Trabalho Miocárdio: uma revisão sistemática do novo método de ecocardiografia e aplicações clínicas / Myocardial Work: a systematic review of novel echocardiography method and clinical applications

Fundamento: O trabalho miocárdico (MW) é uma nova modalidade de imagem que surgiu como uma forma potencial de avaliação da função ventricular esquerda (VE) em vários cenários clínicos. Ele calcula curvas de tensão de ecocardiografia de rastreamento de manchas (STE) com uma curva de pressão LV estimada utilizando curvas padrão de pressão arterial braquial de forma não invasiva. Objetivo: O objetivo desta pesquisa foi fornecer um resumo do conhecimento atual da MW não invasiva e suas aplicações clínicas, incluindo insuficiência cardíaca (IC), doença arterial coronariana (DAC), cardiomiopatia (CMP) e hipertensão (HTN). Além disso, são discutidas as limitações e recomendações da MW na prática clínica. Métodos: Pesquisamos no banco de dados online PubMed para nossa coleta de dados. Usamos as seguintes palavras-chave; (trabalho construtivo do miocárdio) OU (trabalho septal desperdiçado)) OU (trabalho miocárdico global)) OU (trabalho miocárdico)) OU (trabalho construtivo do miocárdio) OU (ecocardiografia nova). Revisamos ainda doze estudos com leitura de texto completo e incluídos nesta revisão sistemática. Resultados: Embora os índices de MW, particularmente GWI e GCW, tenham mostrado uma boa correlação com FE e parâmetros de deformação, a oportunidade de oferecer informações incrementais que não são afetadas pelas condições de carga tornou a aplicação de MW particularmente útil em uma variedade de configurações clínicas. Conclusão: Comparado ao FE e GLS, o MW é um teste promissor com maior sensibilidade e acurácia na identificação de indivíduos com doença cardiovascular. Os médicos também devem depender dos sintomas e dos achados do ECG até que uma extensa pesquisa multicêntrica validando essa estratégia seja feita para estabelecer o valor incremental da MW na avaliação ecocardiográfica diária. (AU)

Background: Myocardial work (MW) is a novel imaging modality that has emerged as a potential left ventricular (LV) function assessment in various clinical settings. MW calculates speckle-tracking echocardiography strain curves with an estimated LV pressure curve by non-invasively utilizing standard brachial blood pressure curves. Objective: This study aimed to provide a summary of current knowledge of non-invasive MW and its clinical applications, including in heart failure, coronary artery disease, cardiomyopathy, and hypertension. In addition, the limitations, and recommendations of MW in clinical practice are discussed. Methods: We searched the PubMed database using the following keywords: (myocardial constructive work) OR (wasted septal work) OR (global myocardial work) OR (myocardial work) OR (myocardial constructive work) OR (novel echocardiography). We further subjected 12 studies to full-text review and included them in this systematic review. Results: While MW indices, particularly global work index and global constructed work, have shown good correlations with ejection fraction (EF) and strain parameters, the opportunity of offering incremental information that is unaffected by loading conditions has made MW application particularly useful in a variety of clinical settings. Conclusion: Compared to EF and global longitudinal strain, MW is a promising test with higher sensitivity and accuracy for identifying individuals with cardiovascular disease. Clinicians should also evaluate symptoms and electrocardiographic findings until extensive multicenter studies validating this strategy are performed to establish the incremental value of MW in daily echocardiographic assessments.(AU)

Manejo de la insuficiencia cardiaca con estimulación hisiana en bloqueo de rama derecha: reporte de caso / Management of heart failure with His bundle pacing in right bundle branch block: case report

Resumen La terapia de resincronización cardiaca mediante estimulación hisiana ha demostrado ser efectiva en pacientes con bloqueo de rama izquierda del haz de His e insuficiencia cardiaca. Paciente masculino, con 47 años de edad, con insuficiencia cardiaca, fracción de expulsión del 17% y miocardio dilatada idiopática, electrocardiograma en ritmo sinusal, bloqueo auriculoventricular de 1.er grado, intervalo PR 400 ms, bloqueo completo de rama derecha del haz de His, bloqueo del fascículo anterior de la rama izquierda del haz de His, duración del QRS 200 ms. Se decidió realizar estimulación selectiva del haz de His. La resincronización cardiaca biventricular convencional en pacientes con presencia de bloqueo completo de la rama derecha del haz de His no está indicada debido a la pobre respuesta al tratamiento. La estimulación hisiana permite reclutar la rama bloqueada y reestablecer la conducción a través de ella, de tal forma que, en ausencia de necrosis, se logre sincronía biventricular. En el caso presentado el reclutamiento de la rama derecha mediante estimulación hisiana se reflejó en el restablecimiento de la sincronía biventricular, medida por rastreo de marcas (speckle tracking) e incremento significativo de la fracción de expulsión del ventrículo izquierdo del 17 al 36.6%, con un incremento absoluto del 19.6%.

