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1.
Arch Cardiol Mex ; 90(4): 379-388, 2020.
Artículo en Español | MEDLINE | ID: mdl-33373342

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. 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.


Asunto(s)
Ablación por Catéter/métodos , Taquicardia Ventricular/cirugía , Fibrilación Ventricular/cirugía , Adulto , Anciano , Femenino , Estudios de Seguimiento , Trasplante de Corazón/estadística & datos numéricos , Humanos , Masculino , México , Persona de Mediana Edad , Pronóstico , Recurrencia , Estudios Retrospectivos , Tasa de Supervivencia , Taquicardia Ventricular/mortalidad , Taquicardia Ventricular/fisiopatología , Fibrilación Ventricular/mortalidad , Fibrilación Ventricular/fisiopatología
2.
Arch. cardiol. Méx ; Arch. cardiol. Méx;90(4): 379-388, Oct.-Dec. 2020. tab, graf
Artículo en Español | LILACS | ID: biblio-1152811

RESUMEN

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.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Fibrilación Ventricular/cirugía , Taquicardia Ventricular/cirugía , Ablación por Catéter/métodos , Pronóstico , Recurrencia , Fibrilación Ventricular/fisiopatología , Fibrilación Ventricular/mortalidad , Tasa de Supervivencia , Estudios Retrospectivos , Estudios de Seguimiento , Trasplante de Corazón/estadística & datos numéricos , Taquicardia Ventricular/mortalidad , México
3.
Sci Rep ; 10(1): 12990, 2020 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-32737400

RESUMEN

Biomaterial injection is a novel therapy to treat ischemic heart failure (HF) that has shown to reduce remodeling and restore cardiac function in recent preclinical studies. While the effect of biomaterial injection in reducing mechanical wall stress has been recently demonstrated, the influence of biomaterials on the electrical behavior of treated hearts has not been elucidated. In this work, we developed computational models of swine hearts to study the electrophysiological vulnerability associated with biomaterial injection therapy. The propagation of action potentials on realistic biventricular geometries was simulated by numerically solving the monodomain electrophysiology equations on anatomically-detailed models of normal, HF untreated, and HF treated hearts. Heart geometries were constructed from high-resolution magnetic resonance images (MRI) where the healthy, peri-infarcted, infarcted and gel regions were identified, and the orientation of cardiac fibers was informed from diffusion-tensor MRI. Regional restitution properties in each case were evaluated by constructing a probability density function of the action potential duration (APD) at different cycle lengths. A comparative analysis of the ventricular fibrillation (VF) dynamics for every heart was carried out by measuring the number of filaments formed after wave braking. Our results suggest that biomaterial injection therapy does not affect the regional dispersion of repolarization when comparing untreated and treated failing hearts. Further, we found that the treated failing heart is more prone to sustain VF than the normal heart, and is at least as susceptible to sustained VF as the untreated failing heart. Moreover, we show that the main features of VF dynamics in a treated failing heart are not affected by the level of electrical conductivity of the biogel injectates. This work represents a novel proof-of-concept study demonstrating the feasibility of computer simulations of the heart in understanding the arrhythmic behavior in novel therapies for HF.


Asunto(s)
Materiales Biocompatibles/farmacología , Simulación por Computador , Sistema de Conducción Cardíaco/fisiopatología , Insuficiencia Cardíaca , Modelos Cardiovasculares , Fibrilación Ventricular , Animales , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/fisiopatología , Humanos , Porcinos , Fibrilación Ventricular/tratamiento farmacológico , Fibrilación Ventricular/fisiopatología
4.
J Pineal Res ; 67(4): e12605, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31408542

RESUMEN

Hypokalemia prolongs the QRS and QT intervals, deteriorates intercellular coupling, and increases the risk for arrhythmia. Melatonin preserves gap junctions and shortens action potential as potential antiarrhythmic mechanisms, but its properties under hypokalemia remain unknown. We hypothesized that melatonin protects against low potassium-induced arrhythmias through the activation of its receptors, resulting in action potential shortening and connexin-43 preservation. After stabilization in Krebs-Henseleit solution (4.5 mEq/L K+ ), isolated hearts from Wistar rats underwent perfusion with low-potassium (1 mEq/L) solution and melatonin (100 µmol/L), a melatonin receptor blocker (luzindole, 5 µmol/L), melatonin + luzindole or vehicle. The primary endpoint of the study was the prevention of ventricular fibrillation. Electrocardiography was used, and epicardial action potentials and heart function were measured and analyzed. The ventricular expression, dephosphorylation, and distribution of connexin-43 were examined. Melatonin reduced the incidence of low potassium-induced ventricular fibrillation from 100% to 59%, delayed the occurrence of ventricular fibrillation and induced a faster recovery of sinus rhythm during potassium restitution. Melatonin prevented QRS widening, action potential activation delay, and the prolongation of action potential duration at 50% of repolarization. Other ECG and action potential parameters, the left ventricular developed pressure, and nonsustained ventricular arrhythmias did not differ among groups. Melatonin prevented connexin-43 dephosphorylation and its abnormal topology (lateralization). Luzindole abrogated the protective effects of melatonin on electrophysiological properties and connexin-43 misdistribution. Our results indicate that melatonin receptor activation protects against low potassium-induced ventricular fibrillation, shortens action potential duration, preserves ventricular electrical activation, and prevents acute changes in connexin-43 distribution. All of these properties make melatonin a remarkable antifibrillatory agent.


