Clinical impact of right ventricular pacing burden in patients with post-transcatheter aortic valve replacement permanent pacemaker implantation.

AIMS: Patients who undergo permanent pacemaker (PPM) implantation after transcatheter aortic valve replacement (TAVR) have a worse outcome. The aim of this study was to identify risk factors of worse outcomes in patients with post-TAVR PPM implantation. METHODS AND RESULTS: This is a single-centre, retrospective study of consecutive patients who underwent post-TAVR PPM implantation from 11 March 2011 to 9 November 2019. Clinical outcomes were evaluated by landmark analysis with cut-off at 1 year after the PPM implantation. Of the 1389 patients underwent TAVR during the study duration and a total of 110 patients were included in the final analysis. Right ventricular pacing burden (RVPB) ≥ 30% at 1 year was associated with a higher likelihood of heart failure (HF) readmission [adjusted hazard ratio (aHR): 6.333; 95% confidence interval [CI]: 1.417-28.311; P = 0.016] and composite endpoint of overall death and/or HF (aHR: 2.453; 95% CI: 1.040-5.786; P = 0.040). The RVPB ≥30% at 1 year was associated with higher atrial fibrillation burden (24.1 ± 40.6% vs. 1.2 ± 5.3%; P = 0.013) and a decrease in left ventricular ejection fraction (-5.0 ± 9.8% vs. + 1.1 ± 7.9%; P = 0.005). The predicting factors of the RVPB ≥30% at 1 year were the presence of RVPB ≥40% at 1 month and the valve implantation depth measured from non-coronary cusp ≥4.0 mm (aHR: 57.808; 95% CI: 12.489-267.584; P < 0.001 and aHR: 6.817; 95% CI: 1.829-25.402; P = 0.004). CONCLUSIONS: The RVPB ≥30% at 1 year was associated with worse outcomes. Clinical benefit of minimal RV pacing algorithms and biventricular pacing needs to be investigated.

Risk stratification of new persistent left bundle branch block after transcatheter aortic valve implantation

ABSTRACT Previous studies reported that new-onset persistent left bundle branch block (NOP-LBBB) was related to worse outcomes after transcatheter aortic valve implantation (TAVI). However, these results can be confounded by the presence of permanent pacemaker (PPM) implantation before and after TAVI. Long-term outcomes and the risk stratification of NOP-LBBB not having PPM implantation before and after TAVI have not been fully investigated. This is an international, multicenter, retrospective study of patients who underwent TAVI from July 31, 2007, to May 8, 2020. A total of 2,240 patients were included, and 17.5% of patients developed NOP-LBBB. NOP-LBBB was associated with cardiac mortality (adjusted hazard ratio [aHR] 1.419, 95% confidence interval [CI] 1.014 to 1.985, p = 0.041) and the composite outcomes of cardiac mortality and/or heart failure readmission (aHR 1.313, 95% CI 1.027 to 1.678, p = 0.030). Patients who developed NOP-LBBB with pre-TAVI left ventricular ejection fraction (LVEF) <40% were significantly associated with cardiac mortality (aHR 2.049, 95% CI 1.039 to 4.041, p = 0.038), heart failure (aHR 3.990, 95% CI 2.362 to 6.741, p <0.001), and the composite outcome (aHR 2.729, 95% CI 1.703 to 4.374, p <0.001). Although NOP-LBBB with pre-TAVI LVEF >40% had a significant decrease in LVEF 6 to 12 months after TAVI (-1.8 ± 9.7% vs +0.6 ± 8.1%, p = 0.003), NOP-LBBB with pre-TAVI LVEF <40% had a significant increase in LVEF 6 to 12 months after TAVI (+9.7 ± 13.6% vs +13.0 ± 11.7%, p = 0.157). In conclusion, patients with NOP-LBBB without pre-TAVI and post-TAVI PPM developed significantly worse long-term outcomes, especially in patients with pre-TAVI LVEF <40%. Further prospective investigation should be undertaken.

Risk Stratification of New Persistent Left Bundle Branch Block After Transcatheter Aortic Valve Implantation.

