Actividad de adiestramiento en cardioversión eléctrica en la unidad de electrocardiología del CCR-ASCARDIO / Training program on electrical cardioversion at the electrocardiology unit of the CCR-ASCARDIO

Las enfermedades cardiovasculares son una de las principales causas de mortalidad siendo los trastornos del ritmo cardiaco una de las patologías cardiacas más frecuentes. La cardioversión eléctrica es una técnica a través de la cual se realiza una transferencia de electrones al miocardio con la finalidad de interrumpir arritmias con mecanismos de reentrada permitiendo al nodo sinusal retomar el control de la frecuencia cardiaca. La correcta selección de los casos susceptibles de cardioversión eléctrica y experiencia en cardioversión aumenta la tasa de éxito y disminuye el número de choques fallidos. En el CCR- ASCARDIO, la Unidad de Electrocardiología cuenta con experiencia en el estudio y tratamiento de arritmias. En este artículo se presenta la elaboración de un programa de adiestramiento en la técnica de cardioversión eléctrica siendo esta terapia una herramienta imprescindible para la práctica clínica del cardiólogo, facilitando la prevención de complicaciones derivadas de los trastornos del ritmo cardiaco(AU)

Cardiovascular diseases are one of the main causes of mortality worldwide being heart rhythm disorders one of the most frequent cardiac pathologies. Electrical cardioversion is a technique that allows the transfer of electrons to the myocardium in order to interrupt arrhythmias with reentry mechanisms allowing the sinus node to take control of heart rate. The appropriate selection of cases susceptible to electrical cardioversion as well as experience on this technique increases the success rate and decreases the number of failed attempts. The Electrocardiology unit of the CCR-ASCARDIO has experience in the study and treatment of arrhythmias. In this article we present the development of a training program on electrical cardioversion, essential tool for cardiologists, with the aim to increase the correct use of this technique in order to prevent complications due to heart rhythm disorders(AU)

Obstructive Sleep Apnea is Common and Associated with Heart Remodeling in Patients with Chagas Disease / Apneia Obstrutiva do Sono é Comum e está Associada à Remodelação Cardíaca em Pacientes com Doença de Chagas

Abstract Background: Chagas Disease (CD) is an important cause of morbimortality due to heart failure and malignant arrhythmias worldwide, especially in Latin America. Objective: To investigate the association of obstructive sleep apnea (OSA) with heart remodeling and cardiac arrhythmias in patients CD. Methods: Consecutive patients with CD, aged between 30 to 65 years old were enrolled. Participants underwent clinical evaluation, sleep study, 24-hour Holter monitoring, echocardiogram and ambulatory blood pressure monitoring. Results: We evaluated 135 patients [age: 56 (45-62) years; 30% men; BMI: 26 ± 4 kg/m2, Chagas cardiomyopathy: 70%]. Moderate to severe OSA (apnea-hypopnea index, AHI, ≥ 15 events/h) was present in 21% of the patients. OSA was not associated with arrhythmias in this population. As compared to patients with mild or no OSA, patients with moderate to severe OSA had higher frequency of hypertension (79% vs. 72% vs. 44%, p < 0.01) higher nocturnal systolic blood pressure: 119 ± 17 vs. 113 ± 13 vs. 110 ± 11 mmHg, p = 0.01; larger left atrial diameter [37 (33-42) vs. 35 (33-39) vs. 33 (30-36) mm, p < 0.01]; and a greater proportion of left ventricular dysfunction [LVEF < 50% (39% vs. 28% vs. 11%), p < 0.01], respectively. Predictor of left atrial dimension was Log10 (AHI) (b = 3.86, 95% CI: 1.91 to 5.81; p < 0.01). Predictors of ventricular dysfunction were AHI > 15 events/h (OR = 3.61, 95% CI: 1.31 - 9.98; p = 0.01), systolic blood pressure (OR = 1.06, 95% CI: 1.02 - 1.10; p < 0.01) and male gender (OR = 3.24, 95% CI: 1.31 - 8.01; p = 0.01). Conclusions: OSA is independently associated with atrial and ventricular remodeling in patients with CD.

