Electrocardiographic changes and changes in cardiac lactate and troponin I levels associated with search and rescue physical activity in military dogs / Alterações eletrocardiográficas e nos níveis de lactato e troponina I cardíaca associadas à atividade física de busca e salvamento em cães militares

Rescue and recovery dogs intercalate the activity intensity developed, which also triggers significant metabolic changes in cardiac physiology. Thus, we evaluated the changes that search simulation causes in glucose, lactate, and cardiac troponin I level (cTnI) and the electrocardiographic and heart rate during the activity and recovery phase to predict the physiological adaptation to the exercise. Five healthy adult dogs from the Rescue and Recovery Service of Military Firefighters Corps were submitted to 60 minutes search operation simulation in the woods. They covered a forest area of approximately 50,000 m2. The dogs were loose and accompanied by their driver, and they could perform any physical activity. Were evaluated serum biochemical analysis of glucose, lactate, cardiac troponin I, electrocardiographic, and heart rate (rest, exercise phase, and recovery time). No changes in glucose levels, heart rate, and cardiac rhythm were detected. In comparison to baseline values, there is an increase: in lactate at the end of the exercise phase [EXER] (60'EXER), and in the recovery phase [RCT] at 30'RCT and 60'RCT, and cTnI at 60'RCT, 120'RCT, and 4hRCT. P wave duration was significantly higher at 60'EXER, 15'RCT, and 30'RCT, with no alterations in wave amplitude. QRS interval duration significantly increased at 30'RCT, and the ST segment presented a significant difference at 60'EXER, 15'RCT, and 60'RCT compared to the rest moment. The moderate alterations in lactate and cTnI and few alterations in the electrocardiographic and heart rate maintenance suggest the adaptation of rescue and recovery dogs to the type, intensity, and duration of search operation simulation performed.(AU)

Cães de busca e resgate intercalam a intensidade da atividade desenvolvida que desencadeia alterações metabólicas significativas, bem como na fisiologia cardíaca. Assim, foram avaliadas as alterações que a simulação de busca produz nos níveis de glicose, lactato, troponina I cardíaca (cTnI), bem como na frequência cardíaca e atividade eletrocardiográfica durante a fase de atividade e recuperação, a fim de predizer a adaptação fisiológica ao exercício. Cinco cães adultos saudáveis do Serviço de Resgate e Salvamento do Corpo de Bombeiros Militares foram submetidos à simulação de operação de busca de 60 minutos na mata e cobriram uma área florestal de aproximadamente 50.000 m2. Os cães estavam soltos, acompanhados pelo condutor e estavam livres para realizar qualquer tipo de atividade física. Foram avaliados os níveis séricos de glicose, lactato e troponina I cardíaca, atividade eletrocardiográfica e frequência cardíaca em repouso, na fase de exercício e no tempo de recuperação. Não foram detectadas alterações nos níveis de glicose, frequência cardíaca e ritmo cardíaco. Em comparação com os valores basais houve aumento de lactato ao final da fase de exercício [EXER] (60'EXER) e na fase de recuperação [RCT] aos 30'RCT e 60'RCT; e cTnI aos 60'RCT, 120'RCT e 4hRCT. Duração da onda P foi significativamente maior em 60'EXER, 15'RCT e 30'RCT, sem alterações na amplitude da onda. Duração do intervalo QRS teve aumento significativo em 30'RCT e o segmento ST apresentou diferença significativa em 60'EXER, 15'RCT e 60'RCT quando comparado ao basal. As alterações moderadas nos níveis de lactato e cTnI, bem como a pouca alteração na atividade eletrocardiográfica e manutenção da frequência cardíaca sugerem boa adaptação dos cães de busca e resgate ao tipo, intensidade e duração da operação de busca simulada realizada.(AU)

Clinical Characteristics of Patients with Tetralogy of Fallot who Underwent an Invasive Procedure for Arrhythmias

Introduction: Tetralogy of Fallot (TOF) is a cyanotic congenital heart disease that has an incidence of sudden cardiac death of 0.2% per year, being arrhythmias the main cause of its occurrence. Objective: To compare characteristics of TOF patients referred for electrophysiological study (EPS) against those that were not (No-EPS). Method: Retrospective cohort with 215 patients (57.2% men; age = 29 ± 4) with corrected TOF (median of three years, ranging from 0.33 to 51) that underwent EPS between 2009-2020. The primary outcome was composed of death, implantable cardiac defibrillator (ICD) requirement and hospitalization. Results: Pre-syncope (EPS = 4.7%, No-EPS = 0%; p = 0.004), syncope (EPS = 7.1%, No-EPS = 1.7%; p = 0.056) and palpitations (EPS = 31%, No-EPS = 5.8%; p < 0.001) were symptoms that justified electrophysiological investigation. ICD was implanted in 24% of EPS and 0.6% of No-EPS (p=0.001). Twenty-six percent of the EPS group presented non-sustained ventricular tachycardia, while 0% in No-EPS (p = 0.012). The EPS group had more atrial fibrillation or atrial Flutter (35.7% vs. 6.9%; p < 0.001). The EPS patients had a wider QRS duration than the no-EPS group (171.12 ± 29.52 ms vs. 147 ± 29.77 ms; p < 0.001). Also, 26.2% of EPS performed ablation to correct macroreentrant atrial tachycardias. The incidence of primary outcome (death + ICD requirement + hospitalization) was higher in patients in the EPS group compared to the No-EPS group (p = 0.001). However, the total of seven deaths occurred during the clinical follow-up, but without differences between the groups (EPS = 4.7% vs. No-EPS = 2.8%; p = 0.480). Conclusion: EPS group had a profile of greater risk, more complex heart disease, and a greater occurrence of the primary outcome when compared to the No-EPS group.

