Catheter ablation of the parahisian accessory pathways from the aortic cusps-Experience of 20 cases-Improving the mapping strategy for better results.

INTRODUCTION: Catheter ablation of the parahisian accessory pathways (PHAP) has been established as the definitive therapy for this type of arrhythmia. However, the PHAP proximity to the normal atrioventricular conduction system makes the procedure technically challenging. Here, we have reported a case series of 20 patients with PHAP who underwent aortic access ablation to evaluate the safety and efficacy of this approach in the PHAP ablation. METHODS AND RESULTS: The ablation through the aortic cusps was the successful approach in 13 of 20 (65%) of the cases. In 11 patients, the aortic approach was the initial strategy for ablation, and the accessory pathway was eliminated in seven (63.6%) of them. The aortic approach followed a failed right-sided attempt in nine patients. In six (66.7%) patients, the ablation was successful with the aortic approach. The only independent predictor for the successful ablation with each approach was the earliest ventricular activation before delta wave (predelta time) and a right-sided earliest ventricular activation of more than 23 ms had high sensitivity and specificity for right-sided success. Systematically using the two strategies (right and left approaches), the ablation of the PHAP was successful in 18 (90%) patients. CONCLUSION: The aortic approach seems to be a safe and effective strategy for the ablation of PHAP. It can be used when the right-sided approach fails or even considered as an initial strategy when the predelta time is less than 23 ms in the right septal region. When combining the right- and left-sided approaches, the success rate is high. We believe that the retrograde aortic approach remains a key tool for this challenging ablation.

Comparative study of strategies to prevent esophageal and periesophageal injury during atrial fibrillation ablation.

OBJECTIVE: To compare the prevalence of esophageal and periesophageal thermal injury in patients undergoing radiofrequency (RF) atrial fibrillation (AF) ablation using 8 mm tip catheters during three different esophageal protection strategies. METHODS: Forty-five consecutive patients with paroxysmal or persistent AF underwent first ablation procedure, besides esophagogastroduodenoscopy (EGD) combined with radial endosonography (EUS) performed before and after the pulmonary vein (PV) isolation. Before the procedure, patients were randomly assigned to one of three esophageal lesion protection strategies: group I-without any protective or monitoring dispositive and limiting RF applications to 30 W for 20 seconds, in left atrium posterior wall (LAPW); group II-power and time of RF delivery, up to 50 W for 20 seconds at LAPW, limited by esophageal temperature monitoring; group III-applications of RF in LAPW with fixed power application of 50 W for 20 seconds during continuous esophageal cooling. RESULTS: Baseline characteristics of patients were similar in all groups. The four PVs were isolated in 14 (93.3%), 13 (86.7%), and 15 (100%) patients, respectively in groups I, II, and III. The mean RF power was significantly higher (P < .001) in the posterior side of PVs in group III. Post-AF ablation EGD and EUS revealed two esophageal wall ulcerations and two periesophageal mediastinal edemas only in the esophageal cooling group (P = .008). CONCLUSION: Esophageal cooling balloon strategy resulted in a higher RF power energy delivery when ablating at the LA posterior wall, using 8 mm nonirrigated tip catheters under temperature mode control. Despite that, patients presented a relatively low incidence of esophageal and periesophaeal injuries.

Atrial-oesophageal fistula following percutaneous radiofrequency catheter ablation of atrial fibrillation: the risk still persists.

Aims: Atrial-oesophageal fistula is a serious complication related to ablation of atrial fibrillation. As its occurrence is rare, there is a great lack of information about their mechanisms, incidence, presentations, and treatment. The objective of this manuscript is to present a series of cases of atrial-oesophageal fistula in Brazil, focusing on incidence, clinical presentation, and follow-up. Methods and results: This is a retrospective multicentre registry of atrial-oesophageal fistula cases that occurred in eight Brazilian centres from 2003 to 2015. Ten cases (0.113%) of atrial-oesophageal fistula were reported in 8863 ablation procedures in the period. Most of the subjects were male (70%) with age 59.6 ± 9.3 years. Eight centres were reference units in atrial fibrillation ablation with an experience over than 200 procedures at the time of fistula occurrence. Oesophageal temperature monitoring was performed in eight cases using coated sensors in six. The first atrial-oesophageal fistula clinical manifestation was typically fever (in six patients), with a median onset time of 16.5 (12­43) days after ablation. There was a delay of 7.8 ± 3.3 days between the first manifestation and the diagnosis in five patients. The treatment was surgical in six cases, clinical in three and stenting in one. Seven patients died (70%) and two developed permanent neurological sequelae. Conclusion: Atrial-oesophageal fistula remains a serious complication following AF ablation despite the incorporation of protective measures and increased technical experience of the groups. The high morbidity and mortality despite the treatment indicates the need to develop adequate preventive strategies.

