Arrhythmic syncope: From diagnosis to management

Arrhythmia; Electrophysiological study; MyocardiopathyArítmia; Estudi electrofisiològic; MiocardiopatiaArritmia; Estudio electrofisiológico; MiocardiopatíaSyncope 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

Multimodality imaging fusion to guide stereotactic radioablation for refractory complex ventricular tachycardia

Hypertrophic cardiomyopathy; Multimodality imaging; Stereotactic radioablationMiocardiopatía hipertrófica; Imágenes multimodales; Radioablación estereotácticaMiocardiopatia hipertròfica; Imatges multimodals; Radioablació estereotàctic

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.

Life-threatening and life-saving inappropriate implantable cardioverter defibrillator shocks

An implantable cardioverter defibrillator (ICD) lead dislodgement into the right atrium is a dangerous situation, particularly in patients in atrial fibrillation because atrial fibrillation can be sensed as ventricular fibrillation and true ventricular fibrillation induced with an inappropriate shock. In the presence of shocks, ICD interrogation should be performed as soon as possible

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

Características electrofisiológicas y factores de riesgo de arritmias ventriculares en pacientes con tetralogía de Fallot corregida

ANTECEDENTES: Los pacientes con tetralogía de Fallot corregida (TFc) tienen mayor riesgo de taquicardia ventricular (TV) y muerte súbita, pero los factores de riesgo conocidos tienen un valor pronóstico limitado. Adicionalmente, poco se conoce sobre los parámetros electrofisiológicos y electro-anatómicos del ventrículo derecho (VD) en estos pacientes. MÉTODOS: Estudio ambispectivo, longitudinal y observacional de los pacientes con TFc sometidos a mapeo electro-anatómico de VD en el Hospital Universitario Vall d´Hebron entre marzo 2006 y diciembre 2016. RESULTADOS: Se incluyeron 43 pacientes (67% hombres, edad media 34,1 ± 10,0 años) que se dividieron en dos grupos según la ausencia (grupo A, n= 28) o presencia (grupo B, n= 15) de TV clínica o inducida. El grupo B presentó un intervalo HV superior (60,9 ± 15,1 vs 48,5 ± 7,9 ms; p = 0,001), un mayor porcentaje de pacientes con HV ≥ 55 ms (73% vs 19%; p = 0,001), un tiempo de activación de VD más prolongado (133,0 ± 34,8 vs 109,8 ± 27,8 ms; p = 0,017) y mayor prevalencia de dobles potenciales (DP) (93% vs 54%; p = 0,015). Los pacientes con extrasistolia ventricular compleja mostraron mayor extensión de tejido cicatricial (voltaje < 0,5 mV) de VD (área 30,7 ± 12,1 vs 20,1 ± 15,6 cm2; p = 0,054 y porcentaje 13,1 ± 6,0 vs 7,3 ± 5,6%; p = 0,035) y de tracto de salida de VD (TSVD) (área 22,3 ± 12,6 vs 15,6 ± 14,2 cm2; p = 0,033 y porcentaje 11,5 ± 5,1 vs 5,7 ± 4,9%; p = 0,010). El intervalo QRS mostró una correlación positiva con el área cicatricial total (r = 0,35; p = 0,027) y el tiempo de activación de VD (r = 0,67; p < 0,001). En el grupo con DP, el intervalo QRS (166,1 ± 25,4 vs 147,8 ± 24,3 ms; p = 0,004), el tiempo de activación (126,6 ± 34,6 vs 99,9 ± 19,4 ms; p = 0,003) y la extensión del tejido cicatricial (25,6 ± 16,4 vs 15,3 ± 12,2 cm2; p = 0,038) fueron superiores. Se documentó una asociación entre variables hemodinámicas de VD y ventrículo izquierdo (VI) y parámetros electrofisiológicos: a) Peor fracción de eyección (FE) de VD en el grupo con HV ≥ 55 ms (40,1 ± 9,4 vs 47,3 ± 7,4%; p = 0,025), b) Correlación entre la extensión cicatricial y el volumen telediastólico indexado (VTDi) de VD (área cicatricial total r = 0,48; p = 0,003 y área cicatricial de TSVD r = 0,54; p = 0,001), el diámetro telediastólico (DTD) de VD (área cicatricial de TSVD r = 0,38; p = 0,017), la función sistólica de VD (área cicatricial total y Doppler tisular (DTI) tricuspídeo r = – 0,40; p = 0,019; área cicatricial total y FEVD r = – 0,58; p < 0,001 y área cicatricial de TSVD y FEVD = – 0,58; p < 0,001) y la FEVI (área cicatricial total r = – 0,56; p = 0,001 y área cicatricial de TSVD r = – 0,54; p = 0,001) y c) Correlación entre el tiempo de activación y la dilatación de VD (DTD r = 0,36; p = 0,024 y VTDi r = 0,45; p = 0,005) y la disfunción sistólica de VD (excursión sistólica anillo tricuspídeo r = – 0,47; p = 0,002, DTI tricuspídeo r = – 0,43; p = 0,011 y FEVD r = – 0,45; p = 0,005). Se han identificado 5 patrones de activación del VD. Los pacientes con QRS < 120 ms mostraron un inicio de activación en ápex y final en TSVD anterior, mientras que el resto de patrones no se pudieron predecir por la duración y morfología del QRS.BACKGROUND: Patients with corrected tetralogy of Fallot (cTOF) have an increased risk of ventricular tachycardia (VT) and sudden death, but known risk factors have a limited prognostic value. Additionally, little is known about electrophysiological and electro-anatomical parameters of the right ventricle (RV) in these patients. METHODS: Ambispective, longitudinal and observational study of patients with cTOF undergoing electro-anatomical mapping of RV at the University Hospital Vall d'Hebron between March 2006 and December 2016. RESULTS: 43 patients (67% men, mean age 34.1 ± 10.0 years) were included and divided into two groups according to the absence (group A, n = 28) or presence (group B, n = 15) of clinical or induced VT. Group B had a higher HV interval (60.9 ± 15.1 vs 48.5 ± 7.9 ms, p = 0.001), a superior percentage of HV ≥ 55 ms (73% vs 19%, p = 0.001), a longer RV activation time (133.0 ± 34.8 vs 109.8 ± 27.8 ms, p = 0.017) and a higher prevalence of double potentials (DP) (93% vs 54%, p = 0.015). Patients with complex ventricular ectopic beats showed a greater extent of scar tissue (voltage <0.5 mV) in the whole RV (area 30.7 ± 12.1 vs 20.1 ± 15.6 cm2, p = 0.054 and percentage 13.1 ± 6.0 vs 7.3 ± 5.6%; p = 0.035) and in the RV outflow tract (RVOT) (area 22.3 ± 12.6 vs 15.6 ± 14.2 cm2, p = 0.033 and percentage 11.5 ± 5.1 vs 5.7 ± 4.9%, p = 0.010). The QRS interval showed a positive correlation with the total scar area (r = 0.35, p = 0.027) and the RV activation time (r = 0.67, p <0.001). In the DP group, the QRS interval (166.1 ± 25.4 vs 147.8 ± 24.3 ms, p = 0.004), the RV activation time (126.6 ± 34.6 vs 99.9 ± 19.4 ms, p = 0.003) and the scar tissue extension (25.6 ± 16.4 vs. 15.3 ± 12.2 cm2, p = 0.038) were higher. It was documented an association between hemodynamic variables of RV and left ventricular (LV) and RV electrophysiological parameters: a) Worse RV ejection fraction (EF) in those patients with HV ≥ 55 ms (40.1 ± 9.4 vs 47.3 ± 7.4%, p = 0.025); b) Correlation between scar extension and indexed telediastolic volume (VTDi) of RV (total scar area r = 0.48, p = 0.003 and RVOT scar area r = 0.54, p = 0.001), telediastolic diameter (DTD) of RV (RVOT scar area r = 0.38, p = 0.017), RV systolic function (total scar area and tricuspid tissue Doppler [DTI] r = – 0.40, p = 0.019; total scar area and RVEF r = – 0.58, p < 0.001 and RVOT scar area and RVEF r= – 0,58, p < 0.001), and LVEF (total scar area r = – 0.56, p = 0.001 and RVOT scar area r = – 0.54, p = 0.001) and c) Correlation between RV activation time and RV dilation (DTD r = 0.36, p = 0.024 and VTDi r = 0.45, p = 0.005) and RV systolic dysfunction (Tricuspid annular plane systolic excursion r = – 0.47, p = 0.002, tricuspid DTI r = – 0.43, p = 0.011 and RVEF r = – 0.45, p = 0.005). Five patterns of RV activation have been identified. Patients with QRS <120 ms showed an onset of activation in the apex and an ending in the anterior RVOT. The other patterns could not be predicted by QRS duration or morphology

