Electrical storm after left ventricular assist device (LVAD) implantation.

INTRODUCTION: Ventricular tachycardia storm or electrical storm (ES) is a common complication following left ventricular assist device (LVAD) implantation. The factors contributing to ES and outcomes are less studied. The study aimed to determine the factors associated with ES and the probability of survival in patients undergoing LVAD in three tertiary centers over a span of 15 years. METHODS: We performed a retrospective cohort study on all patients who underwent LVAD implantation at the Mayo Clinic (Rochester, Phoenix, and Jacksonville) from January 1, 2006 to December 31, 2020. ES was defined as ≥3 episodes of sustained ventricular tachycardia over a period of 24 h with no identifiable reversible cause. Detailed chart reviews of the electronic health records within the Mayo Clinic and outside medical records were performed. RESULTS: A total of 883 patients who underwent LVAD implantation were included in our study. ES occurred in 7% (n = 61) of patients with a median of 13 days (interquartile range [IQR]: 5-297 days) following surgery. We found 57% of patients (n = 35) developed ES within 30 days, while 43% (n = 26) patients developed ES at a median of 545  (IQR 152-1032) days after surgery. Following ES, 26% of patients died within 1 year. Patients with ES had a significant association with a history of ventricular arrhythmias and implantable cardioverter defibrillator (ICD) shocks before the procedure. ES was significantly associated with reduced survival compared to patients without ES (hazards ratio [HR]: 1.92, 95% CI: 1.39-2.64, p < .001). CONCLUSION: Following LVAD implantation, the rate of ES was 7% with majority of ES occurring within 30 days of LVAD. Risk factors for ES included pre-implant history of ventricular arrhythmias and ICD shock. ES was significantly associated with reduced survival compared to patients without ES.

Association of device detected atrial and ventricular tachyarrhythmia with adverse events in patients with an implantable cardioverter-defibrillator.

INTRODUCTION: Heart failure patients with a history of atrial fibrillation (AF) and ventricular tachycardia/ventricular fibrillation (VT/VF) are known to have worse outcomes. However, there are limited data on the temporal relationship between development of these arrhythmias and the risk of subsequent congestive heart failure (CHF) exacerbation and death. METHODS: The study cohort comprised 5511 patients implanted with an implantable cardioverter-defibrillator (ICD) in landmark clinical trials (MADIT-II, MADIT-RISK, MADIT-CRT, MADIT-RIT, and RAID) who were in sinus rhythm at enrollment. Multivariate cox analysis was performed to evaluate the time-dependent association between development of in-trial device detected AF and VT/VF with subsequent CHF exacerbation and death. RESULTS: Multivariate analysis showed that AF occurrence and VT/VF occurrence were both associated with a similar magnitude of risk for subsequent CHF exacerbation (HR = 1.73 and 1.87 respectively, p < .001 for both). In contrast, only in-trial VT/VF was associated with a significant > two-fold increase in the risk of subsequent mortality (HR = 2.13, p < .001) whereas AF occurrence was not associated with a significant mortality increase after adjustment for in-trial VT/VF (HR = 1.36, p = .096). CONCLUSION: Our findings from a large cohort of ICD recipients enrolled in landmark clinical trials show that device detected AF and VT/VF can be used to identify patients with increased risk for CHF exacerbation and mortality. These findings suggest a need for early intervention in CHF patients who develop device-detected atrial and ventricular tachyarrhythmias.

Impact of preventive substrate catheter ablation on implantable cardioverter-defibrillator interventions in patients with ischaemic cardiomyopathy and infarct-related coronary chronic total occlusion.

AIMS: Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation. METHODS AND RESULTS: The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome's components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12-0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151). CONCLUSION: Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs.

Catheter ablation versus antiarrhythmic drug therapy for sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy.