Abstract Cardiac resynchronization therapy has proven to be an effective therapy in patients with left bundle branch block and heart failure. Male, 47 years old, heart failure with a left ventricle ejection fraction of 17%, idiopathic heart failure. ECG with sinus rhythm, 1st degree AV block, PR 400 ms, complete right bundle branch block, anterior hemi-fascicle of the left bundle of His, and QRS duration 200 ms. We decided to perform a selective His bundle pacing. In patients with right bundle branch block the biventricular cardiac resynchronization is not indicated due to low treatment response. His bundle pacing allows recruiting the blocked branch and restoring conduction throughout it, therefore, in the absence of necrosis the biventricular synchrony is achieved. We presented a case of His bundle pacing with recruitment of the right bundle branch, which reestablish biventricular synchrony measured by speckle tracking, and with a significant increase of the left ventricle ejection fraction from 17 to 36.6%, with an absolute increase of 19.6%.

Complications related to cardiac implantable electronic devices / Complicaciones asociadas al implante de dispositivos cardiacos electrónicos

Abstract Introduction: complications due to cardiac implantable electronic devices have been sparsely studied despite the increased number and complexity of these procedures in a population with multiple comorbidities. Objective: to determine the complication rate and associated risk factors at a reference center in Colombia. Methods: retrospective cohort study, which included patients who had a cardiac electronic device implanted between 2012 and 2015. Clinical records were reviewed to determine if patients developed complications during the year after the procedure, and, if so, which type and which clinical variables could be related to. Results: a total of 897 patients were included, 620 with pacemaker implants and 277 with other devices. The average age was 71.4 years, 63.9% were men, almost all the patients had a chronic disease, and 70% were de novo implants. The global complication rate was 10.9%; Lead displacement (3.6%) and pocket hematoma (3.3%) were the most frequent complications; 7.5% were major complications, and 73.5% occurred in the first month after procedure. The hospitalization rate associated with complications was 9.5%, and the median hospital stay was seven days, with 66.3% of these patients requiring new interventions. The mortality rate was 0.2% Conclusions: complications associated with cardiac implantable electronic devices occur red mainly in the first trimester after the initial intervention, were more frequent in patients under 80 years old, increased according to device complexity, and were not related to with the studied comorbidities.

Resumen Introducción: las complicaciones secundarias al implante de dispositivos cardiacos electrónicos han sido poco estudiadas a pesar del aumento en número y complejidad de estos procedimientos en población con múltiples comorbilidades. Objetivo: determinar la tasa de complicaciones del implante de dispositivos y los factores de riesgo asociados, en un centro de referencia en Colombia. Métodos: estudio de cohorte retrospectiva, que incluyó pacientes a quienes se les implantó dispositivo electrónico cardiaco entre 2012 y 2015. Se revisó la historia clínica para determinar si durante un año posterior al procedimiento, presentaron complicaciones, de qué tipo y con qué variables clínicas podría asociarse. Resultados: se incluyeron 897 pacientes, 620 con implante de marcapaso y 277 otros dispositivos. La edad promedio fue 71.4 años, 63.9% hombres, con múltiples enfermedades crónicas, 70% fueron implantes de novo. Se observó una tasa de complicaciones del 10.9%, la cual varía de acuerdo con el tipo de dispositivo. El desalojo del electrodo (3.6%) y el hematoma del bolsillo (3.3%) fueron las complicaciones más frecuentes, 7.5% fueron complicaciones mayores y 73.5% se presentaron en el primer mes postoperatorio. La tasa de hospitalización asociada a complicación fue 9.5%, mediana de estancia de 7 días, con un 66.3% de los pacientes en requerimiento de reintervención. La tasa de mortalidad fue del 0.2%. Conclusiones: las complicaciones asociadas al implante de dispositivos eléctricos cardiacos se presentaron principalmente en el primer trimestre, fueron más frecuentes en menores de 80 años, aumentaron con la complejidad del dispositivo y no se relacionaron con las comorbilidades estudiadas.

La asincronía ventricular izquierda como resultado de la estimulación apical permanente por dispositivos en el ventrículo derecho / Left ventricular dyssynchrony as result of right ventricular permanent apical pacing

Resumen La estimulación apical permanente del ventrículo derecho (VD) puede producir asincronía del ventrículo izquierdo (VI) desde los puntos de vista eléctrico y mecánico. Este fenómeno es efecto de una alteración de la activación normal del VI que lleva al deterioro de la función sistólica y la aparición de insuficiencia cardíaca y sus efectos deletéreos relacionados. Para el estudio de la asincronía eléctrica del VI se ha propuesto en fecha reciente el nuevo sistema electrocardiográfico no invasivo Synchromax, que puede cuantificar el grado de asincronía eléctrica que causa una subsecuente asincronía mecánica. Esta última se ha estudiado casi siempre mediante la ecocardiografía transtorácica bidimensional (ETT2D) a través del Doppler tisular y la deformación miocárdica y ahora con la ecocardiografía tridimensional transtorácica en tiempo real (E3DTR). La relación entre estos fenómenos ha sido motivo de estudio a fin de identificar a los pacientes que se benefician de la transición a un tratamiento de resincronización cardíaca. Conclusiones: La estimulación artificial permanente del VD produce asincronía eléctrica del VI que puede cuantificarse mediante el nuevo sistema electrocardiográfico Synchromax y desencadenar asincronía mecánica estudiada mediante la ecocardiografía transtorácica para reconocer a los pacientes que pueden beneficiarse de un tratamiento de resincronización cardíaca.

