Research progress of visualization methods and localization techniques of the cardiac conduction system / 中国胸心血管外科临床杂志

@#The cardiac conduction system (CCS) is a set of specialized myocardial pathways that spontaneously generate and conduct impulses transmitting throughout the heart, and causing the coordinated contractions of all parts of the heart. A comprehensive understanding of the anatomical characteristics of the CCS in the heart is the basis of studying cardiac electrophysiology and treating conduction-related diseases. It is also the key of avoiding damage to the CCS during open heart surgery. How to identify and locate the CCS has always been a hot topic in researches. Here, we review the histological imaging methods of the CCS and the specific molecular markers, as well as the exploration for localization and visualization of the CCS. We especially put emphasis on the clinical application prospects and the future development directions of non-destructive imaging technology and real-time localization methods of the CCS that have emerged in recent years.

Feasibility of Goal-Directed Fluid Therapy in Patients with Transcatheter Aortic Valve Replacement - An Ambispective Analysis

ABSTRACT Introduction: Goal-directed fluid therapy (GDFT) has been shown to reduce postoperative complications. The feasibility of GDFT in transcatheter aortic valve replacement (TAVR) patients under general anesthesia has not yet been demonstrated. We examined whether GDFT could be applied in patients undergoing TAVR in general anesthesia and its impact on outcomes. Methods: Forty consecutive TAVR patients in the prospective intervention group with GDFT were compared to 40 retrospective TAVR patients without GDFT. Inclusion criteria were age ≥ 18 years, elective TAVR in general anesthesia, no participation in another interventional study. Exclusion criteria were lack of ability to consent study participation, pregnant or nursing patients, emergency procedures, preinterventional decubitus, tissue and/or extremity ischemia, peripheral arterial occlusive disease grade IV, atrial fibrillation or other severe heart rhythm disorder, necessity of usage of intra-aortic balloon pump. Stroke volume and stroke volume variation were determined with uncalibrated pulse contour analysis and optimized according to a predefined algorithm using 250 ml of hydroxyethyl starch. Results: Stroke volume could be increased by applying GDFT. The intervention group received more colloids and fewer crystalloids than control group. Total volume replacement did not differ. The incidence of overall complications as well as intensive care unit and hospital length of stay were comparable between both groups. GDFT was associated with a reduced incidence of delirium. Duration of anesthesia was shorter in the intervention group. Duration of the interventional procedure did not differ. Conclusion: GDFT in the intervention group was associated with a reduced incidence of postinterventional delirium.

Relationship of the T-wave Tpeak-Tend interval with conduction system disorders in arterial hypertension / Relación del intervalo Tpico-Tfinal de la onda T con trastornos del sistema de conducción en hipertensión arterial

Abstract Purpose: The Tpeak-Tend interval of the T wave has emerged as a new electrocardiographic marker of increased transmural dispersion of ventricular repolarization. We aimed to determine the presence of cardiac conduction system disorders in patients with systemic arterial hypertension (SAH) who have altered Tpeak-Tend interval of the T wave. Methods: The 67 patients with SAH were divided into two groups. Those with prolonged (≥ 77 ms) Tpeak-Tend intervals, 21 (31%) patients were in the study group. Those with normal (< 77 ms) Tpeak-Tend intervals, 46 (69%) patients were in the control group. Alteration of ventricular repolarization manifested as a prolongation of the Tpeak-Tend interval was detected by computerized electrocardiographic analysis tools. Results: The median value of QRS complex duration was significantly wider in the study group as compared to the control group (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). There was a significantly greater incidence of left anterior hemiblock in the study group (14% vs. 0% p < 0.04). The median value of the QTc interval was significantly greater in the study group (440 ± 26 vs. 422 ± 15 p < 0.01). There was a significantly greater incidence of patients with prolonged QTc interval in the study group (33% vs. 11% p < 0.02). The median value of the Tpeak-Tend interval was significantly greater in the study group (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), as well as, the Tpeak-Tend/QTc ratio in the study group (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). Conclusion: There is a significantly greater ventricular repolarization disorders and abnormalities of the cardiac conduction system in SAH patients who possess altered Tpeak-Tend interval of the T wave.

Resumen Objetivo: El intervalo Tpico-Tfinal de la onda T es un marcador electrocardiográfico de la dispersión transmural aumentada de la repolarización ventricular. Investigamos la presencia de trastornos del sistema de conducción cardíaca en pacientes con hipertensión arterial sistémica (HA) que poseen alterado el intervalo Tpico-Tfinal de la onda T. Métodos: Los 67 pacientes con HA fueron divididos en dos grupos. Aquellos con intervalos de Tpico-Tfinal prolongados (≥ 77 ms), 21 (31%) pacientes (grupo de estudio). Aquellos con intervalos normales (< 77 ms) Tpico-Tfinal, 46 (69%) pacientes (grupo control). Los intervalos Tpico-Tfinal fueron medidos por herramientas de análisis electrocardiográfico computarizado. Resultados: El valor mediano de la duración del complejo QRS fue significativamente más amplio en el grupo de estudio (110 ± 12 ms vs. 94 ± 8 ms p < 0.001). Hubo una incidencia significativamente mayor de hemibloqueo anterior izquierdo en el grupo de estudio (14% vs. 0% p < 0.04). El valor mediano del intervalo QTc fue significativamente mayor en el grupo de estudio (440 ± 26 vs. 422 ± 15 p < 0.01). Hubo una incidencia significativamente mayor de pacientes con intervalo QTc prolongado en el grupo de estudio (33% vs. 11% p < 0.02). El valor mediano del intervalo Tpico-Tfinal fue significativamente mayor en el grupo de estudio (84 ± 5 ms vs. 65 ± 4 ms p < 0.001), así como el cociente Tpico-Tfinal/QTc (0.19 ± 0.1 vs. 0.16 ± 0.1 p < 0.001). Conclusión: Existe una alteración de la repolarización ventricular significativamente mayor y anomalías del sistema de conducción cardíaca en pacientes con HA que poseen alteración del intervalo Tpico-Tfinal de la onda T.