Asunto(s)
Potenciales de Acción/efectos de los fármacos , Conexina 43/metabolismo , Melatonina/farmacología , Miocardio/metabolismo , Potasio/efectos adversos , Receptores de Melatonina/metabolismo , Fibrilación Ventricular/metabolismo , Animales , Masculino , Miocardio/patología , Potasio/farmacología , Ratas , Ratas Wistar , Fibrilación Ventricular/inducido químicamente , Fibrilación Ventricular/patología , Fibrilación Ventricular/fisiopatología
5.
Thyroid ; 29(12): 1755-1764, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31456501

RESUMEN

Background: Thyroid hormone status in hypothyroidism (HT) downregulates key elements in Ca2+ handling within the heart, reducing contractility, impairing the basal energetic balance, and increasing the risk of cardiovascular disease. Mitochondrial Ca2+ transport is reduced in HT, and tolerance to reperfusion damage has been documented, but the precise mechanism is not well understood. Therefore, we aimed to determine the stoichiometry and activity of the mitochondrial Ca2+ uniporter or uniplex in an HT model and the relevance to the opening of the mitochondrial permeability transition pores (mPTP) during ischemia/reperfusion (I/R) injury. Methods: An HT model was established in Wistar rats by treatment with 6-propylthiouracil for 28 days. Uniplex composition and activity were determined in cardiac mitochondria. Hearts were perfused ex vivo to induce I/R injury, and functional parameters related to contractility and tissue viability were evaluated. Results: The cardiac stoichiometry between two subunits of the uniplex (MICU1/MCU) increased by 25% in animals with HT. The intramitochondrial Ca2+ content was reduced by 40% and was less prone to the mPTP opening. After I/R injury, ischemic contracture and the onset of ventricular fibrillation were delayed in animals with HT, concomitant with a reduction in oxidative damage and mitochondrial dysfunction. Conclusions: Our results suggest that HT is associated with an increase in the cardiac MICU1/MCU ratio, thereby changing the stoichiometry between these subunits to increase the threshold to cytosolic Ca2+ and reduce mitochondrial Ca2+ overload. Our results also demonstrate that this HT model can be used to explore the role of mitochondrial Ca2+ transport in cardiac diseases due to its induced tolerance to cardiac damage.


Asunto(s)
Calcio/metabolismo , Hipotiroidismo/metabolismo , Hipotiroidismo/fisiopatología , Mitocondrias Cardíacas/metabolismo , Daño por Reperfusión Miocárdica/fisiopatología , Animales , Antitiroideos , Citosol/metabolismo , Hipotiroidismo/inducido químicamente , Masculino , Proteínas de Transporte de Membrana Mitocondrial , Poro de Transición de la Permeabilidad Mitocondrial , Estrés Oxidativo , Propiltiouracilo , Ratas , Ratas Wistar , Fibrilación Ventricular/etiología , Fibrilación Ventricular/fisiopatología
8.
Arch Cardiol Mex ; 88(5): 460-467, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29885765

RESUMEN

OBJECTIVE: Ventricular fibrillation (VF)-related sudden cardiac death (SCD) is a leading cause of mortality and morbidity. Current biological and imaging parameters show significant limitations on predicting cerebral performance at hospital admission. The AWAKE study (NCT03248557) is a multicentre observational study to validate a model based on spectral ECG analysis to early predict cerebral performance and survival in resuscitated comatose survivors. METHODS: Data from VF ECG tracings of patients resuscitated from SCD will be collected using an electronic Case Report Form. Patients can be either comatose (Glasgow Coma Scale - GCS - ≤8) survivors undergoing temperature control after return of spontaneous circulation (RoSC), or those who regain consciousness (GCS=15) after RoSC; all admitted to Intensive Cardiac Care Units in 4 major university hospitals. VF tracings prior to the first direct current shock will be digitized and analyzed to derive spectral data and feed a predictive model to estimate favorable neurological performance (FNP). The results of the model will be compared to the actual prognosis. RESULTS: The primary clinical outcome is FNP during hospitalization. Patients will be categorized into 4 subsets of neurological prognosis according to the risk score obtained from the predictive model. The secondary clinical outcomes are survival to hospital discharge, and FNP and survival after 6 months of follow-up. The model-derived categorisation will be also compared with clinical variables to assess model sensitivity, specificity, and accuracy. CONCLUSIONS: A model based on spectral analysis of VF tracings is a promising tool to obtain early prognostic data after SCD.