Abstract Permanent apical pacing of right ventricle (RV) can produce dyssynchrony of the left ventricle (LV) from an electrical and mechanical point of view. This phenomenon is caused by an alteration in the normal activation of LV leading to a deterioration of systolic function and the appearance of heart failure and its associated deleterious effects. For the study of the electrical asynchrony of the LV, a new noninvasive electrocardiographic system Synchromax has recently been proposed, being able to quantify the degree of electrical asynchrony that leads to a subsequent mechanical dyssynchrony. The latter has been traditionally studied by two-dimensional transthoracic echocardiography (2DTTE) through tissue Doppler and myocardial deformation and lately by real-time 3-dimensional echocardiography (RT3DE). The relationship between these phenomena has been the subject of study to predict those patients who benefit from an “upgrade” to cardiac resynchronization therapy. Conclusions: Permanent apical pacing of the RV produces electrical dyssynchrony of the LV that can be quantified using a new electrocardiographic system Synchromax and trigger mechanical asynchrony studied through transthoracic echocardiography allowing to predict those patients who benefit from cardiac resynchronization therapy.

Evaluación del impacto de la terapia de resincronización cardiaca en pacientes de Latinoamérica / Evaluation of the impact of cardiac resynchronisation on patients Latin America

Resumen Objetivo: medir el impacto de la terapia de resincronización cardiaca en términos de variables ecocardiográficas en pacientes de países latinoamericanos. Método: se realizó un estudio prospectivo, multicéntrico, intervencionista, en el que los pacientes elegibles fueron llevados, por primera vez, a implante de un dispositivo de resincronización cardiaca. El objetivo primario fue valorar los cambios del tamaño y la función del ventrículo izquierdo por medio de un ecocardiograma previo al implante del dispositivo y en el sexto mes. Los objetivos secundarios evaluados fueron hospitalizaciones, cambios en la clase funcional, mortalidad, calidad de vida y un score compuesto clínico basado en estos factores de evaluación global del paciente. Resultados: para cumplir el objetivo primario se analizaron datos de 75 sujetos. La edad promedio fue de 63,7 años; 21.3% fueron mujeres y 30.7% tuvieron cardiopatía isquémica. Al sexto mes de seguimiento las mediciones de volumen de fin de diástole y sístole del ventrículo izquierdo disminuyeron en promedio 37.6 ml y 37.8 ml, respectivamente. La fracción de eyección del ventrículo izquierdo en promedio se incrementó un 11%. El puntaje compuesto clínico mostró mejoría en el 86.4% de los pacientes en el sexto mes postimplante del resincronizador. Conclusiones: se observó remodelado inverso del ventrículo izquierdo y mejoría en el estado clínico de los pacientes con insuficiencia cardiaca y disfunción sistólica del ventrículo izquierdo que recibieron terapia de resincronización cardiaca en el ámbito de la práctica clínica de rutina.

Abstract Objective: To measure the impact of cardiac resynchronisation therapy in terms of cardiac ultrasound variables in patients from Latin-American countries. Method: A prospective, multicentre, interventionist study was conducted, in which the eligible patients were those that had a cardiac resynchronisation device implanted for the first time. The primary objective was to assess the changes in size and left ventricular function by means of a cardiac ultrasound carried out prior to implanting the device and in the sixth month. The secondary objectives evaluated were hospital admissions, change in functional class, mortality, quality of life, and an overall assessment of the patient using a combined clinical score based on these factors. Results: A total of 75 subjects were analysed in order to complete the primary objective. The mean age was 63.7 years; 21.3% were female, and 30.7% had ischaemic heart disease. At the sixth month, the left ventricular end-diastolic and systolic volume decreased by a mean of 37.6 ml and 37.8 ml, respectively. The left ventricular ejection fraction increased by a mean of 11%. The combined clinical score showed an improvement in 86.4% of the patients in the sixth month after the implantation of the synchronisation device. Conclusions: A reverse remodelling of the left ventricle was observed, as well as an improvement in the clinical stage of patients with heart failure and left ventricular systolic dysfunction that received cardiac resynchronisation treatment in the setting of routine clinical practice.