¿Es el electrocardiograma correctamente interpretado por médicos residentes de Pediatría? Experiencia previa y posterior a una intervención educacional en un hospital universitario / Are electrocardiograms correctly interpreted by pediatric residents? Experience before and after an educational intervention in a teaching hospital

La incidencia del paro cardíaco pediátrico es desconocida; sus principales etiologías son cardiopatías congénitas, miocardiopatías y arritmias ventriculares. El electrocardiograma es un método diagnóstico que podría detectarlas precozmente y disminuir la morbimortalidad. El objetivo del estudio fue describir las habilidades de residentes de Pediatría para reconocer si un electrocardiograma era normal o anormal y realizar un diagnóstico electrocardiográfico preciso, antes y después de una intervención educativa. Participaron médicos residentes de primer año de Pediatría. Se tomó una evaluación con 12 trazados de electrocardiogramas, antes y después de un módulo educativo, y se compararon los puntajes mediante la prueba de "t" para datos pareados. No se halló diferencia entre ambas evaluaciones para la interpretación de electrocardiogramas como normales o anormales (p: 0,42). Sin embargo, hubo una diferencia estadísticamente significativa en cuanto a los diagnósticos de certeza (p < 0,002). Los diagnósticos de certeza electrocardiográficos mejoraron luego de implementar un módulo educacional

The incidence of pediatric cardiac arrest is unknown; its main etiologies are congenital heart diseases, cardiomyopathies, and ventricular arrhythmias. An electrocardiogram (ECG) is a diagnostic method that may allow to detect them in an early manner and reduce morbidity and mortality.The objective of this study was to describe pediatric residents' skills to determine if an ECG was normal or abnormal and make an accurate electrocardiographic diagnosis before and after an educational intervention. First-year pediatric residents participated in this study. An assessment including 12 ECG tracings was done before and after an educational module, and scores were compared using the t-test for paired data. No differences were observed between both assessments regarding the interpretation of ECG as normal or abnormal (p: 0.42). However, a statistically significant difference was observed in definitive diagnoses (p < 0.002). Definitive electrocardiographic diagnoses improved after the implementation of an educational module.

Descripción de los pacientes de 80 o más años intervenidos quirúrgicamente en el laboratorio de electrofisiología en un hospital de tercer nivel / Description of patients aged 80 or older undergoing surgery in the electrophysiology lab of a tertiary care hospital

Resumen Introducción: en una unidad de electrofisiología de un hospital de tercer nivel de Manizales, Caldas, se han atendido pacientes en la cuarta edad; sin embargo, existe poca claridad en la literatura sobre las conductas terapéuticas en este grupo etario. Presentamos nuestra experiencia de atención e intervención en pacientes mayores de 80 años entre el 20 de septiembre de 2017 y 7 de octubre de 2019. Métodos: estudio tipo cohorte longitudinal, se recogió información con base en revisión de historias clínicas. Se realizaron seguimientos telefónicos al tercer y sexto mes del procedimiento. Se incluyeron pacientes mayores de 80 años intervenidos de cualquier procedimiento en la sala de electrofisiología. Se excluyeron los pacientes sin información sobre los datos de seguimiento. Resultados: se recogieron datos de 75 pacientes llevados a procedimiento. El 62.7% de los pacientes fueron hombres, las edades oscilaron entre 80 y 95 años. 32.7%, de pacientes con diagnóstico de disfunción sinusal. La comorbilidad más prevalente fue hipertensión arterial (92%). El procedimiento más realizado fue el implante de marcapaso bicameral. La mediana del tiempo de estancia hospitalaria fue de 1 día. EL 70% de los pacientes tuvieron riesgo medio o bajo según la escala CHA2DS2VASc. En el lapso de seis meses se encontró una incidencia acumulada de complicaciones de 4%, con 8% de reconsultas y una mortalidad de 1.3%. Conclusiones: las complicaciones posquirúrgicas, la necesidad y duración de la hospitalización, la tasa de reconsulta y la mortalidad asociada a los procedimientos en este grupo de edad son similares a las observadas en estudios con población menor de 80 años.

