Impact of an online course on enhancing the diagnosis of Chagas disease in Latin America.

Objective: Chagas disease poses a public health problem in Latin America, and the electrocardiogram is a crucial tool in the diagnosis and monitoring of this pathology. In this context, the aim of this study was to quantify the change in the ability to detect electrocardiographic patterns among healthcare professionals after completing a virtual course. Materials and Methods: An asynchronous virtual course with seven pre-recorded classes was conducted. Participants answered the same questionnaire at the beginning and end of the training. Based on these responses, pre and post-test results for each participant were compared. Results: The study included 1656 participants from 21 countries; 87.9% were physicians, 5.2% nurses, 4.1% technicians, and 2.8% medical students. Initially, 3.1% answered at least 50% of the pre-test questions correctly, a proportion that increased to 50.4% after the course (p=0.001). Regardless of their baseline characteristics, 82.1% of course attendees improved their answers after completing the course. Conclusions: The implementation of an asynchronous online course on electrocardiography in Chagas disease enhanced the skills of both medical and non-medical personnel to recognize this condition.

Usefulness of the intracardiac electrocardiogram recorded using central venous catheters on P-wave magnification.

BACKGROUND: The detection of atrial electrical activity is extremely valuable in recognizing complex cardiac arrhythmias. However, P-wave detection on a surface electrocardiogram (S-ECG) can sometimes be challenging. The intracardiac electrocardiogram (IC-ECG), recorded by a central venous catheter loaded with saline solution, has proven to be a safe and effective method for amplifying atrial electrical activity. We aim to compare the P-wave amplitude recorded in the S-ECG and the IC-ECG in different venous accesses, catheters, heart rhythms, and atrial dimensions. METHODS: We compared the P wave amplitude obtained by the IC-ECG and the S-ECG recordings from cardiac intensive care unit patients. RESULTS: In 109 nonconsecutive patients, a total of 166 IC-ECG were collected. The median amplitude of the P wave was 0.1 (0.083-0.3) mV in the S-ECG and 0.4 (0.25-2.4) mV in the IC-ECG; p < 0.001. This difference remained significant regardless of the patient's heart rhythm, left atrial dimension, and catheter or vascular access used. CONCLUSION: The IC-ECG acquired using central venous catheters significantly increases atrial electrical activity signals. This technique might help identify complex cardiac arrhythmias.

Comportamiento del tiempo de conducción retrógrada al momento de la inducción de las taquicardias supraventriculares y su rol en el diagnóstico diferencial / Behavior of Retrograde Conduction Time at Supraventricular Tachycardia Induction and its Role in Differential Diagnosis

RESUMEN Antecedentes : El diagnóstico diferencial entre la taquicardia reentrante ortodrómica (TRO) y la taquicardia por reentrada nodal atípica (TRNa) puede ser dificultoso. Nuestra hipótesis es que las TRNa tienen más variabilidad en el tiempo de con ducción retrógrada al comienzo de la taquicardia que las TRO. Nuestros objetivos fueron evaluar la variabilidad en el tiempo de conducción retrógrada al inicio de la taquicardia en TRNa y TRO, y proponer una nueva herramienta diagnóstica para diferenciar estas dos arritmias. Métodos : Se midió el intervalo ventrículo-auricular (VA) de los primeros latidos tras la inducción de la taquicardia, hasta su estabilización. La diferencia entre el intervalo VA máximo y el mínimo se definió como delta VA (ΔVA). También contamos el número de latidos necesarios para que se estabilice el intervalo VA. Se excluyeron las taquicardias auriculares. Resultados : Se incluyeron 101 pacientes. Se diagnosticó TRO en 64 pacientes y TRNa en 37. El ΔVA fue 0 (rango intercuartílico, RIC, 0-5) milisegundos (ms) en la TRO frente a 40 (21-55) ms en la TRNa (p < 0,001). El intervalo VA se estabilizó significativamente antes en la TRO (1,5 [1-3] latidos) que en la TRNa (5 [4-7] latidos; p < 0,001). Un ΔVA < 10 ms diagnosticó TRO con 100% de sensibilidad, especificidad y valores predictivos positivo y negativo. La estabilización del intervalo VA en menos de 3 latidos predijo TRO con buena precisión diagnóstica. Los resultados fueron similares considerando sólo vías accesorias septales. Las TRN típicas tuvieron una variación intermedia. Conclusión : Un ΔVA < 10 ms es un criterio simple, que distingue con precisión la TRO de la TRNa, independientemente de la localización de la vía accesoria.

