Long-term prognosis of idiopathic ventricular fibrillation: An eighteen-year experience from a tertiary center.

INTRODUCTION AND OBJECTIVES: Idiopathic ventricular fibrillation (IVF) is diagnosed in patients who survive sudden cardiac arrest (SCA), preferably with documented ventricular fibrillation (VF), without any identifiable structural or electrical abnormality. Current evidence provides limited guidance on the diagnosis and follow-up of these patients. Our aim was to assess the clinical outcomes of survivors of an aborted SCA attributed to IVF. METHODS: We retrospectively collected clinical data from all patients who survived SCA and implanted a cardiac defibrillator (ICD) between 2005 and 2023. RESULTS: A total of 38 patients, 36.8% female, with a mean age of 44±14 years old were included. Median follow-up time was 8.7 years (interquartile range (IQR) 4.7-14.7 years). All patients underwent a comprehensive diagnostic evaluation that excluded structural and coronary disease. During follow-up, underlying diagnoses were established in 34.2% of the whole cohort. Genetic testing, performed in 37.2%, revealed underlying diagnoses in 57.1% of those tested, compared to only 26.3% of patients who did not undergo genetic testing [p=0.035, OR = 5.1 (95% confidence interval (CI) 1.2-21.5)]. Mortality was 10.5% (due to non-arrhythmic causes) and 36.8% patients received appropriate therapies with a median time to first ICD therapy of 39 [5.4-47.3] months. CONCLUSION(S): Etiological diagnosis and recurrence prediction in patients with IVF remains challenging, even with extensive diagnostic evaluation and long-term follow-up. In our study, genetic testing enhanced diagnostic yield. Consistent with previous findings, our cohort experienced a notable arrhythmic recurrence, with no cardiac deaths, underlining the pivotal role of ICD implantation in these patients.

ECMO for drug-refractory electrical storm without a reversible trigger: a retrospective multicentric observational study.

AIMS: Drug-refractory electrical storm (ES) is a life-threatening medical emergency. We describe the use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in drug-refractory ES without a reversible trigger, for which specific guideline recommendations are still lacking. METHODS AND RESULTS: Retrospective observational study in four Iberian centres on the indications, treatment, complications, and outcome of drug-refractory ES not associated with acute coronary syndromes, decompensated heart failure, drug toxicity, electrolyte disturbances, endocrine emergencies, concomitant acute illness with fever, or poor compliance with anti-arrhythmic drugs, requiring VA-ECMO for circulatory support. Thirty-four (6%) out of 552 patients with VA-ECMO for cardiogenic shock were included [71% men; 57 (44-62) years], 65% underwent cardiopulmonary resuscitation before VA-ECMO implantation, and 26% during cannulation. Left ventricular unloading during VA-ECMO was used in 8 (24%) patients: 3 (9%) with intraaortic balloon pump, 3 (9%) with LV vent, and 2 (6%) with Impella. Thirty (88%) had structural heart disease and 8 (24%) had an implantable cardioverter-defibrillator. The drug-refractory ES was mostly due to monomorphic ventricular tachycardia (VT) and ventricular fibrillation (VF) (59%), isolated monomorphic VT (26%), polymorphic VT (9%), or VF (6%). Thirty-one (91%) required deep sedation, 44% overdrive pacing, 36% catheter ablation, and 26% acute autonomic modulation. The main complications were nosocomial infection (47%), bleeding (24%), and limb ischaemia (21%). Eighteen (53%) were weaned from VA-ECMO, and 29% had heart transplantation. Twenty-seven (79%) survived to hospital discharge (48 (33-82) days). Non-survivors were older [62 (58-67) vs. 54 (43-58); P < 0.01] and had a higher first rhythm disorder-to-ECMO interval [0 (0-2) vs. 2 (1-11) days; P = 0.02]. Seven (20%) had rehospitalization during follow-up [29 (12-48) months], with ES recurrence in 6%. CONCLUSIONS: VA-ECMO bridged drug-refractory ES without a reversible trigger with a high success rate. This required prolonged hospital stays and coordination between the ECMO centre, the electrophysiology laboratory, and the heart transplant programme.

Ostial vs. wide area circumferential ablation guided by the Ablation Index in paroxysmal atrial fibrillation.