Abstract Introduction: fourth age patients have been cared for in the electrophysiology unit of a tertiary care hospital in Manizales, Caldas; however, there is little clarity in the literature regarding therapeutic conduct in this age group. We present our experience of care and intervention in patients over the age of 80 between September 20, 2017 and October 7, 2019. Methods: a longitudinal cohort study in which data was collected from a chart review. Telephone follow up was performed three and six months after the procedure. Patients over the age of 80 who had undergone any procedure in the electrophysiology lab were included. Patients without follow up information were excluded. Results: data were collected on 75 patients undergoing a procedure: 62.7% of the patients were men, ages ranged from 80 to 95, and 32.7% of the patients had a diagnosis of sinus dysfunction. The most prevalent comorbidity was arterial hypertension (92%). The most frequently performed procedure was dual chamber pacemaker implantation. The median hospital stay was one day. Seventy percent of the patients had a medium or low risk according to the CHA2DS2-VASc scale. Over a six-month period, a 4% cumulative incidence of complications was found, with 8% reconsultation and 1.3% mortality. Conclusions: postsurgical complications, the need for and length of hospitalization, the rate of reconsultation and the mortality associated with procedures in this age group are similar to those seen in studies of populations under 80 years old.

El nodo sinusal normal: Lo que ahora sabemos / The normal sinus node: What we know now

RESUMEN El nodo sinusal constituye el marcapasos fisiológico del corazón. Diferentes estados fisiopatológicos conducen a una reducción de su función, lo que es llamado en la clínica, disfunción sinusal. Sin embargo, para la mejor comprensión de su estado de enfermedad se requiere dilucidar cómo opera en condiciones normales. Las nuevas evidencias señalan que el automatismo del nodo sinusal se produce por la interacción del reloj de membrana y el reloj de calcio, lo que le confiere un fuerte carácter que lo protege contra fallas de funcionamiento. Se presentan las evidencias actuales sobre la sincronía celular dentro del nodo sinusal, así como la forma de propagación eléctrica y el acoplamiento fuente-sumidero. Además, se describen recientes hallazgos anatómicos e histológicos.

ABSTRACT The sinus node is the physiological pacemaker of the heart. Different pathophysiological conditions lead to a reduction of its function, which is clinically called sinus dysfunction. However, for a better understanding of its disease state, it is necessary to elucidate how it works under normal conditions. New evidences indicate that the automatism of the sinus node is produced by the interaction of the membrane clock and the calcium clock, which gives it a strong character that protects it against malfunctions. Current evidences on cell synchrony within the sinus node are presented, as well as the form of electrical propagation and the source-sink coupling. In addition, recent anatomical and histological findings are described.

Importancia del mapeo óptico de cultivos de cardiomiocitos HL-1 en estudios electrofisiológicos / Importance of the optical mapping of HL-1 cardiomyocyte cultures in electrophysiological studies

Introducción: El desarrollo de herramientas para investigar la actividad electrofisiológica cardiaca ha permitido profundizar en el conocimiento sobre los mecanismos subyacentes a las arritmias cardiacas. Los sistemas de mapeo óptico constituyen una tecnología que responde a la necesidad de superar varios obstáculos en la experimentación. Objetivo: Proporcionar una visión general de la importancia del mapeo óptico en cultivos celulares HL-1, en las investigaciones en electrofisiología cardiaca. Métodos: Se realizó una revisión sobre los estudios electrofisiológicos que involucran la línea celular HL-1 utilizando la técnica de mapeo óptico. Conclusiones: Los trabajos se caracterizan por la implementación de la técnica respecto a la tecnología de los equipos de mapeo, a la utilización de diferentes colorantes y al objetivo de la investigación. Están enfocados en el estudio de mecanismos arritmogénicos, procesos de estiramiento mecánico o remodelación del tejido y en el análisis de nuevos biomateriales. Lo anterior, sustenta la relevancia del mapeo óptico en la investigación cardiaca(AU)

Introduction: The development of tools to study cardiac electrophysiological activity has made it possible to broaden knowledge about the mechanisms underlying cardiac arrhythmias. Optical mapping systems constitute a technology that responds to the need to overcome several hurdles in experimentation. Objective: Provide an overview of the importance of optical mapping in HL-1 cell cultures in cardiac electrophysiology research. Methods: A review was conducted of electrophysiological studies involving the HL-1 cell line using the optical mapping technique. Conclusions: The studies are characterized by implementation of the technique with respect to the technology of mapping equipment, the use of different colorants and the purpose of the research. They focus on the study of arrhythmogenic mechanisms, mechanical stretch processes or tissue remodeling as well as the analysis of new biomaterials. The above substantiates the relevance of optical mapping in cardiac research(AU)

Case Report: Myocardial Bypass in Left Descending Artery - A Rare Congenital Anomaly

Abstract Myocardial bypass (MB) is known to have scientific relevance and is present in several studies with great statistical significance regarding its clinical manifestations and complications. There are still questions about MB in its relationship with heart disease and repercussion in life-threatening conditions. We present a case report of a MB in the left anterior descending coronary artery, whose objective is to identify this rare congenital anomaly and to highlight the patient's clinical outcome in order to elicit greater contributions about the presence of this variant in the emergency room, its diagnosis by angiography and therapeutic management.

Non-fluoroscopic radiofrequency ablation of left atrial appendage tachycardia during early pregnancy

Abstract Management of symptomatic atrial tachycardia (AT) during pregnancy seems challenging, especially those originating from left atrial appendage (LAA), which easily tend to be incessant and mediate cardiomyopathy. It's contradictory between therapy and pregnancy. In this study, we report a case of a woman who presented with persistent AT, which lead to heart failure, during early pregnancy. She underwent successful catheter ablation using CartoSound and electroanatomic mapping without fluoroscopy. An electrophysiology (EP) study confirmed a focal LAA tachycardia. Soon after, left ventricular function of her heart normalized, and the patient successfully delivered a healthy child.

