Search

Background Atrial fibrillation (AF) triggers within the coronary sinus (CS)/great cardiac vein (GCV) and the left atrial appendage (LAA) have been recognized as nonpulmonary vein triggers of AF. Objective The aim of this study was to describe an electrical connection between the LAA and CS/GCV and its importance in achieving LAA electrical isolation (LAAEI). Methods A total of 488 consecutive patients undergoing catheter ablation for persistent or long-standing persistent AF who showed firing from the LAA and/or from the CS/GCV were enrolled in this multicenter prospective study. In all patients, potential defragmentation of the CS/GCV to achieve isolation and LAAEI was attempted with both endocardial and epicardial ablation. Results In 7% (n = 34) of these patients, after attempting endocardial LAAEI, the LAA was isolated during epicardial ablation in the GCV. In 8% (n = 39) of patients after attempting endocardial LAA isolation, the LAA was isolated during ablation along the endocardial aspect of the GCV. The presence of a venous branch connecting the GCV with the LAA was found in all these patients. In 23% (n = 112) of patients, the isolation of the LAA also isolated the GCV. In all these patients, LAA dissociated firing was present together with the CS/GCV recordings. Conclusion These findings suggest the presence of a distinct electrical connection between the GCV and the LAA. The clinical relevance of our results requires further investigation. Ablation in the CS/GCV can result in inadvertent isolation of the LAA. Ablation of the GCV is relevant to achieve LAAEI. Considering the potential long-term implications, ablation in the distal CS/GCV should prompt assessment of LAA conduction.

Background: Longstanding persistent (LSP) atrial fibrillation (AF) is the most challenging type of AF. In addition to pulmonary vein isolation, substrate modification and triggers ablation ...

Background Catheter ablation reduces ventricular tachycardia (VT) recurrence and implantable cardioverter defibrillator shocks in patients with VT and ischemic cardiomyopathy. The most effective catheter ablation technique is unknown. Objectives This study determined rates of VT recurrence in patients undergoing ablation limited to clinical VT along with mappable VTs (“clinical ablation”) versus substrate-based ablation. Methods Subjects with ischemic cardiomyopathy and hemodynamically tolerated VT were randomized to clinical ablation (n = 60) versus substrate-based ablation that targeted all “abnormal” electrograms in the scar (n = 58). Primary endpoint was recurrence of VT. Secondary endpoints included periprocedural complications, 12-month mortality, and rehospitalizations. Results At 12-month follow-up, 9 (15.5%) and 29 (48.3%) patients had VT recurrence in substrate-based and clinical VT ablation groups, respectively (log-rank p Conclusions An extensive substrate-based ablation approach is superior to ablation targeting only clinical and stable VTs in patients with ischemic cardiomyopathy presenting with tolerated VT. (Ablation of Clinical Ventricular Tachycardia Versus Addition of Substrate Ablation on the Long Term Success Rate of VT Ablation (VISTA); NCT01045668 )

The goal of this study was to evaluate the impact of hypertension on the outcome of atrial fibrillation (AF) ablation.Hypertension is a well-known independent risk factor for incident AF.A total of 531 consecutive patients undergoing AF ablation were enrolled in this study and divided into 3 groups: patients with uncontrolled hypertension despite medical treatment (group I, n = 160), patients with controlled hypertension (group II, n = 192), and patients without hypertension (group III, n = 179). Pulmonary vein (PV) antrum and posterior wall isolation was always performed, and non-PV triggers were identified during isoproterenol infusion. All patients underwent extensive follow-up.Three groups differed in terms of left atrial (LA) size, non-PV triggers, and moderate/severe LA scar. Non-PV triggers were present in 94 (58.8%), 64 (33.3%), and 50 (27.9%) patients in groups I, II, and III, respectively (p 0.001). After 19 ± 7.7 months of follow-up, 65 (40.6%), 54 (28.1%), and 46 (25.7%) patients in groups I, II, and III had recurrences (log-rank test, p = 0.003). Among patients in group I who underwent additional non-PV trigger ablation, freedom from AF/atrial tachycardia was 69.8%, which was similar to groups II and III procedural success (log-rank p = 0.7). After adjusting for confounders, uncontrolled hypertension (group I) (hazard ratio [HR]: 1.52, p = 0.045), non-PV triggers (HR: 1.85, p 0.001), and nonparoxysmal AF (HR: 1.64, p = 0.002) demonstrated significant association with arrhythmia recurrence.Controlled hypertension does not affect the AF ablation outcome when compared with patients without hypertension. By contrast, uncontrolled hypertension confers higher AF recurrence risk and requires more extensive ablation.