Asunto(s)
Algoritmos , Muerte Súbita Cardíaca/epidemiología , Electrocardiografía/métodos , Estudios de Seguimiento , Hospitalización , Humanos , Unidades de Cuidados Intensivos , Modelos Estadísticos , Pronóstico , Sensibilidad y Especificidad , Fibrilación Ventricular/diagnóstico , Fibrilación Ventricular/fisiopatología
11.
Arch. cardiol. Méx ; Arch. cardiol. Méx;88(5): 460-467, dic. 2018. graf
Artículo en Inglés | LILACS | ID: biblio-1142157

RESUMEN

Abstract Objective: Ventricular fibrillation (VF)-related sudden cardiac death (SCD) is a leading cause of mortality and morbidity. Current biological and imaging parameters show significant limitations on predicting cerebral performance at hospital admission. The AWAKE study (NCT03248557) is a multicentre observational study to validate a model based on spectral ECG analysis to early predict cerebral performance and survival in resuscitated comatose survivors. Methods: Data from VF ECG tracings of patients resuscitated from SCD will be collected using an electronic Case Report Form. Patients can be either comatose (Glasgow Coma Scale GCS --- ≤8) survivors undergoing temperature control after return of spontaneous circulation (RoSC), or those who regain consciousness (GCS = 15) after RoSC; all admitted to Intensive Cardiac Care Units in 4 major university hospitals. VF tracings prior to the first direct current shock will be digitized and analyzed to derive spectral data and feed a predictive model to estimate favorable neurological performance (FNP). The results of the model will be compared to the actual prognosis. Results: The primary clinical outcome is FNP during hospitalization. Patients will be categorized into 4 subsets of neurological prognosis according to the risk score obtained from the predictive model. The secondary clinical outcomes are survival to hospital discharge, and FNP and survival after 6 months of follow-up. The model-derived categorisation will be also compared with clinical variables to assess model sensitivity, specificity, and accuracy. Conclusions: A model based on spectral analysis of VF tracings is a promising tool to obtain early prognostic data after SCD.


Resumen Objetivo: La muerte súbita (MS) por fibrilación ventricular (FV) es una importante causa de morbilidad y mortalidad. Los métodos biológicos y de imagen actuales muestran limitaciones para predecir el pronóstico cerebral al ingreso hospitalario. AWAKE es un estudio observacional, multicéntrico, con el objetivo de validar un modelo basado en el análisis espectral del elec- trocardiograma (ECG), que predice precozmente el pronóstico cerebral y la supervivencia en pacientes resucitados y en estado de coma. Métodos: Se recogerán datos de los ECG con FV de pacientes reanimados de MS. Los pacientes pueden ser tanto supervivientes en estado de coma (Glasgow Coma Scale GCS ≤ 8) sometidos a control de temperatura tras la recuperación de circulación espontánea (RCE), como aquellos que recuperan la consciencia (GCS = 15) tras RCE; todos ellos ingresados en unidades de terapia intensiva cardiológica de 4 hospitales de referencia. Los registros de FV previos al primer choque se digitalizarán y analizarán para obtener datos espectrales que se incluirán en un modelo predictivo que estime el pronóstico neurológico favorable (PNF). El resultado del modelo se comparará con el pronóstico real. Resultados: El objetivo principal es el PNF durante la hospitalización. Los pacientes se categorizarán en 4 subgrupos de pronóstico neurológico según la estimación de riesgo obtenida en el modelo predictivo. Los objetivos secundarios son supervivencia al alta hospitalaria, y PNF y supervivencia a los 6 meses. El resultado de este modelo también se comparará con el pronóstico según variables clínicas. Conclusiones: Un modelo basado en el análisis espectral de registros de FV es una herramienta prometedora para obtener datos pronósticos precoces tras MS por FV.


Asunto(s)
Humanos , Algoritmos , Muerte Súbita Cardíaca/epidemiología , Electrocardiografía/métodos , Pronóstico , Fibrilación Ventricular/diagnóstico , Fibrilación Ventricular/fisiopatología , Estudios de Seguimiento , Modelos Estadísticos , Sensibilidad y Especificidad , Hospitalización , Unidades de Cuidados Intensivos
12.
J Am Heart Assoc ; 4(10): e002185, 2015 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-26452987

RESUMEN

BACKGROUND: Targeted automated external defibrillator (AED) programs have improved survival rates among patients who have an out-of-hospital cardiac arrest (OHCA) in US airports, as well as European and Japanese railways. The Sao Paulo (Brazil) Metro subway carries 4.5 million people per day. A targeted AED program was begun in the Sao Paulo Metro with the objective to improve survival from cardiac arrest. METHODS AND RESULTS: A prospective, longitudinal, observational study of all cardiac arrests in the Sao Paulo Metro was performed from September 2006 through November 2012. This study focused on cardiac arrest by ventricular arrhythmias, and the primary endpoint was survival to hospital discharge with minimal neurological impairment. A total of 62 patients had an initial cardiac rhythm of ventricular fibrillation. Because no data on cardiac arrest treatment or outcomes existed before beginning this project, the first 16 months of the implementation was used as the initial experience and compared with the subsequent 5 years of full operation. Return of spontaneous circulation was not different between the initial 16 months and the subsequent 5 years (6 of 8 [75%] vs. 39 of 54 [72%]; P=0.88). However, survival to discharge was significantly different once the full program was instituted (0 of 8 vs. 23 of 54 [43%]; P=0.001). CONCLUSIONS: Implementation of a targeted AED program in the Sao Paulo Metro subway system saved lives. A short interval between arrest and defibrillation was key for good long-term, neurologically intact survival. These results support strategic expansion of targeted AED programs in other large Latin American cities.