Effect of Erxian Decoction on Cardiac Electrophysiology in Peri-menopausal Rats / 中国实验方剂学杂志

Objective: To explore the effect and mechanism of Erxian decoction on peri-menopausal cardiac electrophysiology in rats. Method: Female sprague-dawley rats were randomly divided into six groups:sham operation group, model group, estradiol valerate group, and low, medium and high-dose Erxian decoction groups. Except the sham operation group, the rats in the other groups were completely removed from the ovarian replication peri-menopausal rat model. At the same time, estradiol valerate group (8×10-4 g·kg -1·d-1), low-dose Erxian decoction group (4 g·kg-1·d-1), middle-dose Erxian decoction group (8 g·kg-1·d-1) and high-dose Erxian decoction group (12 g·kg-1·d-1), sham operation group and model group were given the same amount of normal saline. The administration was given once a day for 80 consecutive days. The electrocardiogram of rats was recorded by biosignal detector connected to lead Ⅱ electrode. The content of estradiol (E2) in rat serum was detected by enzyme-linked immuno sorbent assay (ELISA). The pathological changes of rat uterus were observed by hematoxylin-eosin. The expression of the estrogen alpha receptor (ERα) protein was detected by Western blot method in myocardial tissue of rat. Result: Compared with the sham operation group, the amplitudes of P wave, R wave and T wave in the electrocardiogram of the model group were significantly decreased (P2 level was significantly lower (Pα receptor protein in myocardial tissue was significantly decreased (P2 level (Pα receptor protein (PConclusion: Erxian decoction can improve cardiac electrophysiological changes in peri-menopausal rats, and its mechanism may be related to the increase of estrogen activity and estrogen receptor expression in rats.

Electrophysiological characteristics of myocardium after hypothermic ischemia-reperfusion in rats with different degrees of arrhythmia: an in vitro experiment / 中华麻醉学杂志

Objective To investigate the electrophysiological characteristics of myocardium after hypothermic ischemia-reperfusion (I/R) in rats with different degrees of arrhythmia using an in vitro experiment.Methods Healthy clean-grade male Sprague-Dawley rats,aged 2-3 months,weighing 300-400 g,were used in this study.The rats were sacrificed after anesthesia,and their hearts were rapidly excised.Sixteen Langendorff-perfused hearts were prepared and divided into 2 groups (n=8 each) by a random number table method:control group (group C) and hypothermic I/R group (group I/R).The hearts were made globally ischemic for 60 min followed by 30-min hypothermic (4 ℃) reperfusion to establish the model of hypothermic I/R injury.The occurrence and duration of arrhythmia and time of recovery of spontaneous heartbeat were recorded during reperfusion.The rats in group I/R were further divided into low-risk group (I/R-L group,ventricular arrhythmia score≤3 points) and high-risk group (I/R-H group,ventricular arrhythmia score＞3 points) according to the arrhythmia score.Monophasic action potential amplitude (MAPA),monophasic action potential (MAP) duration at 50％ and 90％ repolarization (MAPDs0 and MAPD90) and maximum ascending velocity (Vmax) of phase 0 in the endocardium,myocardium and epicardium of the left ventricular anterior wall were recorded at 30 min of equilibration (T0) and 15 and 30 min of reperfusion (T1,2).The effective refractory period (ERP) and ventricular fibrillation threshold (VFT) of the left ventricle were measured by programmed electrical stimulation,and the ERP/MAPD90 ratio was calculated.Results Compared with the baseline at T0,MAPA in the three layers was significantly decreased,and MAPD50 and MAPD90 were prolonged at T1,2 in I/R-L and I/R-H groups,and V in the three layers was decreased at T1,2 in I/R-H group (P＜0.05).MAPD50 and MAPD90 in the three layers were significantly shorter at T2 than at T1 in I/R-L and I/R-H groups (P＜0.05).Compared with group C,MAPDs0,MAPDg0 and ERP in the three layers were significantly prolonged at T1,2,the ERP/MAPDg0 ratio was decreased,and VFT was increased in I/R-L and I/R-H groups (P ＜ 0.05).Compared with I/R-L group,the duration of arrhythmia and MAPD90 and ERP in the three layers were significantly prolonged at T2,the ERP/MAPDg0 ratio was decreased,and VFT was increased in group I/R-H (P＜0.05).Conclusion Myocardial depolarization is inhibited,repolarization duration is prolonged,and electrophysiological stability is decreased after hypothermic I/R in the rats with arrhythmia,and the prolongation of myocardial repolarization and decrease in electrophysiological stability are more obvious in the rats at high risk of arrhythmia.