Differential diagnosis of wide QRS tachycardias: comparison of two electrocardiographic algorithms.

AIMS: This study's aim is to compare the ability of two ECG criteria to differentiate ventricular (VT) from supraventricular tachycardia (SVT): Brugada et al. [horizontal plane (HP) leads] and Vereckei et al. [frontal plane (FP), specifically aVR lead], having electrophysiological study (EPS) as gold standard. After comparing, suggestions for better diagnosis of wide QRS-complex tachycardia (WCT) in emergency situations were made. METHODS AND RESULTS: Fifty-one consecutive patients with 12-lead ECG registered during EPS-induced regular WCT were selected. Each ECG was split into two parts: HP (V1-V6) and FP (D1-D3, aVR, aVL, and aVF), randomly distributed to three observers, blinded for EPS diagnosis and complementary ECG plane, resulting in total 306 ECG analyses. Observers followed the four steps of both algorithms, counting time-to-diagnosis. Global sensitivity, specificity, percentage of incorrect diagnoses, and step-by-step positive/negative likelihood ratios (+LR and -LR) were calculated. Kaplan-Meier curve was plotted for final time-to-diagnosis. Inter-observer agreement was assessed with kappa-statistic. Global sensitivity was similarly high in FP and HP algorithms (89.2 vs. 90.1%), and incorrect classifications were 27.4 vs. 24.7%. Forty-eight correct analyses by Vereckei criteria took 9.13 s to diagnose VT in the first step, showing that first step was fast, with high +LR, generating nearly conclusive pre- (72.6%) to post-test (98.0%) changes for VT probability. CONCLUSION: Both algorithms as a whole are similar for diagnosis of WTC; however, the first step of Vereckei (initial R in aVR) is a simple, reproducible, accurate, and fast tool to use. The negativity of this step requires a 'holistic' approach to distinguish VT from SVT.

Epicardial ablation for cardiac arrhythmias: techniques, indications and results.

PURPOSE OF REVIEW: To review the most relevant published data on epicardial ablation of cardiac arrhythmias in the last few years. RECENT FINDINGS: Several studies performing epicardial and endocardial ablation have demonstrated that epicardial ablation may improve the results of ventricular tachycardia (VT) ablation in almost all cardiomyopathies. New imaging techniques have been recently applied, refining the identification of patients who actually benefit from epicardial ablation and increasing its safety. SUMMARY: Epicardial VT ablation is an important tool for electrophysiologists to deal with the challenge of scar-related ventricular arrhythmias.

Initial experience on cardiac magnetic resonance-aided VT ablation in South America.

BACKGROUND: Cardiac magnetic resonance (CMR) allowed to precisely identify the substrate in scar-related ventricular tachycardia (VT). New software has been developed to define the 3D scar and corridors to help VT ablation by integrating the scar and electroanatomical mapping (EAM). The objective of this study is to evaluate the results of VT ablation aided by the integration of EAM and CMR software processed scar. METHODS: We selected patients that underwent VT ablation with the integration of EAM and CMR processed using ADAS software and imported to the CARTO system using VTK file format. RESULTS: From 2019 to 2021, eight patients (mean age 63 ± 4.4, 62.5% male; EF 47 ± 12%) underwent CMR-aided VT ablation. Mean procedural time was 281 ± 77 min. There was of 9 ± 4.4 epicardial and 7.9 ± 4.3 endocardial bulls eye segments with at least 2 g of border zone or core scar. In a median follow-up time of 532 days (Q1: 284, Q3: 688), three patients (37.5%) presented VT recurrence, all three underwent a second procedure, with no VT recurrence on the follow-up. No patient died in the follow-up. CONCLUSION: CMR aided is ablation is feasible and effective in patients with scar related VT.

Feasibility of Transatrial Access for Epicardial Ablation: Evaluation of 2 Different Techniques in Swine.

