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BACKGROUND: The extravascular implantable cardioverter-defibrillator (ICD) has a single lead implanted substernally to enable pause-prevention pacing, antitachycardia pacing, and defibrillation energy similar to that of transvenous ICDs. The safety and efficacy of extravascular ICDs are not yet known. METHODS: We conducted a prospective, single-group, nonrandomized, premarket global clinical study involving patients with a class I or IIa indication for an ICD, all of whom received an extravascular ICD system. The primary efficacy end point was successful defibrillation at implantation. The efficacy objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients with successful defibrillation was greater than 88%. The primary safety end point was freedom from major system- or procedure-related complications at 6 months. The safety objective would be met if the lower boundary of the one-sided 97.5% confidence interval for the percentage of patients free from such complications was greater than 79%. RESULTS: A total of 356 patients were enrolled, 316 of whom had an implantation attempt. Among the 302 patients in whom ventricular arrhythmia could be induced and who completed the defibrillation testing protocol, the percentage of patients with successful defibrillation was 98.7% (lower boundary of the one-sided 97.5% confidence interval [CI], 96.6%; P

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.

Introduction: Transcatheter Aortic Valve Replacement (TAVR) is increasingly performed with a decreasing overall complication rate. The risk of complete heart block requiring pacemaker implant (PPI) remains an important complication. Simple and accurate pre-TAVR risk stratification is essential to identify the patients who are at high risk for PPI. Unfortunately, an accurate risk prediction tool is not established yet. Hypothesis: We hypothesized that a pre-existing “electrical fingerprint” on electrocardiography (ECG) is associated with the need for post-TAVR PPI and that using machine learning (ML) approaches on pre-TAVR ECG can predict the need for post-TAVR PPI. Methods: This is a single-center retrospective study of 1032 patients who underwent TAVR from March 2011 to November 2019 at University Hospitals Cleveland Medical Center. Patients with preexisting cardiac implantable electronic devices were excluded. Pre-TAVR ECGs were obtained within 90 days prior to TAVR and a total of 637 features were extracted using ECG MUSE system (GE Healthcare; Milwaukee, WI). We applied hierarchical clustering on 637 ECG features and explored the incidence of post-TAVR PPI in each cluster. Using supervised machine learning, we trained and tested 25 ML algorithms using 445 ECG features (66:34 train:test split). We explored the accuracy of the best 5 ML algorithms on clinical data alone, 26 pre-TAVR clinical variables+ECG, and ECG alone to predict PPI after TAVR. Analysis was done using R Studio (Vienna, Austria) and Waikato Environment for Knowledge Analysis (WEKA, NZ). Results: Hierarchical clustering identified two distinct clusters (cluster 1 has 69% of the patient and cluster has 31% of the patient). The incidence of PPI was 13% in cluster 1 and 33% in cluster 2 (P Conclusions: A pre-existing “electrical fingerprint” accounts for significant variation in post-TAVR PPM implant. Unsupervised and supervised ML approaches can be helpful in predicting PPI without the need for inclusion of clinical data. ML-based models can be broadly applied to automatically-extracted ECG features with minimal data preparation

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.

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 demonstrated40% RV pacing. Compared with patients who had40% RV pacing, those with40% 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.

Whereas several preoperative characteristics have been associated with the risk of Cardiac Implantable Electronic Device (CIED) implantation after transcatheter aortic valve replacement (TAVR), an accurate risk prediction is not established yet. This is a single center, retrospective study of

Adenosine Unmasking Dormant Conduction Across the Cavotricuspid IsthmusBackground 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.

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.

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)

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 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.

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.

Catheter ablation has significantly transformed the clinical management of atrial fibrillation (AF). The safety and efficacy of this procedure are not well understood in patients with pacemakers and defibrillators.The purpose of this study was to study the impact of radiofrequency catheter ablation of AF in patients with pacemakers and implantable cardiac defibrillators.We studied 86 patients with pacemakers and defibrillators (group I) and a similar number of age- and gender-matched controls (group II) who underwent AF ablation between 1999 and 2004. Clinical and procedural variables were compared between the two groups. In group I, various generator and lead parameters were compared before and after the procedure. Resurgence of clinical AF after 2 months was considered recurrence.Both groups were similar with regard to age, gender, body mass index, and type of AF. Group I had a higher incidence of diabetes (17% vs 6%, P = .03), coronary artery disease (25% vs 13%, P = .05), less prolonged AF (31 +/- 21 vs 45 +/- 30 months, P.001), lower left ventricular ejection fraction (49 +/- 13% vs 52 +/- 9%, P = .03), and left ventricular end-diastolic dimensions (4.97 +/- 0.81 vs 4.72 +/- 0.67, P = .03). No changes in the sensing and pacing thresholds, impedance of atrial and ventricular leads, or defibrillator coil impedance after AF ablation were observed in group I. Atrial lead dislodgment was seen in two patients. Transient abnormal but "expected" pulse generator behavior was seen in 25% of patients without permanent malfunction. Stroke (1% vs 1%, P = 1.000), pulmonary vein stenosis (2% vs 1%, P = .77), and AF recurrence rates at 12 months were similar between groups I and II, respectively (19% vs 21%, P = .73).AF ablation is safe and efficacious in patients with pacemakers and defibrillators.

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.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).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.

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 P 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.

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.

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.

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

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.The purpose of this study was to assess whether standard ICE-guided PVAI affects vagal responses induced by endocardial AG stimulation in the LA.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 by50%. 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.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 slowing50% (28%), and AV block (20%). Postablation, vagal responses could no longer be induced in all 20 patients. A diminished response was induced (RR slowing50%) 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.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.

We describe the clinical and electrophysiologic characteristics and management of post "cut and sew" Maze arrhythmias in symptomatic patients.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.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.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.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.

Catheter based treatment of arrhythmia has gained significant attention during the last two decades. Due to the explosive development in ablation treatment of atrial fibrillation, huge interest in new tools was born to help in the atrial fibrillation ablation procedures. The aim of this review is to describe the role of these novel techniques and tools aimed at improving the implementation of catheter based ablations of atrial arrhythmias by focusing on the use of intra-cardiac echocardiogram and robotic navigation.

Objectives We report the first clinical experiences with the CARTO-Merge (Biosense-Webster, Diamond Bar, CA, USA) combined with intracardiac ultrasound (ICE) (Acuson, Mountain View, CA, USA) both used for navigation and catheter ablation of atrial fibrillation (AF). Methods 18 patients (15 men, 61±10 years) underwent pulmonary vein antrum isolation for symptomatic, drug-resistant AF using Lasso catheter, ICE and CARTO-Merge. The latter system integrated 3D CTA images of the left atrium and pulmonary veins with virtual CARTO maps. Firstly, 3-4 points (Landmarks) were registered on CTA scan according to the real-time position on the electroanatomical map, than 20-40 surface points of the CARTO map were added to finish the registration of the CT scan. Subsequently, the 3D CT anatomical map was used for catheter navigation. Correlation between this reconstruction, ICE and fluoroscopy was documented. Accuracy of the system was evaluated by the software statistical analysis. Results The mean surface inaccuracy was: 2.1±1.6 mm and the mean Landmarks inaccuracy was 8.9±3.0 mm, which reaches the recommended range. Conclusion This novel system appears to have a reliable correlation between CTA and real-time CARTO maps.

ObjectivesWe sought to test how catheter ablation using an open irrigation catheter (OIC) compares with standard catheters for pulmonary vein antrum isolation.BackgroundOpen 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.MethodsCatheter 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).ResultsA 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).ConclusionsAlthough 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.