Repercusiones cardíacas en pacientes con pectus excavatum: puesta al día. Segunda parte / Cardiac repercussions in patients with pectus excavatum: update. Part two / Repercussões cardíacas em pacientes com pectus excavatum: atualização. Parte dois

El pectus excavatum (PEX) es una deformación de la pared torácica que obedece a una alteración de los cartílagos costales con el consiguiente hundimiento del esternón. Históricamente, se clasificaba como un defecto únicamente estético o cosmético, sin embargo, en los últimos años se han desarrollado nuevos métodos de estudio para la valoración de las repercusiones de esta patología. Existe cada vez más bibliografía que demuestra importantes repercusiones funcionales. Se realizó una puesta al día de las repercusiones cardíacas de la patología y un análisis de los artículos más relevantes de los últimos años. La evidencia actual permite afirmar que existe una afectación cardíaca por compresión esternal en la mayoría de los pacientes con PEX. Las afectaciones incluyen alteraciones anatomofuncionales (trastornos del ritmo, disminución del llenado ventricular), del volumen sistólico, aumento de la presión de la aurícula derecha, valvulopatías, compresión del ventrículo derecho, derrame pericárdico, entre otras. Todo lo cual permite concluir que el PEX puede presentar importantes alteraciones cardíacas que deben ser tenidas en cuenta a la hora de valorar los pacientes con esta patología.

Pectus excavatum (PEX) is a deformation of the chest wall caused by an alteration of the costal cartilages with the consequent collapse of the sternum. Historically, it had been classified as a solely aesthetic or cosmetic defect, however, in recent years new study methods have been developed to assess the repercussions of this pathology, with increasing bibliography showing important functional consequences. We updated the cardiac pathological repercussions and analyzed the most relevant articles of recent years. The current evidence suggests that there is cardiac involvement due to sternal compression in most patients with PEX. These affectations include anatomical functional alterations: rhythm disorders, decreased ventricular filling, decreased stroke volume, increased right atrial pressure, valve disease, right ventricular compression, pericardial effusion, among others. All of which enables us to conclude that PEX can present important cardiac alterations that must be taken into account when assessing patients with this pathology.

Pectus excavatum (PEX) é uma deformação da parede torácica decorrente de uma alteração das cartilagens costais com consequente colapso do esterno. Historicamente, foi classificado como um defeito exclusivamente estético ou cosmético, porém, nos últimos anos, novos métodos de estudo foram desenvolvidos para avaliar as repercussões dessa patologia, com crescente bibliografia mostrando importantes repercussões funcionais. Foi realizada uma atualização das repercussões cardíacas da patologia e análise dos artigos mais relevantes dos últimos anos. As evidências atuais permitem afirmar que há acometimento cardíaco por compressão esternal na maioria dos pacientes com PEX. As afecções incluem alterações anatomofuncionais: distúrbios do ritmo, diminuição do enchimento ventricular, diminuição do volume sistólico, aumento da pressão atrial direita, doença valvular, compressão do ventrículo direito, derrame pericárdico, entre outras. Tudo isso permite concluir que o PEX pode apresentar alterações cardíacas importantes que devem ser levadas em consideração na avaliação de pacientes com essa patologia.

Dependência de Pacing a Longo-Prazo e Preditores de Implante de Pacemaker após Implante Percutâneo de Prótese Valvular Aórtica - 1 Ano de Seguimento / Long-Term Ventricular Pacing Dependency and Pacemaker Implantation Predictors after Transcatheter Aortic Valve Replacement - A 1-Year Follow-Up

Resumo Fundamento Os distúrbios de condução (DC) são a complicação mais frequente após a substituição da válvula aórtica transcateter (TAVR) e ainda não há consenso sobre seu tratamento. Objetivo Avaliar novos DC e implante de marca-passo definitivo (MPD) após a TAVR e avaliar a porcentagem de estimulação ventricular (EV) até 1 ano de acompanhamento. Métodos Pacientes submetidos a TAVR de outubro de 2014 a novembro de 2019 foram cadastrados; pacientes com MPD anterior foram excluídos. Dados clínicos, do procedimento, do ECG e do MPD foram coletados até 1 ano após o implante. O nível de significância adotado para a análise estatística foi 0,05%. Resultados Um total de 340 indivíduos foram submetidos a TAVR. O DC mais comum foi bloqueio de ramo esquerdo novo (BRE; 32,2%), sendo que 56% destes foram resolvidos após 6 meses. O bloqueio do ramo direito (BRD) foi o maior fator de risco para bloqueio atrioventricular avançado (BAV) [RC=8,46; p<0,001] e implante de MPD [RC=5,18; p<0,001], seguido de BAV de baixo grau prévio [RC=2,25; p=0,016 para implante de MPD]. Em relação às características do procedimento, válvulas de gerações mais recentes e procedimentos de válvula-em-válvula foram associados a menos DC. No total, 18,5% dos pacientes tiveram MPD implantado após a TAVR. Na primeira avaliação do MPD, pacientes com BAV avançado tinham uma porcentagem mediana de EV de 80%, e, após um ano, de 83%. Em relação aos pacientes com BRE e BAV de baixo grau, a EV mediana foi mais baixa (6% na primeira avaliação, p=0,036; 2% após um ano, p = 0,065). Conclusão O BRE foi o DC mais frequente após a TAVR, com mais da metade dos casos se resolvendo nos primeiros 6 meses. O BRD foi o principal fator de risco para BAV avançado e implante de MPD. O BAV avançado foi associado a uma porcentagem mais alta de EV no acompanhamento de 1 ano.