Previous studies reported that new-onset persistent left bundle branch block (NOP-LBBB) was related to worse outcomes after transcatheter aortic valve implantation (TAVI). However, these results can be confounded by the presence of permanent pacemaker (PPM) implantation before and after TAVI. Long-term outcomes and the risk stratification of NOP-LBBB not having PPM implantation before and after TAVI have not been fully investigated. This is an international, multicenter, retrospective study of patients who underwent TAVI from July 31, 2007, to May 8, 2020. A total of 2,240 patients were included, and 17.5% of patients developed NOP-LBBB. NOP-LBBB was associated with cardiac mortality (adjusted hazard ratio [aHR] 1.419, 95% confidence interval [CI] 1.014 to 1.985, p = 0.041) and the composite outcomes of cardiac mortality and/or heart failure readmission (aHR 1.313, 95% CI 1.027 to 1.678, p = 0.030). Patients who developed NOP-LBBB with pre-TAVI left ventricular ejection fraction (LVEF) <40% were significantly associated with cardiac mortality (aHR 2.049, 95% CI 1.039 to 4.041, p = 0.038), heart failure (aHR 3.990, 95% CI 2.362 to 6.741, p <0.001), and the composite outcome (aHR 2.729, 95% CI 1.703 to 4.374, p <0.001). Although NOP-LBBB with pre-TAVI LVEF >40% had a significant decrease in LVEF 6 to 12 months after TAVI (-1.8 ± 9.7% vs +0.6 ± 8.1%, p = 0.003), NOP-LBBB with pre-TAVI LVEF <40% had a significant increase in LVEF 6 to 12 months after TAVI (+9.7 ± 13.6% vs +13.0 ± 11.7%, p = 0.157). In conclusion, patients with NOP-LBBB without pre-TAVI and post-TAVI PPM developed significantly worse long-term outcomes, especially in patients with pre-TAVI LVEF <40%. Further prospective investigation should be undertaken.

First case report: Late-onset coronary artery spasm after radiofrequency catheter ablation for atrial fibrillation in a Caucasian patient.

Most of the coronary vasospasms were found intraprocedurally, and it is very rare to see late-onset vasospasms that happened a few hours after uncomplicated ablations. The recognition of this rare but potentially life-threatening complication is important to improve the conventional practice of catheter ablation for patients with drug-refractory atrial fibrillation.

Risk Prediction Model for Cardiac Implantable Electronic Device Implantation After Transcatheter Aortic Valve Replacement.

OBJECTIVES: The aim of this study was to develop and validate a risk prediction model for high-grade atrioventricular block requiring cardiac implantable electronic device (CIED) implantation after transcatheter aortic valve replacement (TAVR). BACKGROUND: High-grade atrioventricular block requiring CIED remains a significant sequelae following TAVR. Although several pre-operative characteristics have been associated with the risk of post-operative CIED implantation, an accurate and validated risk prediction model is not established yet. METHODS: This was a single center, retrospective study of consecutive patients who underwent TAVR from March 10, 2011, to October 8, 2018. This cohort sample was randomly divided into a derivation cohort (group A) and a validation cohort (group B). A scoring system for risk prediction of post-TAVR CIED implantation was devised using logistic regression estimates in group A and the calibration and validation were done in group B. RESULTS: A total of 1,071 patients underwent TAVR during the study period. After excluding pre-existing CIED, a total of 888 cases were analyzed (group A: 507 and group B: 381). Independent predictive variables were as follows: self-expanding valve (1 point), hypertension (1 point), pre-existing first-degree atrioventricular block (1 point), and right bundle branch block (2 points). The resulting score was calculated from the total points. The internal validation in group B showed an ideal linear relationship in calibration plot (R2 = 0.933) and a good predictive accuracy (area under the curve: 0.693; 95% confidence interval: 0.627 to 0.759). CONCLUSIONS: This prediction model accurately predicts post-operative risk of CIED implantation with simple pre-operative parameters.