Role of sarcolemmal KATP channel in sevoflurane-induced maintenance of electrophysiological stabili-ty of ventricular myocardium in diabetic rats / 中华麻醉学杂志

Objective To evaluate the role of sarcolemmal ATP-sensitive potassium ( sarcKATP ) channel in sevoflurane-induced maintenance of electrophysiological stability of ventricular myocardium in di-abetic rats. Methods Clean-grade healthy male Sprague-Dawley rats, aged 3 months, weighing 280-320 g, in which diabetes mellitus ( DM) was induced by intraperitoneal streptozotocin 60 mg/kg and confirmed by blood glucose ≥16. 7 mmol/L, were used in this study. Their hearts were excised after anesthesia and retrogradely perfused in a Langendorff apparatus at 4 weeks after establishing the DM model. Twenty-four Langendorff-perfused hearts were divided into 3 groups ( n=8 each) using a random number table method:DM group ( group D) , DM plus sevoflurane group ( group DS) and DM plus sevoflurane plus HMR-1098 group (group DSH). Another 8 Langendorff-perfused hearts of normal rats were selected as control group ( group C) . Hearts were perfused with 37℃ K-H solution via the aorta in each group, 15 min of equilibra-tion later hearts were continuously perfused for 30 min with K-H solution in C and D groups, with K-H solu-tion saturated with 2. 5％ sevoflurane in group DS, or with K-H solution saturated with 10 μmol/L HMR-1098 and 2. 5％ sevoflurane in group DSH. Monophasic action potential (MAP) duration at 50％ and 90％repolarization ( MAPD50 and MAPD90 ) in the endocardium and epicardium of the left ventricular anterior wall were recorded at 15 min of equilibration ( T0 ) and 15 and 30 min of reperfusion ( T1,2 ) , transmural dispersion of repolarization ( TDR) was calculated. S1S2 program-controlled stimulation was performed at the end of perfusion to record the effective refractory period (ERP), ventricular arrhythmia (VA) induced and the longest pacing cycle length ( PCL) of ventricular fibrillation threshold ( VFT) induced. ERP/MAPD90 ratio was calculated. Results Compared with group C, TDR was significantly increased at T0 , ERP/MADP90 ratio was decreased, the incidence of VA induced was increased, and the longest PCL of VFT induced was prolonged in group D ( P＜0. 05) . Compared with group D, TDR was significantly decreased at T2 in group DS (P＜0. 05), and ERP/MADP90 ratio was significantly increased, the incidence of VA in-duced was decreased, and the longest PCL of VFT induced was shortened in DS and DSH groups ( P＜0. 05). TDR was significantly smaller at T2 in group DSH than in group DS (P＜0. 05). Conclusion sarcKATP channel is involved in sevoflurane-induced maintenance of electrophysiological stability of ventricu-lar myocardium in diabetic rats.

Effects of different concentrations of desflurane on electrophysiological stability of hearts in female patients / 中华麻醉学杂志

Objective To evaluate the effects of different concentrations of desflurane on the electrophysiological stability of hearts in female patients.Methods Forty female patients,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,aged 20-50 yr,weighing 45-77 kg,scheduled for elective surgery with general anesthesia,were divided into 2 groups (n =20 each) using a random number table method:0.6 MAC group (group D1) and 1.3 MAC group (group D2).The intravenous access was opened after admission to the operating room,midazolam 0.1 mg/kg,vecuronium 0.1 mg/kg,fentanyl 3 μg/kg and etomidate 0.3 mg/kg were injected intravenously,and mechanical ventilation was performed after tracheal intubation.The concentrations of desflurane reached 0.6 and 1.3 MAC in D1 and D2 groups,respectively.Twelve-lead electrocardiograms were collected before anesthesia induction (T1),at 5 min after intubation (T2) and at 20 min after reaching the set concentration of desflurane (T3).The QT interval and Tpe interval were measured,the QTc interval,Tp-e/QT ratio and index of cardiac electrophysiological balance were calculated,and the development of arrhythmia was also observed.Results The QT interval and QTc interval were significantly longer,and the Tp-e/QT ratio was lower at T3 than at T1,2 in two groups (P＜ 0.05).There was no significant difference in QT interval,Tp-e/QT ratio or index of cardiac electrophysiological balance at each time point between two groups (P＞0.05).No arrhythmia was found in neither group.Conclusion The clinical concentration of desflurane affects the electrophysiological stability of hearts to some extent in female patients without causing arrhythmia.

Effect of sevoflurane on electrophysiological stability of isolated rat hearts subjected to hypothermic perfusion / 中华麻醉学杂志

Objective To evaluate the effect of sevoflurane on the electrophysiological stability of i-solated rat hearts subjected to hypothermic perfusion. Methods Clean-grade healthy adult male Sprague-Dawley rats, weighing 280-360 g, were heparinized and anesthetized with pentobarbital sodium. Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95％ O2-5％CO2 at 37℃. Twenty-four Langendorff-perfused hearts were divided into 4 groups ( n=6 each) using a ran-dom number table method: control group ( C group ) , sevoflurane group ( S group ) , 32 ℃ hypothermia group ( H group) and 32℃ hypothermia plus sevoflurane group ( HS group) . After 15 min of equilibration, the isolated hearts were continuously perfused for 30 min with K-H solution at 37℃, with K-H solution con-taining 2. 3％ sevoflurane at 37 ℃, with K-H solution at 32 ℃, and with K-H solution containing 2. 3％sevoflurane at 32℃ in C, S, H and HS groups, respectively. Heart rate and monophasic action potential in three layers of the left ventricular anterior wall were recorded at 15 min of equilibration ( T0 ) and 30 of con-tinuous perfusion ( T2 ) , the transmural dispersion of repolarization ( TDR) were calculated, and the occur-rence of arrhythmia was observed. Results Compared with C and S groups, the heart rate was significantly decreased and TDR was enlarged at T1 , and the incidence of arrhythmia was increased in H and HS groups ( P<0. 05) . Compared with H group, TDR was significantly reduced at T1 , and the incidence of arrhythmia was decreased in HS group ( P<0. 05) . Conclusion Sevoflurane can improve the electrophysiological in-stability of isolated rat hearts subjected to hypothermic perfusion, and thus decrease the development of ar-rhythmia.