BACKGROUND: Ventricular tachycardia (VT) is the primary cause of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). However, the strategy for VT treatment in HCM patients remains unclear. This study is aimed to compare the effectiveness of catheter ablation versus antiarrhythmic drug (AAD) therapy for sustained VT in patients with HCM. METHODS: A total of 28 HCM patients with sustained VT at 4 different centers between December 2012 and December 2021 were enrolled. Twelve underwent catheter ablation (ablation group) and sixteen received AAD therapy (AAD group). The primary outcome was VT recurrence during follow-up. RESULTS: Baseline characteristics were comparable between two groups. After a mean follow-up of 31.4 ± 17.5 months, the primary outcome occurred in 35.7% of the ablation group and 90.6% of the AAD group (hazard ratio [HR], 0.29 [95%CI, 0.10-0.89]; P = 0.021). No differences in hospital admission due to cardiovascular cause (25.0% vs. 71.0%; P = 0.138) and cardiovascular cause-related mortality/heart transplantation (9.1% vs. 50.6%; P = 0.551) were observed. However, there was a significant reduction in the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation in ablation group as compared to that of AAD group (42.9% vs. 93.7%; HR, 0.34 [95% CI, 0.12-0.95]; P = 0.029). CONCLUSIONS: In HCM patients with sustained VT, catheter ablation reduced the VT recurrence, and the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation as compared to AAD.

The significance of non-sustained ventricular tachycardia on life-threatening ventricular arrhythmia events in patients with non-ischemic cardiomyopathy in the contemporary era: A systematic review and meta-analysis.

BACKGROUND: Risk stratification for patients with non-ischemic cardiomyopathy (NICM) remains challenging as previous studies predicting life-threatening ventricular arrhythmia (LTVA) events were conducted before the establishment of the current standard treatment. We investigated the prognostic value of non-sustained ventricular tachycardia (NSVT) in NICM patients among recent studies. METHODS: MEDLINE, Embase were searched from January 2000 to October 2023. The risk of NSVT on LTVA and mortality was assessed using a random-effects model for patients with NICM. A meta-regression analysis was employed to identify sources of heterogeneity. The systematic review and meta-analysis were carried out according to the PRISMA guidelines. RESULTS: A total of 18 studies were identified, including 5238 pooled participants. Meta-analysis demonstrated that the presence of NSVT was considered a significant prognostic indicator for LTVA events [hazard ratio (HR): 2.90; 95 % CI; 2.31-3.64] with low heterogeneity (I2: 19 %) and for mortality (HR; 2.28; 95%CI; 1.26-4.13) with high heterogeneity (I2: 69 %). The prognostic value of NSVT for LTVA was not affected by either ejection fraction or medications at baseline. CONCLUSION: NSVT remained an important predictor of LTVA events even in patients receiving healthcare in contemporary eras. Detection of NSVT helps us to identify the high-risk patients with NICM.

Ventricular Arrhythmias After Primary Percutaneous Coronary Intervention for STEMI.