ABSTRACT Background : Differential diagnosis between orthodromic reentrant tachycardia (ORT) and atypical nodal reentrant tachy cardia (ANRT) can be challenging. Our hypothesis was that ANRT presents more variability in retrograde conduction time at tachycardia onset than ORT. Objectives : The objectives of this study were to assess retrograde conduction time variability at the start of tachycardia in ANRT and ORT, and postulate a new diagnostic tool to differentiate these two types of arrhythmias. Methods : The ventriculoatrial (VA) interval of the first beats after tachycardia induction was measured until stabilization. The difference between the maximum and minimum VA interval was defined as delta VA (ΔVA), and the number of beats needed for VA interval stabilization was also assessed. Atrial tachycardias were excluded. Results : In a total of 101 patients included in the study, ORT was diagnosed in 64 patients and ANRT in 37. ΔVA interval was 0 (interquartile range [IQR] 0-5) milliseconds (ms) in ORT vs. 40 (21-55) ms in ANRT (p <0.001). The VA interval significantly stabilized earlier in ORT (1.5 [1-3] beats) than in ANRT (5 [4-7] beats) (p<0.001). A ΔVA <10 ms diagnosed ORT with 100% sensitivity, specificity, and positive and negative predictive values. Ventriculoatrial interval stabilization in less than 3 beats predicted ORT with good diagnostic accuracy. The results were similar considering only accessory septal pathways. Typical NRTs presented an intermediate variation. Conclusion : Presence of DVA <10 ms is a simple criterion that accurately differentiates ORT from ANRT, independently of the accessory pathway localization.

Variability of the VA interval at tachycardia induction: a simple method to differentiate orthodromic reciprocating tachycardia from atypical atrioventricular nodal reentrant tachycardia.

BACKGROUND: The differential diagnosis between orthodromic atrioventricular reentry tachycardia (AVRT) and atypical AV nodal reentrant tachycardia (aAVNRT) is sometimes challenging. We hypothesize that aAVNRTs have more variability in the retrograde conduction time at tachycardia onset than AVRTs. METHODS: We aimed to assess the variability in retrograde conduction time at tachycardia onset in AVRT and aAVNRT and to propose a new diagnostic tool to differentiate these two arrhythmia mechanisms. We measured the VA interval of the first beats after tachycardia induction until it stabilized. The difference between the maximum and minimum VA intervals (∆VA) and the number of beats needed for the VA interval to stabilize was analyzed. Atrial tachycardias were excluded. RESULTS: A total of 107 patients with aAVNRT (n = 37) or AVRT (n = 64) were included. Six additional patients with decremental accessory pathway-mediated tachycardia (DAPT) were analyzed separately. All aAVNRTs had VA interval variability. The median ∆VA was 0 (0 - 5) ms in AVRTs vs 40 (21 - 55) ms in aAVNRTs (p < 0.001). The VA interval stabilized significantly earlier in AVRTs (median 1.5 [1 - 3] beats) than in aAVNRTs (5 [4 - 7] beats; p < 0.001). A ∆VA < 10 ms accurately differentiated AVRT from aAVNRT with 100% of sensitivity, specificity, and positive and negative predictive values. The stabilization of the VA interval at < 3 beats of the tachycardia onset identified AVRT with sensitivity, specificity, and positive and negative predictive values of 64.1%, 94.6%, 95.3%, and 60.3%, respectively. A ∆VA < 20 ms yielded good diagnostic accuracy for DAPT. CONCLUSIONS: A ∆VA < 10 ms is a simple and useful criterion that accurately distinguished AVRT from atypical AVNRT. Central panel: Scatter plot showing individual values of ∆VA in atypical AVNRT and AVRT. Left panel: induction of atypical AVNRT. The VA interval stabilizes at the 5th beat and the ∆VA is 62 ms (maximum VA interval: 172 ms - minimum VA interval: 110 ms). Right panel: induction of AVRT. The tachycardia has a fixed VA interval from the first beat. ∆VA is 0 ms.

