Exercise Stress Test in The Assessment of Brugada Syndrome Patients

Abstract Brugada syndrome (BS) is a genetic channelopathy, clinically characterized by an increased risk of sudden cardiac death. The diagnosis requires a typical electrocardiographic pattern, and data on risk stratification are limited in the literature. The aim of this study was to conduct a review on the importance of exercise stress test (EST) in risk stratification in BS. Articles were searched in the PubMed, Scielo and Google Scholar databases. From the 200 articles retrieved, eight were included, with a total of 712 patients (95% men) aged between 35 and 60 years. Severe symptoms and ventricular arrhythmias were reported by 256 patients before the EST, with syncope being reported in 70% of cases. The reviewed articles suggest that the EST is a safe method that can help in the diagnosis and risk stratification for malignant arrhythmias in patients with BS. Potential predictors of poor prognosis were: augmentation in ST-segment elevation > 0.5 mV in V1, V2 or V3 in early recovery; J-point elevation in lead > 2mm in aVR in late recovery; heart rate reduction < 40% from maximum heart rate in late recovery and occurrence of ventricular extrasystoles in early recovery.

Electrophysiological study in chagasics with syncope and conduction disorder

SUMMARY BACKGROUND: Investigation of syncope involves the use of electrophysiological study, particularly in patients with cardiac conduction disorder. There is conflicting evidence about the role of electrophysiological study in patients with Chagas disease. OBJECTIVE: The objective of this study was to evaluate the electrophysiological study findings in patients with Chagas disease and bundle branch block and/or divisional block presenting with syncope. METHODS: This is a retrospective study of patients with Chagas disease and cardiac conduction disorder who underwent electrophysiological study from 2017 to 2021 for the investigation of syncope in a tertiary hospital in São Paulo, Brazil. Those with non-interpretable ECG, known coronary artery disease, and/or other cardiomyopathies were excluded. HV interval and electrophysiological study-induced malignant ventricular arrhythmias data were analyzed. RESULTS: A total of 45 patients (60.2±11.29 years, 57.8% males) were included. The mean HV interval was 58.37 ms±10.68; 22.2% of the studied population presented an HV interval of ≥70 ms; and malignant ventricular arrhythmias were induced in 57.8% patients. The use of beta-blockers and amiodarone (p=0.002 and 0.036, respectively), NYHA functional class≥II (p=0.013), wide QRS (p=0.047), increased HV interval (p=0.02), Rassi score >6.5 (p=0.003), and reduced left ventricular ejection fraction (p=0.031) were associated with increased risk of inducible malignant ventricular arrhythmias. CONCLUSION: More than half of the patients with Chagas disease, syncope, and cardiac conduction disorder have inducible malignant ventricular arrhythmias. Prolonged HV interval was observed in only 20% of population. Wide QRS, prolonged HV, reduced ejection fraction, and higher Rassi score were associated with increased risk of malignant ventricular arrhythmias.

Tetralogy of Fallot with an Anomalous Course of the Brachiocephalic Vein

ABSTRACT Clinical data: Infant, 11-month-old, male, diagnosis of Tetralogy of Fallot with retrotracheoesophageal course of the brachiocephalic vein. Usual findings of Tetralogy of Fallot on physical examination. Technical description: Chest radiography showed slightly reduced pulmonary vascular markings and no cardiomegaly. Normal preoperative electrocardiogram with postoperative right bundle branch block. Usual findings of Tetralogy of Fallot on echocardiogram. Postoperative computed tomography angiography confirmed left brachiocephalic vein with anomalous retrotracheoesophageal course, configuring a U-shaped garland vein, in addition to postoperative findings of total correction of Tetralogy of Fallot. Operation: Complete surgical repair was performed with pulmonary valve commissurotomy and placement of bovine pericardial patch to solve right ventricular outflow tract obstruction, pulmonary trunk enlargement, and ventricular septal defect closure. Comments: Systemic venous drainage may show variations in patients with Tetralogy of Fallot. These abnormalities are usually of little clinical relevance, as they are asymptomatic. We presented a rare case of retrotracheoesophageal course of an anomalous left brachiocephalic vein with intraoperative diagnosis, confirmed by imaging during postoperative follow-up, without compromising clinical management or surgical approach.