Asunto(s)
Reanimación Cardiopulmonar/instrumentación , Muerte Súbita Cardíaca/prevención & control , Desfibriladores , Cardioversión Eléctrica/instrumentación , Paro Cardíaco Extrahospitalario/terapia , Vías Férreas , Servicios Urbanos de Salud , Fibrilación Ventricular/terapia , Anciano , Brasil , Reanimación Cardiopulmonar/efectos adversos , Reanimación Cardiopulmonar/mortalidad , Cardioversión Eléctrica/efectos adversos , Cardioversión Eléctrica/mortalidad , Servicios Médicos de Urgencia , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Paro Cardíaco Extrahospitalario/diagnóstico , Paro Cardíaco Extrahospitalario/mortalidad , Paro Cardíaco Extrahospitalario/fisiopatología , Admisión del Paciente , Alta del Paciente , Evaluación de Programas y Proyectos de Salud , Estudios Prospectivos , Recuperación de la Función , Factores de Riesgo , Factores de Tiempo , Tiempo de Tratamiento , Transporte de Pacientes , Resultado del Tratamiento , Fibrilación Ventricular/diagnóstico , Fibrilación Ventricular/mortalidad , Fibrilación Ventricular/fisiopatología
13.
JACC Cardiovasc Interv ; 8(7): 984-90, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26088516

RESUMEN

OBJECTIVES: This study aimed to assess 6-month outcomes in patients with implantable cardioverter-defibrillators (ICDs) undergoing renal sympathetic denervation (RSD) for refractory ventricular arrhythmias (VAs). BACKGROUND: ICDs are generally indicated for patients at high risk of malignant VAs. Sympathetic hyperactivity plays a critical role in the development, maintenance, and aggravation of VAs. METHODS: A total of 10 patients with refractory VA underwent RSD. Underlying conditions were Chagas disease (n = 6), nonischemic dilated cardiomyopathy (n = 2), and ischemic cardiomyopathy (n = 2). Information on the number of ventricular tachycardia (VT)/ventricular fibrillation (VF) episodes and device therapies (antitachycardia pacing/shocks) in the previous 6 months as well as 1 and 6 months post-treatment was obtained from ICD interrogation. RESULTS: The median number of VT/VF episodes/antitachycardia pacing/shocks 6 months before RSD was 28.5 (range 1 to 106)/20.5 (range 0 to 52)/8 (range 0 to 88), respectively, and was reduced to 1 (range 0 to 17)/0 (range 0 to 7)/0 (range 0 to 3) at 1 month and 0 (range 0 to 9)/0 (range 0 to 7)/0 (range 0 to 3) at 6 months afterward, respectively. There were no major procedure-related complications. Two patients experienced sustained VT within the first week; in both cases, no further episodes occurred during follow-up. Two patients were nonresponders: 1 with persistent idioventricular rhythm and 1 with multiple renal arteries and incomplete ablation. Three patients died during follow-up. None of the deaths was attributed to VA. CONCLUSIONS: In patients with ICDs and refractory VAs, RSD was associated with reduced arrhythmic burden with no procedure-related complications. Randomized controlled trials investigating RSD for treatment of refractory VAs in patients with increased sympathetic activity are needed.


Asunto(s)
Desfibriladores Implantables , Cardioversión Eléctrica/instrumentación , Riñón/irrigación sanguínea , Arteria Renal/inervación , Simpatectomía/métodos , Taquicardia Ventricular/terapia , Fibrilación Ventricular/terapia , Anciano , Brasil , Ablación por Catéter/efectos adversos , Cardioversión Eléctrica/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Simpatectomía/efectos adversos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Fibrilación Ventricular/diagnóstico , Fibrilación Ventricular/fisiopatología
14.
Arq. bras. cardiol ; Arq. bras. cardiol;103(6): 460-467, 12/2014. tab, graf
Artículo en Inglés | LILACS, Sec. Est. Saúde SP | ID: lil-732174