Incidence of Early Atrial Fibrillation After Transcatheter versus Surgical Aortic Valve Replacement: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Post-operative atrial fibrillation (POAF) is common after aortic valve replacement (AVR) and is associated with worse outcomes. We performed a meta-analysis of randomized controlled trials comparing Surgical Aortic Valve Replacement (SAVR) and Transcatheter Aortic Valve Replacement (TAVR) for incidence of POAF at 30 days. METHODS: We searched databases from 1/1/1990 to 1/1/2020 for randomized studies comparing TAVR and SAVR. POAF was defined as either worsening or new-onset atrial fibrillation. Random effects model was used to estimate the risk of POAF with TAVR vs SAVR in all trials, and in subgroups (low, intermediate, high risk, and in self-expandable vs balloon expandable valves). Sensitivity analysis was performed including only studies reporting new-onset atrial fibrillation. RESULTS: Seven RCTs were identified that enrolled 7,934 patients (3,999 to TAVR and 3,935 to SAVR). The overall incidence of POAF was 9.7% after TAVR and 33.3% after SAVR. TAVR was associated with a lower risk of POAF compared with SAVR (OR 0.21 [0.18-0.24]; P < 0.0001). Compared with SAVR, TAVR was associated with a significantly lower risk of POAF in the high-risk cohort (OR 0.37 [0.27-0.49]; P < 0.0001), in the intermediate-risk cohort (OR 0.23 [0.19-0.28]; P < 0.0001), low-risk cohort (OR 0.13 [0.10-0.16]; P < 0.0001). Sensitivity analysis of 4 trials including only new-onset POAF showed similar summary estimates (OR 0.21, 95% CI [0.18-0.25]; P< 0.0001). CONCLUSIONS: TAVR is associated with a significantly lower risk of post-operative atrial fibrillation compared with SAVR in all strata. Further studies are needed to identify the contribution of post-operative atrial fibrillation to the differences in clinical outcomes after TAVR and SAVR.

Sequential Use of Aminophylline and Theophylline for Temporizing Neck Cancer-Induced Carotid Sinus Syncope.

Carotid sinus syncope due to head and neck cancer is uncommon and the management is challenging. Permanent pacemaker implantation is generally considered but malnutrition with subsequent chemo-radiation increases the risk of device infection. This is a first case report of the sequential use of aminophylline and theophylline for pharmacological temporization. (Level of Difficulty: Advanced.).

Impact of Right Ventricular Pacing in Patients Who Underwent Implantation of Permanent Pacemaker After Transcatheter Aortic Valve Implantation.

Atrioventricular conduction disturbances requiring implantation of permanent pacemaker (PPM) are a common complication following transcatheter aortic valve implantation (TAVI). Previous registry data are conflicting but suggestive of an increased risk in heart failure admissions in the post-TAVI PPM cohort. Given the expanding use of TAVI, the present study evaluates the effects of chronic right ventricular pacing (RV pacing) in post-TAVI patients. This is a single-center study of 672 patients who underwent TAVI from 2011 to 2017 of which 146 underwent PPM. Follow-up 1-year post-TAVI outcome data were available for 55 patients and were analyzed retrospectively. Patients who underwent PPM were more likely to have heart failure admissions (17.1% vs 10.1%; hazard ratio [HR] 1.70; 95% confidence interval [CI] 1.10 to 2.64; p 0.019) and a trend toward increased mortality (21.9% vs 15.4%; HR 1.42; 95% CI 0.99 to 2.05; p 0.062). At 1-year follow-up, 30 of 55 (54.5%) patients demonstrated >40% RV pacing. Compared with patients who had <40% RV pacing, those with >40% RV pacing were more likely to have heart failure admissions (8% vs 40%; HR 5.0; 95% CI 1.23 to 20.27; p 0.007) and demonstrated a trend toward increased mortality (12% vs 33.3%; HR 2.78; 95% CI 0.86 to 9.00; p 0.064). This is suggestive that the post-TAVI PPM cohort is particularly sensitive to chronic RV pacing.

Adenosine testing in atrial flutter ablation: unmasking of dormant conduction across the cavotricuspid isthmus and risk of recurrence.