AIMS: Pulmonary vein isolation (PVI) guided by the Ablation Index (AI) has shown high acute and mid-term efficacy in the treatment of paroxysmal atrial fibrillation (AF). Previous data before the AI-era had suggested that wide-area circumferential ablation (WACA) was preferable to ostial ablation. However, with the use of AI, we hypothesize that ostial circumferential ablation is non-inferior to WACA and can improve outcomes in paroxysmal AF. METHODS AND RESULTS: Prospective, multicentre, non-randomized, non-inferiority study of consecutive patients were referred for paroxysmal AF ablation from January 2020 to September 2021. All procedures were performed using the AI software, and patients were separated into two different groups: WACA vs. ostial circumferential ablation. Acute reconnection, procedural data, and 1-year arrhythmia recurrence were assessed. During the enrolment period, 162 patients (64% males, mean age of 60 ± 11 years) fulfilled the study inclusion criteria-81 patients [304 pulmonary vein (PV)] in the WACA group and 81 patients (301 PV) in the ostial group. Acute PV reconnection was identified in 7.9% [95% confidence interval (CI), 4.9-11.1%] of PVs in the WACA group compared with 3.3% (95% CI, 1.8-6.1%) of PVs in the ostial group [P < 0.001 for non-inferiority; adjusted odds ratio 0.51 (95% CI, 0.23-0.83), P = 0.05]. Patients in the WACA group had longer ablation (35 vs. 29 min, P = 0.001) and procedure (121 vs. 102 min, P < 0.001) times. No significant difference in arrhythmia recurrence was seen at 1-year of follow-up [11.1% in WACA vs. 9.9% in ostial, hazard ratio 1.13 (95% CI, 0.44-1.94), P = 0.80 for superiority]. CONCLUSION: In paroxysmal AF patients treated with tailored AI-guided PVI, ostial circumferential ablation is not inferior to WACA with regard to acute PV reconnection, while allowing quicker procedures with less ablation time.

Long-term prognosis of out-of-hospital cardiac arrest due to idiopathic ventricular arrhythmias.

Life-threatening ventricular arrhythmias (VA) may occur in patients with unknown cardiac disease. A sizable part of them remains labeled as Idiopathic VA and limited data is available regarding their natural history. Our aim was to evaluate the long-term clinical outcomes of survivors of an idiopathic life-threatening VA. Patients who survived an idiopathic life-threatening VA referred to an ICD were included and followed for a median follow-up of 7 years. Clinical and device data were collected and a comparison between genders was made. A total of 29 patients, 41% female, mean age of 50 (19) years were studied; all were implanted with an ICD at index hospitalization. At follow-up, an etiological diagnosis was established in 38% of patients. Genetic testing improved the diagnosis and allowed the identification of a distinct clinical entity in 60% of patients (p=0.04, OR=7.0), especially in women. Regarding ICD data, 31% received appropriate therapies with a median time to first appropriate shock of 39 months (IQR 12-46 months). Men had a significantly higher prevalence of appropriated shocks (50% vs 8%, p=0.04), with a similar time to the first arrhythmic event between genders. Two of the patients died, both from non-arrhythmic causes. Etiologic diagnosis and recurrence prediction in patients with idiopathic VA is challenging, even with long-term follow-up and sophisticated diagnostic evaluation.  Genetic testing significantly improved the diagnostic yield, especially in women. Arrhythmia recurrence occurred in about one-third of patients and is significantly higher in men, underscoring the importance of ICD implantation.

High-power short-duration versus low-power long-duration ablation guided by the ablation index.