Importance: Currently, mortality risk for patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) with an uncomplicated postprocedure course is low. Less is known regarding the risk of in-hospital ventricular tachycardia (VT) and ventricular fibrillation (VF). Objective: To evaluate the risk of late VT and VF after primary PCI for STEMI. Design, Setting, and Participants: This cohort study included adults aged 18 years or older with STEMI treated with primary PCI between January 1, 2015, and December 31, 2018, identified in the US National Cardiovascular Data Registry Chest Pain-MI Registry. Data were analyzed from April to December 2020. Main Outcomes and Measures: Multivariable logistic regression was used to evaluate the risk of late VT (≥7 beat run of VT during STEMI hospitalization ≥1 day after PCI) or VF (any episode of VF≥1 day after PCI) associated with cardiac arrest and associations between late VT or VF and in-hospital mortality in the overall cohort and a cohort with uncomplicated STEMI without prior myocardial infarction or heart failure, systolic blood pressure less than 90 mm Hg, cardiogenic shock, cardiac arrest, reinfarction, or left ventricular ejection fraction (LVEF) less than 40%. Results: A total of 174 126 eligible patients with STEMI were treated with primary PCI at 814 sites in the study; 15 460 (8.9%) had VT or VF after primary PCI, and 4156 (2.4%) had late VT or VF. Among the eligible patients, 99 905 (57.4%) at 807 sites had uncomplicated STEMI. The median age for patients with late VT or VF overall was 63 years (IQR, 55-73 years), and 75.5% were men; the median age for patients with late VT or VF with uncomplicated STEMI was 60 years (IQR, 53-69 years), and 77.7% were men. The median length of stay was 3 days (IQR, 2-7 days) for the overall cohort with late VT or VF and 3 days (IQR, 2-4 days) for the cohort with uncomplicated STEMI with late VT or VF. The risk of late VT or VF was 2.4% (overall) and 1.7% (uncomplicated STEMI). Late VT or VF with cardiac arrest occurred in 674 patients overall (0.4%) and in 117 with uncomplicated STEMI (0.1%). LVEF was the most significant factor associated with late VT or VF with cardiac arrest (adjusted odds ratio [AOR] for every 5-unit decrease ≤40%: 1.67; 95% CI, 1.54-1.85). Late VT or VF events were associated with increased odds of in-hospital mortality in the overall cohort (AOR, 6.40; 95% CI, 5.63-7.29) and the cohort with uncomplicated STEMI (AOR, 8.74; 95% CI, 6.53-11.70). Conclusions and Relevance: In this study, a small proportion of patients with STEMI treated with primary PCI had late VT or VF. However, late VT or VF with cardiac arrest was rare, particularly in the cohort with uncomplicated STEMI. This information may be useful when determining the optimal timing for hospital discharge after STEMI.

Association between survival and number of shocks for pulseless ventricular arrhythmias during pediatric in-hospital cardiac arrest in a national registry.

BACKGROUND: Annually 15,200 children suffer an in-hospital cardiac arrest (IHCA) in the US. Ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) is the initial rhythm in 10-15% of these arrests. We sought to evaluate the association of number of shocks and early dose escalation with survival for initial VF/pVT in pediatric IHCA. METHODS: Using 2000-2020 data from the American Heart Association's (AHA) Get with the Guidelines®-Resuscitation (GWTG-R) registry, we identified children >48 hours of life and ≤18 years who had an IHCA from initial VF/pVT and received defibrillation. RESULTS: There were 251 subjects (37.7%) who received a single shock and 415 subjects (62.3%) who received multiple shocks. Baseline and cardiac arrest characteristics did not differ between those who received a single shock versus multiple shocks except for duration of arrest and calendar year. The median first shock dose was consistent with AHA dosing recommendations and not different between those who received a single shock versus multiple shocks. Survival was improved for those who received a single shock compared to multiple shocks. However, no difference in survival was noted between those who received 2, 3, or ≥4 shocks. Of those receiving multiple shocks, no difference was observed with early dose escalation. CONCLUSIONS: In pediatric IHCA, most patients with initial VF/pVT require more than one shock. No distinctions in patient or pre-arrest characteristics were identified between those who received a single shock versus multiple shocks. Subjects who received a single shock were more likely to survive to hospital discharge even after adjusting for duration of resuscitation.

Digoxin and Risk of Ventricular Tachyarrhythmia and Death in ICD Recipients.