RESUMEN

Background: The QRS-T angle correlates with prognosis in patients with heart failure and coronary artery disease, reflected by an increase in mortality proportional to an increase in the difference between the axes of the QRS complex and T wave in the frontal plane. The value of this correlation in patients with Chagas heart disease is currently unknown. Objective: Determine the correlation of the QRS-T angle and the risk of induction of ventricular tachycardia / ventricular fibrillation (VT / VF) during electrophysiological study (EPS) in patients with Chagas disease. Methods: Case-control study at a tertiary center. Patients without induction of VT / VF on EPS were used as controls. The QRS-T angle was categorized as normal (0-105º), borderline (105-135º) or abnormal (135-180º). Differences between groups for continuous variables were analyzed with the t test or Mann-Whitney test, and for categorical variables with Fisher's exact test. P values < 0.05 were considered significant. Results: Of 116 patients undergoing EPS, 37.9% were excluded due to incomplete information / inactive records or due to the impossibility to correctly calculate the QRS-T angle (presence of left bundle branch block and atrial fibrillation). Of 72 patients included in the study, 31 induced VT / VF on EPS. Of these, the QRS-T angle was normal in 41.9%, borderline in 12.9% and abnormal in 45.2%. Among patients without induction of VT / VF on EPS, the QRS-T angle was normal in 63.4%, borderline in 14.6% and abnormal in 17.1% (p = 0.04). When compared with patients with normal QRS-T angle, those with abnormal angle had a fourfold higher risk of inducing ventricular tachycardia / ventricular fibrillation on EPS [odds ratio (OR) 4; confidence interval (CI) 1.298-12.325; p = 0.028]. After adjustment for other variables such as age, ejection fraction (EF) and QRS size, there was a trend for the abnormal QRS-T angle to identify patients with ...


Fundamento: O ângulo QRS-T mostra correlação com prognóstico em pacientes com insuficiência cardíaca e doença coronariana, traduzido por um aumento na mortalidade proporcional ao aumento na diferença entre os eixos do complexo QRS e da onda T no plano frontal. Até hoje, nenhuma informação a este respeito foi obtida em pacientes com cardiopatia chagásica. Objetivo: Correlacionar o ângulo QRS-T com a indução de taquicardia ventricular / fibrilação ventricular (TV / FV) em chagásicos durante estudo eletrofisiológico (EEF). Métodos: Estudo caso-controle em centro terciário. Pacientes sem indução de TV / FV ao EEF foram utilizados como controles. O ângulo QRS-T foi categorizado como normal (0-105º), limítrofe (105-135º) e anormal (135-180º). As diferenças entre os grupos foram analisadas pelo teste t ou teste de Mann-Whitney para variáveis contínuas, e teste exato de Fisher ou qui-quadrado para variáveis categóricas. Valores de p < 0,05 foram considerados significativos. Resultados: De 116 pacientes submetidos ao EEF, 37,9% foram excluídos por estarem com dados incompletos / prontuários inativos ou pela impossibilidade de se calcular corretamente o ângulo QRS-T (presença de bloqueio de ramo esquerdo e fibrilação atrial). De 72 pacientes incluídos, 31 induziram TV / FV ao EEF. Destes, o ângulo QRS-T se encontrava normal em 41,9%, limítrofe em 12,9% e anormal em 45,2%. No grupo de pacientes sem indução de TV / FV, o ângulo QRS-T se encontrava normal em 63,4%, limítrofe em 14,6% e anormal em 17,1% (p = 0,04). Quando comparados aos pacientes com ângulo QRS-T normal, o risco de indução de TV / FV nos pacientes com ângulo anormal foi quatro vezes maior [odds ratio (OR) 4; intervalo de confiança ...


Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Enfermedad de Chagas/fisiopatología , Taquicardia Ventricular/fisiopatología , Fibrilación Ventricular/fisiopatología , Factores de Edad , Estudios de Casos y Controles , Enfermedad de Chagas/complicaciones , Ecocardiografía , Electrocardiografía , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Estadísticas no Paramétricas , Volumen Sistólico/fisiología , Taquicardia Ventricular/etiología , Factores de Tiempo , Fibrilación Ventricular/etiología
15.
J Thorac Cardiovasc Surg ; 148(6): 3213-8, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25173125

RESUMEN

OBJECTIVES: Cardiac arrest after open surgery has an incidence of approximately 3%, of which more than 50% of the cases are due to ventricular fibrillation. Electrical defibrillation is the most effective therapy for terminating cardiac arrhythmias associated with unstable hemodynamics. The excitation threshold of myocardial microstructures is lower when external electrical fields are applied in the longitudinal direction with respect to the major axis of cells. However, in the heart, cell bundles are disposed in several directions. Improved myocardial excitation and defibrillation have been achieved by applying shocks in multiple directions via intracardiac leads, but the results are controversial when the electrodes are not located within the cardiac chambers. This study was designed to test whether rapidly switching shock delivery in 3 directions could increase the efficiency of direct defibrillation. METHODS: A multidirectional defibrillator and paddles bearing 3 electrodes each were developed and used in vivo for the reversal of electrically induced ventricular fibrillation in an anesthetized open-chest swine model. Direct defibrillation was performed by unidirectional and multidirectional shocks applied in an alternating fashion. Survival analysis was used to estimate the relationship between the probability of defibrillation and the shock energy. RESULTS: Compared with shock delivery in a single direction in the same animal population, the shock energy required for multidirectional defibrillation was 20% to 30% lower (P < .05) within a wide range of success probabilities. CONCLUSIONS: Rapidly switching multidirectional shock delivery required lower shock energy for ventricular fibrillation termination and may be a safer alternative for restoring cardiac sinus rhythm.