Resumo Fundamento: A doença de Chagas (DC) é uma causa importante de morbimortalidade por insuficiência cardíaca e arritmias malignas em todo o mundo, especialmente na América Latina. Objetivo: Investigar a associação entre apneia obstrutiva do sono (AOS) com remodelação cardíaca e arritmias cardíacas em pacientes com DC. Métodos: Foram incluídos pacientes consecutivos com DC, com idade entre 30 e 65 anos. Os participantes foram submetidos à avaliação clínica, estudo do sono, Holter de 24 horas, ecocardiograma e monitorização ambulatorial da pressão arterial. Resultados: Foram avaliados 135 pacientes [idade: 56 (45-62) anos; 30% homens; IMC: 26 ± 4 kg/m2, cardiomiopatia chagásica: 70%]. AOS moderada a grave (índice de apneia-hipopneia, IAH, ≥ 15 eventos/h) estava presente em 21% dos pacientes. AOS não estava associada a arritmias nessa população. Em comparação com pacientes com AOS leve ou ausente, pacientes com AOS moderada a grave apresentaram maior frequência de hipertensão (79% vs. 72% vs. 44%, p < 0,01) e pressão arterial sistólica noturna mais alta: 119 ± 17 vs. 113 ± 13 vs. 110 ± 11 mmHg, p = 0,01; diâmetro do átrio esquerdo maior [37 (33‑42) vs. 35 (33-39) vs. 33 (30-36) mm, p < 0,01]; e maior proporção de disfunção ventricular esquerda [FEVE < 50% (39% vs. 28% vs. 11%), p < 0,01], respectivamente. O preditor de dimensão do átrio esquerdo foi Log10 (IAH) (β = 3,86, IC 95%: 1,91 a 5,81; p < 0,01). Os preditores de disfunção ventricular foram IAH >15 eventos/h (OR = 3,61, IC 95%: 1,31 - 9,98; p = 0,01), pressão arterial sistólica (OR = 1,06, IC95%: 1,02 - 1,10; p < 0,01) e sexo masculino (OR = 3,24, IC 95%: 1,31 - 8,01; p = 0,01). Conclusões: A AOS está independentemente associada à remodelação atrial e ventricular em pacientes com DC.

Application of molecular autopsy in sudden death caused by inherited arrhythmia / 法医学杂志

Sudden cardiac death (SCD) refers to sudden stop of breath and heartbeat and death within one hour caused by underlying cardiac diseases. Clinical manifestation of inherited arrhythmia is lethal arrhythmia without gross cardiac lesions, which can lead to SCD. The autopsy and pathological examination are difficult to identify the cause of death. Fatal mechanism of inherited arrhythmia is the change in the genes encoding for cardiac ion channel protein, which causes the dysfunctions of cardiac electrical activity. It is very important to detect genetic mutation by the technique of molecular biology in negative autopsy. This review presents the latest research on the relation between SCD and inherited arrhythmia, and the application of molecular autopsy used in identifying SCD due to inherited arrhythmia and its candidate gene.

Narrowed lumen of the right coronary artery in chronic chagasic patients is associated with ischemic lesions of segmental thinnings of ventricles / El lumen estrecho de la arteria coronaria derecha en pacientes chagásicos crónicos está asociado con lesiones de adelgazamientos segmentales de los ventrículos