AIMS: To compare the two different ablation strategies, both guided by the Ablation Index (AI), in the setting of atrial fibrillation (AF) ablation: high-power short-duration (HPSD) ablation using 40 W on the posterior wall and 50 W elsewhere versus low-power long-duration (LPLD) using 25 W posteriorly and 35 W elsewhere. METHODS: Prospective, multicenter nonrandomized, noninferiority study of consecutive patients referred for paroxysmal AF ablation from January 2018 to July 2019. Ablation was guided by the AI (≥500 for anterior segments, ≥450 for the roof and inferior segments and 400 posteriorly) and an interlesion distance (ILD) ≤ 6 mm. Patients were separated into two groups: HPSD vs LPLD. Acute reconnection (after adenosine trial) and 2-year outcomes were assessed. RESULTS: 160 patients (61% males, median age of 62 [IQR 51-69] years), fulfilled the study inclusion criteria - 80 patients (316 pulmonary veins [PV]) in the HPSD group and 80 patients (314 PV) in the LPLD. The probability of acute PV reconnection was similar between both groups: 2.2% in HPSD, 95%CI 0.6% to 3.8% vs. 3.4% in LPLD, 95%CI 1.4% to 5.4%; p < 0.001 for noninferiority. Median PV ablation time (20 min vs 30 min, p < 0.01) and procedure duration (80 min vs 100 min, p < 0.001) were shorter in the HPSD group. After a median follow-up of 26 months, arrhythmia recurrence was similar between groups (17.5% in HPSD group vs. 18.8% in LPLD group, p = 0.79). CONCLUSIONS: In paroxysmal AF patients treated with the Ablation Index, a HPSD strategy is noninferior to the more standard LPLD ablation, while allowing for quicker procedures with shorter ablation times.

Dependência de Pacing a Longo-Prazo e Preditores de Implante de Pacemaker após Implante Percutâneo de Prótese Valvular Aórtica - 1 Ano de Seguimento / Long-Term Ventricular Pacing Dependency and Pacemaker Implantation Predictors after Transcatheter Aortic Valve Replacement - A 1-Year Follow-Up

Resumo Fundamento Os distúrbios de condução (DC) são a complicação mais frequente após a substituição da válvula aórtica transcateter (TAVR) e ainda não há consenso sobre seu tratamento. Objetivo Avaliar novos DC e implante de marca-passo definitivo (MPD) após a TAVR e avaliar a porcentagem de estimulação ventricular (EV) até 1 ano de acompanhamento. Métodos Pacientes submetidos a TAVR de outubro de 2014 a novembro de 2019 foram cadastrados; pacientes com MPD anterior foram excluídos. Dados clínicos, do procedimento, do ECG e do MPD foram coletados até 1 ano após o implante. O nível de significância adotado para a análise estatística foi 0,05%. Resultados Um total de 340 indivíduos foram submetidos a TAVR. O DC mais comum foi bloqueio de ramo esquerdo novo (BRE; 32,2%), sendo que 56% destes foram resolvidos após 6 meses. O bloqueio do ramo direito (BRD) foi o maior fator de risco para bloqueio atrioventricular avançado (BAV) [RC=8,46; p<0,001] e implante de MPD [RC=5,18; p<0,001], seguido de BAV de baixo grau prévio [RC=2,25; p=0,016 para implante de MPD]. Em relação às características do procedimento, válvulas de gerações mais recentes e procedimentos de válvula-em-válvula foram associados a menos DC. No total, 18,5% dos pacientes tiveram MPD implantado após a TAVR. Na primeira avaliação do MPD, pacientes com BAV avançado tinham uma porcentagem mediana de EV de 80%, e, após um ano, de 83%. Em relação aos pacientes com BRE e BAV de baixo grau, a EV mediana foi mais baixa (6% na primeira avaliação, p=0,036; 2% após um ano, p = 0,065). Conclusão O BRE foi o DC mais frequente após a TAVR, com mais da metade dos casos se resolvendo nos primeiros 6 meses. O BRD foi o principal fator de risco para BAV avançado e implante de MPD. O BAV avançado foi associado a uma porcentagem mais alta de EV no acompanhamento de 1 ano.