Factores asociados al bloqueo de rama derecha en adultos mayores / Factors associated with right bundle branch block in older adults

RESUMEN Introducción: Existe poca literatura sobre la asociación entre el bloqueo de rama derecha y factores de riesgo como la hipertensión y la diabetes en pacientes de Latinoamérica y Perú. Objetivo: Determinar los factores asociados al bloqueo de rama derecha en adultos mayores. Métodos: Estudio transversal que incluyó 376 pacientes adultos mayores atendidos en el Hospital Almanzor Aguinaga Asenjo, Lambayeque-Perú. La variable dependiente fue la presencia de bloqueo de rama derecha y las variables independientes fueron edad, sexo, antecedente de hipertensión arterial y diabetes. Se estimaron razones de prevalencia e intervalos de confianza al 95 %. Resultados: De 376 pacientes, la mayoría eran varones (55,9 %), la edad media fue de 75,6 años, el 11,4 % tuvo antecedente de hipertensión y el 9 % era diabético. El 41 % tuvo diagnóstico de bloqueo de rama derecha. En la regresión múltiple; el sexo femenino (RP=1,53, IC 95 %: 1,21 - 1,95), antecedente de hipertensión (RP=1,55; IC 95 %: 1,21 - 2,00) y diabetes mellitus (RP=1,49, IC 95 %: 1,12 - 2,00) se asociaron de forma positiva a presentar bloqueo de rama derecha. El modelo anidado seleccionó las variables: sexo femenino (RP=1,54, IC 95 %: 1,21 - 1,96) y antecedente de hipertensión arterial (RP=1,61, IC 95 %: 1,25 - 2,08). Conclusión: El sexo femenino, antecedente de hipertensión arterial y de diabetes mellitus se asocian positivamente a presentar bloqueo de rama derecha.

ABSTRACT Introduction: There is little literature on the association between right bundle branch block and risk factors such as hypertension and diabetes in patients in Latin America and Peru. Objective: To determine the factors associated with right bundle branch block in older adults. Methods: Analytical cross-sectional study completed by 376 elderly patients treated at Almanzor Aguinaga Asenjo Hospital, Lambayeque-Peru. The dependent variable was the presence of right bundle branch block, and the independent variables were age, sex, history of hypertension, and diabetes. Prevalence ratios and 95 % confidence intervals were estimated. Results: Of 376 patients, the majority were male (55,9 %), the mean age was 75,6 years, 11,4 % had a history of hypertension and 9 % were diabetic; 41 % had a diagnosis of right bundle branch block. In simple regression, the frequency of right bundle branch block was 56 % (PR= 1,56; 95 % CI: 1,22-1,99), 65 % (PR=1,65; 95 % CI: 1,26 - 2,15) and 59 % (PR= 1,59; CI 95 %: 1,18 - 2,14) higher in women, hypertensive and diabetics; respectively. In the multiple regression; female sex (PR= 1,53; 95 % CI: 1,21 - 1,95), history of hypertension (PR= 1,55; 95 % CI: 1,21 - 2,00) and diabetes mellitus (PR= 1,49; 95 % CI: 1,12 - 2,00) were positively associated with right bundle branch block. The nested model selected the variables: female sex (PR= 1,54; 95 % CI: 1,21 - 1,96) and history of arterial hypertension (PR= 1,61; 95 % CI: 1,25 - 2,08). Conclusion: Female sex, history of arterial hypertension and diabetes mellitus were positively associated with presenting right bundle branch block in older adults.

Prognosis of new-onset left bundle branch block after transcatheter aortic valve replacement in patients with aortic stenosis: A systematic review and meta-analysis / 中国胸心血管外科临床杂志

@#Objective    To systematically review the clinical outcome of patients with new-onset left bundle branch block (LBBB) following transcatheter aortic valve replacement (TAVR). Methods    Electronic search was performed in PubMed, EMbase, Cochrane Library, Web of Science, CNKI, Wanfang and CBM databases to identify studies about the new-onset LBBB after TAVR from inception to March 19, 2022. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using Stata 15.0 software. Results    A total of 17 cohort studies were included, covering 9 205 patients, including 2 202 patients with new-onset LBBB and 7 003 without new-onset LBBB after TAVR. The results of meta-analysis showed that patients with new-onset LBBB after TAVR at 30-day (RR=1.65, 95%CI 1.30 to 2.10, P<0.001) and 1-year (RR=1.30, 95%CI 1.16 to 1.45, P<0.001) all-cause mortality was higher than no new-onset LBBB group. One-year cardiovascular mortality was higher in the new-onset LBBB group (RR=1.47, 95%CI 1.21 to 1.79, P<0.001). In the occurrence of 30-day (RR=1.51, 95%CI 1.10 to 2.08, P=0.011) and 1-year (RR=1.34, 95%CI 1.14 to 1.58, P=0.001) rehospitalization rate, 30-day (RR=3.05, 95% CI 1.49 to   6.22, P=0.002) and 1-year (RR=2.15, 95%CI 1.52 to 3.03, P<0.001) pacemaker implantation, the incidence of patients with new-onset LBBB was higher than that of the no new-onset LBBB group. Conclusion    Compared with the patients without LBBB after TAVR, the clinical prognosis of patients with new-onset LBBB after TAVR is poor. In the future, the management and follow-up of the patients with LBBB after TAVR should be further strengthened to improve the prognosis of patients.