CardioResyncApp: Un aplicativo móvil para recolectar datos de investigación en Cardiología / CardioResyncApp: A mobile phone application for recording research data in Cardiology

Resumen Objetivo: diseñar y desarrollar un aplicativo móvil, innovador y útil que facilite el registro, la extracción y el análisis de datos en cardiología, y que permita la realización de investigaciones de alta calidad en pacientes con insuficiencia cardiaca llevados a terapia de resincronización. Metodología: se utilizó el marco de trabajo Scrum, ya que ofrece características de agilidad necesarias para la definición de requerimientos en un entorno colaborativo y en equipo; se realizaron entregas parciales de un producto final, lo cual facilitó la rapidez en el desarrollo de la aplicación. CardioResyncApp es una aplicación móvil que estará disponible en las dos plataformas móviles más importantes: App Store y Google Play. Resultado: se diseñó y desarrolló un aplicativo móvil, innovador, especializado en la recolección de datos para estudios de investigación en cardiología referentes a insuficiencia cardiaca y terapia de resincronización. Conclusiones: CardioResyncApp es un aplicativo móvil, ágil, fácil de usar, que revolucionará la recolección de datos en Colombia, para investigación en cardiología. No tendrá limitaciones geográficas para la recolección de datos ya que se encuentra disponible en las plataformas móviles más populares, como IOS y Android, lo cual facilitará la realización de estudios multicéntricos en Colombia, aproximándonos a la realidad de la enfermedad en las diversas poblaciones a pesar de las variaciones sociodemográficas.

Abstract Objective: The aim of this study is to design and develop a new and useful mobile application that facilitates the recording, extraction and analysis of data in cardiology, and can help in the carrying out of high quality research on patients with heart failure receiving resynchronisation therapy. Methodology: Scrum development technology was used, since it offers the dynamic features necessary to define the requirements in collaborative and team environment. Partial deliveries will be made of a final product, which will help to speed up the development of the application. CardioResyncApp is a mobile phone application that will be available on the two most important mobile platforms: App Store and Google Play. Results: A novel mobile application was designed and developed to collect data for research studies in cardiology as regards heart failure and resynchronisation therapy. Conclusions: CardioResyncApp is a dynamic, easy to use, mobile application what will revolutionise data collection in Colombia for cardiology research. It will have no geographic limitations for the collection of data, since it is available on the most popular mobile platforms such as IOS and Android, which will help in the conducting of multicentre studies in Colombia, and approaching the reality of the disease in the various populations despite the sociodemographic variations.

Correlation between cardiac resynchronization response and pulmonary artery hemodynamic parameters / 中南大学学报(医学版)

OBJECTIVES@#To evaluate the response to cardiac resynchronization therapy (CRT) and the correlation between CRT and pulmonary artery hemodynamic parameters.@*METHODS@#The patients with chronic heart failure indicator for CRT were enrolled. The left ventricular end-systolic volume (LVESV) was measured by echocardiography and New York Heart Association (NYHA) classification was evaluated between one week before and six months after CRT. Mean pulmonary artery pressure (mPAP), pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance (PVR) were measured by right heart catheterization. Left ventricular reverse remodeling (LVRR) is defined as a decrease of 15% or more in LVESV at the 6th month after CRT; Clinical response is defined as a decrease of NYHA classification at or above grade 1 at the 6th month after CRT. Pulmonary hypertension (PH) was defined as mPAP≥25 mmHg. According to the response, patients were divided into 3 groups: group A (LVRR+clinical response), group B (no LVRR+clinical response) and group C (no LVRR+no clinical response). The changes of NYHA classification, echocardiographic and pulmonary hemodynamic parameters were observed in the 3 groups. The Kaplan-Meier survival curve was used to analyze the differences in all-cause mortality, combined end-point events of death or re-hospitalization due to heart failure among different groups.@*RESULTS@#A total of 45 patients with CRT implantation [aged (63.27±9.55) years, 36 males] were included. The average follow-up period was (33.76±11.50) months. Thirty-one patients (68.89%) were in group A, 9 of whom with PH. Eight patients (17.78%) were in group B, 7 of whom with PH. Six patients were in group C, all with PH. Cardiac function including NYHA classification, echocardiographic and pulmonary hemodynamic parameters had been significantly improved in group A after CRT implantation (0.05). There were no significant changes in NYHA classification, echocardiographic and pulmonary hemodynamic parameters in group C (>0.05). Compared with group C, group A and group B had lower all-cause mortality (=0.005) and lower incidence of composite endpoint events (=0.001).@*CONCLUSIONS@#Patients with LVRR and clinical response after CRT have a good prognosis. Patients with clinical response but without LVRR have a better prognosis than those without clinical response and LVRR, which may be related to the decrease of pulmonary hemodynamic parameters such as mPAP and TPG.

Application and efficacy of the adjustment on left ventricular electrical delay and the distance between right and left ventricular pacing polar in optimizing the left ventricular pacing polar / 中华心血管病杂志