BACKGROUND: Adenosine-induced hyperpolarization may identify pulmonary veins at risk of reconnection following electrical isolation for atrial fibrillation. The potential role of adenosine testing in other arrhythmic substrates, such as cavotricuspid isthmus (CTI)-dependent atrial flutter, remains unclear. We assessed whether dormant conduction across the CTI may be revealed by adenosine after ablation-induced bidirectional block, and its association with recurrent flutter. METHODS AND RESULTS: Patients undergoing catheter ablation for CTI-dependent flutter were prospectively studied. After confirming bidirectional block across the CTI by standard pacing maneuvers, adenosine (≥ 12 mg IV) was administered to assess resumption of conduction, followed by isoproterenol (ISP) bolus. Further CTI ablation was performed for persistent (but not transient) resumption of conduction. Bidirectional block across the CTI was achieved in all 81 patients (63 males), age 61.2 ± 11.0 years. The trans-CTI time increased from 71.9 ± 18.1 milliseconds preablation to 166.2 ± 26.4 milliseconds postablation. Adenosine elicited resumption of conduction across the CTI in 7 patients (8.6%), 2 of whom had transient recovery. No additional patient with dormant conduction was identified by ISP. Over a follow-up of 11.8 ± 8.0 months, atrial flutter recurred in 4 (4.9%) patients, 3/7(42.9%) with a positive adenosine challenge versus 1/74 (1.3%) with a negative response, P = 0.0016 (relative risk 31.7). CONCLUSION: Adenosine challenge following atrial flutter ablation provoked transient or persistent resumption of conduction across the CTI in almost 9% of patients and identified a subgroup at higher risk of flutter recurrence. It remains to be determined whether additional ablation guided by adenosine testing during the index procedure may further improve procedural outcomes.

Unusual combination of holt-oram syndrome and persistent left superior vena cava.

UNLABELLED: Holt-Oram (HO) is a syndrome characterized by congenital cardiovascular malformations, specifically atrial and ventricular septal defects, and skeletal abnormalities of the upper limbs bones. Associations of HO cardiac disorders with other congenital cardiac malformations, specifically persistent left superior vena cava (PLSVC) are rarely reported and its real incidence is unknown. We present a case of this unusual combination in a patient undergoing cardiac resynchronization therapy (CRT) device implant. METHODS AND RESULTS: A 63-year-old male with HO and a history of repaired atrial septal defect was presented for implantable cardioverter defibrillator (ICD) upgrade to CRT. The old implant was located in the right prepectoral area. The old device pocket in the right was accessed and a venous access to the right subclavian vein was obtained. The coronary sinus (CS) was easily cannulated and a long sheath advanced into the CS. A contrast injection revealed an unusually big-sized CS, with a diameter 2.5 times the fully deployed balloon. A 0.035 wire was advanced retrograde reaching the confluence of the innominate and left subclavian veins. The outer sheath was advanced to this location and contrast venography through the sheath allowed visualization of the left jugular and subclavian veins and visualization of the PLSVC draining into the CS. No target veins for lead implant were identified. The patient was referred for surgical implant of an epicardial lead. Transesophageal echocardiogram showed a CS identified as an unusually big vascular structure located between the left atrium and the left atrial appendage. CONCLUSION: We report an uncommon association of HO and PLSVC. This association was only reported twice in the past and this is the first one that constitutes a casual finding during the attempt of CRT device implant. This is a combination that may complicate a device implant and recognition of it in advance may avoid performing potentially unsuccessful procedures.

Subclavian balloon venoplasty to facilitate lead implant in patient with subclavian venous obstruction.

Implanting new leads for defibrillation or pacing leads could be problematic as a result of venous obstruction. Up to 50% of patients with pacemaker/implantable cardioverter defibrillator leads have an asymptomatic subclavian vein obstruction. Overcoming this obstruction could be very challenging. The current approaches of contralateral access, extraction and surgical intervention have significant drawbacks. This report presents an alternative approach that uses percutaneous subclavian balloon venoplasty successfully to regain venous access. We believe that this technique is safe and effective.

Is there an association between external cardioversions and long-term mortality and morbidity? Insights from the Atrial Fibrillation Follow-up Investigation of Rhythm Management study.

BACKGROUND: Cardiac electric therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardioverter-defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regard to cardiovascular mortality and morbidity. METHODS AND RESULTS: We analyzed the data of the 4060 patients from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality, and hospitalizations after ECVe were studied. Over an average follow-up of 3.5 years, 660 (16.3%) patients died, 331 (8.2%) from cardiovascular causes. A total of 207 (5.1%) and 1697 (41.8%) patients had low ejection fraction and nonparoxysmal atrial fibrillation, respectively; 2460 patients received no ECVe, whereas 1600 experienced ≥ 1 ECVe. Death occurred in 412 (16.7%), 196 (16.5%), 39 (13.5%), and 13 (10.4%) of patients with 0, 1, 2, and ≥ 3 ECVe, respectively. There was no significant association between ECVe and mortality within any of the 4 subgroups defined by ejection fraction and atrial fibrillation type, although myocardial infarction, coronary artery bypass graft, and digoxin were significantly associated with death (estimated hazard ratios, 1.65, 1.59, and 1.62, respectively; P < 0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% versus 5.8%; estimated odds ratio, 1.39; P < 0.0001). CONCLUSIONS: In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, myocardial infarction, and coronary artery bypass graft were significantly associated with mortality.