Abstract Background Conduction disturbances (CD) are the most frequent complication after transcatheter aortic valve replacement (TAVR), and there continues to be a lack of consensus on their management. Objective To assess new CD and permanent pacemaker (PPM) implantation after TAVR and to evaluate the ventricular pacing percentage (VP) up to 1 year of follow-up. Methods Patients who underwent TAVR from October 2014 to November 2019 were enrolled; patients with previous PPM were excluded. Clinical, procedure, ECG, and PPM data were collected up to 1 year after implantation. The significance level adopted in the statistical analysis was 0.05. Results A total of 340 patients underwent TAVR. The most frequent CD was the new left bundle branch block (LBBB; 32.2%), which 56% resolved after 6 months. Right bundle branch block (RBBB) was the biggest risk factor for advanced atrioventricular block (AVB) [OR=8.46; p<0.001] and PPM implantation [OR=5.18, p<0.001], followed by previous low-grade AVB [OR=2.25; p=0.016 for PPM implantation]. Regarding procedure characteristics, newer generation valves and valve-in-valve procedures were associated with fewer CDs. Overall, 18.5% of patients had a PPM implanted post-TAVR. At first PPM evaluation, patients with advanced AVB had a median percentage of VP of 80% and 83% at one year. Regarding patients with LBBB plus low-grade AVB, median VP was lower (6% at first assessment, p=0.036; 2% at one year, p = 0.065). Conclusion LBBB was the most frequent CD after TAVR, with more than half being resolved in the first six months. RBBB was the major risk factor for advanced AVB and PPM implantation. Advanced AVB was associated with a higher percentage of VP at 1 year of follow-up.

Iatrogenic ventricular fibrillation in Wolff-Parkinson-White syndrome.

Wolff-Parkinson-White (WPW) syndrome is the most common manifestation of ventricular pre-excitation syndrome and is mostly found in individuals with no structural heart disease. Although the risk of malignant arrhythmias is low, sudden cardiac death (SCD) as the first clinical manifestation of WPW syndrome is well documented, and atrial fibrillation (AF) with a rapid ventricular response is the main mechanism involved. Unfortunately, the signs of pre-excitation and arrhythmias are sometimes under-diagnosed and under-treated. We describe the case of a 31-year-old man who was admitted with an irregular wide complex tachycardia consistent with pre-excited AF, which was not promptly diagnosed, and who developed ventricular fibrillation (VF) after administration of atrioventricular (AV) nodal blockers, as a primary manifestation of WPW syndrome. Blocking the AV node in patients with pre-excited AF may increase the ventricular rate and potentially result in hemodynamic instability. Among patients with WPW syndrome who survive an episode of SCD, catheter ablation of the accessory pathway is the treatment of choice.

Long-Term Ventricular Pacing Dependency and Pacemaker Implantation Predictors after Transcatheter Aortic Valve Replacement - A 1-Year Follow-Up. / Dependência de Pacing a Longo-Prazo e Preditores de Implante de Pacemaker após Implante Percutâneo de Prótese Valvular Aórtica ­ 1 Ano de Seguimento.

BACKGROUND: Conduction disturbances (CD) are the most frequent complication after transcatheter aortic valve replacement (TAVR), and there continues to be a lack of consensus on their management. OBJECTIVE: To assess new CD and permanent pacemaker (PPM) implantation after TAVR and to evaluate the ventricular pacing percentage (VP) up to 1 year of follow-up. METHODS: Patients who underwent TAVR from October 2014 to November 2019 were enrolled; patients with previous PPM were excluded. Clinical, procedure, ECG, and PPM data were collected up to 1 year after implantation. The significance level adopted in the statistical analysis was 0.05. RESULTS: A total of 340 patients underwent TAVR. The most frequent CD was the new left bundle branch block (LBBB; 32.2%), which 56% resolved after 6 months. Right bundle branch block (RBBB) was the biggest risk factor for advanced atrioventricular block (AVB) [OR=8.46; p<0.001] and PPM implantation [OR=5.18, p<0.001], followed by previous low-grade AVB [OR=2.25; p=0.016 for PPM implantation]. Regarding procedure characteristics, newer generation valves and valve-in-valve procedures were associated with fewer CDs. Overall, 18.5% of patients had a PPM implanted post-TAVR. At first PPM evaluation, patients with advanced AVB had a median percentage of VP of 80% and 83% at one year. Regarding patients with LBBB plus low-grade AVB, median VP was lower (6% at first assessment, p=0.036; 2% at one year, p = 0.065). CONCLUSION: LBBB was the most frequent CD after TAVR, with more than half being resolved in the first six months. RBBB was the major risk factor for advanced AVB and PPM implantation. Advanced AVB was associated with a higher percentage of VP at 1 year of follow-up.