Objective: To investigate the application and efficacy of left ventricular (LV) electrical delay (LVED) and the distance of right ventricular(RV) pacing polar to LV(DRLV) in optimizing LV pacing polar. Methods: Heart failure (HF) patients who implanted cardiac resynchronization therapy (CRT) device with a LV quadripolar lead from January 2014 to January 2018 at General Hospital of Northern Theater Command were enrolled in the study. Measurements of LVED and DRLV of each polar of the lead were performed in patients with HF who underwent CRT with LV quadripolar lead. The principle in turn for polar selecting used for clinical LV pacing was the pacing polar: (1)without phrenic nerve stimulation(PNS); (2)with appropriate capture threshold; (3)not located in apical; (4)with maximal LVED; (5)with maximal DRLV. The LV pacing polar was selected for CRT according to the procedure. The distribution of target veins implanted with LV quadripolar lead were calculated. The percentage of biventricular pacing at 6-month follow-up was recorded. The following indexes were compared before and 6-month after surgery, including QRS duration, LV end-systolic volume(LVESV), LV ejection fraction(LVEF), LV end-diastolic dimension(LVEDD), 6 minute walking distance(6MWD), New York Heart Association(NYHA) class. The efficacy and echocardiographic efficacy of CRT was evaluated. Results: There were twenty-nine HF patients enrolled. The mean age of enrolled patients was(61.7±7.6)years old, nineteen (66%)of them were male. There were seventeen(59%) patients diagnosed as dilated cardiomyopathy and twelve(41%) patients as ischemic cardiomyopathy. All patients were successfully implanted with LV quadripolar lead into target veins, and all four pacing sites were also in target veins. Target veins were located in lateral veins in 15 patients (52%), anterior veins in 2 patients (7%), posterior veins in 11 patients (38%), and lateral branches of great cardiac veins in 1 patient (3%). After 6-month of follow-up, the percentage of biventricular pacing was greater than 95%.There were nineteen(66%) patients optimized LV pacing polar by the largest LVED and four (14%) patients by the DRLV. Of the 29 patients, 5(17%) patients used D1 as the pacing polar, 5(17%) patients used M2 as the pacing polar, 7(24%) patients used M3 as the pacing polar, and 12(41%) patients used P4 as the pacing polar. The pacing polars (D1, M2) of traditional bipolar lead were used in 10(34%) patients, and the LV quadripolar lead specific pacing polars (M3, P4) were used in 19(66%) patients.Compared to a LV quadripolar lead, the LV pacing polar (M3, P4) selected in 19(66%) patients were not achievable with the traditional LV bipolar lead (D1, M2). Preoperative QRS duration, LVESV, LVEF, LVEDD, 6MWD and NYHA class were (171±24)ms, (231±79)ml, (28±5)%, (74±11)mm, (294±103)m, (3.2±1.0)class and the postoperative 6-month were (130±12)ms, (158±73)ml, (36±10)%, (66±12)mm, (371±86)m, (1.9±0.5)class. These indexes were significantly improved after 6 months operation(P<0.001). 97% and 83% patients were responders of CRT as assessed by 6-month efficacy and echocardiographic efficacy. Conclusion: The maximal LVED and DRLV can be used to select LV pacing polar with a high rate of CRT response rate.

Cardiac resynchronization therapy in a patient with pacemaker-induced cardiomyopathy / Terapia de resincronización cardiaca en un paciente con miocardiopatía inducida por marcapasos

Abstract There is a high prevalence of cardiac stimulation therapy complications; however, they are frequently forgotten by medical personnel. Cardiomyopathy secondary to biventricular dyssynchrony due to high right ventricular stimulation is a frequent cause of heart failure, increasing the risk of death and hospitalization and decreasing the quality of life of patients with pacemakers. We present a case of a patient who developed heart failure. The most common causes of left ventricular dysfunction were ruled out, and it was determined to be secondary to pacemaker-induced cardiomyopathy. The patient's device was changed to biventricular cardiac resynchronization therapy, with an adequate clinical response. We highlight the importance of looking for complications related to right ventricular stimulation devices in patients with heart failure, and of considering a change to biventricular stimulation within the treatment plan. (Acta Med Colomb 2019; 44. DOI:https://doi.org/10.36104/amc.2019.1300).

Resumen Las complicaciones derivadas de la terapia de estimulación cardiaca tienen alta prevalencia, sin embargo, a menudo son olvidadas por el personal médico. La miocardiopatía secundaria a la disincronía biventricular por la alta carga de estimulación ventricular derecha es una causa frecuente de falla cardiaca, aumentando el riesgo de muerte, hospitalizaciones y disminuyendo la calidad de vida en los pacientes con marcapasos. Presentamos un caso de una paciente que desarrolló falla cardiaca, se descartaron las causas más comunes de disfunción ventricular izquierda y se consideró secundaria a miocardiopatía inducida por marcapasos, se le realizó cambio de dispositivo por terapia de resincronización cardiaca biventricular con adecuada respuesta clínica. Resaltamos la importancia de buscar en los pacientes con falla cardiaca complicaciones asociadas a dispositivos de estimulación ventricular derecha y considerar dentro del tratamiento el cambio a estimulación biventricular. (Acta Med Colomb 2019; 44. DOI:https://doi.org/10.36104/amc.2019.1300).

