EPM algorithm: A stepwise approach to accessory pathway localization in ventricular pre-excitation.

BACKGROUND: Accurate estimation of accessory pathway (AP) localization in patients with ventricular pre-excitation or Wolff-Parkinson-White (WPW) syndrome remains a diagnostic challenge. Existing algorithms have contributed significantly to this area, but alternative algorithms can offer additional perspectives and approaches to AP localization. OBJECTIVE: This study introduces and evaluates the diagnostic accuracy of the EPM algorithm in AP localization, comparing it with established algorithms Arruda and EASY. METHODS: A retrospective analysis was conducted on 138 patients from Hospital São Paulo who underwent catheter ablation. Three blinded examiners assessed the EPM algorithm's diagnostic accuracy against the Arruda and EASY algorithms. The gold standard for comparison was the radioscopic position of the AP where radiofrequency ablation led to pre-excitation disappearance on the ECG. RESULTS: EPM showed a diagnostic accuracy of 51.45%, closely aligning with Arruda (53.29%) and EASY (44.69%). Adjacency accuracy for EPM was 70.67%, with Arruda at 66.18% and EASY at 72.22%. Sensitivity for EPM in distinguishing left vs. right APs was 95.73%, with a specificity of 74.33%. For identifying septal vs. lateral right APs, EPM sensitivity was 82.79% with a specificity of 46.15%. These measures were comparable to those of Arruda and EASY. Inter-observer variability was excellent for EPM, with Kappa statistics over 0.9. CONCLUSION: The EPM algorithm emerges as a reliable tool for AP localization, offering a systematic approach beneficial for therapeutic decision-making in electrophysiology. Its comparable diagnostic accuracy and excellent inter-observer variability underscore its potential clinical applicability. Future research may further validate its efficacy in a broader clinical setting.

Pacemaker lead-related macroreentrant atrial tachycardia.

Macroreentrant atrial circuits are frequently associated with scarring. Previous reports have shown the possible development of scar tissue that is adjacent to pacemaker (PM) leads. However, reports of PM lead-related reentrant tachycardia are scarce. We report the case of a 63-year-old woman who presented with macroreentrant atrial tachycardia (MAT), related to the atrial trajectory of an old single-lead ventricular PM, that was successfully treated with radiofrequency ablation after a conventional electrophysiological study ruled out isthmus-dependent atrial flutter and provided sufficient data to confirm this diagnosis. This report presents a case of MAT originating around the trajectory of a PM lead, probably because of scar tissue that developed adjacent to the lead. Experimental studies have already shown that interstitial atrial fibrosis may develop adjacent to a ventricular single-lead. This finding suggests that MAT develops in patients with this specific condition. Recognizing this condition is important for managing these arrhythmias and performing safe ablation with the preservation of PM lead integrity.

Catheter entrapment in Chiari network: Extraction with radiofrequency.

We report a challenging case of a duodecapolar mapping catheter entrapment in Chiari network and its release by radiofrequency energy application with an ablation catheter.

Radiofrequency ablation of a middle cardiac vein inserted accessory pathway resulting in posterolateral coronary artery occlusion: A case report.

INTRODUCTION: Posteroseptal accessory pathways account for 34.5% of the total. Of these, 36% are located within the coronary sinus (CS). Its ablation requires technical alternatives to avoid damage to surrounding tissues, especially branches of the right coronary artery. CASE REPORT: A 22-year-old man was referred for re-do ablation of an accessory left septal-septal (PSE) pathway. Inside the CS, a precocity of 25 ms was found in the region of the median cardiac vein (VCM) (Fig. 2, panel A). Radiofrequency (RF) was administered with a non-irrigated bidirectional catheter within this vessel with resolution of the pre-excitation after 5 seconds. Immediately after, the patient presented chest pain and revealed a ST segment elevation of 1 mm in the inferior leads of ECG. Coronary angiography showed occlusion of the middle third of the posterior ventricular branch of the right coronary artery, with no signs of thrombus or dissection. Arterial angioplasty was performed with a bare metal stent, followed by TIMI III distal flow. Retrograde aortic mapping was performed and a precocity of 20 ms was found in the PSE region. The RF was applied followed by loss of pre-excitation after 1.5 seconds of application. CONCLUSION: This case demonstrates the risks involving delivering radiofrequency within the coronary sinus. We discuss some strategy that could help electrophysiologists in similar cases.

