables associated with an increased risk of clinical or induced ventricular tachycardia (VT), or clinical VT exclusively. RESULTS: Twenty-one of the 56 patients included had clinical or induced VT. A high-frequency of premature ventricular contractions/nonsustained VT (OR, 11.34; 95%CI, 1.50-85.97; P=.019), an HV interval > 55 ms (OR, 21.20; 95%CI, 3.12-144.14; P=.002), and RV activation time (ms) (OR [per 10ms intervals], 1.34; 95%CI, 1.02-1.75; P=.035) proved to be associated with clinical or induced VT. The model including this information had good discrimination ability, with an area under the curve of 0.884 (95%CI, 0.79-0.97; P <.001). When considering only clinical VT as the outcome of interest, only an HV interval > 55ms (OR, 9.65; 95%CI, 1.41-66.14; P=.021) and high-frequency of premature ventricular contractions/nonsustained VT (OR, 13.14; 95%CI, 1.95-88.54; P=.008) were independently associated (area under the curve of 0.836 [95%CI, 0.663-1.000; P=.002]). CONCLUSIONS: High-frequency of premature ventricular contractions/nonsustained VT, an HV interval> 55ms and RV activation time are factors associated with an increased risk of ventricular arrhythmias in patients with rTOF.

Etiology and prognosis of patients with unexplained syncope and mid-range left ventricular dysfunction.

BACKGROUND: Syncope in patients with mid-range left ventricular ejection fraction (LVEF) can be due to potentially serious arrhythmic causes. However, there is no clear consensus on the best way to manage these patients. OBJECTIVES: The objectives of this study were to determine the causes of syncope and assess the diagnostic yield and safety of a stepwise workup protocol in this population. METHODS: This was a prospective observational study. A stepwise workup protocol was applied to patients with LVEF 35%-50% and unexplained syncope after the initial assessment (step 1). RESULTS: One hundred four patients were included {median age 75.6 years; (interquartile range [IQR] 67.6-81.2 years); median LVEF 45% (IQR 40%-48%); median follow-up 2.0 years (IQR 0.7-3.3 years). In 71 patients (68.3%), a diagnosis was reached: 55 (77.5%) in step 2 (hospital admission and electrophysiology study) and 16 (36.5%) in step 3 (implantable cardiac monitor). Arrhythmic causes were the most common etiology (45.2% auriculoventricular block and 9.6% ventricular tachycardia). Sixty patients (57.7%) required the implantation of a cardiac device and 11 had a defibrillation function. Patients diagnosed in step 3 had a higher global risk of recurrence of syncope (hazard ratio 6.5; 95% confidence interval 2.3-18.0). The mortality rate was 8.1 per 100 person-years, and the sudden or unknown death rate was 0.9 per 100 person-years. CONCLUSION: In patients with mid-range left ventricular dysfunction and syncope of unknown cause, a systematic diagnostic strategy based on electrophysiology study and/or implantable cardiac monitor implantation allows a diagnosis to be reached in a high proportion of cases and guides the treatment. Arrhythmia is the most common cause of syncope in this population, particularly auriculoventricular block.

Cardiac biometric variables and arrhythmic events during COVID-19 pandemic lockdown in patients with an implantable cardiac monitor for syncope work-up.

Aim: To assess the changes induced by the COVID-19 lockdown on cardiac biometric variables recorded using an implantable cardiac monitor (ICM) in a patient population monitored for syncope work-up, as well to assess whether there has been an effect on arrhythmic events among the patients. Methods: Longitudinal cohort study. We included 245 adult patients monitored with an ICM indicated for the investigation of syncope. The records from days 1 to 12 March 2020 (prior to the institution of lockdown by the state government) with days 16 to 28 March 2020 were compared. Results: Daily physical exercise reduced markedly after the imposition of lockdown (132 [55-233] minutes vs. 78 [21-154] minutes). The mean daytime HR prior to lockdown was 77 [69-85] bpm, whereas during lockdown it was 74 [66-81] bpm. During the lockdown period, a drop in the variability in heart rate (114 [94-136] ms vs. 111 [92-133] ms) was observed. Although the incidence of AF was similar over both periods, the daily AF burden was significantly higher post-lockdown (405 [391-425] minutes vs. 423 [423-537] minutes). No differences in the number of other arrhythmias were found. Conclusions: The establishment of mandatory lockdown has led to a marked drop in daily physical activity in this population which probably explains changes observed in other cardiac biometric variables. Although, in the short term, we have not documented an increased risk of arrhythmia, we cannot rule out an effect in the medium to long term or in other populations of at-risk patients.