Umbral de desfibrilación elevado: ¿los vectores de desfibrilación son importantes?: Are Defibrillation Vectors Important? / Elevated Defibrillation Threshold / Elevated Defibrillation Threshold: Are Defibrillation Vectors Important?

La evaluación del umbral de desfibrilación (UDF) es una práctica habitual en la mayoría de los implantes de cardiodesfibriladores implantables (CDI). La práctica estándar busca obtener una desfibrilación exitosa de la fibrilación ventricular. En pacientes con umbrales de desfibrilación elevados en los cuales esto no resulta posible se da inicio a una serie de maniobras tendientes a corregir la situación. En esta presentación se describe un caso en el que se recurrió a una estrategia de uso poco frecuente para mejorar resultados durante la falla del UDF. Se trata de un paciente de 78 años, de sexo masculino, con antecedentes de miocardiopatía dilatada, que fue derivado al laboratorio de electrofisiología para el implante de un CDI para prevención primaria. Durante el procedimiento, el CDI falló en desfibrilar al paciente aun luego de haber posicionado el cable en diferentes áreas del ventrículo derecho y de haber optimizado la onda de choque. El paciente finalmente recibió el implante de un electrodo de desfibrilador en la vena ácigos, lo que permitió la reorientación del vector de desfibrilación hacia el eje posterior, con el resultado de una desfibrilación exitosa de la fibrilación ventricular por el CDI.

The evaluation of the defibrillation threshold (DFT) is common after the implantation of implantable cardioverter defibrillator (ICD) devices. The goal of this standard of care is to achieve successful defibrillation of ventricular fibrillation. In patients with elevated defibrillation thresholds, alternative techniques are required to correct the situation. We describe a case in which an uncommon strategy was used to improve DFT after failed defibrillation. A 78-year old man with a history of dilated cardiomyopathy was referred to the electrophysiology laboratory to have an ICD implanted as primary prevention strategy. During the procedure, the ICD failed to defibrillate the patient even after the lead was placed in different areas of the right ventricle and after optimizing the shock wave. A defibrillation lead was implanted in the azygos vein, and the shock vector was directed towards the posterior axis; a successful defibrillation was thus achieved.

The relationship between warfarin, aspirin, and clopidogrel continuation in the peri-procedural period and the incidence of hematoma formation after device implantation.

BACKGROUND: Many patients requiring permanent pacemaker (PPM) or implantable cardiac defibrillator (ICD) placement are anticoagulated with warfarin, aspirin (ASA), and clopidogrel for a number of thromboembolic risk indications. The present review sought to evaluate the relationship between continuation of these medications in the peri-procedural period and the incidence of hematoma formation after implantation. METHODS: We retrospectively reviewed consecutive patients undergoing PPM and ICD implantation at our hospital from January 2007-2009. All patients on warfarin, aspirin, and clopidogrel were maintained on these medications peri-operatively. We collected data on the use of warfarin at implantation, INR prior to device implantation, use of dual-antiplatelet therapy (DAPT), such as concomitant aspirin and clopidogrel and subsequent formation of hematoma in the peri-procedure period. RESULTS: PPM and ICD implantations were performed in 194 men and six women. The mean age was 73 years old. Fifty eight patients were taking warfarin with an average international normalized ratio of 1.9 +/- 0.6; 112 were on ASA, 23 on clopidogrel, and 20 of them on DAPT. Only five patients were on DAPT and warfarin combined at the time of device implantation. Hematomas formed in a total of seven patients (3.5%), five of whom were on DAPT consisting of ASA and clopidogrel (P < 0.0001) while only two of them were on warfarin (P = 0.67). Pocket revision for hematoma evacuation was needed in four patients (2%), three of whom were on DAPT and only one on warfarin. CONCLUSION: This study suggests that hematoma formation after PPM or ICD implantation is rare, even among those who are anticoagulated. There were more patients with hematoma on DAPT than warfarin therapy and half of these patients with this complication needed pocket revision for evacuation. (PACE 2010; 385-388).