BACKGROUND: The subxiphoid pericardial access is technically difficult and has a considerable rate of complications, thus transatrial access may be an alternative. OBJECTIVES: This study sought to assess the feasibility and safety of this strategy regarding periprocedural period and after 1-week follow-up. METHODS: The investigators performed epicardial mapping through transatrial puncture in 20 swine. Animals were divided into group A, in which aspiration of the sheath was performed to maintain negative pressure after the withdraw of the catheters, and group B, in which a device (Konar-MF VSD Occluder) was delivered to occlude the right atrial appendage perforation. Bleeding was investigated immediately and 1 week after. RESULTS: Access was safe in 19 of 20 animals (95%) with small amount of bleeding (6.4 ± 6 mL). In group A (n = 10), 1 animal presented hemopericardium right after the puncture. In the other 9, epicardial ablation was performed and 60.0 ± 28.0 mL of blood was aspirated without events. After 1 week, fibrin-hemorrhagic pericarditis was identified in 3 animals. In group B (n = 10), reaching the epicardial surface was possible in all animals. An adequate position of the prosthesis was obtained in 90% (9 of 10). One death occurred in the immediate postoperative period, secondary to pneumothorax. After 1 week, postmortem analysis showed absence of pericardial bleeding and a normal-appearing pericardium in the 8 animals with adequate prosthesis position. CONCLUSIONS: Transatrial access allows epicardial mapping and ablation. Sheath removal after negative pressure contributes to achieving acute bleeding control but does not prevent its occurrence. The use of the device prevents bleeding and hemorrhagic pericarditis.

Advanced Therapies for Ventricular Arrhythmias in Patients With Chagasic Cardiomyopathy: JACC State-of-the-Art Review.

Chagas disease is caused by infection from the protozoan parasite Trypanosoma cruzi. Although it is endemic to Latin America, global migration has led to an increased incidence of Chagas in Europe, Asia, Australia, and North America. Following acute infection, up to 30% of patients will develop chronic Chagas disease, with most patients developing Chagasic cardiomyopathy. Chronic Chagas cardiomyopathy is highly arrhythmogenic, with estimated annual rates of appropriate implantable cardioverter-defibrillator therapies and electrical storm of 25% and 9.1%, respectively. Managing arrhythmias in patients with Chagasic cardiomyopathy is a major challenge for the clinical electrophysiologist, requiring intimate knowledge of cardiac anatomy, advanced training, and expertise. Endocardial-epicardial mapping and ablation strategy is needed to treat arrhythmias in this patient population, owing to the suboptimal long-term success rate of endocardial mapping and ablation alone. We also describe innovative approaches to improve acute and long-term clinical outcomes in patients with refractory ventricular arrhythmias following catheter ablation, such as bilateral cervicothoracic sympathectomy and bilateral renal denervation, among others.

Validation of a Simple Electrocardiographic Algorithm for Detection of Ventricular Tachycardia. / Validação de um Algoritmo Simples para Detecção de Taquicardia Ventricular no Eletrocardiograma.

BACKGROUND: The differential diagnosis of wide QRS complex tachycardia (WCT) between ventricular tachycardia (VT) or supraventricular tachycardia with aberrant conduction (SVT-A) is sometimes difficult in the emergency room. OBJECTIVE: The aim of this study was to evaluate the accuracy of a new simple electrocardiographic algorithm to recognize VT in patients with wide complex tachycardia. METHODS: The 12-lead electrocardiograms (ECG) for WCT were prospectively obtained from 120 patients during electrophysiological study. Six physicians with different expertise analyzed the electrocardiographic recordings, and made the diagnosis based on the D12V16 algorithm, that involves the analysis of the predominant polarity of QRS in leads I, II, V1 and V6. The diagnosis was compared with that made using the traditional Brugada algorithm and the "gold-standard" electrophysiological study. Statistical analyses were performed with a significance level of 5% (p<0.05). RESULTS: According to the EPS study, 82 ECG recordings were VT and 38 SVT-A. Structural heart diseases were present in 71 (86.6%) patients with VT and in 8 (21.1%) with SVT-A. The Brugada algorithm had higher global sensitivity (87.2%), and the D12V16 algorithm had higher global specificity (85.1%) for VT. Both D12V16 and Brugada's algorithms presented a high positive predictive value (90.9% vs 85.8%, respectively) and similar accuracy (73.8% vs 81.4%, respectively) for the diagnosis of VT. Experienced evaluators were more accurate using Brugada algorithm than the D12V16 algorithm, but the accuracy of both algorithms was similar according to less experienced examiners. CONCLUSION: The simplified algorithm may be a useful method to recognize VT in the ECG, especially for less experienced doctors. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0).