BACKGROUND: Some studies have shown digoxin use to be associated with adverse outcomes, including increased mortality. There are limited data on whether digoxin use is associated with increased risk of ventricular tachycardia/ventricular fibrillation (VT/VF) in heart failure patients with an implantable cardioverter-defibrillator (ICD). OBJECTIVES: This study sought to assess whether digoxin use is associated with increased risk of VT/VF in patients with heart failure with reduced ejection fraction with a primary prevention ICD in landmark clinical trials. METHODS: The study cohort consisted of patients with an ICD or cardiac resynchronization therapy-defibrillator who were enrolled in 4 landmark MADIT trials (Multicenter Automatic Defibrillator Implantation Trials). We employed propensity score quintile stratification for treatment with digoxin as well as additional multivariable adjustment to assess the risk of digoxin vs no-digoxin therapy for the endpoints of first and recurrent VT/VF and all-cause mortality. The proportional hazards regression models for arrhythmia-specific endpoints incorporated adjustments for the competing risk of death. RESULTS: At baseline, 1,155 of 4,499 patients were on digoxin (26%). After propensity score quintile stratification, patients prescribed digoxin were shown to exhibit a statistically significant 48% increased risk of VT/VF (P < 0.001), 42% increased risk of the composite of VT/VF or death (P < 0.001), and a 37% increased risk of all-cause mortality (P = 0.006). Digoxin use was also associated with increased risk of appropriate ICD shocks (HR: 1.91; P < 0.001) and with increased burden of VT/VF events (HR: 1.46; P = 0.001). CONCLUSIONS: Our findings suggests that digoxin use is associated with ventricular tachyarrhythmia and death in heart failure with reduced ejection fraction patients with an ICD.

Active Arrhythmia Pattern: A Novel Predictor of ICD Shocks-A Subanalysis From the PARTITA Study.

BACKGROUND: In the PARTITA trial (Does Timing of Ventricular Tachycardia Ablation Affect Prognosis in Patients With an Implantable Cardioverter Defibrillator?), antitachycardia pacing (ATP) predicted the occurrence of implantable cardioverter defibrillator (ICD) shocks. Catheter ablation of ventricular tachycardia after the first shock reduced the risk of death or worsening heart failure. A threshold of ATPs that might warrant an ablation procedure before ICD shocks is unknown. Our aim was to identify a threshold of ATPs and clinical features that predict the occurrence of shocks and cardiovascular events. METHODS: We analyzed data from 517 patients in phase A of the PARTITA study. We used classification and regression tree analysis to develop and test a risk stratification model based on arrhythmia patterns and clinical data to predict ICD shocks. Secondary end points were worsening heart failure and cardiovascular hospitalization. RESULTS: Classification and regression tree classified patients into 6 leaves by increasing shock probability. Patients treated with ≥5 ATPs in 6 months (active arrhythmia pattern) had the highest risk of ICD shocks (93% and 86%, training and testing samples, respectively). Patients without ATPs had the lowest (1% and 2%). Other predictors included left ventricle ejection fraction<35%, age of <60 years, and obesity. Survival analysis revealed a higher risk of worsening heart failure (hazard ratio, 5.45 [95% CI, 1.62-18.4]; P=0.006) and cardiovascular hospitalization (hazard ratio, 7.29 [95% CI, 3.66-14.5]; P<0.001) for patients with an active arrhythmia pattern compared with those without ATPs. CONCLUSIONS: Patients with an active arrhythmia pattern (≥5 ATPs in 6 months) are associated with an increased risk of ICD shocks, as well as heart failure hospitalization and cardiovascular hospitalization. These data suggest that additional treatments may be helpful to this high-risk group as a preventive strategy to reduce the incidence of major events. Further prospective randomized trials are needed to confirm the benefits of early ventricular tachycardia ablation in this setting.

Bleeding and Thrombosis in Patients With Out-of-Hospital Ventricular Tachycardia/Ventricular Fibrillation Arrest Treated With Extracorporeal Cardiopulmonary Resuscitation.