Coronary sinus diverticulum complicating CRT device implantation.

Coronary sinus diverticula are rare findings usually associated with the presence of accessory pathways. We report the case of a 74-year-old man, who underwent cardiac resynchronization therapy (CRT) device implant. Coronary sinus diverticulum was an incidental finding while attempting to subselectively cannulate the coronary sinus for left ventricle lead implant. The case was able to be completed without complications.

Prognostic value of electrocardiographic measurements before and after cardiac resynchronization device implantation in patients with heart failure due to ischemic or nonischemic cardiomyopathy.

Postimplant QRS narrowing may predict clinical response after cardiac resynchronization therapy (CRT), but identification of nonresponders remains difficult. We studied the predictive value of electrocardiographic characteristics for mortality or cardiac transplantation in patients after CRT. Patients who had electrocardiograms available for review from before and after CRT device implantation were identified from a clinical database. Bivariate and multivariate Cox regression analyses were performed for the end point of death or transplantation. Of 337 patients (age 65+/-12 years, 76% men, left ventricular ejection fraction 22+/-12%, pre-QRS 175+/-30 ms), 84 died and 7 underwent transplantation during a follow-up of 27+/-15 months. Variables predictive of death or transplantation included QRS increase after CRT (45% vs 32%, p=0.03), older age, higher New York Heart Association class, lower left ventricular ejection fraction, and higher tertile of postimplant QRS (p=0.04), but not preimplant rhythm, QRS duration, or QRS morphology. After adjusting for confounding variables, independent predictors of mortality were older age (hazard ratio [HR] 1.03, 95% confidence interval [CI] 1.00 to 1.05, p=0.04), lack of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker (HR 2.17, 95% CI 1.16 to 4.08, p<0.02), and longer postimplant QRS by tertile (HR 1.50, 95% CI 1.09 to 2.05, p=0.01). In conclusion, wider QRS after CRT device implantation is an independent predictor of mortality or transplantation. In patients with increased QRS durations despite CRT, closer follow-up or reassessment for alternative management strategies may be warranted.

Vagal responses induced by endocardial left atrial autonomic ganglion stimulation before and after pulmonary vein antrum isolation for atrial fibrillation.

BACKGROUND: Elimination of vagal inputs into the left atrium (LA) may be necessary for successful catheter ablation of atrial fibrillation (AF). These vagal inputs are clustered in autonomic ganglia (AG) that are close to the pulmonary vein antrum (PVA) borders, but whether standard intracardiac echocardiography (ICE)-guided PVA isolation (PVAI) affects these inputs is unknown. OBJECTIVE: The purpose of this study was to assess whether standard ICE-guided PVAI affects vagal responses induced by endocardial AG stimulation in the LA. METHODS: Twenty consecutive patients undergoing first-time PVAI (group 1) and 20 consecutive patients undergoing repeat PVAI for AF recurrence (group 2) were enrolled in the study. Before ablation, electrical stimulation (20 Hz, pulse duration 10 ms, voltage range 12-20 V) was performed through an 8-mm-tip ablation catheter. Based on prior data, regions around all four PVA borders were carefully mapped and stimulated to localize AG inputs. A positive stimulated vagal response was defined as atrioventricular (AV) block, asystole, or increase in mean RR interval by >50%. Locations of positive vagal responses were recorded wth biplane fluoroscopy and CARTO. All patients then underwent standard ICE-guided PVAI by an operator blinded to the locations of vagal responses. Stimulation of the AG locations was then repeated postablation. RESULTS: Patients (age 54 +/- 11 years, 30% female, ejection fraction 54% +/- 7%) had a history of paroxysmal (75%) and persistent (25%) AF. In group 1, vagal responses were induced in all 20 patients around a mean of 3.8 +/- 0.4 PVAs per patient. The most common response was asystole (53%), mean RR slowing >50% (28%), and AV block (20%). Postablation, vagal responses could no longer be induced in all 20 patients. A diminished response was induced (RR slowing <50%) in 2/20 patients around one PVA each. In group 2, vagal responses were not induced in any of the 20 repeat patients. Stimulation capture postablation was confirmed because transient, nonsustained (<30 seconds) AF or atrial flutter was induced in all 40 patients with stimulation, whether vagal responses were induced or not. CONCLUSIONS: Standard ICE-guided PVAI eliminates vagal responses induced by AG stimulation. Responses are not seen in patients presenting for repeat PVAI, despite clinical recurrence of AF.