Abstract Background Conduction disturbances (CD) are the most frequent complication after transcatheter aortic valve replacement (TAVR), and there continues to be a lack of consensus on their management. Objective To assess new CD and permanent pacemaker (PPM) implantation after TAVR and to evaluate the ventricular pacing percentage (VP) up to 1 year of follow-up. Methods Patients who underwent TAVR from October 2014 to November 2019 were enrolled; patients with previous PPM were excluded. Clinical, procedure, ECG, and PPM data were collected up to 1 year after implantation. The significance level adopted in the statistical analysis was 0.05. Results A total of 340 patients underwent TAVR. The most frequent CD was the new left bundle branch block (LBBB; 32.2%), which 56% resolved after 6 months. Right bundle branch block (RBBB) was the biggest risk factor for advanced atrioventricular block (AVB) [OR=8.46; p<0.001] and PPM implantation [OR=5.18, p<0.001], followed by previous low-grade AVB [OR=2.25; p=0.016 for PPM implantation]. Regarding procedure characteristics, newer generation valves and valve-in-valve procedures were associated with fewer CDs. Overall, 18.5% of patients had a PPM implanted post-TAVR. At first PPM evaluation, patients with advanced AVB had a median percentage of VP of 80% and 83% at one year. Regarding patients with LBBB plus low-grade AVB, median VP was lower (6% at first assessment, p=0.036; 2% at one year, p = 0.065). Conclusion LBBB was the most frequent CD after TAVR, with more than half being resolved in the first six months. RBBB was the major risk factor for advanced AVB and PPM implantation. Advanced AVB was associated with a higher percentage of VP at 1 year of follow-up.

Asociación entre interleuquinas inflamatorias y la presencia de trastornos intraventriculares de la conducción en pacientes con serología positiva para enfermedad de Chagas y función ventricular conservada / Association between inflammatory interleukins and intraventricular conduction disturbances in patients with positive serology for Chagas disease and preserved ventricular function

RESUMEN Introducción: Los trastornos intraventriculares de la conducción constituyen una manifestación habitual en los pacientes con enfermedad de Chagas con función ventricular izquierda conservada. Se desconoce si su presencia puede estar asociada a una mayor actividad inflamatoria. Objetivos: Determinar si existe una correlación entre los niveles de interleuquinas y la presencia de trastornos intraventriculares de la conducción en pacientes con serología positiva para enfermedad de Chagas y fracción de eyección ventricular izquierda conservada. Material y métodos: Se evaluó a 22 pacientes con edades comprendidas entre 21 y 80 años, seropositivos para enfermedad de Chagas, de más de 20 años de evolución y fracción de eyección ventricular izquierda mayor del 50%. Se analizó, además, un grupo control de 14 individuos sanos. Se determinaron las concentraciones en plasma de IFN-γ, IL-1β, IL-6, IL-10, IL-12 (p70), IL-15, IL-17A, MCP-1/CCL2, MIP-1 a/CCL3, TNF-a e IL-2. Se consideró trastornos intraventriculares de la conducción a la presencia de bloqueo de rama derecha, hemibloqueo anterior izquierdo o bloqueo de rama izquierda. Resultados: De los 22 pacientes con serología positiva para enfermedad de Chagas, 10 presentaron trastornos de la intraventriculares de la conducción (45,4%). En el grupo con trastornos intraventriculares de la conducción, se observaron niveles elevados de interleuquinas de alto efecto inflamatorio como INF-γ, IL-15, IL-2 (p70), IL-12, MP1-a, en comparación al grupo control, además de presentar altos valores de IL-10 como mecanismo modulador de una respuesta inmunitaria excesiva. Conclusiones: La asociación entre niveles elevados de interleuquinas y la presencia de trastornos intraventriculares de la conducción plantea un posible proceso inflamatorio crónico para su desarrollo en pacientes chagásicos con fracción de eyección ventricular izquierda conservada.

ABSTRACT Background: Intraventricular conduction disturbances are common in patients with Chagas disease and preserved left ventricular ejection fraction, but their association with higher inflammatory activity is unknown. Objectives: The aim of this study was to determine the presence of an association between interleukin levels and intraventricular conduction disturbances in patients with positive serology for Chagas disease and preserved left ventricular function. Methods: Twenty-two patients between 22 and 80 years of age with positive serology test for Chagas disease with more than 20 years progression and left ventricular ejection fraction ≥50% were included in the study and compared with a control group of 14 healthy individuals. Plasma levels of IFN-γ, IL-1β, IL-6, IL-10, IL-12 (p70), IL-15, IL-17A, MCP-1/CCL2, MIP-1 a/CCL3, TNF-a and IL-2 were measured in patients and controls. Right bundle branch block, left anterior hemiblock or left bundle branch block were considered intraventricular conduction disturbances. Results: Among the 22 patients with positive serology for Chagas disease, 10 presented intraventricular conduction disturbances (45.4%). This group had elevated levels of interleukins with high inflammatory effect such as INF-γ, IL-15, IL-2, IL-12, MIP-1 a, compared with the control group, and high levels of IL-10 as a regulatory mechanism of an excessive immune response. Conclusions: The association between elevated levels of inflammatory interleukins and intraventricular conduction disturbances suggests that chronic inflammation may play a role in the development of these abnormalities in patients with positive serology for Chagas disease and preserved left ventricular ejection function.