BACKGROUND: Extracorporeal cardiopulmonary resuscitation improves outcomes after out-of-hospital cardiac arrest. However, bleeding and thrombosis are common complications. We aimed to describe the incidence and predictors of bleeding and thrombosis and their association with in-hospital mortality. METHODS AND RESULTS: Consecutive patients presenting with refractory ventricular tachycardia/ventricular fibrillation out-of-hospital cardiac arrest between December 2015 and March 2022 who met the criteria for extracorporeal cardiopulmonary resuscitation initiation at our center were included. Major bleeding was defined by the Extracorporeal Life Support Organization's criteria. Adjusted analyses were done to seek out risk factors for bleeding and thrombosis and evaluate their association with mortality. Major bleeding occurred in 135 of 200 patients (67.5%), with traumatic bleeding from cardiopulmonary resuscitation in 73 (36.5%). Baseline demographics and arrest characteristics were similar between groups. In multivariable analysis, decreasing levels of fibrinogen were independently associated with bleeding (adjusted hazard ratio [aHR], 0.98 per every 10 mg/dL rise [95% CI, 0.96-0.99]). Patients who died had a higher rate of bleeds per day (0.21 versus 0.03, P<0.001) though bleeding was not significantly associated with in-hospital death (aHR, 0.81 [95% CI. 0.55-1.19]). A thrombotic event occurred in 23.5% (47/200) of patients. Venous thromboembolism occurred in 11% (22/200) and arterial thrombi in 15.5% (31/200). Clinical characteristics were comparable between groups. In adjusted analyses, no risk factors for thrombosis were identified. Thrombosis was not associated with in-hospital death (aHR, 0.65 [95% CI, 0.42-1.03]). CONCLUSIONS: Bleeding is a frequent complication of extracorporeal cardiopulmonary resuscitation that is associated with decreased fibrinogen levels on admission whereas thrombosis is less common. Neither bleeding nor thrombosis was significantly associated with in-hospital mortality.

Membrana de circulación extracorpórea veno-arterial para ablación de tormenta eléctrica en shock cardiogénico: caso clínico / Veno-arterial extracorporeal membrane oxygenation (ECMO) used for support during ablation of ventricular electrical storm: case report

RESUMEN: Se presenta el caso clínico de un paciente que presenta un infarto del miocardio con trombolisis no exitosa y posterior implantación de 2 stents coronarios quien desarrolla, algunos días después, una tormenta eléctrica ventricular. Una ablación de la taquicardia se realizó bajo ECMO, con buen resultado. Se detalla la descripción del caso, revisa y discute el tema.

ABSTRAC: A patient with a myocardial infarction whom, following a failed thrombolisis and implantion of 2 stents developed a ventricular electrical storm and hemodynamic instability. A successful ablation of the tachycardia with the use of ECMO was performed. A full description is included, along with a discussion of the subject.

Muerte súbita intrahospitalaria luego de infarto agudo de miocardio en Cuba en los últimos tres años. Análisis de registros institucionales / Sudden intra-hospital death after acute myocardial infarction in Cuba in the last three years. Analysis of institutional records

Resumen Objetivo: Analizar el comportamiento de posibles causas predisponentes de muerte súbita (MS) intrahospitalaria luego de un infarto agudo de miocardio (IMA) en registros cubanos. Material y método: Se realizó una búsqueda de registros clínicos de pacientes con IMA en Cuba en las bases de datos de revistas nacionales, Scientific Library On-line (ScieLO) y Medline. Se priorizaron los artículos publicados desde 2016 para ser incluidos. Se definió como muerte súbita aquélla secundaria a arritmias ventriculares malignas (TV y FV), así como los pacientes con rotura cardíaca y actividad eléctrica sin pulso o asistolia como forma de presentación. Con posterioridad se evaluó la relación de este parámetro con la aparición de muerte súbita en 710 pacientes del Registro de Síndromes Coronarios Agudos (RESCUE). Resultados: En el contexto extrahospitalario, más de la mitad de las muertes súbitas cardíacas son secundarias a un infarto agudo de miocardio. En el hospital, la mortalidad en Cuba por IMA es homogénea. Sólo los centros con intervencionismo coronario escapan a este fenómeno. Aunque no del todo letales, las arritmias ventriculares malignas se relacionan con un peor pronóstico y su prevalencia no es homogénea en los registros revisados. Conclusiones: La muerte súbita luego de infarto agudo de miocardio será aún en Cuba una de las principales causas de muerte en los pacientes de fase aguda.