Arrhythmia-induced cardiomyopathy: a specific pediatric dilated cardiomyopathies / 中国小儿急救医学

Arrhythmia-induced cardiomyopathy(AIC) is an reversible dilated cardiomyopathy and appears to occur at any age.The morbidity of AIC is unclear and likely underestimated.The pathophysiology and mechanism of AIC is unknown.It is often difficult to determine whether arrhythmias are the cause or result of cardiac dysfunction.The diagnosis of AIC can be only confirmed after recovery or improvement of cardiac function after elimination of the tachyarrhythmia.Tachycardias, ventricular premature contraction, left bundle branch block and ventricular preexcitation are known to trigger AIC.Appropriate diagnosis and treatment of AIC can reverse cardiac function.However, arrhythmia recurrence can lead to rapid recurrence of AIC and symptoms of heart failure.

Short-term and medium-term changes of the left ventricular ejection fraction in children with dilated cardiomyopathy complicated with complete left bundle branch block and the predictive value of relevant electrocardiogram indexes / 中华实用儿科临床杂志

Objective:To investigate the short-term and medium-term changes of the left ventricular ejection fraction (LVEF) and the predictive value of relevant electrocardiogram (ECG) indexes in children with dilated cardiomyopathy (DCM) complicated with complete left bundle branch block (CLBBB).Methods:Children clinically diagnosed with DCM in the Department of Heart Center, Women and Children′s Hospital, Qingdao University and Beijing Anzhen Hospital, Capital Medical University between November 2011 and August 2020 were retrospectively recruited.According to the combination of CLBBB, they were divided into CLBBB group and non-CLBBB group.Echocardiogram and ECG were regularly performed.Short-term and medium-term changes of LVEF based on the 1-5-year follow-up data were compared between groups.COX proportional hazards model and Kaplan-Meier multiplicative limit method were used to analyze the predictive value of ECG indexes of LVEF changes in children with DCM combined with CLBBB.Results:Ninety-four children with DCM were enrolled, including 35 cases in CLBBB group and 59 cases in non-CLBBB group.There was no difference in baseline LVEF between groups.However, significant differences were found in QRS duration, corre-cted QT interval(QTc), R peak time in lead V 5 (T V5R) and QRS notching or slurring between groups ( P<0.05). LVEF of all children showed an upward trend within one year after onset, while the Z value of eft ventricular end diastolic diameter(LVEDd) showed a downward trend, and the two indexes tended to be stable within 1 - 5 years.The Z value of LVEDd in CLBBB group was significantly higher than that of non-CLBBB group, while LVEF was significantly lower (all P<0.05). The mean LVEF of CLBBB group slightly fluctuated around 50%, that of LVEF in non-CLBBB group was 60%.The multivariate COX regression analysis showed that QRS duration ( HR=0.979; 95% CI: 0.960-0.999, P<0.05) and QTc ( HR=0.988; 95% CI: 0.979-0.998, P<0.05) were independent predictors of LVEF recovery in children with DCM.Kaplan-Meier method showed a significant difference of LVEF normalization between DCM children with different QRS durations ( P<0.05), which was also detected in those with QTc interval ( P<0.05). Conclusions:LVEF of children with DCM combined with CLBBB increases in the short term after standard treatment, and then being stable.CLBBB can affect the recovery of left ventricular systolic function in children with DCM.Moreover, QRS duration and QTc interval are independent predictors of LVEF recovery in DCM children.

El fenómeno de la memoria eléctrica como simulador de isquemia miocárdica

RESUMEN Los trastornos de la repolarización ventricular son manifestaciones comunes de una amplia variedad de situaciones, entre las que se incluye la memoria cardíaca; un fenómeno no reconocido frecuentemente en la práctica diaria. La gravedad de cada una de estas causas es muy variable; sin embargo, el diagnóstico definitivo de cada una de ellas no siempre es evidente. Se presenta el caso de un paciente que acude al servicio de urgencias con dolor torácico y ondas T negativas profundas en el electrocardiograma, que simulan una isquemia miocárdica grave, y que fue definido como memoria eléctrica cardíaca.