Syncope in patients with cardiac pacemakers

Abstract Introduction: It is challenging to diagnose syncope in patients with pacemakers. Because these patients have increased morbidity and mortality risks, they require immediate attention to determine the causes in order to provide appropriate treatment. This study aimed to investigate the causes and predictive factors of syncope as well as the methods used to diagnose syncope in cardiac pacemaker patients. Methods: Patients with pacemakers implanted owing to sinus node disease or atrioventricular block were evaluated with standardized questionnaires, endocavitary electrograms, and other tests based on the suspected causes of syncope. Mann-Whitney U tests were used to analyze continuous variables and Chi-squared or Fisher's exact tests were used for categorical variables. Logistic regression was used for multivariate analyses. Statistical significance was P<0.05. Results: The study included 95 patients with pacemakers: 47 experienced syncope in the last 12 months and 48 did not. Of the 100 documented episodes of syncope, 48.9% were vasovagal syncopes, 17% had cardiac-related causes, 10.6% had unknown causes, and 8.5% had pacemaker failure. The multivariate analysis showed that a New York Heart Association (NYHA) Functional Class II was a significant factor for developing syncope (P<0.01). Conclusion: While the most common type of syncope in pacemaker patients was neurally mediated, it is important to perform detailed evaluations in this population as the causes of syncope can be life-threatening. The best diagnostic methods were stored electrogram analysis and the tilt table test. NYHA Functional Class II patients were found to have a higher risk for syncope.

Bloqueo de rama alternante: reporte de una complicación inusual tras implante valvular aórtico transcatéter / Alternating bundle branch block: report of an unusual complication after transcatheter aortic valve implantation

Resumen Los trastornos de la conducción representan una potencial complicación de los reemplazos valvulares percutáneos. Los bloqueos alternantes de rama, aunque son inusuales, reflejan daño extenso del sistema His Purkinje con riesgo potencial de bloqueo auriculoventricular completo, por lo cual es importante su identificación y abordaje oportuno. Se presenta el caso de una paciente femenina de 82 años con múltiples comorbilidades y estenosis aórtica severa, en seguimiento médico desde hacía un año, en quien no se había realizado reemplazo quirúrgico por negativa de la paciente y por el alto riesgo intraoperatorio. Ingresó a la institución con un cuadro clínico de disnea progresiva de un mes de evolución, se realizó ecocardiograma transtorácico documentando estenosis aórtica crítica y fue llevada a implante valvular aórtico percutáneo. Por el alto riesgo de necesidad de marcapasos peri o postprocedimiento, se realizó seguimiento con monitoreo Holter, documentando bloqueo alternante de rama, el cual no progresó a bloqueo auriculoventricular completo luego de 72 horas de seguimiento, por lo que no se implantó marcapasos permanente. MÉD.UIS.2020;33(3): 37-42

Abstract Conduction disorders represent a potential complication of percutaneous valve replacements. Alternating bundle branch block, although unusual, reflect extensive damage of the His-Purkinje system with potential risk of complete atrioventricular block, therefore, its identification and timely approach is important. We present the case of an 82 years old female patient with multiple comorbidities and a medical history of severe aortic stenosis in medical follow-up for a year, in whom surgical replacement had not been conducted due to the patient's refusal and to the high surgical risk. She was admitted to the institution referring one month of progressive shortness of breath and an echocardiogram documented critical aortic stenosis. Percutaneous aortic valve implantation was performed. Due to her high risk of needing a peri or post-procedure pacemaker, Holter monitoring was performed, documenting alternating bundle branch block, which did not progress to complete atrioventricular block after 72 hours of follow-up, in consequence, a permanent pacemaker was not implanted. MÉD.UIS.2020;33(3): 37-42

Anatomopathological changes in canine distemper seropositive dogs and virus detection in sinoatrial nodes / Alterações anatomopatológicas em cães soropositivos para cinomose e detecção de vírus em nódulos sinoatriais

Canine distemper is a viral disease that affects several systems on dogs, among them, the cardiovascular system. The aim of this study was to identify canine distemper virus (CDV) in the sinoatrial node (SAN) of dogs serologically positive for distemper by Polymerase Chain Reaction preceded by reverse transcription (RT-PCR), and to analyze gross and microscopic changes of distemper in the heart and other tissues. SAN and tissue fragments were collected from 17 serologically positive dead animals, necropsied from October 2015 to December 2016. In the heart, right heart dilatation was observed in 13 dogs (76.47%) and left concentric hypertrophy in two dogs (11.76%). Microscopically, lymphocytic myocarditis was observed in four (23.53%) dogs and 41.18% presented viral inclusion corpuscles of CDV in the bladder epithelium. Only one (5.88%) dog presented a 319 bp target fragment for distemper virus using primers CDV 1 and CDV 2 at the sinoatrial node. In conclusion, CDV can be located in the sinoatrial node of naturally infected dogs, as demonstrated in this study by the RT-PCR technique, reinforcing the hypothesis that CDV is capable of causing inflammatory lesions in the sinoatrial node of this species. Macroscopic and microscopic cardiac changes are frequently observed in dogs with distemper, mainly cardiac dilatation and myocarditis. Viral inclusions of CDV in bladder epithelial cells are an important microscopic finding for the diagnosis of distemper.