Thinning of myocardial segments, mainly at the apex and basal posterior region of left ventricle, are frequent lesions in chronic chagasic cardiopathy (CCC), but still without a well determined etiology. Previously we found severe myocardial microvascular dilatation that could cause ischemia in watershed regions. In this study we analyzed whether narrowness in epicardial coronary arteries in CCC might explain these thinned ventricular lesions. Two groups of dilated hearts with similar weights were compared: eleven hearts from patients with CCC versus four hearts from patients with dilated cardiomyopathy (IDCM). As normal controls we studied three non dilated normal weight hearts. There were no atherosclerotic plaques in the main branches of epicardial coronary arteries and cross-sectional luminal areas of proximal and distal segments were histologically measured. It was found that CCC hearts presented a lower mean luminal area in the right coronary artery (RCA) branch than IDCM, in proximal (4.3 ± 1.4 vs 6.6 ± 2.0 mm2; p= 0.02) and in distal (1.6 ± 1.0 vs 3.4 ± 0.9 mm²; p= 0.01) segments, with no statistical differences with normal hearts (2.7 ± 1.3 and 1.5 ± 0.3 mm²) in proximal (p= 0.2) and distal (p=0.11) sections. In conclusion thinning of ventricular wall in CCC patients seems to be ischemic lesions in the peripheral territory irrigated by the right coronary artery, possibly due to a steal phenomenon by the left coronary, induced by micro vessels dilatation.

Adelgazamientos segmentares del miocardio son frecuentes lesiones en la cardiomiopatía crónica chagásica (CCC), principalmente en el ápice de la región posterior del ventrículo izquierdo, cuya etiopatogenia todavía no está bien conocida. En trabajos anteriores se observó intensa dilatación de la micro circulación que podría llevar a isquemia en regiones de irrigaciones limítrofes. Este estudio analizó si estrechez de las arterias epicárdicas in CCC podrían explicar las lesiones de adelgazamientos ventriculares. Se compararon 2 grupos de corazones con pesos semejantes: 11 corazones de pacientes con CCC versus 4 corazones de pacientes con cardiomiopatia dilatada idiopática (IDCM). Como controles normales fueran estudiados 3 corazones no dilatados y con pesos normales. No estuvieron presentes placas ateroscleróticas en los principales ramos de las arterias coronarias epicárdicas. Las áreas de lumen en cortes transversales de los segmentos proximales e distales arteriales fueran medidas por histología. Los corazones con CCC mostraron una media de lumen menor en el ramo de la coronaria derecha que en los con IDCM, tanto en los segmentos proximales (4,3 ± 1,4 vs 6,6 ± 2,0 mm2; p= 0,02) como en los distales (1, 6 ± 1, 0 vs 3,4 ± 0,9 mm²; p= 0,01) y ninguna diferencia estadística fue observada cuando se compararon con los corazones normales (2,7 ± 1,3 vs 1,5 ± 0,3 mm²) tanto proximal (p= 0,2) como distal (p=0,11). Adelgazamientos ventriculares en pacientes con CCC parecen ser lesiones isquémicas en territorios distales, irrigados por la arteria coronaria derecha, posiblemente por un fenómeno de sustracción por la coronaria izquierda, debido a vasodilatación de micro circulación.

Alteración del sodio y potasio en pacientes hospitalizados por insuficiencia cardíaca / Alteration of sodium and potassium levels in patients hospitalized for heart failure

La insuficiencia cardíaca es un síndrome ocasionado por múltiples factores y va produciendo un proceso de remodelado ventricular. Es un verdadero problema de salud pública que incrementa el número de hospitalizaciones. Los diuréticos siguen siendo útiles en el tratamiento, aún así se producen alteraciones de los electrólitos que pueden ocasionar arritmias, empeoramiento de la insuficiencia cardíaca y disminución de la fracción de eyección. Este trabajo evalúa la alteración del sodio y potasio en pacientes hospitalizados por este síndrome. Se revisaron las historias de pacientes con insuficiencia cardíaca ingresados al servicio de Cardiología, registrando datos en base a un protocolo. Se revisaron 33 historias de las cuales 11 pacientes eran mujeres y 22 eran hombres, con un promedio de edad de 72,64 y 71,52 años respectivamente. Días de hospitalización promedio de 14,91 días. Todos los pacientes tenían dieta hiposódica excepto uno debido a diarrea. El 57,6% tenían una sola patología y el resto dos o tres. La hipertensión arterial es la patología más frecuente en un 81,8%, seguido de cardiopatía isquémica en un 30,3%. Recibieron tres diuréticos (furosemida, espirolactona, hidroclorotiazida) el 48,5% de los pacientes y dos diuréticos el 48,5%. El 51,5% de los pacientes tenían potasio bajo y el 57,6% sodio bajo. En un 50% de los pacientes se encuentra que el potasio y sodio están bajos que se relaciona con el uso de diuréticos y una dieta hiposódica. Habría que considerar el uso de suplemento de potasio en estos casos.