Clinimetric analysis of heart failure in Mexican patients / Análisis clinimétrico de la insuficiencia cardiaca en pacientes mexicanos

Abstract Heart failure (HF) is a syndrome characterized basically by a circulatory deficit to cover the metabolic and energetic demands of the body. This condition has a broad spectrum in its clinical presentation, affects the quality of life significantly, impacts the family/social environment, and generates a great demand for health services. The purpose of this research is to report the situational diagnose of patients with HF in Mexico. We evaluated 292 patients, 70.2% were men. Average age was 56.7 +- 14.3 years. Ischemic heart disease is the main etiology (98 patients, 33.9%) followed by hypertensive (22.6%) and idiopathic (23.3%) heart disease. The associated clinical background was obesity (31.1%), systemic hypertension (36.7%), myocardial infarction (26.4%), and dyslipidemia (15.1%). The most common symptom was stress dyspnea (41.4%) and jugular vein engorgement at physical examination (32.5%). Anemia was observed in 1% of patients. The average left ventricular ejection fraction was 29.2 +- 10.6%. Sinus rhythm was the most frequently detected in 84.9%. 19.9% of patients had an implantable cardioverter-defibrillator or cardiac resynchronization therapy. 13.7% of patients with QRS > 130 ms. In our population, the meta-analysis global group in chronic heart failure risk score calculated was 16.8 +- 5.7 and for EMPHASIS 3.3 +- 1.5. We observed that age at presentation in HF in this analysis is at least 10 years younger than in other reports. The grade of obesity takes relevance in our group. The association of anemia and HF in Mexico is rare.

Resumen La insuficiencia cardiaca es un síndrome caracterizado fundamentalmente por un déficit circulatorio para cubrir las demandas metabólicas y energéticas del organismo. Esta entidad tiene un amplio espectro en su presentación clínica, afecta de manera significativa la calidad de vida, impacta en el entorno familiar/social y genera una gran demanda de los servicios de salud. El propósito de esta investigación es reportar el diagnóstico situacional de pacientes con insuficiencia cardiaca (IC) en México. Evaluamos 292 enfermos, 70.2% eran hombres. Con edad promedio 56.7 +- 14.3 años. La principal etiología es la cardiopatía isquémica (33.9%), seguida de la hipertensiva (22.6%) e idiopática (23.3%). Los antecedentes clínicos asociados fueron: obesidad (31.1%), hipertensión arterial sistémica (36.7%), infarto al miocardio (26.4%) y dislipidemia (15.1%). El síntoma con mayor presentación fue la disnea de esfuerzos (41.4%) y a la exploración física la ingurgitación yugular (32.5%). Se observó anemia en 1% de los enfermos. La fracción de expulsión del ventrículo izquierdo (FEVI) promedio fue de 29.2 + 10.6%. El ritmo sinusal fue el más frecuentemente detectado en 84.9%. El 19.9% de los pacientes tenían instalado un desfibrilador automático implantable (DAI) o tratamiento de resincronización cardiaca (TRC). El 13.7% de los enfermos con QRS mayor de 130 ms. El riesgo (MAGGIC) calculado en nuestro grupo poblacional fue de 16.8 +- 5.7 y para EMPHASIS 3.3 +- 1.5. Observamos que la edad de presentación de la IC en el presente análisis es menor por 10 años en comparación con otros reportes. El grado de obesidad toma relevancia en nuestro grupo. La asociación de anemia e IC en México es poco frecuente.

Chagas disease is associated with a poor outcome at 1-year follow-up after cardiac resynchronization therapy

SUMMARY BACKGROUND: Cardiac resynchronization therapy (CRT) is a therapeutic modality for patients with heart failure (HF). The effectiveness of this treatment for event reduction is based on clinical trials where the population of patients with Chagas' disease (DC) is underrepresented. OBJECTIVE: To evaluate the prognosis after CRT of a population in which CD is an endemic cause of HF. METHODS: A retrospective cohort conducted between January 2015 and December 2016 that included patients with HF and left ventricular ejection fraction (LVEF) of less than 35% and undergoing CRT. Clinical and demographic data were collected to search for predictors for the combined outcome of death or hospitalization for HF at one year after CRT implantation. RESULTS: Fifty-four patients were evaluated, and 13 (24.1%) presented CD as the etiology of HF. The mean LVEF was 26.2± 6.1%, and 36 (66.7%) patients presented functional class III or IV HF. After the mean follow-up of 15 (±6,9) months, 17 (32.1%) patients presented the combined outcome. In the univariate analysis, CD was associated with the combined event when compared to other etiologies of HF, 8 (47%) vs. 9 (13,5%), RR: 3,91 CI: 1,46-10,45, p=0,007, as well as lower values of LVEF. In the multivariate analysis, CD and LVEF remained independent risk factors for the combined outcome. CONCLUSION: In a population of HF patients undergoing CRT, CD was independently associated with mortality and hospitalization for HF.