Epicardial mapping complicated by multi-vessel coronary spasm and electrical storm.

The case report describes a severe multi-vessel coronary spasm complicating the epicardial mapping in a patient with chronic Chagas cardiomyopathy.

Epicardial and Endocardial Ablation Based on Channel Mapping in Patients With Ventricular Tachycardia and Chronic Chagasic Cardiomyopathy: Importance of Late Potential Mapping During Sinus Rhythm to Recognize the Critical Substrate.

Background Ventricular tachycardia (VT) in patients with chronic chagasic cardiomyopathy (CCC) is associated with considerable morbidity and mortality. Catheter ablation of VT in patients with CCC is very complex and challenging. The main goal of this work was to assess the efficacy of VT catheter ablation guided by late potentials (LPs) in patients with CCC. Methods and Results Seventeen consecutive patients with refractory VT and CCC were prospectively included in the study. Combined endo-epicardial voltage and late activation mapping were obtained during baseline rhythm to define scarred and LP areas, respectively. The end point of the ablation procedure was the elimination of all identified LPs. Epicardial and endocardial dense scars (<0.5 mV) were detected in 17/17 and 15/17 patients, respectively. LPs were detected in the epicardial scars of 16/17 patients and in the endocardial scars of 14/15 patients. A total of 63 VTs were induced in 17 patients; 22/63 (33%) were stable and entrained, presenting LPs recorded in the isthmus sites. The end point of ablation was achieved in 15 of 17 patients. Ablation was not completed in 2 patients because of cardiac tamponade or vicinity of the phrenic nerve and circumflex artery. Three patients (2 with unsuccessful ablation) had VT recurrence during follow-up (39 months). Conclusions Endo-epicardial LP mapping allows us to identify the putative isthmuses of different VTs and effectively perform catheter ablation in patients with CCC and drug-refractory VTs.

Economy- and Social-Based Strategies for Anticoagulation of Patients with Atrial Fibrillation. / Estratégias Econômicas e Sociais para Anticoagulação de Pacientes com Fibrilação Atrial.

BACKGROUND: Atrial fibrillation is a public health problem associated with a fivefold increased risk of stroke or death. Analyzing costs is important when introducing new therapies and must be reconsidered in special situations, such as the novel coronavirus pandemic of 2020. OBJECTIVE: This study aimed to evaluate the costs related to anticoagulant therapy in a one-year period, and the quality of life of atrial fibrillation patients treated in a public university hospital. METHODS: Patient costs were those related to the anticoagulation and calculated by the average monthly costs of warfarin or direct oral anticoagulants (DOACs). Patient non-medical costs (eg., food and transportation) were calculated from data obtained by questionnaires. The Brazilian SF-6D was used to measure the quality of life. P-values < 0.05 were considered statistically significant. RESULTS: The study population consisted of 90 patients, 45 in each arm (warfarin vs direct oral anticoagulants). Costs were 20% higher in the DOAC group ($55,532.62 vs $46,385.88), and mainly related to drug price ($23,497.16 vs $1,903.27). Hospital costs were higher in the warfarin group ($31,088.41 vs $24,604.74) and related to outpatient visits. Additionally, non-medical costs were almost twice higher in the warfarin group ($13,394.20 vs $7,430.72). Equivalence of price between the two drugs could be achieved by a 39% reduction in the price of DOACs. There were no significant group differences regarding quality of life. CONCLUSIONS: Total costs were higher in the group of patients taking DOACs than those taking warfarin. However, a nearly 40% reduction in the price of DOACs could make it feasible to incorporate these drugs into the Brazilian public health system.