Video Caso Clínico: Estimulación Vagal Directa Como Maniobra Electrofisiológica Alternativa en el Diagnóstico de Taquicardia Durante Estudio Electrofisiológico / Case Report: Direct Vagal Stimulation as Alternative Electrophysiological Procedure in the Diagnosis of Tachycardias During Electrophysiological Study

INTRODUCCIÓN: El síndrome de Wolff Parkinson White se caracteriza por la conexión anómala entre la aurícula y el ventrículo durante el paso del estímulo sinusal, generalmente causada por una vía accesoria que conecta el músculo auricular con el músculo ventricular llamado haz de Kent, caracterizándose por la presencia de síntomas como: palpitaciones, sincope o muerte súbita y sumado a la presencia de onda delta, intervalo PR corto, QRS ancho y alteraciones de la repolarización ventricular en el electrocardiograma. El estudio electrofisiológico tiene como objetivo confirmar la presencia, localización y características de este haz anómalo y posteriormente, con seguridad, proceder a la ablación por radiofrecuencia eliminando esta vía accesoria, siendo considerado un procedimiento curativo en el caso del síndrome de Wolff Parkinson White. Durante el estudio se realiza estimulaciones eléctricas en los sitios específicos, tanto de la aurícula como del ventrículo, además se utiliza medicación intravenosa como la adenosina que actúa bloqueando al nódulo aurículoventricular y así observar el paso residual de la estimulación sinusal normal y/o el paso retrogrado del estímulo ventricular hacia la aurícula a través del haz de Kent, permitiendo de esta forma analizar las características de las conexiones aurículoventriculares previo a la ablación. La posibilidad de realizar una estimulación vagal selectiva de alta frecuencia y baja amplitud a nivel infraorbitario, descrita por Pachón et al [1], a través de la vena yugular interna y el consecuente bloqueo aurículoventricular transitorio que esta ocasiona, permite realizar el estudio sin necesidad de utilizar otras maniobras electrofisiológicas o medicación endovenosa

BACKGROUND: Wolff Parkinson White Syndrome is characterized by the bypass of the electrical signal through an abnormal pathway, different from the atrioventricular node that connects the atrial and ventricular muscles (Bundle of Kent). It presents with palpitations, syncope or can even cause sudden death. Electrocardiogram findings consist on Delta waves, shortened PR interval, widened QRS complex and altering of the ventricular repolarization. In the presence of Ventricular pre-excitation (Wolff Parkinson White Syndrome), the electrophysiological testing is key to confirm the presence, site and features of this accessory pathway. Later, with the certainty of the diagnosis proceed to perform the Radiofrequency Ablation, the definitive treatment to eliminate this abnormal pathway. This test is usually done with the use of electrophysiological maneuvers, stimulating key sites in the atria and the ventricle, with the help of intravenous drugs like Adenosine. The objective is to block the AV node to look how the remnants of the normal electrical signal move through the abnormal pathway, thus letting the physician analyze the characteristics previously mentioned of this pathway. After the ablation, these maneuvers are repeated to confirm the complete elimination of the accessory pathway that has direct relation with the prognostic. Based on the possibility of high frequency and low amplitude selective vagal stimulation described by Pachón et al [1], at infraorbital level through the internal jugular vein and the resulting transitory atrioventricular block. It is possible to study the abnormal pathway without the need of electrophysiological maneuvers or the use of IV drugs, either pre or post ablation.

Paroxysmal Atrial Fibrillation in Females: Understanding gender diferences / Ablação de Fibrilação Atrial Paroxística em Mulheres: Compreendendo a Diferença entre os Gêneros

Abstract Background: The catheter ablation of atrial fibrillation (AF) is performed less frequently in women. In addition, there is divergent information in the literature regarding the effectiveness and safety for the ablative procedure to females. Objectives: The objective of this study was to compare the clinical characteristics and outcomes in men and women undergoing paroxysmal atrial fibrillation (PAF) ablation. Methods: Cohort study of patients undergoing first-ever PAF catheter ablation procedure refractory to antiarrhythmic drugs. The information was taken from patients' records by means of a digital collection instrument and indexed to an online database (Syscardio®). Clinical characteristics and procedures were compared between each gender (M x F), adopting a level of statistical significance of 5%. The primary endpoint associated with efficacy was freedom from atrial arrhythmia over the follow-up time. Results: 225 patients were included in the study, 64 (29%) women and 161 (71%) men. Women presented more symptoms due to AF according to the CCS-SAF score (1.8 ± 0.8M x 2.3 ± 0.8F p = 0.02) and higher CHADS2 score compared to men (0.9 ± 0.8M x 1.2 ± 1F). Post-ablation recurrence occurred in 20% of the patients, with no difference based on gender (21% M x 20% F p = 0.52). The rate of complications was less than 3% for both groups (p = 0.98). Conclusion: Women undergoing the first-ever PAF catheter ablation procedure present similar complication rate and clinical outcome compared to men. These findings suggest that the current underutilization of AF catheter ablation in women may represent a discrepancy in care.