Heart failure a syndrome caused by multiple factors engenders a process of ventricular remodeling. It is an enormous public health problem, with an increasing number of hospitalizations. Diuretics, still useful for treatment, produce electrolyte abnormalities can cause arrhythmias, worsening heart failure and larger reduction in the ejection fraction. This study evaluated the alteration of sodium and potassium levels in patients hospitalized with this syndrome. We reviewed the charts of patients with heart failure admitted to the cardiology service, recording data with the use of a standardized form. We reviewed 33 records for 11 women and 22 men with a mean age of 72.64 and 71.52 years respectively. The average number of days of hospitalization was 14.91 days. All patients had a low sodium diet except one because of diarrhea. A single pathology was present in 57.6% with the rest having two or three. Hypertensión was the most frequent pathology in 81.8% , followed by ischemic heart disease in 30.3%. Three diuretics (furosemide, spironolactone, hydrochlorothiazide) were used in 48.5% of patients and two diuretics in 48.5%. In 51.5 of patients there was low potassium and in 57.6% low sodium. Potassium and sodium were low in 50% of patients, which was associated with the use of diuretics and a low salt diet. Potassium supplements should be considered in these cases.

Fórmulas para el QT corregido y consideraciones clínicas

La medición del intervalo QT y QT corregido es importante en el seguimiento de pacientes cardiópatas así como de aquellos que reciben medicamentos que de una u otra forma afectan dicho intervalo. Se revisan las fórmulas más conocidas para el cálculo del QT corregido y se estudia su aplicación clínica

The measurement of the interval QT and corrected QT is important in the follow-up of cardiac patients as well as from those who receive medicines which of one or another form affect this interval. The most well-known formulas for the calculation of the corrected QT are reviewed and its clinical application are studied

En torno a las arritmias ventriculares en la miocardiopatía chagásica crónica / On the ventricular arrhythmias in Chagasic chronic cardiomyopathy

Some authors have shown a high prevalence of electric circuits localized in the epicardium in Chagasic cardiomyopathy. Other authors have found in these patients, during electric mapping, mid-diastolic potentials and earlier myocardial activation in epicardial regions than in the endocardium. In a previous study, we found electrocardiographic signs of subepicardial ischemia in 66% of seropositive Chagasic patients against 16% of seronegative Chagasic ones. In the case presented here, a Chagasic dilated cardiomyopathy, we found electrocardiographic signs of subepicardial injury in the left free ventricular wall, related with histological findings of lymphocytic inflammation in these regions. In contrast, the endocardium was completely free from inflammation foci.

Immunohistochemical study of Cx43 dephosphorylation in human left ventricular myocardium suffered by acute ischemia / 法医学杂志

OBJECTIVE@#This study was performed to detect the phosphorylation state of Cx43 in human left ventricular myocardium among sudden deaths caused by acute myocardial ischemia (AMI) especially sudden coronary death (SCD) and control groups. And then evaluate the significance of these findings in diagnosing the early pathological changes of acute myocardial ischemia.@*METHODS@#Immunohistochemistry (IHC) SP techniques were adopted to detect the phosphorylation state of Cx43 in the left ventricular myocardium samples of 45 deceased, which classified as group I--SCD, group II & III (other two groups of AMI) and Group IV & V (two control groups, sudden death caused by lethal acute cranio-cerebral injury or pathologic intracranial hemorrhage). In addition, we selected anti-Pan-Cadherin (construction protein of adherent junctions on the intercalated disc) and PHA-E+L/Bio, to detect the integration of myocardial mechanical coupling and membranes (applying affinityhistochemistry, AHC) respectively.@*RESULTS@#(1) Phosphorylated Cx43 positive staining was almost invisible in Group I, II and III or scattered in sarcoplasm in few samples; but it was assembling at the IDs clearly in group IV and V. (2) Strongly positive staining of Pan-Cadherin could be observed at the IDs and (3) integrated myocardial membranes were found in all samples.@*CONCLUSION@#These findings suggested that compared with the control groups, the integration of myocardial mechanical coupling and membranes did not alter in AMI. But Cx43, the key protein of electrical coupling on myocardial gap junctions, occurred dephosphorylation remarkably in AMI. Thus applying IHC techniques to detect the Cx43 dephosphorylation in human left ventricular myocardium maybe useful to recognize the onset of arrhythmia in AMI, especially in SCD whose myocardium without apparent morphological changes.