FUNDAMENTO: A fibrilação atrial é um problema de saúde pública associado com um risco cinco vezes maior de acidente vascular cerebral e mortalidade. A análise de custos é importante para a introdução de novas terapias, e deve ser reconsiderada em situações especiais, tais como a pandemia do coronavírus em 2020. OBJETIVO: Avaliar os custos (em um período de um ano) relacionados à terapia anticoagulante e a qualidade de vida de pacientes com fibrilação atrial tratados em um hospital público universitário. MÉTODOS: Os custos do paciente foram aqueles relacionados à anticoagulação e calculados pela média de custos mensais da varfarina ou de anticoagulantes orais diretos (DOACs). As despesas não médicas, como alimentação e transporte, foram calculadas a partir de dados obtidos de questionários. O questionário brasileiro SF-6D foi usado para medir a qualidade de vida. Valores p<0,05 foram considerados estatisticamente significativos. RESULTADOS: A população do estudo consistiu em 90 pacientes, 45 em cada braço (varfarina vs. DOACs). Os custos foram 20% mais altos no grupo dos DOACs (US$55 532,62 vs. US$46 385,88), e principalmente relacionados ao preço dos medicamentos (US$23 497,16 vs. US$1903,27). Os custos hospitalares foram mais altos no grupo da varfarina (US$31 088,41 vs $24 604,74), e relacionados às visitas ao ambulatório. Ainda, as despesas não médicas foram duas vezes maiores no grupo varfarina ($13 394,20 vs $7 430,72). A equivalência de preço entre os dois medicamentos seria alcançada por uma redução de 39% no preço dos DOACs. Não foram observadas diferenças quanto à qualidade de vida. CONCLUSÕES: Os custos totais foram mais altos no grupo de pacientes tratados com DOACs que no grupo da varfarina. No entanto, uma redução de cerca de 40% no preço dos DOACs tornaria viável a incorporação desses medicamentos no sistema de saúde público brasileiro.

Underuse of Catheter Ablation as First-Line Therapy for Supraventricular Tachycardia.

Background Catheter ablation (CA) is a safe, effective, cost-effective technique and may be considered a first-line strategy for the treatment of symptomatic supraventricular tachycardias (SVT). Despite the high prospect of cure and the recommendations of international guidelines in considering CA as a first-line treatment strategy, the average time between diagnosis and the procedure may be long. The present study aims to evaluate predictors related to non-referral for CA as first-line treatment in patients with SVT. Methods and Results The model was derived from a retrospective cohort of patients with SVT or ventricular pre-excitation referred for CA in a tertiary center. Clinical and demographical features were used as independent variables and non-referral for CA as first-line treatment the dependent variable in a stepwise logistic regression analysis. Among 20 clinical-demographic variables from 350 patients, 10 were included in initial logistic regression analysis: age, women, presence of pre-excitation on ECG, palpitation, dyspnea and chest discomfort, number of antiarrhythmic drugs before ablation, number of concomitant symptoms, symptoms' duration and evaluations in the emergency room due to SVT. After multivariable adjusted analysis, age (odds ratio [OR], 1.2; 95% CI 1.01-1.32; P=0.04), chest discomfort during supraventricular tachycardia (OR, 2.7; CI 1.6-4.7; P<0.001) and number of antiarrhythmic drugs before ablation (OR, 1.8; CI 1.4-2.3; P<0.001) showed a positive independent association for non-referral for CA as SVT first-line treatment. Conclusions The independent predictors of non-referral for CA as first-line treatment in our logistic regression analysis indicate the existence of biases in the decision-making process in the referral process of patients who would benefit the most from catheter ablation. They very likely suggest a skewed medical decision-making process leading to catheter ablation underuse.

Change in cycle length during pacemaker-mediated tachycardia: What is the mechanism?

A thorough understanding of advanced device algorithms designed to promote intrinsic atrioventricular conduction is mandatory to allow appropriate management of arrhythmias induced by pacing, particularly when other types of tachycardia are involved.

Prevalence of atrial fibrillation and stroke risk assessment based on telemedicine screening tools in a primary healthcare setting.