Resumo Fundamento: A ablação por cateter da fibrilação atrial (FA) é realizada com menor frequência em mulheres. Além disso, há informações divergentes na literatura em relação à eficácia e segurança do procedimento ablativo no sexo feminino. Objetivos: O objetivo deste estudo é comparar as características clínicas e desfechos em homens e mulheres submetidos à ablação de fibrilação atrial paroxística (FAP). Métodos: Estudo do tipo coorte de pacientes submetidos ao primeiro procedimento de ablação por cateter de FAP refratária a drogas antiarrítmicas. As informações foram retiradas dos prontuários dos pacientes por meio de instrumento digital de coleta e indexadas a uma base de dados online (Syscardio®). As características clínicas e procedimentos foram comparados entre gêneros (H x M), sendo adotado nível de significância estatística de 5%. O desfecho primário associado à eficácia foi ausência de arritmia atrial ao longo do seguimento com único procedimento. Resultados: 225 pacientes foram incluídos no estudo, 64 (29%) mulheres e 161 (71%) homens. Mulheres apresentaram mais sintomas devido à FA segundo o escore CCS-SAF (1,8 ± 0,8H x 2,3 ± 0,8M p = 0,02) e maior escore CHADS2 em relação aos homens (0,9 ± 0,8H x 1,2 ± 1M). A recorrência pós-ablação ocorreu em 20% dos pacientes, não havendo diferença associada ao gênero (21%H x 20%M p = 0,2). A taxa de complicações foi inferior a 3%, tanto para homens como mulheres (p = 0,8). Conclusão: Mulheres submetidas ao primeiro procedimento de ablação por cateter de FAP apresentam taxa de complicação e desfecho clínico semelhante comparado aos homens. Estes achados sugerem que a atual subutilização da ablação de FA por cateter em mulheres possa representar uma discrepância no cuidado.

Effect of sevoflurane-containing HTK solution on electrophysiological stability of rat donor heart during reperfusion / 中华麻醉学杂志

Objective To evaluate the effect of sevoflurane-containing HTK solution on electro-physiological stability of rat donor heart during reperfusion. Methods Male Sprague-Dawley rats, weighing 280-320 g, aged 3 months, in which a Langendorff-perfused isolated rat donor heart model was estab-lished, were used in this study. Sixteen donor hearts were obtained and divided into 2 groups (n＝8 each) using a random number table method: control group (group C) and sevoflurane group (group S). HTK so-lution was used as preservation solution in group C. HTK solution containing 2. 5% sevoflurane was used as preservation solution in group S. Hearts were stored for 6 h in the corresponding preservation solution at 4℃ and then reperfused, and the perfusion temperature was gradually restored to 37 ℃ in two groups. The time of spontaneous recovery of heart beat and development of arrhythmia were recorded. Heart rate, monophasic action potential (MAP) duration at 50% and 90% repolarization (MAPD50, MAPD90), MAP amplitude and maximum velocity and development of early after-depolarization and delayed after-depolariza-tion were recorded at 30 and 45 min of reperfusion. Results Compared with group C, the time of sponta-neous recovery of heart beat was significantly shortened, the incidence of ventricular fibrillation and arrhyth- mia score were decreased, the ventricular fibrillation interval was shortened, and MAPD50and MAPD90of epicardium and endocardium were shortened at 30 and 45 min of reperfusion (P＜0. 05), and no significant change was found in hear rate, maximum velocity or MAP amplitude in group S (P＞0. 05). Early after-de-polarization and delayed after-depolarization were not found in two groups. Conclusion Sevoflurane-contai-ning HTK solution can maintain electrophysiological stability of rat donor heart during reperfusion and de-crease the occurrence of arrhythmia.

The effects of full marathon on hemodynamics related to cardiac electrophysiology of marathon amateurs / 中华急诊医学杂志