RESUMO INTRODUÇÃO: A terapia de ressincronização cardíaca (TRC) é uma modalidade terapêutica para pacientes com insuficiência cardíaca (IC). A eficácia desse tratamento para redução de eventos baseia-se em ensaios clínicos em que a população de pacientes com doença de Chagas (DC) é sub-representada. OBJETIVO: Avaliar o prognóstico após TRC em uma população em que a DC é uma causa frequente de IC. MÉTODOS: Coorte retrospectiva realizada entre janeiro de 2015 e dezembro de 2016, sendo incluídos pacientes portadores de IC com fração de ejeção do ventrículo esquerdo (Feve) menor que 35% e submetidos à TRC. Os dados clínicos e demográficos foram coletados para pesquisa de preditores para o desfecho combinado de morte ou internação por IC após implante da TRC. RESULTADOS: Foram avaliados 54 pacientes, dos quais 13 (24,1%) apresentavam a DC como etiologia da IC. A Feve média foi de 26,2% (±6,1) e 36 (66,7%) pacientes apresentavam classe funcional de IC III ou IV. Após o seguimento médio de 15 meses, 17 (32,1%) pacientes apresentaram o desfecho combinado. Na análise univariada, a DC esteve associada ao evento combinado quando comparada a outras etiologias de IC, 8 (47%) vs 9 (13,5%), RR: 3,91 IC: 1,46-10,45, p=0,007, assim como valores mais baixos da Feve. Na análise multivariada, a DC e a Feve permaneceram como fatores de risco independentes para o desfecho combinado. CONCLUSÃO: Em uma população de pacientes com IC submetidos à TRC, a doença de Chagas esteve independentemente associada à mortalidade e internação por insuficiência cardíaca no seguimento de 15 meses.

Terapia de resincronización cardíaca: Índice del QRS como predictor de respuesta / Cardiac resynchronization therapy: QRS index as a response predictor

RESUMEN Introducción: La terapia de resincronización cardíaca (TRC) es indicación en la insuficiencia cardíaca con QRS ancho y disminución grave de la fracción de eyección del ventrículo izquierdo. Objetivos: Definir los predictores de respuesta favorable a la TRC. Método: Se realizó un estudio observacional, descriptivo, retrospectivo, para evaluar el índice del QRS (diferencia entre anchura del QRS antes y después del implante, dividido entre su valor antes del implante, multiplicado por 100) como predictor de respuesta favorable a la TRC. Se realizaron electrocardiogramas antes del procedimiento, a los 6 y a los 12 meses del implante. Las mediciones se hicieron por dos observadores independientes, la primera digital en el monitor del salón de operaciones y el resto manual. Resultados: Se incluyeron 91 pacientes (edad media 61,2 años, 76% hombres), QRS mayor de 120 ms y fracción de eyección menor de 35%. Se obtuvo respuesta favorable en un 59%. No hubo diferencias significativas pre-implante en la duración del QRS entre respondedores y no respondedores (151,3 ms vs 151,34 ms, p=0,98), pero sí post-implante (100 vs 115 ms, p<0,0001), así como en el porcentaje de disminución del QRS (33,2% vs 24,3%, p<0,0001). La curva ROC mostró que un valor de corte del índice de QRS del 30% fue sensible (62%) y específico (75%), para predecir respuesta favorable. Conclusiones: La disminución de la anchura del QRS luego del implante de la TRC se relaciona con una respuesta favorable a la misma.

ABSTRACT Introduction: Cardiac resynchronization therapy (CRT) is an indication in heart failure with wide QRS and severely reduced left ventricular ejection fraction. Objectives: To define the response predictors favorable to CRT. Method: An observational, descriptive, retrospective study was conducted to evaluate the QRS index (difference between the QRS width before and after implantation, divided by its value before implantation, multiplied by 100) as a predictor of favorable response to CRT. Electrocardiograms were performed before the procedure, at 6 and 12 months after implantation. The measurements were made by two independent observers, the first digital on the operating room monitor and the rest manual. Results: A total of 91 patients (mean age 61.2 years, 76% men) were included, with QRS wider than 120 ms and ejection fraction less than 35%. A favorable response was obtained in 59%. There were no significant pre-implant differences in the QRS duration between responders and non-responders (151.3 ms vs. 151.34 ms, p=0.98), but there were differences post-implant (100 vs. 115 ms, p<0.0001), as well as in the QRS percentage of decrease (33.2% vs. 24.3%, p<0.0001). The ROC curve showed that a cut-off value of the QRS index of 30% was sensitive (62%) and specific (75%) in order to predict a favorable response. Conclusions: The decrease in the QRS width after the CRT implant is related to a favorable response to it.

Uso de desfibriladores implantables y terapia de resincronización cardiaca en ancianos mayores de 70 a 80 años: controversias y evidencia / Use of implantable defibrillators and cardiac resynchronisation therapy in patients more than 70 to 80 years old: arguments and evidence

Resumen Prevenir la muerte súbita y aumentar la supervivencia y la calidad de vida en los pacientes con falla cardiaca son las principales indicaciones para el uso de los desfibriladores implantables y la terapia de resincronización cardiaca respectivamente. Hay certeza de la eficacia clínica de estos dispositivos para la población general; sin embargo, no es tan clara para los pacientes mayores de 70 años dado que esta población no está lo suficientemente representada en los diseños de los estudios clínicos. La evidencia disponible hasta el momento precisa que en este grupo etario existe beneficio de la terapia de resincronización cardiaca, pero es cuestionable el uso de cardiodesfibriladores. Así mismo, es indispensable tener en cuenta no sólo el riesgo de mortalidad de los pacientes sino también su funcionalidad y fragilidad para definir si se benefician o no de estos dispositivos.