BACKGROUND: Worldwide atrial fibrillation (AF) prevalence varies between 0.1% and 4.0%, and has been increasing. Little is known about the prevalence of AF in Brazil. Our objective was to estimate the prevalence of AF in several regions of Brazil using recordings of long-distance electrocardiogram (ECG) transmission. METHODS: Patients from 125 outpatient general practitioner units covered by the telemedicine service of the Federal University of São Paulo were included. Only one ECG was considered per patient. A scripted telephone interview was also performed. We analyzed the data to project the prevalence of AF in the Brazilian population and estimate it for the year 2025. The overall AF prevalence was calculated based on ECGs from primary care units where patients went for routine visits. RESULTS: Based on 676,621 ECG exams from January 2009 through April 2016, the mean age (±SD) of patients was 51.38 (±19.05) years, with 57.5% being female. The 7-year period prevalence of AF was 2.2% (n = 14,968). The prevalence of AF countrywide was projected to be 1.5% in 2016 and 1.7% in 2025. In the subset of patients with AF who were interviewed (n = 301), 91 (30.2%) were not receiving any type of treatment for rate or rhythm control. Among patients interviewed, 189 (62.8%) were at high risk for stroke; only 28 (14.8%) were regular oral anticoagulant users. CONCLUSIONS: Our study highlights the importance of screening for AF in the primary care setting in Brazil and identifies important gaps in the treatment of AF in this population.

EPM algorithm: a stepwise approach to accessory pathway localization in ventricular pre-excitation

BACKGROUND: Accurate estimation of accessory pathway (AP) localization in patients with ventricular pre-excitation or Wolff-Parkinson-White (WPW) syndrome remains a diagnostic challenge. Existing algorithms have contributed significantly to this area, but alternative algorithms can offer additional perspectives and approaches to AP localization. OBJECTIVE: This study introduces and evaluates the diagnostic accuracy of the EPM algorithm in AP localization, comparing it with established algorithms Arruda and EASY. METHODS: A retrospective analysis was conducted on 138 patients from Hospital São Paulo who underwent catheter ablation. Three blinded examiners assessed the EPM algorithm's diagnostic accuracy against the Arruda and EASY algorithms. The gold standard for comparison was the radioscopic position of the AP where radiofrequency ablation led to pre-excitation disappearance on the ECG. RESULTS: EPM showed a diagnostic accuracy of 51.45%, closely aligning with Arruda (53.29%) and EASY (44.69%). Adjacency accuracy for EPM was 70.67%, with Arruda at 66.18% and EASY at 72.22%. Sensitivity for EPM in distinguishing left vs. right APs was 95.73%, with a specificity of 74.33%. For identifying septal vs. lateral right APs, EPM sensitivity was 82.79% with a specificity of 46.15%. These measures were comparable to those of Arruda and EASY. Inter-observer variability was excellent for EPM, with Kappa statistics over 0.9. CONCLUSION: The EPM algorithm emerges as a reliable tool for AP localization, offering a systematic approach beneficial for therapeutic decision-making in electrophysiology. Its comparable diagnostic accuracy and excellent inter-observer variability underscore its potential clinical applicability. Future research may further validate its efficacy in a broader clinical setting.

Estratégias Econômicas e Sociais para Anticoagulação de Pacientes com Fibrilação Atrial / Economy- and Social-Based Strategies for Anticoagulation of Patients with Atrial Fibrillation

Resumo Fundamento: A fibrilação atrial é um problema de saúde pública associado com um risco cinco vezes maior de acidente vascular cerebral e mortalidade. A análise de custos é importante para a introdução de novas terapias, e deve ser reconsiderada em situações especiais, tais como a pandemia do coronavírus em 2020. Objetivo: Avaliar os custos (em um período de um ano) relacionados à terapia anticoagulante e a qualidade de vida de pacientes com fibrilação atrial tratados em um hospital público universitário. Métodos: Os custos do paciente foram aqueles relacionados à anticoagulação e calculados pela média de custos mensais da varfarina ou de anticoagulantes orais diretos (DOACs). As despesas não médicas, como alimentação e transporte, foram calculadas a partir de dados obtidos de questionários. O questionário brasileiro SF-6D foi usado para medir a qualidade de vida. Valores p<0,05 foram considerados estatisticamente significativos. Resultados: A população do estudo consistiu em 90 pacientes, 45 em cada braço (varfarina vs. DOACs). Os custos foram 20% mais altos no grupo dos DOACs (US$55 532,62 vs. US$46 385,88), e principalmente relacionados ao preço dos medicamentos (US$23 497,16 vs. US$1903,27). Os custos hospitalares foram mais altos no grupo da varfarina (US$31 088,41 vs $24 604,74), e relacionados às visitas ao ambulatório. Ainda, as despesas não médicas foram duas vezes maiores no grupo varfarina ($13 394,20 vs $7 430,72). A equivalência de preço entre os dois medicamentos seria alcançada por uma redução de 39% no preço dos DOACs. Não foram observadas diferenças quanto à qualidade de vida. Conclusões: Os custos totais foram mais altos no grupo de pacientes tratados com DOACs que no grupo da varfarina. No entanto, uma redução de cerca de 40% no preço dos DOACs tornaria viável a incorporação desses medicamentos no sistema de saúde público brasileiro.