ABSTRACT The abnormalities in ventricular repolarization are common manifestations of several conditions, among these, we can include cardiac memory, a frequently unrecognized phenomenon in medical practice. The severity of each of these causes is variable; nonetheless, a definitive diagnosis of each of them is not always evident. We present the case of a patient admitted at the emergency room with chest pain and deeply inverted T waves in the electrocardiogram, mimicking a severe myocardial ischemia, which was defined as cardiac electrical memory.

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

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

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

Hybrid transthoracic periventricular device closure of ventricular septal defects: single-center experience

Abstract Objective: To evaluate the efficacy of hybrid transthoracic periventricular device closure of ventricular septal defects (VSDs) in a single center. Methods: All patients who underwent hybrid transthoracic periventricular device closure of VSDs between January 2018 and December 2019 were retrospectively analyzed. The preoperative, operative and postoperative findings and clinical follow-ups were reviewed. Results: A total of 59 patients underwent the procedure. Transesophageal echocardiographic guidance was used in all procedures. The procedure was successful in 57 procedures (97%). The procedures of two patients were changed to open-heart surgery during the same intervention due to severe aortic insufficiency (the device was not deployed) and significant residual shunt after device deployment. One major complication (1.7%) was observed after the procedure. The patient's device was dislodged within 12 hours after the procedure, and this patient underwent device extraction and VSD patch closure due to significant residual shunt. Eight (14%) minor complications were observed after the procedure, and three of them persisted during follow-up. Three of these eight complications were incomplete right bundle branch block, one of which resolved during follow-up; two were mild residual shunts, one of which resolved during follow-up; two were mild new-onset tricuspid valve insufficiencies; and one was mild new-onset mitral valve insufficiency; all valvular insufficiencies were resolved during follow-up. Conclusions: Hybrid transthoracic periventricular device closure of VSD seems to be a good alternative approach due to its procedural success and low risk rates. The best advantage of the procedure is the possibility of switching to open-heart surgery, if necessary.

Sgarbossa Criteria in Left Bundle Branch Block in a Hypertensive Emergency, a Case Report

Abstract Left bundle branch block and hypertensive emergency are very common conditions in clinical cardiovascular and emergency practice. Hypertensive emergency encompasses a spectrum of clinical presentations in which uncontrolled blood pressure leads to progressive end-organ dysfunction. Suspected acute myocardial infarction in the setting of a left bundle branch block presents a unique diagnostic and therapeutic challenge to the clinician. The diagnosis is especially difficult due to electrocardiographic changes caused by altered ventricular depolarization. However, reports on the use of the Sgarbossa's criteria during the management of hypertensive emergency are rare. My current case is a hypertensive emergency patient with acute chest pain and left bundle branch block. Sgarbossa's criteria were initially very weak and, over time, became highly suggestive of acute ST-segment elevation myocardial infarction. Interestingly, chest pain increased as the Sgarbossa's diagnostic criteria were met. Here, we present a case of developing ST-segment elevation myocardial infarction with left bundle branch block that is indicating for thrombolytic therapy. Thrombolytic therapy was strongly indicated because of a higher developing of Sgarbossa criteria scoring. Thus, the higher Sgarbossa criteria scoring in the case was the only indication for thrombolytic. Therefore, how did Sgarbossa criteria developing during the course of the case to indicating the need for thrombolytic therapy?

Complex uninterpretable electrocardiogram and syncope

Electrocardiogram(ECG) is an essential component as diagnostic modalities in cardiovascular diseases. A wide spectrum of diseases can be diagnosed by ECG. Conduction disturbances manifest in ECG with characteristics manner. Sometimes these manifestations are not interpretable with the current concept of cardiovascular physiology. Here I have reported such an interesting ECG which is complex and difficult to interpret

Bloqueo de rama enmascarado / Masquerading bundle branch block

RESUMEN El bloqueo de rama enmascarado es una forma poco frecuente de bloqueo bifascicular de la cual se desconoce su mecanismo con exactitud. Es más frecuente encontrarlo en pacientes de edad avanzada o aquellos con una cardiopatía estructural como: enfermedad coronaria, hipertrofia ventricular, miocardiopatías, miocarditis chagásica y degeneración idiopática del sistema excitoconductor del corazón. Su diagnóstico electrocardiográfico se obtiene por la presencia de ondas R altas y anchas en V1 (patrón de bloqueo de rama derecha), desviación del eje eléctrico a la izquierda (entre -80 y -120 grados) y una onda S inferior a 1 mm o ausente en DI y aVL. Su presencia denota un factor de mal pronóstico en los pacientes.