Asunto(s)
Cardioversión Eléctrica/métodos , Fibrilación Ventricular/terapia , Animales , Desfibriladores , Modelos Animales de Enfermedad , Cardioversión Eléctrica/instrumentación , Diseño de Equipo , Femenino , Hemodinámica , Factores de Tiempo , Fibrilación Ventricular/diagnóstico , Fibrilación Ventricular/fisiopatología
16.
Arq Bras Cardiol ; 103(6): 460-7, 2014 Dec.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-25590925

RESUMEN

BACKGROUND: The QRS-T angle correlates with prognosis in patients with heart failure and coronary artery disease, reflected by an increase in mortality proportional to an increase in the difference between the axes of the QRS complex and T wave in the frontal plane. The value of this correlation in patients with Chagas heart disease is currently unknown. OBJECTIVE: Determine the correlation of the QRS-T angle and the risk of induction of ventricular tachycardia / ventricular fibrillation (VT / VF) during electrophysiological study (EPS) in patients with Chagas disease. METHODS: Case-control study at a tertiary center. Patients without induction of VT / VF on EPS were used as controls. The QRS-T angle was categorized as normal (0-105º), borderline (105-135º) or abnormal (135-180º). Differences between groups for continuous variables were analyzed with the t test or Mann-Whitney test, and for categorical variables with Fisher's exact test. P values < 0.05 were considered significant. RESULTS: Of 116 patients undergoing EPS, 37.9% were excluded due to incomplete information / inactive records or due to the impossibility to correctly calculate the QRS-T angle (presence of left bundle branch block and atrial fibrillation). Of 72 patients included in the study, 31 induced VT / VF on EPS. Of these, the QRS-T angle was normal in 41.9%, borderline in 12.9% and abnormal in 45.2%. Among patients without induction of VT / VF on EPS, the QRS-T angle was normal in 63.4%, borderline in 14.6% and abnormal in 17.1% (p = 0.04). When compared with patients with normal QRS-T angle, those with abnormal angle had a fourfold higher risk of inducing ventricular tachycardia / ventricular fibrillation on EPS [odds ratio (OR) 4; confidence interval (CI) 1.298-12.325; p = 0.028]. After adjustment for other variables such as age, ejection fraction (EF) and QRS size, there was a trend for the abnormal QRS-T angle to identify patients with increased risk of inducing VT / VF during EPS (OR 3.95; CI 0.99-15.82; p = 0.052). The EF also emerged as a predictor of induction of VT / VF: for each point increase in EF, there was a 4% reduction in the rate of sustained ventricular arrhythmia on EPS. CONCLUSIONS: Changes in the QRS-T angle and decreases in EF were associated with an increased risk of induction of VT / VF on EPS.


Asunto(s)
Enfermedad de Chagas/fisiopatología , Taquicardia Ventricular/fisiopatología , Fibrilación Ventricular/fisiopatología , Factores de Edad , Anciano , Estudios de Casos y Controles , Enfermedad de Chagas/complicaciones , Ecocardiografía , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Estadísticas no Paramétricas , Volumen Sistólico/fisiología , Taquicardia Ventricular/etiología , Factores de Tiempo , Fibrilación Ventricular/etiología
17.
Rev Bras Cir Cardiovasc ; 28(3): 325-30, 2013.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-24343681

RESUMEN

INTRODUCTION: Reoperations of the mitral valve have a higher rate of complications when compared with the first surgery. With the field of video-assisted techniques for the first surgery of mitral valve became routine, reoperation cases began to arouse interest for this less invasive procedures. OBJECTIVE: To assess the results and the technical difficulties in 10 patients undergoing minimally invasive redo mitral valve surgery. METHOD: Cardiopulmonary bypass was installed through a cannula placed in the femoral vessels and right internal jugular vein, conducted in 28 degrees of temperature in ventricular fibrillation. A right lateral thoracotomy with 5 to 6 cm in the third or fourth intercostal space was done, pericardium was displaced only at the point of atriotomy. The aorta was not clamped. RESULTS: Ten patients with mean age of 56.9 ± 10.5 years, four were in atrial fibrilation rhythm and six in sinusal. Average time between first operation and reoperations was 11 ± 3.43 years. The mean EuroSCORE group was 8.3 ± 1.82. The mean ventricular fibrillation and cardiopulmonary bypass was respectively 70.9 ± 17.66 min and 109.4 ± 25.37 min. The average length of stay was 7.6 ± 1.5 days. There were no deaths in this series. CONCLUSION: Mitral valve reoperation can be performed through less invasive techniques with good immediate results, low morbidity and mortality. However, this type of surgery requires a longer duration of cardiopulmonary bypass, especially in cases where the patient already has prosthesis. The presence of a minimal aortic insufficiency also makes this procedure technically more challenging.