FUNDAMENTO: O diagnóstico diferencial de taquicardia de QRS largo, entre taquicardia ventricular (TV) ou taquicardia supraventricular com condução aberrante (TSV-A) é algumas vezes difícil de ser feito na sala de emergência. OBJETIVO: Avaliar a acurácia de um algoritmo novo e simples para a detecção de TV no eletrocardiograma (ECG) em pacientes com taquicardia de QRS largo. MÉTODOS: ECGs de 12 derivações para detecção de taquicardia de QRS largo foram obtidos prospectivamente de 120 pacientes durante estudo eletrofisiológico. Seis médicos com diferentes experiências analisaram os ECGs, e fizeram o diagnóstico com base no algoritmo D12V16, que envolve a análise da polaridade predominante do complexo QRS nas derivações I, II, V1 e V6. O diagnóstico foi comparado com os obtidos pelo algoritmo tradicional de Brugada e pelo estudo eletrofisiológico, o qual é considerado padrão ouro. Adotou-se um nível de significância de 5% (p<0,05) nas análises estatísticas. RESULTADOS: De acordo com o estudo eletrofisiológico, 82 ECGs eram de TV e 38 de TSV-A. Doenças cardíacas estruturais estavam presentes em 71 (86,6%) dos pacientes com TV e em oito (21,1%) com TSV-A. O algoritmo de Brugada teve uma maior sensibilidade global (87,2%), enquanto o algoritmo D12V16 apresentou maior especificidade global (85,1%) para TV. Tanto o algoritmo D12V16 como o de Brugada apresentou um alto valor preditivo positivo (90,9% vs. 85,8%, respectivamente) e acurácia similar (73,8% vs. 81,4%, respectivamente) para o diagnóstico de TV. Nos avaliadores experientes, a acurácia foi maior utilizando o algoritmo de Brugada que o algoritmo D12V16, mas a acurácia dos dois algoritmos foi similar segundo os avaliadores menos experientes. CONCLUSÃO: O algoritmo simplificado pode ser um método útil para reconhecer TV no ECG, principalmente para médicos menos experientes. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0).

Efficacy and safety of combined endocardial/epicardial catheter ablation for ventricular tachycardia in Chagas disease: A randomized controlled study.

BACKGROUND: Epicardial mapping and ablation are frequently necessary to eliminate ventricular tachycardia (VT) in patients with Chagas disease. Nonetheless, there are no randomized controlled trials demonstrating the role of this strategy. OBJECTIVE: We conducted this randomized controlled trial to evaluate the efficacy and safety of combined epicardial ablation in patients with Chagas disease. METHODS: We randomized patients with Chagas disease and VT in a 1:1 fashion to either the endocardial (endo) mapping and ablation group or the combined endocardial/epicardial (endo/epi) mapping and ablation group. The efficacy end points were measured by VT inducibility and all-ventricular arrhythmia recurrence. Safety was assessed by the rate of periprocedural complications. RESULTS: Thirty patients were enrolled, and most were male. The median age was 67 (Q1: 58; Q3: 70) years in the endo group and 58 (Q1: 43; Q3: 66) years in the endo/epi group. The left ventricular ejection fraction was 33.0% ± 9.5% and 35.2% ± 11.5%, respectively P = .13. Acute success (non-reinducibility of clinical VT) was obtained in 13 patients (86%) in the endo/epi group and in 6 patients (40%) in the endo-only group (P = .021). There were 12 patients with VT recurrence (80%) in the endo-only group and 6 patients (40%) in the endo/epi group (P = .02) (by intention-to-treat analysis). Epicardial ablation was ultimately performed in 9 patients (60%) in the endo-only group because of an absence of endocardial scar or maintenance of VT inducibility. There was no difference in complications between the groups. CONCLUSION: Combining endo/epi VT catheter ablation in patients with Chagas disease significantly increases short- and long-term freedom from all-ventricular arrhythmias. Epicardial access did not increase periprocedural complication rates.

Gastric hypomotility following epicardial vagal denervation ablation to treat atrial fibrillation.

We report a case of a 55-year-old man with vagal paroxysmal atrial fibrillation (AF) who was submitted to selective epicardial and endocardial atrial vagal denervation with the objective of treating AF. Radiofrequency pulses were applied on epicardial and endocardial surface of the left atrium close to right pulmonary veins (PVs) and also on epicardial surface close to left inferior PV. Following the procedure, patient presented with symptoms of gastroparesis, which was documented on CT scan and gastric emptying scintigraphy. Symptoms were transient and the patient recovered completely.