A cinomose canina é uma doença viral que afeta vários sistemas, dentre eles o cardiovascular. Objetivou-se identificar o vírus da cinomose canina no nó sinoatrial (NSA) de cães sorologicamente positivos para cinomose, através da reação em cadeia da polimerase, precedida de transcrição reversa (RT-PCR), além de analisar os achados macroscópicos e histológicos da cinomose no coração e outros tecidos. Foram coletados fragmentos de tecidos e do NSA de 17 cães sorologicamente positivos para cinomose que vieram a óbito e foram necropsiados no período de outubro de 2015 a dezembro de 2016. No coração observou-se dilatação cardíaca direita em 76,47% dos cães e hipertrofia concêntrica esquerda em 11,76% dos cães. Microscopicamente observou-se miocardite linfocítica em 23,53% dos cães e 41,18% apresentou corpúsculos de inclusão viral no epitélio vesical. Somente um (5,88%) cão apresentou fragmento alvo de 319 bp para cinomose utilizando os primers VCC1 e VCC2, no nó sinoatrial. Conclui-se que o VCC pode localizar-se no nó sinoatrial de cães naturalmente infectados, como demonstrados neste estudo pela técnica de RT-PCR, reforçando a hipótese de que o VCC é capaz de provocar lesões inflamatórias no nó sinoatrial dessa espécie. Alterações cardíacas macroscópicas e microscópicas, principalmente dilatação cardíaca e miocardite, são frequentemente observadas em cães com cinomose. Inclusões virais nas células epiteliais da bexiga são importantes achados microscópicos para diagnóstico da cinomose.

Prognostic Implication of Ventricular Conduction Disturbance Pattern in Hospitalized Patients with Acute Heart Failure Syndrome

BACKGROUND AND OBJECTIVES: Conflicting data exist regarding the prognostic implication of ventricular conduction disturbance pattern in patients with heart failure (HF). This study investigated the prognostic impact of ventricular conduction pattern in hospitalized patients with acute HF. METHODS: Data from the Korean Acute Heart Failure registry were used. Patients were categorized into four groups: narrow QRS (<120 ms), right bundle branch block (RBBB), left bundle branch block (LBBB), and nonspecific intraventricular conduction delay (NICD). The NICD was defined as prolonged QRS (≥120 ms) without typical features of LBBB or RBBB. The primary endpoint was the composite of all-cause mortality or rehospitalization for HF aggravation within 1 year after discharge. RESULTS: This study included 5,157 patients. The primary endpoint occurred in 39.7% of study population. The LBBB group showed the highest incidence of primary endpoint followed by NICD, RBBB, and narrow QRS groups (52.5% vs. 49.7% vs. 44.4% vs. 37.5%, p<0.001). In a multivariable Cox-proportional hazards regression analysis, LBBB and NICD were associated with 39% and 28% increased risk for primary endpoint (LBBB hazard ratio [HR], 1.392; 95% confidence interval [CI], 1.152–1.681; NICD HR, 1.278; 95% CI, 1.074–1.520) compared with narrow QRS group. The HR of RBBB for the primary endpoint was 1.103 (95% CI, 0.915–1.329). CONCLUSIONS: LBBB and NICD were independently associated with an increased risk of 1-year adverse event in hospitalized patients with HF, whereas the prognostic impacts of RBBB were limited. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01389843

Assessment of Subclinical Cardiac Alterations and Atrial Electromechanical Delay by Tissue Doppler Echocardiography in Patients with Nonfunctioning Adrenal Incidentaloma / Avaliação de Alterações Cardíacas Subclínicas e Atraso Eletromecânico Atrial por Ecocardiografia com Doppler Tecidual em Pacientes com Incidentaloma Adrenal Não Funcionante

Abstract Background: Majority of the incidentally discovered adrenal masses, called adrenal incidentaloma (AI), are nonfunctioning adrenal adenomas. The appropriate management of AI is still a matter debate, so it is necessary to investigate their associated morbidity. However, data regarding morphological and functional cardiac alterations are limited in this group. Objective: In this study, we aimed to assess cardiac structural and functional characteristics and atrial conduction properties in patients with nonfunctioning AI. Methods: Thirty patients with nonfunctioning AI and 46 properly matched control subjects were included in the study. After hormonal and biochemical analysis, all participants underwent transthoracic echocardiography to obtain systolic and diastolic parameters of both ventricles, in addition to atrial conduction times by tissue Doppler echocardiography. Data were analyzed with Statistical Package for the Social Sciences (SPSS, Chicago, IL, United States) statistics, version 17.0 for Windows. P < 0.05 was considered statistically significant. Results: Left ventricular (LV) mass index and LV myocardial performance index were significantly increased in AI group. Among atrial conduction times, both intra- and interatrial electromechanical delays were significantly prolonged in patients with nonfunctioning AI. Other laboratory and echocardiographic findings were similar between groups. Conclusion: Our study revealed that intra- and inter-atrial conduction times were prolonged, and LV mass index was increased in patients with nonfunctioning AI. These findings may be markers of subclinical cardiac involvement and tendency to cardiovascular complications. Close follow-up is necessary for individuals with nonfunctioning AI for their increased cardiovascular risk.