ABSTRACT Masquerading bundle branch block is a rare form of bifascicular block, whose exact mechanism is unknown. It is more frequently found in elderly patients or those with structural heart disease such as: coronary artery disease, ventricular hypertrophy, cardiomyopathies, Chagas myocarditis and idiopathic degeneration of the cardiac conduction system. Its electrocardiographic diagnosis is obtained by the presence of high and wide R waves in V1 (right bundle branch block pattern), left axis deviation (between -80 and -120 degrees) and an S wave of less than 1 mm or absent in I and aVL leads. Its presence denotes a poor prognostic factor in patients.

Incidence of Conduction Disorders and Requirements for Permanent Pacemaker After Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has become a therapeutic option for high-risk or non-operable patients with severe symptomatic aortic stenosis. Atrioventricular conduction disturbances requiring permanent pacemaker (PPM) are a common and clinically important complication. Objectives: To evaluate the incidence of conduction disorders (CDs) after TAVI and the need for subsequent PPM implantation. To identify the predictors of postoperative PPM implantation. Methods: Retrospective study. All patients who underwent TAVI in a public hospital from December/2011 to June/2016 were included. Multivariate analysis was conducted to establish the predictor of permanent pacemaker implantation. Survival curves were constructed by the Kaplan-Meyer method. Statistically significant variables were those with p value < 0.05. Results: 64 patients with AS underwent TAVI. Eleven patients were excluded. TAVI induced a new CD in 40 (77%) of the remaining 53 patients. The most common new CDs were 3rd degree AV block (32%) and left bundle branch block (30%). Sixteen patients (30,2%) underwent PPM implantation during the index hospitalization. On univariate analysis the risk factors for PPM implantation were CoreValve® use (OR: 1,76; P = 0,005), larger prosthesis implantation (P = 0,015), presence of a QRS ≥ 120 ms (OR: 5,62; P = 0,012), and 1st degree AV block (OR: 13; P = 0.008). On multivariate analysis the presence of 1st degree AV block predicted the need for PPM. Conclusion: TAVI induced CDs requiring PPM in 30% of the patients. The presence of 1st degree AV block predicted the need for PPM

Bloqueo de rama alternante en una taquicardia supraventricular: ¿Cuál es el mecanismo subyacente? / Alternating bundle branch block in a supraventricular tachycardia: Which is the mechanism ?

El bloqueo de rama funcional durante una taquicardia supraventricular puede ser observado con longitudes de ciclo cortas y representa una respuesta fisiológica del sistema de conducción intraventricular por la existencia de conducción nodal auriculo ventricular acelerada. Presentamos el caso de un paciente joven con taquicardia reentrante aurículo-ventricular ortodrómica y bloqueo de rama alternante. Esta respuesta infrecuente se explica por el hallazgo obtenido durante el estudio electrofisiológico. Una conducción nodal aurículo-ventricular acelerada produce un frente de onda que despolariza las ramas durante sus períodos refractarios. Una vez que ocurrió el bloqueo en una de las ramas, dicho bloqueo persistió debido al fenómeno de linking, que es por conducción oculta retrógrada repetitiva de la rama contralateral. Después de la ablación transcatéter de una vía accesoria oculta lateral izquierda, el marcapaseo auricular rápido a la misma longitud de ciclo de la taquicardia, reprodujo la misma aberrancia observada durante la taquicardia. Este procedimiento demostró que el bloqueo de rama funcional fue debido a la longitud de ciclo corto y no a la presencia de una vía accesoria aurículo-ventricular.

Functional bundle branch block during a supraventricular tachycardia can be observed with shorter cycle lengths and represent a physiologic response by the specialized intraventricular conduction system to accelerated AV nodal conduction. The present case corresponds to a young patient with exercise induced orthodromic A-V reentrant tachycardia and alternating bundle branch block. This unusual response is explained by the finding obtained during the electrophysiology study. An accelerated AV nodal conduction made the depolarizing wave front reach the bundle branches during their refractory period. Once block in one bundle was stablished, block persisted due to the linking phenomenon that is repetitive retrograde concealed conduction from the contralateral bundle. After catheter ablation of a concealed left-sided accessory A-V pathway, rapid atrial pacing at the same cycle length of the tachycardia reproduced the same aberrancies observed during tachycardia. This response proved that functional bundle branch block is due to the short cycle length and not the presence of an accessory A-V pathway.