FUNDAMENTO: Os distúrbios de condução (DC) são a complicação mais frequente após a substituição da válvula aórtica transcateter (TAVR) e ainda não há consenso sobre seu tratamento. OBJETIVO: Avaliar novos DC e implante de marca-passo definitivo (MPD) após a TAVR e avaliar a porcentagem de estimulação ventricular (EV) até 1 ano de acompanhamento. MÉTODOS: Pacientes submetidos a TAVR de outubro de 2014 a novembro de 2019 foram cadastrados; pacientes com MPD anterior foram excluídos. Dados clínicos, do procedimento, do ECG e do MPD foram coletados até 1 ano após o implante. O nível de significância adotado para a análise estatística foi 0,05%. RESULTADOS: Um total de 340 indivíduos foram submetidos a TAVR. O DC mais comum foi bloqueio de ramo esquerdo novo (BRE; 32,2%), sendo que 56% destes foram resolvidos após 6 meses. O bloqueio do ramo direito (BRD) foi o maior fator de risco para bloqueio atrioventricular avançado (BAV) [RC=8,46; p<0,001] e implante de MPD [RC=5,18; p<0,001], seguido de BAV de baixo grau prévio [RC=2,25; p=0,016 para implante de MPD]. Em relação às características do procedimento, válvulas de gerações mais recentes e procedimentos de válvula-em-válvula foram associados a menos DC. No total, 18,5% dos pacientes tiveram MPD implantado após a TAVR. Na primeira avaliação do MPD, pacientes com BAV avançado tinham uma porcentagem mediana de EV de 80%, e, após um ano, de 83%. Em relação aos pacientes com BRE e BAV de baixo grau, a EV mediana foi mais baixa (6% na primeira avaliação, p=0,036; 2% após um ano, p = 0,065). CONCLUSÃO: O BRE foi o DC mais frequente após a TAVR, com mais da metade dos casos se resolvendo nos primeiros 6 meses. O BRD foi o principal fator de risco para BAV avançado e implante de MPD. O BAV avançado foi associado a uma porcentagem mais alta de EV no acompanhamento de 1 ano.

Two years after pulmonary vein isolation guided by ablation index-a multicenter study.

Background: The use of the Ablation Index (AI) software for paroxysmal atrial fibrillation (AF) has been associated with higher acute effectiveness and higher 1-year arrhythmia freedom. There is, however, a lack of data concerning longer follow-up. We aim to evaluate the 2-year outcomes after a standardized AI-guided pulmonary vein isolation (PVI). Methods: Prospective, multicenter study of consecutive patients referred for paroxysmal AF ablation from January 2018 to July 2019. PVI was guided by a tailored AI value (≥500 for anterior segment, ≥450 for the roof segments and inferior segments, and 400 for the posterior wall) and an ILD ≤6 mm. The primary endpoints were acute and long-term effectiveness. Results: The study included 218 (842 PV) patients (61% males, median age of 60 [IQR 49-68] years) with paroxysmal AF. First-pass isolation was obtained in 93% of the patients, with an acute reconnection occurring in 10.6% of the patients (3.2% of the PV) following adenosine trial. After a median follow-up of 26 (IQR 20-30) months, freedom from any documented atrial arrhythmia was 83.4%, off-AAD. The rate of adverse events was 1.4%. Although procedural parameters differ across centers (p < 0.001), the acute (p = 0.56) and long-term effectiveness (p = 0.83) were consistent between centers. Conclusions: Patients with paroxysmal AF submitted to an AI-guided PVI workflow presented high arrhythmia freedom at 2-years of follow-up.

Assessment of the need of a waiting period after pulmonary vein isolation with the ablation index software.