Abstract Objective: To analyze possible predisposing causes of in hospital sudden cardiac death (SCD) after an acute myocardial infarction (IMA) in Cuban registries. Material and methods: A search of clinical records of patients with IMA in Cuba was performed in the databases of national journals, Scientific Library On-line and Medline. Those articles published since 2016 were prioritized for inclusion. Sudden death is defined as that secondary to malignant ventricular arrhythmias (ventricular tachycardia, ventricular fibrillation) as well as patients with cardiac rupture with pulseless electrical activity or asystole as a form of presentation. Subsequently, the relationship of this parameter with the occurrence of sudden death was evaluated in 710 patients from the Registry of Acute Coronary Syndromes (RESCUE). Results: In the out-of-hospital setting, more than half of SCD are secondary to an IMA. Once in the hospital, mortality in Cuba from IMA is homogeneous. Only centers with coronary interventionism escape this phenomenon. Although not totally lethal, the presence of malignant ventricular arrhythmias is associated with a worse prognosis and its prevalence is not homogeneous in the reviewed records. Conclusions: Sudden death after IMA will continue to be one of the main causes of death of patients in the acute phase in Cuba.

Tratamiento con radiofrecuencia de la tormenta eléctrica: evolución y seguimiento / Radiofrequency treatment for electrical storm: evolution and monitoring

Resumen Introducción y objetivos: La tormenta eléctrica (TE) se caracteriza por episodios repetidos de taquicardia ventricular o fibrilación ventricular relacionados con mal pronóstico a corto y largo plazos. El objetivo fue evaluar la prevalencia, resultados y supervivencia de los pacientes sometidos a tratamiento intervencionista por TE en un centro de referencia. Métodos: Estudio unicéntrico, observacional y retrospectivo. Se revisaron los procedimientos de ablación por TE y se evaluaron las características basales de los pacientes, tipo de procedimiento, mortalidad total, recurrencia de arritmia, mortalidad cardiovascular y necesidad de trasplante. Resultados: Desde enero de 2009 hasta diciembre de 2016 se realizaron 67 procedimientos (38% de complejos: 19% de ablación endoepicárdica, 7.5% de crioablación epicárdica quirúrgica, 3% de simpatectomía, 3% de inyección coronaria con alcohol; 6% de apoyo con oxigenación con membrana extracorpórea) en 41 pacientes (61% de causa isquémica) por TE. La mortalidad intraprocedimiento fue del 1.5%. La mediana de seguimiento fue de 23.5 meses (RIQ, 14.2-52.7). Tras el primer ingreso por TE (uno o varios procedimientos), la mortalidad a un año fue de 9.8%. La incidencia acumulada de trasplante cardiaco por TE fue de 2.4%. En el análisis multivariado, el riesgo de recurrencias arrítmicas o muerte por cualquier causa fue significativamente mayor en pacientes con arritmias clínicas inducibles (HR, 9.03; p = 0.017). Conclusiones: El tratamiento de pacientes con TE, instituido en un centro de referencia y con experiencia, se relacionó con una tasa baja de recurrencia y supervivencia elevada, con una tasa de trasplante cardiaco por TE muy baja. Ante una recurrencia temprana es recomendable practicar un nuevo procedimiento durante el ingreso.