Bloqueo de rama izquierda como equivalente ST, ¿cuándo sí, cuándo no? / Left bundle branch block as equivalent of ST-segment elevation myocardial infarction: when yes, when not?

Resumen La presencia de un bloqueo de rama izquierda del haz de His nuevo o presumiblemente nuevo junto con síntomas isquémicos se ha considerado tradicionalmente un equivalente electrocardiográfico de infarto agudo de miocardio con elevación del segmento ST, el cual debe ser llevado a reperfusión emergente. Para su definición se han propuesto varios criterios, pero ninguno ha alcanzado un rendimiento diagnóstico óptimo. A continuación detallaremos dichos criterios, sus principales problemas y las ventajas que han demostrado.

Abstract A new or presumably new left bundle branch block along with ischemic symptoms has traditionally been considered an electrocardiographic equivalent of ST-segment elevation myocardial infarction, which should be brought to emergent reperfusion. However, several criteria have been proposed for its definition, but none has reached out an optimal diagnostic yield. Below we detail these criteria, their main problems and the advantages they have shown.

Hallazgos clínicos y electrocardiográficos en pacientes pediátricos con comunicación interauricular / Clinical and electrocardiographic findings in pediatric patients with atrial septal defects

Introducción: La comunicación interauricular (CIA) es una cardiopatía congénita frecuente, cuyo diagnóstico es difícil en pacientes paucisintomáticos. Sin tratamiento, puede complicarse con insuficiencia cardiaca, arritmias e hipertensión pulmonar. El electrocardiograma puede proporcionar indicios de esta cardiopatía. Objetivo: Describir los hallazgos clínicos y electrocardiográficos de pacientes portadores de CIA. Materiales y Métodos: Trabajo retrospectivo, de pacientes menores de 18 años, evaluados cardiológicamente de enero 2008 a diciembre de 2013. Se describen las variables electrocardiográficas y semiológicas sugestivas de CIA. Resultados: Hubo 77 pacientes con CIA. Los motivos de consulta más frecuentes entre los pacientes con CIA fueron el soplo cardiaco, el síndrome de Down y la disnea. En el examen físico de los pacientes con CIA: soplo sistólico en 69% y R2 desdoblado en 56%. En el electrocardiograma, los pacientes tuvieron QRS de 79 ms, eje eléctrico desviado hacia la derecha, BIRD y notch. Los criterios de sobrecarga ventricular derecha (SVD) más frecuentes fueron la onda S profunda en V6 y la onda R alta en V1. La auscultación de un R2 desdoblado en el examen físico, así como la SVD y el patrón notch fueron los hallazgos más frecuentes en pacientes con CIA. Conclusión: el electrocardiograma constituye una herramienta válida en la evaluación de pacientes con sospecha de CIA pero precisa de la combinación de hallazgos clínicos para llegar al diagnóstico.

Introduction: Atrial Septal Defect (ASD) is a frequent congenital heart disease, the diagnosis of which is difficult in paucisymptomatic patients. Without treatment, it can lead to heart failure, arrhythmias and pulmonary hypertension. The electrocardiogram may provide evidence of this condition. Objective: To describe the clinical and electrocardiographic findings of patients with ASD. Materials and Methods: This was a retrospective study of patients under age 18 who underwent cardiac evaluation from January 2008 to December 2013. The electrocardiographic and clinical finding variables suggestive of ASD are described. Results: There were 77 patients with ASD. The most frequent reasons for consultation among patients with ASD were heart murmur, Down syndrome and dyspnea. Findings on physical examination of patients with ASD were: systolic murmur in 69% and S2 split in 56%. On the electrocardiogram, the patients had QRS of 79 ms, electric axis deviated to the right, Incomplete Right Bundle Branch and notch pattern. The most frequent right ventricular volume overload (RVVO) criteria were the deep S wave in V6 and the high R wave in V1. Auscultation of a split S2 on the physical examination, as well as the RVVO and the notch pattern were the most frequent findings in patients with ASD. Conclusion: the electrocardiogram is a valid tool in the evaluation of patients with suspected ASD but requires the combination of clinical findings to reach the diagnosis.