PURPOSE: Since the widespread availability of contact-force sensing catheters, the need for a waiting period after pulmonary vein isolation (PVI) has not been reassessed. We aim to evaluate whether a waiting period is still necessary after PVI guided by the ablation Index (AI). METHODS: Prospective, multicenter, randomized study of consecutive patients referred for paroxysmal atrial fibrillation (AF) ablation from May 2019 to February 2020. Patients were randomized in a 1:1 ratio to PVI with versus without a waiting period of 20 min. Acute pulmonary vein (PV) reconnection after adenosine challenge was the primary endpoint. A per-protocol analysis was designed to determine whether a strategy of dismissing the waiting period after PVI was noninferior to waiting for 20 min for identifying acute PV reconnection. PVI was guided by tailored AI values and an interlesion distance ≤6 mm. RESULTS: During the enrollment period, 167 patients (56% males, mean age of 57 ± 14 years) fulfilled the study inclusion criteria - 84 patients (308 PV) in the waiting period group (Group A) and 83 patients (314 PV) in the group without a waiting period (Group B). Acute PV reconnection was identified in 3.8% (95% confidence interval [CI], 1.7%-5.9%) of PVs in the study group B compared to 2.9% (95% CI, 1.0%-4.8%) of PVs in the Group A (p = .002 for non-inferiority). At 1-year follow-up, there was no significant difference in arrhythmia recurrence between groups (9.5% in Group A vs. 9.6% in Group B, hazard ratio: 1.03 [95% CI, 0.39-2.73], p = .98). CONCLUSION: In paroxysmal AF patients submitted to ablation, a tailored PVI guided by the AI rendered a 20-min waiting period unnecessary.

Clinical outcomes of leadless pacemaker: a systematic review.

INTRODUCTION: Transvenous pacemakers are associated with a significant amount of complications. Leadless pacemakers (LP) are emerging as an alternative to conventional devices. This article provides a systematic review of patient eligibility, safety and clinical outcomes of the LP devices. EVIDENCE ACQUISITION: A systematic search for articles describing the use of LP was conducted. Out of two databases, 24 articles were included in the qualitative analysis. These articles comprised a total of 4739 patients, with follow-up times of 1-38 months. Further information was obtained from 10 more studies. EVIDENCE SYNTHESIS: From a population of 4739 patients included in the qualitative analysis, 4670 LP were implanted with success (98.5%). A total of 248 complications were described (5.23%) during the follow-up. The most common were pacing issues such as elevated thresholds, dislodgements or battery failure (68 patients), events at the femoral access site such as hemorrhage, hematoma or pseudoaneurysms (64 patients) and procedure related cardiac injuries such as cardiac perforation, tamponade or pericardial effusion (47 patients). There were 360 deaths during the follow-up and 11 were described as procedure or device related. Four studies presented the strategy of using a combined approach of atrioventricular node ablation (AVNA) and LP implantation. CONCLUSIONS: Leadless pacemakers seem to have a relatively low complication rate. These devices may be a good option in patients with an indication for single-chamber pacing, in patients with conditions precluding conventional transvenous pacemaker implantations. Studies directly comparing LP and transvenous pacemakers and data on longer follow-up periods are needed.

Safety, efficacy, and reproducibility of cavotricuspid isthmus ablation guided by the ablation index: acute results of the FLAI study.

AIMS: Ablation index (AI) is a marker of lesion quality during catheter ablation that incorporates contact force, time, and power in a weighted formula. This index was originally developed for pulmonary vein isolation as well as other left atrial procedures. The aim of our study is to evaluate the feasibility and efficacy of the AI for the ablation of the cavotricuspid isthmus (CTI) in patients presenting with typical atrial flutter (AFL). METHODS AND RESULTS: This prospective multicentre non-randomized study enrolled 412 consecutive patients with typical AFL undergoing AI-guided cavotricuspid isthmus ablation. The procedure was performed targeting an AI of 500 and an inter-lesion distance measurement of ≤6 mm. The primary endpoints were CTI 'first-pass' block and persistent block after a 20-min waiting time. Secondary endpoints included procedural and radiofrequency duration and fluoroscopic time. A total of 412 consecutive patients were enrolled in 31 centres (mean age 64.9 ± 9.8; 72.1% males and 27.7% with structural heart disease). The CTI bidirectional 'first-pass' block was reached in 355 patients (88.3%), whereas CTI block at the end of the waiting time was achieved in 405 patients (98.3%). Mean procedural, radiofrequency, and fluoroscopic time were 56.5 ± 28.1, 7.8 ± 4.8, and 1.9 ± 4.8 min, respectively. There were no major procedural complications. There was no significant inter-operator variability in the ability to achieve any of the primary endpoints. CONCLUSION: AI-guided ablation with an inter-lesion distance ≤6 mm represents an effective, safe, and highly reproducible strategy to achieve bidirectional block in the treatment of typical AFL.

Left ventricular pacing with a temporary pacemaker: Case report.