Objetivo: Evaluar los cambios inducidos por el confinamiento durante la pandemia de COVID-19 en las variables biométricas cardiacas registradas, utilizando un monitor cardíaco implantable (ICM) en una población de pacientes monitorizada para el diagnóstico de síncope, así como evaluar si ha habido un efecto sobre los eventos arrítmicos. Métodos: Estudio de cohorte prospectivo. Se incluyeron 245 pacientes adultos monitorizados con un ICM indicado para la investigación del síncope. Se compararon los registros de los días uno al 12 de marzo del 2020 (antes del establecimiento del confinamiento por parte del gobierno estatal) con los días 16 al 28 de marzo del 2020. Resultados: El ejercicio físico diario se redujo notablemente después de la imposición del confinamiento (132 [55 a 233] vs. 78 [21 a 154] min). La frecuencia cardiaca diurna media antes del confinamiento fue de 77 (69 a 85) lpm, mientras que durante el mismo fue de 74 (66 a 81) lpm. Durante el período de confinamiento, se observó una disminución de la variabilidad de la frecuencia cardiaca (114 [94 a 136] vs. 111 [92 a 133] ms). Aunque la incidencia de fibrilación auricular (FA) fue similar en ambos períodos, la carga diaria de FA fue significativamente mayor después del bloqueo (405 [391 a 425] vs. 423 [423 a 537] min). No se encontraron diferencias en el número de otras arritmias. Conclusiones: El establecimiento de un confinamiento obligatorio ha provocado un marcado descenso de la actividad física diaria en esta población, lo que probablemente explica los cambios observados en otras variables biométricas cardiacas. Si bien, a corto plazo, no se ha documentado un aumento del riesgo de arritmia, no podemos descartar un efecto a medio-largo plazo o en otras poblaciones de pacientes de riesgo.

Syncope in Patients With Severe Aortic Stenosis: More Than Just an Obstruction Issue.

BACKGROUND: Severe aortic stenosis (AoS) is considered a primary cause of syncope. However, other mechanisms may be present in these patients and accurate diagnosis can have important clinical implications. The aim of this study is to assess the different etiologies of syncope in patients with severe AoS and the impact on prognosis of attaining a certain or highly probable diagnosis for the syncope. METHODS: Out of a cohort of 331 patients with AoS and syncope, 61 had severe AoS and were included in the study. Main cause of syncope and adverse cardiac events were assessed. RESULTS: In 40 patients (65.6%), we reached a certain or highly probable diagnosis of the main cause of the syncope. AoS was considered the primary cause of the syncope in only 7 patients (17.5% of the patients with known etiology). Atrioventricular block (14 patients, 35.0%) and vasovagal syncope (6 patients, 15.0%) were the most frequently diagnosed causes. The presence of a known cause for syncope during the admission was not associated with a lower incidence of recurrence during follow-up (hazard ratio [HR] 0.69, 95% confidence interval [CI] 0.20-2.40). Syncope of unknown etiology was independently associated with greater mortality during 1-year follow-up (HR 5.4, 95% CI 1.3-21.6) and 3-year follow-up (HR 3.5, 95% CI 1.2-10.3). CONCLUSIONS: In a high proportion of patients with severe AoS admitted for syncope, the valvulopathy was not the main cause of the syncope. Syncope in two-thirds of this population was caused by either bradyarrhythmia or reflex causes. Syncope of unknown cause was associated with increased short- and medium-term mortality, independently from treatment of the valve disease. An exhaustive work-up should be conducted to determine the main cause for syncope.

¿Hay un nuevo fármaco disponible para el control de la frecuencia cardiaca de pacientes con fibrilación auricular permanente? / Do we have a new drug for heart rate control in patients with permanent atrial fibrillation?

No disponible