Asunto(s)
Implantación de Prótesis de Válvulas Cardíacas/métodos , Hipotermia Inducida/métodos , Válvula Mitral/cirugía , Cirugía Torácica Asistida por Video/métodos , Anciano , Puente Cardiopulmonar , Femenino , Enfermedades de las Válvulas Cardíacas/cirugía , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Reoperación/métodos , Reproducibilidad de los Resultados , Toracotomía/métodos , Factores de Tiempo , Resultado del Tratamiento , Fibrilación Ventricular/fisiopatología
18.
West Indian med. j ; West Indian med. j;62(8): 721-723, Nov. 2013. tab
Artículo en Inglés | LILACS | ID: biblio-1045740

RESUMEN

OBJECTIVE: To discuss the positive rate of ventricular late potential (VLP) between patients with acute ST-segment elevation myocardial infarction (STEMI) and patients with acute non NSTEMI. METHODS: One hundred and sixty-three cases of acute myocardial infarction (90 patients with STEMI and 73 with NSTEMI), admitted to the first hospital of China Medical University between June 2011 and August 2011, underwent VLP examination. RESULTS: The VLP positive rate of the STEMI group was 54.4%, while that of the NSTEMI group was 38.4%, and the differences have statistical meaning (χ2 = 4.186, p < 0.05). The occurrence rate of ventricular arrhythmia in VLP positive patients was 11.7%, while in VLP negative patients it was 3.5% (χ2 = 4.005, p < 0.05). CONCLUSION: The VLP positive rate of the STEMI group is higher than that of the NSTEMI group.


OBJETIVO: Analizar la tasa positiva del potencial tardío ventricular (PTV) entre pacientes con infarto agudo del miocardio sin elevación del segmento ST (NSTEMI por sus siglas en inglés) y el infarto agudo del miocardio con elevación del segmento ST (STEMI por sus siglas en inglés). MÉTODOS: Ciento sesenta y tres casos de infarto agudo de miocardio (90pacientes con STEMI) y 73 con NSTEMI, ingresados en la Universidad primer hospital de Medicina China entre junio y agosto de 2011, fueron sometidos a examen de PTV. RESULTADOS: La tasa positiva PVT del grupo STEMI fue 54.4%, mientras que la del grupo NSTEMI fue 38.4%, y las diferencias tienen significado estadístico (χ² = 4.186, p < 0.05). La tasa de ocurrencia de arritmia ventricular en pacientes PVTpositivos fue 11.7%, mientras que en los pacientes PVT negativos fue 3.5% (χ² = 4.005, p < 0.05). CONCLUSIÓN: La tasa PTV positiva del grupo STEMI es mayor que la del grupo NSTEMI.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Fibrilación Ventricular/fisiopatología , Disfunción Ventricular/fisiopatología , Infarto del Miocardio sin Elevación del ST/fisiopatología , Infarto del Miocardio con Elevación del ST/fisiopatología , Electrocardiografía
19.
Rev. bras. cir. cardiovasc ; Rev. bras. cir. cardiovasc;28(3): 325-330, jul.-set. 2013. ilus
Artículo en Portugués | LILACS | ID: lil-697217

RESUMEN

INTRODUÇÃO: Reoperações da valva mitral apresentam maior índice de complicações quando comparadas com a primeira cirurgia. Com o domínio das técnicas videoassistidas para as primeiras cirurgias da valva mitral, os casos de reoperações passaram a despertar interesse para esses procedimentos menos invasivos. OBJETIVO: Analisar os resultados e as dificuldades técnicas da retroca valvar mitral minimamente invasiva em 10 pacientes. MÉTODO: A circulação extracorpórea foi instalada por meio de colocação de cânulas femorais e cânula na veia jugular interna direita, conduzida em 28 graus de temperatura em fibrilação ventricular. Realizada toracotomia lateral direita com 5 a 6 cm no terceiro ou quarto espaço intercostal. Pericárdio foi descolado apenas na região do átrio esquerdo no ponto da atriotomia. A aorta não foi pinçada. RESULTADOS: Foram avaliados 10 pacientes com idade média de 56,9±10,5 anos. Quatro encontravam-se em ritmo de fibrilação atrial e 6 em ritmo sinusal. O tempo médio entre a primeira operação e a reoperações foi de 11 ± 3,43 anos. O EuroSCORE médio do grupo foi de 8,3 ± 1,82. O tempo médio de fibrilação ventricular e de circulação extracorpórea foi respectivamente 70,9 ± 17,66 min e 109,4 ± 25,37 min. O tempo médio de internamento foi de 7,6 ± 1,5 dias. Não houve óbitos nessa série. CONCLUSÃO: A reoperação da valva mitral pode ser feita por meio de técnicas menos invasivas com bons resultados imediatos e baixa morbimortalidade. Entretanto, esse tipo de cirurgia requer maior tempo de circulação extracorpórea, especialmente nos casos em que o paciente já tenha uma prótese. A presença de uma mínima insuficiência aórtica também torna esse procedimento tecnicamente mais desafiador.