We report a case of temporary pacemaker lead malposition in the left ventricle crossing the interventricular septum (IVS). The majority of described cases occur due to a patent foramen ovale and are frequently incidental findings. A course across the IVS is rarely found and this complication with temporary leads is not even reported in the literature. This very rare location entails a risk of dangerous complications associated with left-to-right flow after lead removal. Echocardiography was an essential tool to diagnose the lead's course inside the heart and enabled secure removal of the lead with cardiac surgery backup.

Lead Extraction of Cardiac Rhythm Devices: A Report of a Single-Center Experience.

INTRODUCTION AND OBJECTIVES: The rate of implanted cardiac electronic devices is increasing as is the need to manage long-term complications. Lead removal is becoming an effective approach to treat such complications. We present our experience in lead removal using different approaches, analyzing the predictors of the use of mechanical extractors/surgical removal. METHODS: Retrospective analysis of lead extractions in a series of 76 consecutive patients (mean age 70.4 ± 13.8 years, 73.7% men) between January 2009 and November 2015. RESULTS: One hundred thirty-five leads from permanent pacemakers (single chamber 19.7%; dual-chamber 61.8%), implantable cardioverter defibrillators (5.3%), and cardiac resynchronization devices (CRT-P 2.6%; CRT-D 7.9%) were removed, 72.5 ± 73.2 months after implantation. A total of 45.9% were ventricular leads, 40.0% atrial leads, 8.9% defibrillator leads, and 5.2% leads in the coronary sinus; 64.4% had passive fixation. The most common indications for removal were pocket infection (77.8%), infective endocarditis (9.6%), and lead dislodgement (3.7%). A total of 76.3% of the leads were explanted, 20.0% were extracted, and 3.7% were surgically removed. Extraction of the entire lead was achieved in 96.3% of the procedures. After logistic regression (age adjusted), time since implantation was the sole predictor of the need of mechanical extractors/surgical removal. All patients were discharged without major complications. There were no deaths at 30 days. CONCLUSION: Our experience in lead removal was effective and safe. Performing these procedures by experienced electrophysiologists with an adequate cardiothoracic surgery team on standby to cope with any complications is required. Referral of high-risk patients to a high-volume center is recommended to optimize clinical success and minimize procedural complications.

Late atypical atrial flutter after ablation of atrial fibrillation. / Flutter auricular atípico tardio após ablação de fibrilhação auricular.

Cardiac surgery for structural heart disease (often involving the left atrium) and radiofrequency catheter ablation of atrial fibrillation have led to an increased incidence of regular atrial tachycardias, often presenting as atypical flutters. This type of flutter is particularly common after pulmonary vein isolation, especially after extensive atrial ablation including linear lesions and/or defragmentation. The authors describe the case of a 51-year-old man, with no relevant medical history, referred for a cardiology consultation in 2009 for paroxysmal atrial fibrillation. After failure of antiarrhythmic therapy, he underwent catheter ablation, with criteria of acute success. Three years later he again suffered palpitations and atypical atrial flutter was documented. The electrophysiology study confirmed the diagnosis of atypical left flutter and reappearance of electrical activity in the right inferior pulmonary vein. This vein was again ablated successfully and there has been no arrhythmia recurrence to date. In an era of frequent catheter ablation it is essential to understand the mechanism of this arrhythmia and to recognize such atypical flutters.

Transcatheter aortic valve implantation and requirements of pacing over time.

BACKGROUND: A permanent pacemaker (PPM) implantation is common after transcatheter aortic valve implantation (TAVI). We sought to evaluate requirements of pacing and incidence of pacemaker dependency during the first year after TAVI. METHODS: From August 2007 until May 2011, 65 patients underwent TAVI with self-expandable prosthesis. Five patients paced at baseline and two procedure-related deaths were excluded. Evaluation of ventricular pacing percentage (VP%) and look for spontaneous rhythm were performed at 3, 6, and 12 months. RESULTS: PPM implantation was required in 19/58 patients (33%). Mean VP% decreased between assessments (59% at 3 months, 48% at 6 months, 50% at 12 months), but overall VP% at 1 year was high (57% ± 43%) and most patients were paced ≥10% of time. A favorable annulus-to-aorta angle was associated with lower pacing requirements (60% of patients paced ≤10% of time vs 10% of patients paced >10% of time presented an angle ≤30°, P = 0.039). Pacemaker dependency was established in 27% of patients and could be predicted by the presence of porcelain aorta (odds ratio = 30, confidence interval 95% 1-638, P = 0.029). New postprocedural left bundle branch block (LBBB) had a negative impact on 1-year survival (58% vs 82% in non-LBBB group, P = 0.111). PPM implantation had no impact on 1-year survival. CONCLUSIONS: One third of patients required PPM after TAVI and full recovery of advanced conduction abnormalities seems unlikely. Unfavorable aortic root orientation may hinder the deployment of the valve and contribute to the continued impairment of the conduction system. Porcelain aorta was a strong predictor of pacemaker dependency.