Abstract The prevention of sudden death, to increase the survival, and quality of life in patients with heart failure, are the main indications for the use of implantable defibrillators and cardiac resynchronisation therapy, respectively. There is confidence in the clinical efficacy of these devices for the general population, but it is not so clear in patients over 70 years-old, given that this population is not sufficiently represented in clinical study designs. Although the evidence available up until now shows that there is a benefit in this age group for the use cardiac resynchronisation therapy, the use of cardiac defibrillators is questionable. It is also indispensable to not only to take into account the mortality risk in these patients, but also their functionality and frailty in order to determine whether or not they would benefit from these devices.

Electrofisiología / Electrophysiology

El tratamiento de los trastornos del ritmo cardíaco ha sufrido recientemente una verdadera revolución. El empleo de avanzadas terapéuticas por catéter para tratar una gran variedad de arritmias, utilizando diferentes fuentes de energía, han permitido evolucionar de un tratamiento antiguamente basado casi con exclusividad en el empleo de fármacos antiarrítmicos, como terapia aguda y/o preventiva, a uno actualmente curativo, con el consiguiente avance que estos últimos métodos conllevan para la calidad de vida de nuestros pacientes y sus familias. La tendencia ha continuado con el empleo de navegadores 3 D que ya no requieren el empleo de radiación ionizante para efectuar estos procedimientos y permiten una mayor exactitud para mejorar los excelentes resultados alcanzados. El desarrollo de dispositivos eléctricos como los marcapasos, sumado a la aparición de otros más avanzados como defibriladores y resincronizadores cardíacos también ha contribuido a mejorar la expectativa de vida de muchos niños con cardiopatías diversas. La mejora evidenciada con el empleo de registradores de eventos implantables y el seguimiento mediante monitoreo a distancia de los diferentes dispositivos eléctricos han demostrado mejorar los resultados obtenidos con dichos métodos a largo plazo. Sin duda con la ayuda de la genética en un futuro cercano será posible hacer tratamientos cada vez más específicos para ayudar en casos de arritmias graves hereditarias o causadas por mutaciones en los canales iónicos de las células cardíacas. Si bien existen aún controversias respecto de algunos ítems muy puntuales los mismos se irán aclarando con las experiencias colaborativas en marcha en diferentes centros médicos especializados (AU)

Recently, treatment of heart rhythm disorders has revolutionized. The use of advanced catheter-based therapies to treat a wide spectrum of arrhythmias, using different energy sources, has led the treatment to evolve from an almost exclusively antiarrhythmic drug-based treatment, such as acute and/or preventive therapy, to a currently curative one, with the consequent advance that these latter methods add to the quality of life of our patients and their families. The trend has continued with the use of 3D navigators that no longer require the use of ionizing radiation to perform these procedures and allow greater accuracy to improve the excellent results achieved. The development of electrical devices, such as pacemakers, coupled with the emergence of more advanced devices, such as defibrillators and cardiac resynchronizers, has also been useful to improve the life expectancy of many children with different types of heart disease. The advances evidenced by the use of implantable event loggers and remote monitoring of different electrical devices have shown to improve the long-term results obtained with such methods. Undoubtedly, with the help of genetics in the near future it will be possible to develop increasingly specific therapies to treat patients with severe hereditary arrhythmias or those caused by mutations in the ion channels of the heart cells. Although controversy still exists regarding some very specific issues, these will be clarified with the collaborative experience underway at different specialized medical centers

Left Ventricular End-Systolic Volume Can Predict 1-Year Hierarchical Clinical Composite End Point in Patients with Cardiac Resynchronization Therapy

PURPOSE: This study aimed to elucidate which echocardiographic criteria at three time points, for cardiac resynchronization therapy (CRT) response, are accurate in discriminating the hierarchical clinical composite end point (HCCEP). MATERIALS AND METHODS: We included 120 patients (age, 66.1±12.6 years; men, 54.2%) who underwent CRT implantation for heart failure (HF). Echocardiography was performed before and at 3, 6, and 12 months after CRT implantation. The 1-year HCCEP included all-cause mortality, hospitalization for HF, and New York Heart Association functional class for 12 months. CRT response criteria were decrease in left ventricular (LV) end-systolic volume (LVESV) >15%, decrease in LV end-diastolic volume >15%, absolute increase in LV ejection fraction (LVEF) ≥5%, relative increase in LVEF ≥15%, and decrease in mitral regurgitation ≥1 grade. Temporal changes in CRT response rates, accuracy of CRT response criteria at each time and cutoff value for the discrimination of improvement in HCCEP, and agreements with improvement in HCCEP were analyzed. RESULTS: HCCEP improvement rates were 65.8% in total group. In nonischemic group, CRT response rates according to all echocardiographic criteria significantly increased with time. In ischemic group, CRT response rate did not significantly change with time. In total group, ΔLVESV at 6 months (ΔLVESV6) had the most significant accuracy for the discrimination of HCCEP (area under the curve=0.781). The optimal cutoff value of ΔLVESV6 was 13.5% (sensitivity=0.719, specificity=0.719). ΔLVESV6 had fair agreement with HCCEP (κ=0.391, p < 0.001). CONCLUSION: ΔLVESV6 is the most useful echocardiographic CRT response criterion for the prediction of 1-year HCCEP.