Abstract Background: Atrial fibrillation is a public health problem associated with a fivefold increased risk of stroke or death. Analyzing costs is important when introducing new therapies and must be reconsidered in special situations, such as the novel coronavirus pandemic of 2020. Objective: This study aimed to evaluate the costs related to anticoagulant therapy in a one-year period, and the quality of life of atrial fibrillation patients treated in a public university hospital. Methods: Patient costs were those related to the anticoagulation and calculated by the average monthly costs of warfarin or direct oral anticoagulants (DOACs). Patient non-medical costs (eg., food and transportation) were calculated from data obtained by questionnaires. The Brazilian SF-6D was used to measure the quality of life. P-values < 0.05 were considered statistically significant. Results: The study population consisted of 90 patients, 45 in each arm (warfarin vs direct oral anticoagulants). Costs were 20% higher in the DOAC group ($55,532.62 vs $46,385.88), and mainly related to drug price ($23,497.16 vs $1,903.27). Hospital costs were higher in the warfarin group ($31,088.41 vs $24,604.74) and related to outpatient visits. Additionally, non-medical costs were almost twice higher in the warfarin group ($13,394.20 vs $7,430.72). Equivalence of price between the two drugs could be achieved by a 39% reduction in the price of DOACs. There were no significant group differences regarding quality of life. Conclusions: Total costs were higher in the group of patients taking DOACs than those taking warfarin. However, a nearly 40% reduction in the price of DOACs could make it feasible to incorporate these drugs into the Brazilian public health system.

Correlation of accessory pathway location with gender and their manifest or concealed presentation.

BACKGROUND: Atrioventricular reentrant tachycardias account for approximately one third of cases referred for electrophysiological study (EPS). The anatomical substrate responsible for the reentry is an accessory pathway (AP) able to conduct the electrical stimulus in an anterograde, retrograde or bidirectional manner. OBJECTIVE: To evaluate the correlation of AP location with the male and female genders and AP clinical presentation, whether manifest or concealed. METHODS: Retrospective observational study including 942 consecutive patients, all diagnosed with EPS-confirmed AP from January 1994 to December 2008. APs were classified into eight anatomical groups: left lateral (LL), left posterior (LP), left posteroseptal (LPS), right posteroseptal (RPS), right midseptal (RMS), right anteroseptal (RAS), right lateral (RL), and right posterior (RP). RESULTS: Of the 942 patients, 52.6% were males. The mean age was 31.2±13.8years. As regards gender, APs were more prevalent among men. However, a statistically significant difference was observed only in the LPS (p=0.029) and RL (p=0.003) regions. In relation to the form of presentation of AP, the manifest form was more frequent than the concealed form in six of the eight regions studied, except for the LL and LPS regions. CONCLUSION: AP predominated in males and the manifest form was more frequent than the concealed form in most of the regions studied.