Pulmonary vein antral isolation using an open irrigation ablation catheter for the treatment of atrial fibrillation: a randomized pilot study.

OBJECTIVES: We sought to test how catheter ablation using an open irrigation catheter (OIC) compares with standard catheters for pulmonary vein antrum isolation. BACKGROUND: Open irrigation catheters have the advantage of delivering greater power without increasing the temperature of the catheter tip, which enables deeper and wider lesions without the formation of coagulum on catheters. METHODS: Catheter ablation was performed using an 8-mm catheter (8MC) or an OIC. Patients were randomized to 3 groups: 8MC; OIC-1, OIC with a higher peak power (50 W); and OIC-2, OIC with lower peak power (35 W). RESULTS: A total of 180 patients were randomized to the 3 treatment strategies. Isolation of pulmonary vein antra was achieved in all patients. The freedom from atrial fibrillation was significantly greater in the 8MC and OIC-1 groups compared with the OIC-2 group (78%, 82%, and 68%, respectively, p = 0.043). Fluoroscopy time was lower in OIC-1 compared with OIC-2 and 8MC (28 +/- 1 min, 53 +/- 2 min, and 46 +/- 2 min, respectively, p = 0.001). The mean left atrium instrumentation time was lower in the OIC-1 compared with the OIC-2 and 8MC groups (59 +/- 3 min, 90 +/- 5 min, and 88 +/- 4 min, respectively, p = 0.001). However, there was a greater incidence of "pops" in the OIC-1 (100%, 0%, 0%, p < 0.001) along with higher incidences of pericardial effusion (20%, 0%, 0%, p < 0.001) and gastrointestinal complaints (17% in OIC-1, 3% in 8MC, and 5% in OIC-2, p = 0.031). CONCLUSIONS: Although there was a decrease in fluoroscopy and left atrium instrumentation time with the use of OIC at higher power, this setting was associated with increased cardiovascular and gastrointestinal complications.

Atrial arrhythmias after surgical maze: findings during catheter ablation.

OBJECTIVES: We describe the clinical and electrophysiologic characteristics and management of post "cut and sew" Maze arrhythmias in symptomatic patients. BACKGROUND: The Cox Maze procedure was developed as a surgical treatment of atrial fibrillation. Until recently, invasive electrophysiologic studies in patients with symptomatic post-operative arrhythmias in this patient population have not been described. METHODS: The management and clinical course of consecutive patients with post-Maze arrhythmias refractory to antiarrhythmic drugs (AADs) between January 2000 and December 2003 are presented. RESULTS: Twenty-three patients (15 men) presented 14 +/- 14 months after Maze surgery for treatment of atrial fibrillation (AF). Eight patients underwent "cut and sew" Maze for lone AF with no other surgical indication. Fifteen patients underwent the "cut and sew" Maze procedure in addition to another surgical procedure: mitral valve surgery (11 patients) and coronary artery bypass graft surgery (4 patients). Eight patients (35%) had recurrent AF secondary to recovered conduction around the lines encircling the pulmonary veins. Five patients were documented to have focal atrial tachycardia, which was mapped to the coronary sinus in 3 patients, to the posterolateral right atrium in 1 patient, and to the left atrial (LA) septum in 1 patient. Four patients had right atrium incisional atrial flutter (AFL), and 6 had LA incisional AFL, which was mapped around the mitral valve annulus in 4 patients and around the right pulmonary veins in 2 patients. Twenty-two of the 23 patients were treated successfully with radiofrequency ablation. At 1-year follow-up, 19 patients were arrhythmia-free and taking no AADs. CONCLUSIONS: After surgical "cut and sew" Maze, approximately one-third of patients experiencing atrial arrhythmias have AF secondary to pulmonary vein-left atrium conduction recovery. Moreover, incisional AFL seems to be a common finding in this group of patients. Catheter-based mapping and ablation of these arrhythmias seems to be feasible and effective.