Importance of accessory pathway location in the efficacy and safety of radiofrequency ablation.

INTRODUCTION: Atrioventricular accessory pathways can be asymptomatic, or can cause reentrant tachycardia and, rarely, sudden cardiac death. In general, radiofrequency ablation is the curative treatment of choice. The aim of this study was to determine the importance of accessory pathway location in the efficacy and safety of radiofrequency ablation. METHODS: We performed a cross-sectional study based on the clinical and electrophysiological data of 858 consecutive patients undergoing accessory pathway radiofrequency ablation in our hospital between November 1997 and December 2008. RESULTS: Median age was 37.2 +/- 19.8 years (56.0% males); most patients were symptomatic (94.2%) and without structural heart disease (95.1%). The prevalence of concealed pathways was 28.0%. Slightly over half of the patients were on antiarrhythmic therapy. The anatomical distribution of the accessory pathways was as follows: left ventricular free wall (LVFW) (53.8%), posteroseptal (25.6%), right ventricular free wall (7.7%), anteroseptal (4.3%), midseptal (3.5%) and multiple (5.0%). The acute success rate was highest in LVFW accessory pathways (97.0%) and lowest in multiple accessory pathways (88.4%). Significant complications occurred in 0.5% of cases, midseptal and anteroseptal accessory pathways being most affected (3.3% and 2.7%, respectively). At one-year follow-up there were no deaths, and 4.4% of patients had recurrence of accessory pathway conduction, with no significant differences between anatomical locations. CONCLUSIONS: The anatomical position of the accessory pathway affects the efficacy and safety of radiofrequency ablation.

Incidence and predictors of permanent pacemaker requirement after transcatheter aortic valve implantation with a self-expanding bioprosthesis.

BACKGROUND: Previous reports have suggested the occurrence of cardiac conduction disorders and permanent pacemaker (PPM) requirement after transcatheter aortic valve implantation (TAVI). Based on a single-center experience, we aim to assess the incidence of postprocedural conduction disorders, need for PPM, and its determinants after TAVI with a self-expanding bioprosthesis. METHODS: From August 2007 to October 2009, 32 consecutive patients underwent TAVI with the Medtronic CoreValve (MCV) System (Medtronic Inc., Minneapolis, MN, USA). Three patients paced at baseline and two cases of procedure-related mortality were excluded. We analyzed the 12-lead electrocardiogram at baseline, immediately after procedure and at discharge. Requirements for PPM were documented and potential clinical, electrophysiological, echocardiographic, and procedural predictors of PPM requirement were studied. RESULTS: After TAVI, eight patients (29.6%) required PPM implantation due to high-grade atrioventricular (AV) block. The prevalence of left bundle branch block increased from 13.8% to 57.7% directly after implantation (P = 0.001). Need for PPM was correlated to the depth of prosthesis implantation (r = 0.590; P = 0.001). At a cutoff point of 10.1 mm, the likelihood of pacemaker could be predicted with 87.5% sensitivity and 74% specificity and a receiver operator characteristic curve area of 0.86 ± 0.07 (P = 0.003). Of the seven patients with preexisting right bundle branch block (RBBB), four (57.1%) required PPM implantation after TAVI. CONCLUSIONS: High-grade AV block requiring PPM implantation is a common complication following TAVI and could be predicted by a deeper implantation of the prosthesis. Patients with preexisting RBBB also seem to be at risk for the development of high-grade AV block and subsequent pacemaker implantation.