MANEJO DO HIPERTENSO COM FIBRILAÇÃO ATRIAL. O QUE MUDOU NA PRÁTICA MÉDICA? / HYPERTENSION AND ATRIAL FIBRILLATION: RECENT ADVANCES

A fibrilação atrial (FA) é a arritmia cardíaca sustentada mais comum na prática clínica. Estima se que 1 a 2% da população mundial seja acometida dessa arritmia e ainda se reconhece que este número está subestimado, dado que até um terço dos pacientes com FA são assintomáticos. Além dos fatores de risco clássicos como diabetes, doença valvar, infarto do miocárdio e insuficiência cardíaca, insuficiência renal crônica, obesidade e apneia obstrutiva do sono, a hipertensão tem um papel muito impactante no surgimento da FA pela sua alta prevalência, com isso sendo o fator de risco mais comum para o desenvolvimento de FA. O manejo adequado da HA é importante para prevenção da FA, controle do ritmo, insuficiência cardíaca e prevenção do acidente vascular cerebral (AVC). O tratamento deve ser integrado por equipe multidisciplinar, individualizando caso a caso, estando sujeito a mudanças ao longo do tempo, com o desenvolvimento de novos fatores de risco, sintomas, progressão da doença e com advento de novos tratamentos. Algumas drogas, tais como os BRAs e iECA parecem apresentar mecanismos específicos de atuação na redução do risco de arritmias. A ablação por cateter pode ser a estratégia mais eficaz para manutenção do ritmo sinusal, em paciente sintomáticos. O objetivo dessa revisão é resumir os dados atuais referente ao manejo do paciente hipertenso com fibrilação atrial.

Worldwide, AF is the most common sustained cardiac arrhythmia in adults. The currently estimated prevalence and incidence in the world are rising, owing to extended longevity and increased survival with chronic diseases. This multifactorial arrhythmia is intertwined with common concomitant cardiovascular diseases, which share classical cardiovascular risk factors, including hypertension, diabetes mellitus, heart failure (HF), coronary artery disease (CAD), chronic kidney disease (CKD), obesity, and obstructive sleep apnoea (OSA). The most common risk factor for AF in the general population is hypertension, and in these patients, left ventricular hypertrophy followed by left atrial enlargement creates the anatomical substrate for AF. Adequate management of hypertension is important for AF prevention, rhythm control, heart failure, and stroke prevention. Integrated management of AF patients requires a coordinated and agreed patient-individualized care pathway to deliver optimized treatment by an interdisciplinary team. The effect of some anti hypertensives, such as RAAS Inhibitors seems to be superior to other antihypertensive treatment to prevent AF recurrences in hypertensive patients with paroxysmal AF beyond the BP reduction. Guidelines suggest a more prominent role for radiofrequency ablation in the treatment of atrial fibrillation (AF), including its use as first-line therapy in recurrent symptomatic paroxysmal or persistent AF in whom a rhythm control strategy is chosen. The objective of this review is to summarize current data on the hypertension in relation to AF, their management, and ongoing research in the field.

Diagnostic Accuracy of Several Electrocardiographic Criteria for the Prediction of Atrioventricular Nodal Reentrant Tachycardia.

BACKGROUND AND AIMS: Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common form of paroxysmal supraventricular tachycardia (SVT) whose diagnosis can be strongly suspected based on the surface eletrocardiogram alone. The purpose of this study is to determine the diagnostic accuracy of several electrocardiographic (ECG) criteria for the prediction of AVNRT. METHODS: Between November 2010 and January 2014, a total of 256 patients who underwent electrophysiological testing (EP) with regular, paroxysmal and narrow QRS complex tachycardia were prospectively enrolled. We classified the ECG recordings during tachycardia for the presence of the following criteria: a) classical ECG findings of pseudo S wave in inferior leads and/or pseudo r' wave in lead V1, b) notch in lead aVL, c) no retrograde P waves visible during tachycardia; d) pseudo r' wave in lead aVR, e) notch in lead D1, f) any deflection after 100 ms of the QRS complex during tachycardia. RESULTS: On multivariate analysis, independent predictors of AVNRT diagnosis were female sex (OR 4.17; 95% CI [2.11-8.24]; p <0.001), age >60 years (OR 3.53; 95% CI [1.25-9.96]; p = 0.017) and the classical ECG criteria (OR 7.41; 95% CI [3.62-15.17]; p <0.001). CONCLUSIONS: Female, age >60 years and the classical ECG criteria were the independent predictors of AVNRT diagnosis. Although several of the ECG criteria for AVNRT diagnosis showed acceptable sensitivities and specificities, they do not improve its accuracy.