Resumo Fundamento: A maioria das massas adrenais descobertas incidentalmente, denominadas incidentaloma adrenal (IA), são adenomas adrenais não funcionantes. O manejo adequado da IA ainda é um tema de debate, e por isso é necessário investigar suas morbidades associadas. Entretanto, dados referentes a alterações cardíacas morfológicas e funcionais são limitados nesse grupo. Objetivo: Neste estudo, objetivamos avaliar as características estruturais e funcionais cardíacas e as propriedades de condução atrial em pacientes com IA não funcionante. Métodos: Trinta pacientes com IA não funcionante e 46 controles adequadamente pareados foram incluídos no estudo. Após análise hormonal e bioquímica, todos os participantes foram submetidos a ecocardiograma transtorácico para obtenção de parâmetros sistólicos e diastólicos de ambos os ventrículos, além dos tempos de condução atrial pelo ecocardiograma com Doppler tecidual. Os dados foram analisados com o Statistical Package for the Social Sciences (SPSS, Chicago, IL, Estados Unidos), versão 17.0 para Windows. P < 0,05 foi considerado estatisticamente significativo. Resultados: O índice de massa do ventrículo esquerdo (VE) e o índice de desempenho miocárdico do VE foram significativamente aumentados no grupo IA. Entre os tempos de condução atrial, os atrasos eletromecânicos intra- e interatriais foram significativamente prolongados em pacientes com IA não funcionante. Outros achados laboratoriais e ecocardiográficos foram semelhantes entre os grupos. Conclusão: Nosso estudo revelou que os tempos de condução intra- e interatrial estavam prolongados e o índice de massa do VE estava aumentado em pacientes com IA não funcionante. Esses achados podem ser marcadores de envolvimento cardíaco subclínico e de tendência a complicações cardiovasculares. Um acompanhamento rigoroso é necessário para indivíduos com IA não funcionante, devido ao aumento do risco cardiovascular.

Effects of different doses of dexmedetomidine on cardiac conduction system / 临床麻醉学杂志

Objective To investigate the effect of dexmedetomidine on cardiac conduction system at different loading doses.Methods Eighty male patients with orthopedic surgery,aged 20-65 years,falling into ASA physical atatus Ⅰ or Ⅰ,were randomly divided into groups D1,D2,D3 and C with 20 in each.Groups D1,D2 and D3 were infused with dexmedetomidine 0.3,0.5 and 0.8μg/ kg using a micro-pump for 10 min,group C infused 0.9％ NaCl solution in the same manner.MAP,HR,SpO2 were recorded and ECG was traced before injection (T1),5 min (T2),10 min (T3) after injection and 10 min after the end of pumping (T4).P wave duration,P-R interval,QRS time,and QTc value were calculated.Results There was no significant difference in SpO2,P wave duration,P R interval and QRS time among the four groups.There was no significant difference in MAP,HR and QTc value in group C and group D1.Compared with that in group C,MAP was significantly decreased,HR was significantly slowed down and QTc value was significantly shortened in group D2 and D3 from T2 to T4 (P ＜ 0.05).Conclusion Dexmedetomidine does not affect the cardiac conduction system.0.5 μg/kg and 0.8μg/kg dexmedetomidine can effectively shorten the QT interval.To avoid severe bradycardia,patients with low heart rate should use no more than 0.5 μg/kg dexmedetomidine.

Evaluation of fetal cardiac conduction time by simultaneous recording of Doppler blood flow spectrum of fetal pulmonary artery and vein / 中华超声影像学杂志

Objective To investigate the value of synchronous recording of Doppler blood flow spectrum of fetal pulmonary artery and vein in quantitative measurement of fetal heart conduction time. Methods A total of 221 fetuses aged 16-41 weeks were enrolled in this study.Each fetus was measured by pulsed Doppler (PD),tissue Doppler (DTI) and pulmonary arteriovenous synchrony (PA-PV). Atrioventricular conduction time (AV) and the time period from ventricular contraction began to shrink to the next cardiac atrial contractions (VA) were recorded for comparing the consistency of three measure methods.Results ①The AV and VA obtained by three different measurement methods have no significant difference after any comparison( P >0.05). ②There was a significant positive correlation between AV and gestational age (r= 0.825, P = 0.000). There was a weak correlation between VA and gestational age (r=0.216,P =0.000). ③AV was negatively related to heart rate ( r = -0.236,P =0.000);VA was negatively related to heart rate( r = -0.860,P =0.000). ④There was a positive correlation between AV and biparietal diameter ( r = 0.188, P = 0.005). There was no significant correlation between VA and biparietal diameter ( r = 0.054, P = 0.428). ⑤ AV and VA in different gestational weeks fetuses were analyzed by ANOVA. The differences in AV among PD,DTI and PA-PV groups were statistically significant ( P =0.014),AV > 36 weeks was the longest,and there was no significant difference in VA among PD,DTI and PA-PV groups ( P =0.941). ⑥ According to different biparietal diameter grouping, the differences in AV among PD,DTI and PA-PV groups were statistically significant ( P = 0.004),and biparietal diameter was 8~9 cm.There was no significant difference in VA among PD,DTI and PA-PV groups ( P = 0.829). Conclusions PA-PV method,PD method and DTI determination of fetal heart conduction time have the same clinical value,the measured data can be used as a clinical reference value, quantitative analysis of fetal arrhythmia has important clinical potential value.

Pathological changes of the sudden deaths due to the dysplasia of the cardiac conduction system in 26 cases / 中国法医学杂志

Objective To study the pathological changes of the sudden death cases due to the dysplasia of the cardiac conduction system. Methods Using the newly established pathological sampling method by our research team, 26 hearts of unidentified sudden deaths excluding trauma, poisoning and diseases were collected and observed optically with H&E staining, Masson staining and immunohistochemical staining. Results Among the 26 cases, there were dysplasia in the cardiac conduction system,structural abnormalities, tissue or structure shift, fibrous cushion in the sinoatrial node and 9 cases have 2~3 abnormalities at the same time. Among the age groups from 16 to 30, 21 cases (80.8%) showed dysplasia of the cardiac conduction system. Conclusion The dysplasia of the cardiac conduction system may be one of the predominant reasons for the sudden death in young adults.