Características electrofisiológicas y factores de riesgo de arritmias ventriculares en pacientes con tetralogía de Fallot corregida

Antecedentes: Los pacientes con tetralogía de Fallot corregida (TFc) tienen mayor riesgo de taquicardia ventricular (TV) y muerte súbita, pero los factores de riesgo conocidos tienen un valor pronóstico limitado. Adicionalmente, poco se conoce sobre los parámetros electrofisiológicos y electro-anatómicos del ventrículo derecho (VD) en estos pacientes. Métodos: Estudio ambispectivo, longitudinal y observacional de los pacientes con TFc sometidos a mapeo electro-anatómico de VD en el Hospital Universitario Vall d́Hebron entre marzo 2006 y diciembre 2016. Resultados: Se incluyeron 43 pacientes (67% hombres, edad media 34,1 ± 10,0 años) que se dividieron en dos grupos según la ausencia (grupo A, n= 28) o presencia (grupo B, n= 15) de TV clínica o inducida. El grupo B presentó un intervalo HV superior (60,9 ± 15,1 vs 48,5 ± 7,9 ms; p = 0,001), un mayor porcentaje de pacientes con HV ≥ 55 ms (73% vs 19%; p = 0,001), un tiempo de activación de VD más prolongado (133,0 ± 34,8 vs 109,8 ± 27,8 ms; p = 0,017) y mayor prevalencia de dobles potenciales (DP) (93% vs 54%; p = 0,015). Los pacientes con extrasistolia ventricular compleja mostraron mayor extensión de tejido cicatricial (voltaje 0,5 mV) de VD (área 30,7 ± 12,1 vs 20,1 ± 15,6 cm2; p = 0,054 y porcentaje 13,1 ± 6,0 vs 7,3 ± 5,6%; p = 0,035) y de tracto de salida de VD (TSVD) (área 22,3 ± 12,6 vs 15,6 ± 14,2 cm2; p = 0,033 y porcentaje 11,5 ± 5,1 vs 5,7 ± 4,9%; p = 0,010). El intervalo QRS mostró una correlación positiva con el área cicatricial total (r = 0,35; p = 0,027) y el tiempo de activación de VD (r = 0,67; p 0,001). En el grupo con DP, el intervalo QRS (166,1 ± 25,4 vs 147,8 ± 24,3 ms; p = 0,004), el tiempo de activación (126,6 ± 34,6 vs 99,9 ± 19,4 ms; p = 0,003) y la extensión del tejido cicatricial (25,6 ± 16,4 vs 15,3 ± 12,2 cm2; p = 0,038) fueron superiores. Se documentó una asociación entre variables hemodinámicas de VD y ventrículo izquierdo (VI) y parámetros electrofisiológicos: a) Peor fracción de eyección (FE) de VD en el grupo con HV ≥ 55 ms (40,1 ± 9,4 vs 47,3 ± 7,4%; p = 0,025), b) Correlación entre la extensión cicatricial y el volumen telediastólico indexado (VTDi) de VD (área cicatricial total r = 0,48; p = 0,003 y área cicatricial de TSVD r = 0,54; p = 0,001), el diámetro telediastólico (DTD) de VD (área cicatricial de TSVD r = 0,38; p = 0,017), la función sistólica de VD (área cicatricial total y Doppler tisular (DTI) tricuspídeo r = - 0,40; p = 0,019; área cicatricial total y FEVD r = - 0,58; p 0,001 y área cicatricial de TSVD y FEVD = - 0,58; p 0,001) y la FEVI (área cicatricial total r = - 0,56; p = 0,001 y área cicatricial de TSVD r = - 0,54; p = 0,001) y c) Correlación entre el tiempo de activación y la dilatación de VD (DTD r = 0,36; p = 0,024 y VTDi r = 0,45; p = 0,005) y la disfunción sistólica de VD (excursión sistólica anillo tricuspídeo r = - 0,47; p = 0,002, DTI tricuspídeo r = - 0,43; p = 0,011 y FEVD r = - 0,45; p = 0,005). Se han identificado 5 patrones de activación del VD. Los pacientes con QRS 120 ms mostraron un inicio de activación en ápex y final en TSVD anterior, mientras que el resto de patrones no se pudieron predecir por la duración y morfología del QRS.ANTECEDENTES: Los pacientes con tetralogía de Fallot corregida (TFc) tienen mayor riesgo de taquicardia ventricular (TV) y muerte súbita, pero los factores de riesgo conocidos tienen un valor pronóstico limitado. Adicionalmente, poco se conoce sobre los parámetros electrofisiológicos y electro-anatómicos del ventrículo derecho (VD) en estos pacientes. MÉTODOS: Estudio ambispectivo, longitudinal y observacional de los pacientes con TFc sometidos a mapeo electro-anatómico de VD en el Hospital Universitario Vall d'Hebron entre marzo 2006 y diciembre 2016. RESULTADOS: Se incluyeron 43 pacientes (67% hombres, edad media 34,1 ± 10,0 años) que se dividieron en dos grupos según la ausencia (grupo A, n= 28) o presencia (grupo B, n= 15) de TV clínica o inducida. El grupo B presentó un intervalo HV superior (60,9 ± 15,1 vs 48,5 ± 7,9 ms; p = 0,001), un mayor porcentaje de pacientes con HV ≥ 55 ms (73% vs 19%; p = 0,001), un tiempo de activación de VD más prolongado (133,0 ± 34,8 vs 109,8 ± 27,8 ms; p = 0,017) y mayor prevalencia de dobles potenciales (DP) (93% vs 54%; p = 0,015). Los pacientes con extrasistolia ventricular compleja mostraron mayor extensión de tejido cicatricial (voltaje 0,5 mV) de VD (área 30,7 ± 12,1 vs 20,1 ± 15,6 cm2; p = 0,054 y porcentaje 13,1 ± 6,0 vs 7,3 ± 5,6%; p = 0,035) y de tracto de salida de VD (TSVD) (área 22,3 ± 12,6 vs 15,6 ± 14,2 cm2; p = 0,033 y porcentaje 11,5 ± 5,1 vs 5,7 ± 4,9%; p = 0,010). El intervalo QRS mostró una correlación positiva con el área cicatricial total (r = 0,35; p = 0,027) y el tiempo de activación de VD (r = 0,67; p 0,001). En el grupo con DP, el intervalo QRS (166,1 ± 25,4 vs 147,8 ± 24,3 ms; p = 0,004), el tiempo de activación (126,6 ± 34,6 vs 99,9 ± 19,4 ms; p = 0,003) y la extensión del tejido cicatricial (25,6 ± 16,4 vs 15,3 ± 12,2 cm2; p = 0,038) fueron superiores. Se documentó una asociación entre variables hemodinámicas de VD y ventrículo izquierdo (VI) y parámetros electrofisiológicos: a) Peor fracción de eyección (FE) de VD en el grupo con HV ≥ 55 ms (40,1 ± 9,4 vs 47,3 ± 7,4%; p = 0,025), b) Correlación entre la extensión cicatricial y el volumen telediastólico indexado (VTDi) de VD (área cicatricial total r = 0,48; p = 0,003 y área cicatricial de TSVD r = 0,54; p = 0,001), el diámetro telediastólico (DTD) de VD (área cicatricial de TSVD r = 0,38; p = 0,017), la función sistólica de VD (área cicatricial total y Doppler tisular (DTI) tricuspídeo r = - 0,40; p = 0,019; área cicatricial total y FEVD r = - 0,58; p 0,001 y área cicatricial de TSVD y FEVD = - 0,58; p 0,001) y la FEVI (área cicatricial total r = - 0,56; p = 0,001 y área cicatricial de TSVD r = - 0,54; p = 0,001) y c) Correlación entre el tiempo de activación y la dilatación de VD (DTD r = 0,36; p = 0,024 y VTDi r = 0,45; p = 0,005) y la disfunción sistólica de VD (excursión sistólica anillo tricuspídeo r = - 0,47; p = 0,002, DTI tricuspídeo r = - 0,43; p = 0,011 y FEVD r = - 0,45; p = 0,005). Se han identificado 5 patrones de activación del VD. Los pacientes con QRS 120 ms mostraron un inicio de activación en ápex y final en TSVD anterior, mientras que el resto de patrones no se pudieron predecir por la duración y morfología del QRS.BACKGROUND: Patients with corrected tetralogy of Fallot (cTOF) have an increased risk of ventricular tachycardia (VT) and sudden death, but known risk