Abstract Introduction and objective: Electrical storm (ES) is characterized by repeated episodes of ventricular tachycardia or ventricular fibrillation, with poor short and long term prognosis. Our objective was to evaluate the prevalence, results of interventional treatment and survival of patients undergoing interventional treatment for ES in our center. Methods: Retrospective, unicentric and observational study. ES ablation procedures were revised and data regarding baseline characteristics of the patients, type of procedure, total mortality, recurrence of arrhythmia, cardiovascular mortality and the need for transplantation were evaluated. Results: From January 2009 to December 2016, 67 procedures (38% complex procedures: 19% epicardial ablation, 7.5% surgical epicardial crioablation, 3% simpatectomy, 3% coronary alcohol injection, 6% extracorporeal membrane oxygenation support) were performed in 41 patients (61% Ischemic etiology) due to ES. Intraprocedural mortality was 1.5%. The median follow-up was 23.5 months (IQR [14.2-52.7]). After the first admission for ES (one or several procedures), 1-year mortality was 9.8%. The cumulative incidence of cardiac transplantation was 2.4%. The risk of arrhythmic recurrences or death was significantly higher in patients with inducible clinical arrhythmias after ablation (HR: 9.03, p = 0.017). Conclusions: The treatment of patients with ES, performed in a reference center, allows obtaining good rates of recurrence and survival, with very low rates of cardiac transplantation for ES. In the presence of an early recurrence, it is advisable to perform a new procedure during admission.

Prognostic Factors in Severe Chagasic Heart Failure / Fatores Prognósticos na Insuficiência Cardíaca Grave de Etiologia Chagásica

Abstract Background: Prognostic factors are extensively studied in heart failure; however, their role in severe Chagasic heart failure have not been established. Objectives: To identify the association of clinical and laboratory factors with the prognosis of severe Chagasic heart failure, as well as the association of these factors with mortality and survival in a 7.5-year follow-up. Methods: 60 patients with severe Chagasic heart failure were evaluated regarding the following variables: age, blood pressure, ejection fraction, serum sodium, creatinine, 6-minute walk test, non-sustained ventricular tachycardia, QRS width, indexed left atrial volume, and functional class. Results: 53 (88.3%) patients died during follow-up, and 7 (11.7%) remained alive. Cumulative overall survival probability was approximately 11%. Non-sustained ventricular tachycardia (HR = 2.11; 95% CI: 1.04 - 4.31; p<0.05) and indexed left atrial volume ≥ 72 mL/m2 (HR = 3.51; 95% CI: 1.63 - 7.52; p<0.05) were the only variables that remained as independent predictors of mortality. Conclusions: The presence of non-sustained ventricular tachycardia on Holter and indexed left atrial volume > 72 mL/m2 are independent predictors of mortality in severe Chagasic heart failure, with cumulative survival probability of only 11% in 7.5 years.

Resumo Fundamento: Fatores prognósticos são bastante estudados na insuficiência cardíaca (IC), mas ainda não possuem um papel estabelecido na IC grave de etiologia chagásica. Objetivo: Identificar a associação de fatores clínicos e laboratoriais com o prognóstico da IC grave de etiologia chagásica, bem como a associação desses fatores com a taxa de mortalidade e a sobrevida em um seguimento de 7,5 anos. Métodos: 60 pacientes portadores de IC grave de etiologia chagásica foram avaliados com relação às seguintes variáveis: idade, pressão arterial, fração de ejeção, sódio plasmático, creatinina, teste de caminhada de 6 minutos, taquicardia ventricular não sustentada, largura do QRS, volume do átrio esquerdo indexado e classe funcional. Resultados: 53 (88,3%) pacientes foram a óbito durante o período de seguimento e 7 (11,7%) permaneceram vivos. A probabilidade de sobrevida geral acumulada foi de aproximadamente 11%. Taquicardia ventricular não sustentada (HR = 2,11; IC 95%: 1,04 - 4,31; p<0,05) e volume do átrio esquerdo indexado ≥ 72 ml/m2 (HR = 3,51; IC 95%: 1,63 - 7,52; p<0,05) foram as únicas variáveis que permaneceram como preditores independentes de mortalidade. Conclusão: A presença de taquicardia ventricular não sustentada ao Holter e o volume do átrio esquerdo indexado > 72 ml/m2 são preditores independentes de mortalidade na IC chagásica grave, com probabilidade de sobrevida acumulada de apenas 11% em 7,5 anos.