Highlights and comments on EHRA/HRS/APHRS/LAHRS expert consensus on risk assessment in cardiac arrhythmias: use the right tool for the right outcome.

Patients with heart disease, or at high risk of developing a cardiac condition, usually undergo risk assessment by primary care physicians, internal medicine doctors, or cardiologists. There are several methods that can be used for this risk assessment, and their applicability differs with respect to availability, complexity, and usefulness in different geographic populations. This document focuses on some of the many relevant clinical topics recently presented in the "Expert Consensus on Risk Assessment in Cardiac Arrhythmias: Use the Right Tool for the Right Outcome," which include statements based on the best available evidence. In this review, we want to highlight and make some pertinent comments on some of the most relevant points of this Consensus.

Catheter ablation of ventricular tachycardia in patients with electrical storm, with a special focus on patients with Chagas disease.

BACKGROUND: There are few reports on the benefits of catheter ablation (CA) in patients with electrical storm (ES). None of these publications included patients with Chagas disease (ChD). Our aims are to analyze (1) all the cases of ES treated with CA and (2) the subgroup of patients with ChD. METHODS: Prospective analysis of consecutive patients with ES due to monomorphic ventricular tachycardia (VT) treated with CA. RESULTS: We included 38 patients: 28 males; median age of 63.5 (IQR 55-71) years old; ejection fraction (LVEF) 0.30 (0.25-0.40). Sixteen patients (42.1%) had ChD. The patients experienced 21 (15-37) VT episodes and received 7 (3-13) ICD shocks before CA. Forty-six procedures were performed (7 required epicardial access). All patients experienced ES suppression after CA. After 35 (10-64) months of follow-up (1.21 procedures per patient), 23 patients (60.5%) remain free from any VT; 35 patients (92.1%) were free from ES, and 11 patients (28.9%) died from non-arrhythmic causes. One patient underwent heart transplantation. Patients with ChD were younger (60 vs. 67 years old; p = 0.033), significantly more women (50% vs. 9.1%; p = 0.005), and had higher LVEF (0.40 vs. 0.28; p < 0.001) than the other patients. Long-term outcome of ChD patients was similar to that of the overall population. Only age and LVEF independently predicted mortality. CONCLUSION: CA was associated with acute ventricular arrhythmia suppression in all patients with ES. Freedom rates from ES and VT were 92.1% and 60.5% respectively. Despite having a lower-risk clinical profile, patients with ChD had a comparable outcome to that of the other patients.

Intramural Venous Ethanol Infusion for Refractory Ventricular Arrhythmias: Outcomes of a Multicenter Experience.

OBJECTIVES: The aim of this study was to assess the long-term efficacy and outcomes of retrograde venous ethanol ablation in treating ventricular arrhythmias (VAs). BACKGROUND: Retrograde coronary venous ethanol ablation (RCVEA) can be effective for radiofrequency ablation (RFA)-refractory VAs, particularly those arising in the LV summit (LVS). METHODS: Patients with drug and RFA-refractory VAs were considered for RCVEA after RF failure attempts. Intramural coronary veins (tributaries of the great cardiac, anterior interventricular, lateral cardiac, posterolateral, and middle cardiac) were mapped using an angioplasty wire. Ethanol infusion was delivered in veins with appropriate signals. RESULTS: Of 63 patients (age 63 ± 14 years; 60% men) with VAs (71% extrasystole, 29% ventricular tachycardia, 76% LVS origin), RCVEA was performed in 56 patients who had suitable vein branches. These were defined as those amenable to cannulation and with intramural signals that preceded those mapped in the epicardium or endocardium and had better matching pace maps or entrainment responses. Seven patients had no suitable veins and underwent RFA. In 38 of 56 (68%) patients, the VAs were successfully terminated exclusively with ethanol infusion. In 17 of 56 (30%) patients, successful ablation was achieved using ethanol with adjunctive RFA in the vicinity of the infused vein due to acute recurrence or ethanol-induced change in VA morphology. Overall, isolated or adjuvant RCVEA was successful in 55 of 56 (98%) patients. At 1-year follow-up, 77% of patients were free of recurrent arrhythmias. Procedural complications included 2 venous dissections that led to pericardial effusions. CONCLUSIONS: RCVEA offers a significant long-term effective treatment for patients with drug and RF-refractory VAs.