factors have a limited prognostic value. Additionally, little is known about electrophysiological and electro-anatomical parameters of the right ventricle (RV) in these patients. METHODS: Ambispective, longitudinal and observational study of patients with cTOF undergoing electro-anatomical mapping of RV at the University Hospital Vall d'Hebron between March 2006 and December 2016. RESULTS: 43 patients (67% men, mean age 34.1 ± 10.0 years) were included and divided into two groups according to the absence (group A, n = 28) or presence (group B, n = 15) of clinical or induced VT. Group B had a higher HV interval (60.9 ± 15.1 vs 48.5 ± 7.9 ms, p = 0.001), a superior percentage of HV ≥ 55 ms (73% vs 19%, p = 0.001), a longer RV activation time (133.0 ± 34.8 vs 109.8 ± 27.8 ms, p = 0.017) and a higher prevalence of double potentials (DP) (93% vs 54%, p = 0.015). Patients with complex ventricular ectopic beats showed a greater extent of scar tissue (voltage 0.5 mV) in the whole RV (area 30.7 ± 12.1 vs 20.1 ± 15.6 cm2, p = 0.054 and percentage 13.1 ± 6.0 vs 7.3 ± 5.6%; p = 0.035) and in the RV outflow tract (RVOT) (area 22.3 ± 12.6 vs 15.6 ± 14.2 cm2, p = 0.033 and percentage 11.5 ± 5.1 vs 5.7 ± 4.9%, p = 0.010). The QRS interval showed a positive correlation with the total scar area (r = 0.35, p = 0.027) and the RV activation time (r = 0.67, p 0.001). In the DP group, the QRS interval (166.1 ± 25.4 vs 147.8 ± 24.3 ms, p = 0.004), the RV activation time (126.6 ± 34.6 vs 99.9 ± 19.4 ms, p = 0.003) and the scar tissue extension (25.6 ± 16.4 vs. 15.3 ± 12.2 cm2, p = 0.038) were higher. It was documented an association between hemodynamic variables of RV and left ventricular (LV) and RV electrophysiological parameters: a) Worse RV ejection fraction (EF) in those patients with HV ≥ 55 ms (40.1 ± 9.4 vs 47.3 ± 7.4%, p = 0.025); b) Correlation between scar extension and indexed telediastolic volume (VTDi) of RV (total scar area r = 0.48, p = 0.003 and RVOT scar area r = 0.54, p = 0.001), telediastolic diameter (DTD) of RV (RVOT scar area r = 0.38, p = 0.017), RV systolic function (total scar area and tricuspid tissue Doppler [DTI] r = - 0.40, p = 0.019; total scar area and RVEF r = - 0.58, p 0.001 and RVOT scar area and RVEF r= - 0,58, p 0.001), and LVEF (total scar area r = - 0.56, p = 0.001 and RVOT scar area r = - 0.54, p = 0.001) and c) Correlation between RV activation time and RV dilation (DTD r = 0.36, p = 0.024 and VTDi r = 0.45, p = 0.005) and RV systolic dysfunction (Tricuspid annular plane systolic excursion r = - 0.47, p = 0.002, tricuspid DTI r = - 0.43, p = 0.011 and RVEF r = - 0.45, p = 0.005). Five patterns of RV activation have been identified. Patients with QRS 120 ms showed an onset of activation in the apex and an ending in the anterior RVOT. The other patterns could not be predicted by QRS duration or morphology

Life-threatening and life-saving inappropriate implantable cardioverter defibrillator shocks

An implantable cardioverter defibrillator (ICD) lead dislodgement into the right atrium is a dangerous situation, particularly in patients in atrial fibrillation because atrial fibrillation can be sensed as ventricular fibrillation and true ventricular fibrillation induced with an inappropriate shock. In the presence of shocks, ICD interrogation should be performed as soon as possible