Intermittent left bundle branch block - reversal to normal conduction during general anesthesia / Bloqueio intermitente de ramo esquerdo - reversão para condução normal durante anestesia geral

Abstract Background and objectives: Transient changes in intraoperative cardiac conduction are uncommon. Rare cases of the development or remission of complete left bundle branch block under general and locoregional anesthesia associated with myocardial ischemia, hypertension, tachycardia, and drugs have been reported. Complete left bundle branch block is an important clinical manifestation in some chronic hypertensive patients, which may also be a sign of coronary artery disease, aortic valve disease, or underlying cardiomyopathy. Although usually permanent, it can occur intermittently depending on heart rate (when heart rate exceeds a certain critical value). Case report: This is a case of complete left bundle branch block recorded in the preoperative period of urgent surgery that reverted to normal intraoperative conduction under general anesthesia after a decrease in heart rate. It resurfaced, intermittently and in a heart-rate-dependent manner, in the early postoperative period, eventually reverting to normal conduction in a sustained manner during semi-intensive unit monitoring. The test to identify markers of cardiac muscle necrosis was negative. Pain due to the emergency surgical condition and in the early postoperative period may have been the cause of the increase in heart rate up to the critical value, causing blockage. Conclusions: Although the development or remission of this blockade under anesthesia is uncommon, the anesthesiologist should be alert to the possibility of its occurrence. It may be benign; however, the correct diagnosis is very important. The electrocardiographic manifestations may mask or be confused with myocardial ischemia, factors that are especially important in a patient under general anesthesia unable to report the characteristic symptoms of ischemia.

Resumo Justificativa e objetivos: Alterações transitórias da condução cardíaca no intraoperatório são pouco frequentes. Foram reportados raros casos de desenvolvimento ou remissão de bloqueio completo de ramo esquerdo sob anestesia (geral e locorregional), associados a isquemia do miocárdio, hipertensão, taquicardia e fármacos. O bloqueio completo de ramo esquerdo é uma manifestação clínica importante em alguns hipertensos crônicos, pode também significar doença arterial coronária, doença valvular aórtica ou cardiomiopatia subjacentes. Embora habitualmente permanente, pode ocorrer na forma intermitente dependente da frequência cardíaca (quando a frequência cardíaca excede determinado valor crítico). Relato de caso: Este é um caso de bloqueio completo de ramo esquerdo registrado no pré-operatório de cirurgia urgente que reverteu para condução normal no intraoperatório sob anestesia geral após diminuição da frequência cardíaca. Ressurgiu, de forma intermitente e dependente da frequência cardíaca, no pós-operatório imediato, acabou por reverter novamente à condução normal de forma sustentada durante vigilância em unidade semi-intensiva. O estudo com marcadores de necrose muscular cardíacos foi negativo. A dor do quadro cirúrgico urgente e pós-operatório imediato pode ter estado na origem da subida da frequência cardíaca até ao valor crítico e causado bloqueio. Conclusões: Embora o desenvolvimento ou a remissão desse bloqueio sob anestesia sejam incomuns, o anestesiologista deverá estar alertado para a possibilidade da sua ocorrência. Pode ter caráter benigno, contudo o diagnóstico correto é muito importante. As manifestações eletrocardiográficas podem ser confundidas com ou encobrir isquemia miocárdica, fatos de especial importância num paciente sob anestesia geral incapaz de referir sintomatologia característica de isquemia.

Impact of Myocardial Infarction and Abnormalities of Cardiac Conduction System on Sudden Cardiac Death / 法医学杂志

Sudden cardiac death (SC D ),m ostcom m only seen in coronary heart disease, is a kind of sud-den death caused by series of cardiac param eters, w hich usually com bines w ith m yocardial infarction. H ow ever, som e SC D s (including early m yocardial infarction) happen suddenly and cause death in a very short tim e. In these circum stances, typical m orphological changes are lack in m acroscopic or m icroscopic fields, w hich m ake such SC D s becom e the em phasis and difficulty in the present research. SC D caused by m yocardial infarction and abnorm alities of cardiac conduction system (C C S ) is related to atheroscle-rosis of coronary artery closely. T his paper review s cardiac dysfunction caused by m yocardial infarction and diseases of C C S from m orphology and m olecular biology, and explores potential relationship be-tw een them . T his paper aim s to provide clues to the m echanism of m yocardial infarction related sudden death and possible assistance for forensic diagnosis of SC D .

Impact of Myocardial Infarction and Abnormalities of Cardiac Conduction System on Sudden Cardiac Death / 法医学杂志

Sudden cardiac death （SCD）, most commonly seen in coronary heart disease, is a kind of sudden death caused by series of cardiac parameters, which usually combines with myocardial infarction. However, some SCDs （including early myocardial infarction） happen suddenly and cause death in a very short time. In these circumstances, typical morphological changes are lack in macroscopic or microscopic fields, which make such SCDs become the emphasis and difficulty in the present research. SCD caused by myocardial infarction and abnormalities of cardiac conduction system （CCS） is related to atherosclerosis of coronary artery closely. This paper reviews cardiac dysfunction caused by myocardial infarction and diseases of CCS from morphology and molecular biology, and explores potential relationship between them. This paper aims to provide clues to the mechanism of myocardial infarction related sudden death and possible assistance for forensic diagnosis of SCD.