The sudden cardiac death in negative autopsy / 法医学杂志

The advancement of studies about the molecular biology and electronic physiology on sudden cardiac death was summarized in this article, including particularly cardiac concussion(commotio cordis), congenital long QT syndrome, and Brugada syndrome which probably resulting in fatal arrhythmia and sudden cardiac death. These corpses of fatal functional disorders often show the results of negative autopsy without obvious organic pathological changes. So when come across negative autopsy the medical examiner and the pathologist should be careful to investigate the inductive cause of sudden death, the history of disease, and the family history, then to rule out the possibility of the above disorders.

Arritmias em crianças / Cardiac arrhythmias in children

Neste artigo apresentam-se as arritmias mais encontradas na criança e no adolescente. Enfoca-se sob a óptica do cardiologista pediátrico, enfatizando-se o diagnóstico da arritmia e a conduta terapêutica.

Arritmias no idoso / Arrhythmias in the elderly

Com o envelhecimento, ocorrem mudanças estruturais nos tecidos do coraçäo, com consequentes alteraçöes eletrofisiológicas que podem gerar vários tipos de arritmias e distúrbios de conduçäo. Muitas vezes torna-se difícil para o clínico decidir até onde säo alteraçöes devidas ao processo normal de envelhecimento e onde se iniciam as alteraçöes patológicas. Neste artigo, säo condensados os conhecimentos atuaia sobre as mudanças fisiológicas encontradas nos coraçöes dos idosos, assim como os processos patológicos que podem causar arritmias nesses pacientes. Foram analisadas as arritmias mais prevalentes na populaçäo idosa, divididas como arritmias supraventriculares, ventriculares e distúrbios de conduçäo. Além disso, foram feitas consideraçöes acerca das principais drogas antiarrítmicas utilizadas neses pacientes, com ênfase nas peculiaridades de seu uso nos idosos. Finalmente, tecemos consideraçöes sobre as técnicas invasivas para tratamento das arritmias nos idosos, que, entre todas, têm apresentado os resultados mais promissores também nessa faixa populacional.

Arritmias no esforço físico / Cardiac arrhythmias and exercise

A importância das arritmias cardíacas, em sua relação com o exercício físico, cresceu de forma exponencial após o advento da reabilitação cardíaca e da masssificação da prática regular de exercícios pela população geral com finalidades preventivas. Nesta revisão, os autores abordam os mecanismos pelos quais o exercício físico pode interferir no ritmo cardíaco, dividindo-os em neuro-humorais, eletrofisiológicos e hemodinâmicos. São comentadas as alteraçöes funcionais e estruturais que a prática regular do exercício e o treinamento atlético produzem com suas repercussöes, vistas por meio dos métodos não-invasivos, representados pela eletrocardiografia, ecocardiografia, eletrocardiografia ambulatorial pelo sistema Holter e teste ergométrico. Por meio desses métodos é que se faz a avaliação dos indivíduos que apresentam sintomas suspeitos de dependerem de arritmias induzidas por esfoço ou daqueles assintomáticos que tiveram uma arritmia fortuitamente detectada durante ou imediatamente após a prática de exercício. As arritmias graves e a morte súbita provocadas pelo exercício geralmente dependem de cardiopatia orgânica e as principais cardiopatias e síndromes arritmogências são a miocardiopatia hipertrófica, a displasia ventricular direita, a síndrome do QT longo, a síndorme de Woll-Parkinson-White e a cardiopatia isquêmica. Todas são analisadas quanto a sua ocorrência, diagnóstico, comportamento durante o exercício. Como causa de arritmias graves ou morte durante o exercício, até a idade de 30 anos, a miocardipatia hipertrófica é a mais importante; após essa idade, a cardiopatia isquêmica responde cerca de 98,5 'por cento' dos casos. Na experiência dos autores, o condicionamento físico em portadores de cardiopatia isquêmica foi benéfico, reduzindo as arritmias ventriculares induzidas por esforço. Em 21 anos de experiência com reabilitação cardíaca para coronarianos, os autores registraram 10 casos de fibrilação ventricular durante o exercício, todos recuperados e representando apenas um evento para cada 50 mil horas-exercício, o que indica serem os programas de condicionamento físico um procedimento, além de benéfico, seguro.