INTRODUCTION: Reoperations of the mitral valve have a higher rate of complications when compared with the first surgery. With the field of video-assisted techniques for the first surgery of mitral valve became routine, reoperation cases began to arouse interest for this less invasive procedures. OBJECTIVE: To assess the results and the technical difficulties in 10 patients undergoing minimally invasive redo mitral valve surgery. METHOD: Cardiopulmonary bypass was installed through a cannula placed in the femoral vessels and right internal jugular vein, conducted in 28 degrees of temperature in ventricular fibrillation. A right lateral thoracotomy with 5 to 6 cm in the third or fourth intercostal space was done, pericardium was displaced only at the point of atriotomy. The aorta was not clamped. RESULTS: Ten patients with mean age of 56.9 ± 10.5 years, four were in atrial fibrilation rhythm and six in sinusal. Average time between first operation and reoperations was 11 ± 3.43 years. The mean EuroSCORE group was 8.3 ± 1.82. The mean ventricular fibrillation and cardiopulmonary bypass was respectively 70.9 ± 17.66 min and 109.4 ± 25.37 min. The average length of stay was 7.6 ± 1.5 days. There were no deaths in this series. CONCLUSION: Mitral valve reoperation can be performed through less invasive techniques with good immediate results, low morbidity and mortality. However, this type of surgery requires a longer duration of cardiopulmonary bypass, especially in cases where the patient already has prosthesis. The presence of a minimal aortic insufficiency also makes this procedure technically more challenging.


Asunto(s)
Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Implantación de Prótesis de Válvulas Cardíacas/métodos , Hipotermia Inducida/métodos , Válvula Mitral/cirugía , Cirugía Torácica Asistida por Video/métodos , Puente Cardiopulmonar , Enfermedades de las Válvulas Cardíacas/cirugía , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Tiempo de Internación , Reproducibilidad de los Resultados , Reoperación/métodos , Factores de Tiempo , Resultado del Tratamiento , Toracotomía/métodos , Fibrilación Ventricular/fisiopatología
20.
J Cardiovasc Comput Tomogr ; 7(3): 173-81, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23849490

RESUMEN

BACKGROUND: Myocardial fibrosis (MF) occurs in up to 80% of subjects with asymptomatic or mildly symptomatic hypertrophic cardiomyopathy (HCM) and can constitute an arrhythmogenic substrate for re-entrant, life-threatening ventricular arrhythmias in predisposed persons. OBJECTIVE: The aim was to investigate whether MF detected by delayed enhancement cardiac CT is predictive of ventricular tachycardia (VT) and fibrillation (VF) that require appropriate therapy by an implantable cardioverter defibrillator (ICD) in patients with HCM. METHODS: Twenty-six patients with HCM with previously (for at least 1 year) implanted ICD underwent MF evaluation by cardiac CT. MF was quantified by myocardial delayed enhanced cardiac CT. Data on ICD firing were recorded every 3 months after ICD implantation. Risk factors for sudden cardiac death in patients with HCM were evaluated in all patients. RESULTS: MF was present in 25 of 26 patients (96%) with mean fibrosis mass of 20.5 ± 15.8 g. Patients with appropriate ICD shocks for VF/VT had significantly greater MF mass than patients without (29.10 ± 19.13 g vs 13.57 ± 8.31 g; P = .01). For a MF mass of at least 18 g, sensitivity and specificity for appropriate ICD firing were 73% (95% CI, 49%-88%) and 71% (95% CI, 56%-81%), respectively. Kaplan-Meier curves indicated a significantly greater VF/VT event rate in patients with MF mass ≥18 g than in patients with MF <18 g (P = .02). In the Cox regression analysis, the amount of MF was independently associated with VF/VT in ICD-stored electrograms. CONCLUSION: The mass of MF detected by cardiac CT in patients with HCM at high risk of sudden death was associated with appropriate ICD firings.


Asunto(s)
Cardiomiopatía Hipertrófica/complicaciones , Cardiomiopatía Hipertrófica/terapia , Desfibriladores Implantables , Fibrosis Endomiocárdica/diagnóstico por imagen , Taquicardia Ventricular/diagnóstico por imagen , Taquicardia Ventricular/etiología , Fibrilación Ventricular/diagnóstico por imagen , Fibrilación Ventricular/etiología , Adolescente , Adulto , Medios de Contraste , Fibrosis Endomiocárdica/fisiopatología , Femenino , Humanos , Yopamidol , Masculino , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Curva ROC , Interpretación de Imagen Radiográfica Asistida por Computador , Factores de Riesgo , Taquicardia Ventricular/fisiopatología , Fibrilación Ventricular/fisiopatología
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