Cardiac sodium channel, its mutations and their spectrum of arrhythmia phenotypes

The mechanisms of cellular excitability and propagation of electrical signals in the cardiac muscle are very important functionally and pathologically. The heart is constituted by three types of muscle: atrial, ventricular, and specialized excitatory and conducting fibers. From a physiological and pathophysiological point of view, the conformational states of the sodium channel during heart function constitute a significant aspect for the diagnosis and treatment of heart diseases. Functional states of the sodium channel (closed, open, and inactivated) and their structure help to understand the cardiac regulation processes. There are areas in the cardiac muscle with anatomical and functional differentiation that present automatism, thus subjecting the rest of the fibers to their own rhythm. The rate of these (pacemaker) areas could be altered by modifications in ions, temperature and especially, the autonomic system. Excitability is a property of the myocardium to react when stimulated. Another electrical property is conductivity, which is characterized by a conduction and activation process, where the action potential, by the all-or-nothing law, travels throughout the heart. Heart relaxation also stands out as an active process, dependent on the energetic output and on specific ion and enzymatic actions, with the role of sodium channel being outstanding in the functional process. In the gene mutation aspects that encode the rapid sodium channel (SCN5A gene), this channel is responsible for several phenotypes, such as Brugada syndrome, idiopathic ventricular fibrillation, dilated cardiomyopathy, early repolarization syndrome, familial atrial fibrillation, variant 3 of long QT syndrome, multifocal ectopic ventricular contractions originating in Purkinje arborizations, progressive cardiac conduction defect (Lenègre disease), sudden infant death syndrome, sick sinus syndrome, sudden unexplained nocturnal death syndrome, among other sodium channel alterations with clinical overlapping. Finally, it seems appropriate to consider the "sodium channel syndrome" (mutations in the gene of the alpha subunit of the sodium channel, SCN5A gene) as a single clinical entity that may manifest in a wide range of phenotypes, to thus have a better insight on these cardiac syndromes and potential outcomes for their clinical treatment.

Os mecanismos da excitabilidade celular e de propagação dos sinais elétricos no músculo cardíaco são de grande importância funcional e patológica. O coração é composto por três tipos de músculo: atrial, ventricular e das fibras especializadas excitatórias e condutoras. Do ponto de vista fisiológico e fisiopatológico os estados conformacionais do canal de sódio constitui-se um importante aspecto para o diagnóstico e tratamento de doenças cardíacas. A descrição dos estados funcionais do canal de sódio (fechado, aberto e inativado) e sua estrutura ajudam a compreensão dos processos de regulação cardíaca. Há áreas no músculo cardíaco com diferenciação anatômica e funcional que possuem automatismo submetendo as demais fibras ao seu próprio ritmo. A frequência dessas áreas (marca-passo) pode ser alterada por modificações iônicas, pela temperatura e, especialmente, do sistema autonômico. Já a excitabilidade é a propriedade que tem o miocárdio de reagir quando estimulado. A outra propriedade elétrica é a condutibilidade, que se caracteriza por um processo de condução e ativação, no qual o potencial de ação, pela ei do tudo ou nada, percorre todo o coração. Destaca-se que o relaxamento do coração também é um processo ativo, dependente de gasto energético e de ações iônicas e enzimáticas específicas, destacando o papel dos canais de sódio no processo funcional. Nos aspectos das mutações no gene que codifica o canal rápido de sódio (gene SCN5A), este é responsável por vários fenótipos, tais como a síndrome de Brugada; a fibrilação ventricular idiopática, a miocardiopatia dilatada; a síndrome de repolarização precoce; a fibrilação atrial familiar; a síndrome do QT longo variante 3; as contrações ventriculares ectópicas multifocais originadas nas arborizações de Purkinje; o distúrbio progressivo de condução intraventricular cardíaco (doença de Lenègre); a síndrome da morte súbita do recém-nascido; a síndrome do nódulo sinusal doente; a síndrome da morte súbita noturna inesperada, entre outras alterações do canal de sódio com sobreposições clínicas, as chamadas "overpping". Por fim, parece ser apropriado considerar a "síndrome do canal de sódio" (mutações no gene da subunidade alfa do canal de sódio, gene SCN5A) como uma entidade clínica única que pode manifestar-se com um amplo espectro de fenótipos e assim, prover um melhor entendimento destas síndromes cardíacas e potencial desfecho para seu tratamento clínico.

Bloqueo aurículo ventricular congénito completo. Reporte de un caso y revisión de la literatura / Full congenital atrioventricular blockage: case report and literature review

Introducción: el bloqueo aurículo ventricular (AV) completo congénito (BCC) es una entidad poco común, siendo una lesión del tejido de conducción cardíaco que surge antes del nacimiento, en la que se produce una alteración de la transmisión de los impulsos auriculares a los ventrículos y puede aparecer de forma aislada o familiar; se debe hacer el diagnóstico diferencial con la coexistencia de una cardiopatía estructural o su asociación a enfermedades autoinmunes clínicas o subclínicas; su diagnóstico se realiza mediante ecografía y ecocardiografía fetal, técnicas que permiten el seguimiento y manejo perinatal óptimo, aconsejándose la finalización de la gestación en casos de sufrimiento fetal o signos de insuficiencia cardíaca; presenta alta morbilidad y mortalidad y requiere alto índice de sospecha para su diagnóstico. La implantación de un marcapasos es el tratamiento definitivo que contribuye a la sobrevida y pronóstico de estos pacientes.

Introduction: congenital complete auricular ventricular Blockage is a rare entity, being a cardiac conduction tissue lesion that develops before birth, which produces an alteration of the transmission of the auricular impulses towards the ventricules, and it could appear isolated or familiar form; the differential diagnosis must be performed with the coexistence of a structural cardiopathy, or its association with clinical or subclinical autoimmune diseases; its diagnosis is done by means of a fetal echography or echocardiography, techniques which allow an optimal perinatal follow up and management, advising the termination of the gestation period in cases of fetal suffering or signs of cardiac insuffciency; there is high morbidity and mortality rates which require high suspicion indication for its diagnosis. The implantation of a pacemaker is the definite treatment of choice which contributes to patient´s life expectancy and prognosis.