Objective To observe and assess the effects of full marathon on hemodynamics and cardiac electrophysiology of marathon amateurs without adverse event after the race.Methods Fiftyone subjects were included in the final analysis of the study,blood pressure,heart rate,body surface electrocardiogram (ECG) of all subjects under static status before the race and within (15-30) min after the race were detected,and sufficient amounts of the peripheral blood and the radial arterial blood specimens of all subjects under static status before the race and within (15-30) min after the race were collected instantly.The peripheral blood was used for measuring markers of muscle injury and NT-proBNP,and the radial arterial blood was taken for blood gas analysis.The QTc interval,QRS,PR interval,and QTd interval were recorded from the 12-lead ECG report.Results Compared with those under static status before the race,the systolic blood pressure,diastolic blood pressure,mean arterial blood pressure and heart rate of all the subjects within (15-30) min after the race were significantly higher (P＜0.05).When the markers of striated muscle injury were compared before and after the competition,levels of CK,cTNI,LDH,and myoglobin after the race were significantly increased compared with them under static status before the race (P ＜0.05),and the level of NT-proBNP after the race was also significantly increased compared with it before the race (P＜0.05).When blood gas analysis before the race was compared with that after the race,the PH values after race were significantly lower than it before race (P＜0.05).The level of lactic acid after the race was significantly higher than it before race (P＜0.05).After the race,the levels of PCO2,SBE and HCO3-decreased significantly compared with those before race (P＜0.05),and the QTc and QTd intervals after the race increased significantly compared with those before the race,however,the QTc interval and QTd interval for all subjects before and after the competition were within the normal range.Conclusions Full marathon significantly affect the myocardial electrophysiological markers of healthy amateur athletes without chronic diseases,but those markers fluctuate within the normal range.

Bone-Marrow-Derived Mesenchymal Stromal Cells (MSC) from Diabetic and Nondiabetic Rats Have Similar Therapeutic Potentials / Células Estromais Mesenquimais (CEM) Derivadas de Medula Óssea de Ratos com e sem Diabetes têm Potencial Terapêutico Similar

Abstract Background: Diabetes mellitus is a severe chronic disease leading to systemic complications, including cardiovascular dysfunction. Previous cell therapy studies have obtained promising results with the use bone marrow mesenchymal stromal cells derived from healthy animals (MSCc) in diabetes animal models. However, the ability of MSC derived from diabetic rats to improve functional cardiac parameters is still unknown. Objectives: To investigate whether bone-marrow-derived MSC from diabetic rats (MSCd) would contribute to recover metabolic and cardiac electrical properties in other diabetic rats. Methods: Diabetes was induced in Wistar rats with streptozotocin. MSCs were characterized by flow cytometry, morphological analysis, and immunohistochemistry. Cardiac electrical function was analyzed using recordings of ventricular action potential. Differences between variables were considered significant when p < 0.05. Results: In vitro properties of MSCc and MSCd were evaluated. Both cell types presented similar morphology, growth kinetics, and mesenchymal profile, and could differentiate into adipogenic and osteogenic lineages. However, in an assay for fibroblast colony-forming units (CFU-F), MSCd formed more colonies than MSCc when cultured in expansion medium with or without hydrocortisone (1 µM). In order to compare the therapeutic potential of the cells, the animals were divided into four experimental groups: nondiabetic (CTRL), diabetic (DM), diabetic treated with MSCc (DM + MSCc), and diabetic treated with MSCd (DM + MSCd). The treated groups received a single injection of MSC 4 weeks after the development of diabetes. MSCc and MSCd controlled hyperglycemia and body weight loss and improved cardiac electrical remodeling in diabetic rats. Conclusions: MSCd and MSCc have similar in vitro properties and therapeutic potential in a rat model of diabetes induced with streptozotocin.

Resumo Fundamentos: O diabetes mellitus é uma doença crônica grave que leva a complicações sistêmicas, como a disfunção cardiovascular. Estudos anteriores de terapia celular obtiveram resultados promissores com utilização de células estromais mesenquimais (CEM) derivadas de medula óssea de animais saudáveis (CEMc) em modelos de animais diabéticos. No entanto, a capacidade das CEM derivadas de ratos diabéticos em melhorar parâmetros cardíacos funcionais é ainda desconhecida. Objetivos: Investigar se CEM derivadas de medula óssea de ratos diabéticos (CEMd) poderiam contribuir para a recuperação metabólica e de propriedades elétricas cardíacas em outros ratos também com diabetes. Métodos: O diabetes foi induzido em ratos Wistar com estreptozotocina. As CEM foram caracterizadas por citometria de fluxo, análise morfológica e imunohistoquímica. A função elétrica cardíaca foi analisada através de registro do potencial de ação ventricular. As diferenças entre as variáveis foram consideradas significativas quando p < 0,05. Resultados: As propriedades in vitro das CEMc e CEMd foram avaliadas. Ambos os tipos celulares apresentaram morfologia, cinética de crescimento e perfil mesenquimal semelhante, e puderam ser diferenciadas em linhagens adipogênica e osteogênica. No entanto, em ensaios para unidades formadoras de colônias de fibroblastos (UFC-F), as CEMd formaram mais colônias em comparação às CEMc quando cultivadas em meio com ou sem hidrocortisona (1 µM). Para comparar o potencial terapêutico das células, os animais foram divididos em quatro grupos experimentais: não diabéticos (CTRL), diabéticos (DM), diabéticos tratados com CEMc (DM + CEMc) e diabéticos tratados com CEMd (DM + CEMd). Os grupos tratados receberam uma única injeção de CEM 4 semanas após o estabelecimento do diabetes. Ambas CEMc e CEMd controlaram a hiperglicemia e a perda de peso corporal e melhoraram o remodelamento elétrico cardíaco em ratos com diabetes. Conclusão: As CEMd e CEMc possuem propriedades in vitro e potencial terapêutico semelhante em um modelo de rato com diabetes induzido por estreptozotocina. (Arq Bras Cardiol. 2017; 109(6):579-589)