Estudio clínico de seguimiento a lo largo de la enfermedad de chagas en grandes alturas / Clinic study at Chagas disease at high altitude

Se efectuó un seguimiento clínico, electrocardiográfico en 64 pacientes ambulatorios, Clase I-II procedentes de áreas endémicas de enfermedad de Chagas a baja altitud, y actualmente residentes en altura (3,700 m) con serología positiva para enfermedad de Chagas, seguidos durante 6 años (2 a 12 años). Clínicamente no se observó desmejoría sintomática, ni insuficiencia cardíaca durante el seguimiento. El electrocardiograma fue normal en 27 por ciento de los casos al principio del seguimiento, persistiendo normal en el 19 por ciento hasta el fin del estudio. Las alteraciones electrocardiográficas observadas incluyeron: Bradicardia sinusual, hemobloqueo ántero-superior izquierdo, bloquepo de rama derecha, extrasistolia ventricular. La bradicardia sinusual constituye la característica electrocardiográfica más importante en este grupo. Los transtornos de conducción presentes en 20 por ciento de los pacientes al inicio del estudio, se observaron en 25 por ciento al concluir el mismo. Los pacientes con hemibloqueo ántero-superior izquierdo (14 por ciento del grupo al inicio del seguimiento, 15 por ciento al final) no presentaron evolución desfavorable, ninguno sintomática ni electrocardiográfica; los pacientes con bloqueo de Rama Derecha (6 por ciento al inicio, y 10,7 por ciento al final), tampoco tuvieron evolución desfavorable, ninguno desarrolló bloqueo aurículo ventricular completo. El ecocardiograma no mostró diferencias significativas en las dimensiones de cavidades ventriculares, tampoco en el grosor de paredes del ventrículo izquierdo. La función ventricular: fracción de eyección y fracción de acortamiento, no se detrioró durante este período. El seguimiento de este grupo de pacientes con enfermedad de Chagas mostró una evolución benigna, sin deterioro sintomático, ni alteraciones significativas del electrocardiograma ni ecocardiograma. No se detectó compromiso de la función ventricular ni insuficiencia cardíaca en el transcurso del estudio

Acute electrocardiographic lead II changes following experimental pulmonary air embolization

The effect of venous air embolization on the heart's electrical activity is not well demonstrated in the literature. This is a study of the acute electrocardiographic [ECG] lead II changes following experimental injection of 40 ml of air in two groups of dogs [7 dogs in each group]. In group I [GI], air was injected peripherally in the femoral vein and in group II [GII], air was injected directly into the central pulmonary artery. Six dogs were used as control. All dogs were subjected to general endotracheal anesthesia and sternotomy to expose the heart. ECG changes were recorded using lead II. Cardiac dysrhythmia was the most frequently encountered ECG change. It occurred in 85.7% of dogs of GI and in 100% of dogs of GII. Sinus tachycardia was the commonest in GI [85.7%]. Sinus tachycardia and premature ventricular contractions were commonest in GII [42.8% each]. The incidence of T wave inversion was greater in GI [42.8%], while ST segment changes were greater in GII. The only significant difference between the two groups was the presence of P-pulmonale in GI only [57.1%]. Venous air embolism should be thought of in patients with any access to their systemic venous circulation and whose monitoring reveals unexplained ECG changes