Resultados del primer registro de implante de cardiodesfibriladores y resincronizadores SAC (RENCARE) / Results of the First SAC Implantable Cardioverter-Defibrillator and Cardiac Resynchronization Therapy Registry (RENCARE)

RESUMEN Introducción: La prevención de la muerte súbita y el tratamiento de la insuficiencia cardíaca son temas de gran importancia. Para prevenir la muerte súbita y mejorar el pronóstico de la insuficiencia cardíaca se utilizan los cardiodesfibriladores y cardioresincronizadores. Objetivos: Evaluar la cantidad y tipo de dispositivos implantados en nuestro país, así como las características de los pacientes, las complicaciones agudas y las que se presentan en el seguimiento. Material y métodos: Se realizó un estudio observacional, prospectivo, multicéntrico en centros de salud con la capacidad de implantar cardiodesfibriladores y cardioresincronizadores. Se incluyeron pacientes a los que se les realizó implante de estos dispositivos desde enero del 2016 hasta enero de 2017, con un seguimiento de 12 meses. Resultados: Se incluyeron 249 pacientes (edad promedio de 64,8 ± 13,7 años, 73,9% de sexo masculino, 72,1% con Fey < 35%). La etiología subyacente de la miocardiopatía era isquémica en el 39,8%, dilatada 26,7% y chagásica en el 11,2% de los casos. El 58% de los implantes realizados fueron cardiodesfibriladores y el 39%, cardiodesfibriladores asociados con cardioresincronizadores. El 84% de los procedimientos fueron primoimplantes. La indicación más frecuente del implante fue por prevención primaria de muerte súbita (67,9%). La tasa de complicaciones menores fue del 4,4% y no se reportaron complicaciones mayores. Conclusiones: El siguiente registro evidenció una gran proporción de implantes en pacientes con cardiopatía isquémica, la indicación principal fue por prevención primaria de muerte súbita y la tasa de complicaciones fue similar a la reportada internacionalmente.

ABSTRACT Background: Prevention of sudden death and treatment of heart failure are very important topics. Implantable cardioverter-defibrillator and cardiac resynchronization devices are used to prevent sudden death and improve heart failure symptoms and prognosis. Objectives: The aim of this study was to evaluate the number, type of implanted devices, clinical characteristics of the patients and acute and follow-up complications. Methods: An observational, prospective, multicenter study was carried out in healthcare centers with the capacity to implant cardioverter-defibrillator and cardiac resynchronization devices. The study included all patients who underwent implantation of these devices from January 2016 to January 2017, with a 12-month follow-up. Results: A total of 249 patients (73.9% men) with mean age of 64.8±13.7 years, and 72.1% with ejection fraction <35%, were included in the study. The underlying cardiomyopathy etiology was ischemic in 39.8% of cases, dilated in 26.7% and chagasic in 11.2%. Fifty-eight percent of implants were implantable cardioverter-defibrillators and 39% were cardioverter-defibrillators associated with cardiac resynchronization devices. In 84% of cases, procedures were first implants. The most frequent indica-tion of implantation was for primary prevention of sudden death (67.9%). Minor complication rate was 4.4% and no major complications were reported. Conclusions: The present registry evidenced a large proportion of cardioverter-defibrillator and cardiac resynchronization implants in patients with ischemic heart disease. The main indication was for primary prevention of sudden death and the complication rate was similar to that reported internationally.