Utilidad del desfibrilador automático implantable en la prevención de muerte súbita: resultados de la medicina basada en evidencia / Usefulness of the implantable cardiodefibrillator (ICD) in the prevention of sudden death: results of evidence based medicine

A great percentage of patients who have suffered a myocardial infarction have ventricular left dysfunction. In agreement with the different prospective studies, many of these patients will have an event of ventricular arrhythmias that does them candidates for receiving a strategy of primary or secondary prevention with an ICD. The same studies have showed a significant reduction in mortality with the therapy of the ICD compared with the conventional therapy what demonstrates the balance cost - benefit in favor of the use of these devices in long periods of follow-up. The benefits of mortality with the use of the therapy with ICD at the primary prevention are at least so good as those of the secondary prevention of agreement to the results of different prospective studies.

Abordagem e investigação clínica em pacientes com taquicardia ventricular sustentada / Approach and clinical research in patients with sustained ventricular tachycardia

A taquicardia ventricular sustentada (TVS) é uma emergência clínica em que há risco de mortalidade súbita cardíaca, daí a necessidade de ser abordada de modo objetivo e sistemático. História clínica, exame físico e ECG são fundamentais na abordagem do paciente com taquicardia de QRS largo. Devem ser pesquisados ativamente os preditores clínicos, sinais clínicos e critérios eletrocardiográficos capazes de diagnosticar com grande probabilidade de acerto a TVS. Após a abordagem de emergência, o paciente deve ser encaminhado para avaliação da cardiopatia. Os testes diagnósticos incluem métodos gráficos (ECG basal, teste de esforço, ECGAR e eletrocardiografia dinâmica) e de imagem (ecocardiograma, ressonância magnética e tomografia computadorizada). Há ainda a possibilidade de avaliação invasiva (estudo eletrofisiológico). Apresenta-se uma revisão das estretégicas de abordagem de pacientes com taquicardia ventricular e dos métodos diagnósticos que auxiliam a busca da cardiopatia subjacente.

Muerte súbita ambulatoria / Ambulatory sudden death

Se seleccionaron en forma retrospectiva 12 registros de muerte súbita ambulatoria. Se analizaron las arritmias causantes de la muerte súbita, las alteraciones del ritmo y del electrocardioograma que la precedieron y las circunstancias en las que ocurrió. En diez pacientes (83,33 por ciento) la muerte súbita se debió a fibrilación ventricular, precedida en 6 por taquicardia ventricular sostenida, en 2 por torsades de pointes y en los otros 2 pacientes la fibrilación ventricular fue la única arritmia. Dos pacientes fallecieron en bradiarritmia (16,66 por ciento), uno en asistolia y el otro en disociación electromecánica. Las taquiarritmias ventriculares son la causa más común de muerte súbita ambulatoria

Cardioversor-desfibrilador implantável: conceitos básicos relacionados ao seu funcionamento e impacto na sobrevida de pacientes portadores de taquiarritmias ventriculares / Implantable cardioverter-defibrillator: basic concepts related to its operation and impact in survival of ventricular tachycardia carrier inpatients

O tratamento farmacológico dos pacientes que sobreviveram a um episódio de morte súbita é muitas vezes frustrante. Mesmo com o mais moderno esquema terapêutico, a mortalidade deste subgrupo de pacientes continua elevada, em torno de 30 por cento ao ano. O cardioversor-desfibrilador implantável modificou este sombrio panorama ao praticamente eliminar a ocorrência de morte súbita relacionada a recorrência das taquiarritmias ventriculares. Esta revisao focaliza conceitos básicos relacionados ao funcionamento dos cardioversores-desfibriladores implantáveis e seu impacto na sobrevida de pacientes portadores de taquiarritmias ventriculares.