Background Islets of myocytes within fibrofatty scars represent the substrate for reentrant ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy (ARVC). Electroanatomic mapping can reliably identify such areas. Objective To prospectively test the association between late and fragmented electrograms within scar and arrhythmic events in patients with ARVC. Methods High-density right ventricle electroanatomic mapping was performed in 32 patients with ARVC without history of cardiac arrest or sustained ventricular arrhythmias. Standard definitions of electroanatomic scars and fragmented, isolated, and very late potentials were used. All patients received an implantable cardioverter-defibrillator for the primary prevention of sudden death. Results After a mean follow-up of 25 ± 7 months, 12 (38%) patients received appropriate implantable cardioverter-defibrillator shock for sustained ventricular arrhythmias. With the exception of a higher rate of previous syncope ( P = .053), patients with arrhythmic events at follow-up did not differ from those who remained free from arrhythmic events in terms of other clinical variables, including cardiac magnetic resonance findings. Electroanatomic scars were present in all patients. The distribution and extent of electroanatomic scars were similar in the 2 groups (38 ± 25 cm 2 vs 33 ± 20 cm 2 ; P = .51). However, patients with implantable cardioverter-defibrillator shock had a higher prevalence of fragmented electrograms (92% vs 20%; P P = .004), and of very late potentials (67% vs 25%; P = .030). Fragmented electrograms were the only variable independently associated with arrhythmic events at follow-up (hazard ratio 21; P = .015). Conclusion The presence of fragmented and delayed electrograms within the scar predicts arrhythmic events in ARVC.

Objectives This study investigated the impact on recurrences of 2 different substrate approaches for the treatment of these arrhythmias. Background Catheter ablation of electrical storms (ES) for ventricular arrhythmias (VAs) has shown moderate long-term efficacy in patients with ischemic cardiomyopathy. Methods Ninety-two consecutive patients (81% male, age 62 ± 13 years) with ischemic cardiomyopathy and ES underwent catheter ablation. Patients were treated either by confining the radiofrequency lesions to the endocardial surface with limited substrate ablation (Group 1, n = 49) or underwent endocardial and epicardial ablation of abnormal potentials within the scar (homogenization of the scar, Group 2, n = 43). Epicardial access was obtained in all Group 2 patients, whereas epicardial ablation was performed in 33% (14) of these patients. Results Mean ejection fraction was 27 ± 5. During a mean follow-up of 25 ± 10 months, the VAs recurrence rate of any ventricular tachycardia (VTs) was 47% (23 of 49 patients) in Group 1 and 19% (8 of 43 patients) in Group 2 (log-rank p = 0.006). One patient in Group 1 and 1 patient in Group 2 died at follow-up for noncardiac reasons. Conclusions Our study demonstrates that ablation using endo-epicardial homogenization of the scar significantly increases freedom from VAs in ischemic cardiomyopathy patients.

We thank Dr. Yang and colleagues for their interest in the BELIEF (Effect of Empirical Left Atrial Appendage Isolation on Long-Term Procedure Outcome in Patients With Persistent or Long-Standing Persistent Atrial Fibrillation Undergoing Catheter Ablation) trial [(1)][1]. Nonetheless, we believe it

Background Urban roadway intersections are key components of urban transportation networks. They are traditionally viewed and designed as primarily motorized-traffic facilities thus their physical and operational designs aimed at maximizing traffic throughput. Seen from a systems’ viewpoint, however, they are transport and community facilities with direct and indirect impacts on traffic functionalities, public health and the livability of communities. Thus, an integrated physical and operational design approach is necessary to design and/or analyze those intersections. Methods This study proposes a new methodology for measuring intersection performance called the Holistic Intersection Rating System (HIRS). It is based on design and technology innovation to improve operations and foster public health and community well-being. HIRS will assess the intersection design and functionalities with respect to two main categories: enabling technologies and physical design aimed at the transport functionality, and physical design and operability aimed at public health and community well-being. In particular, HIRS examines transportation intersections as system components of the urban environment. It rates the physical features of the road and the different motorized and non-motorized traffic flow design and operation parameters that equitably optimize throughput and support desired public health and community well-being outcomes. The public health and community well-being outcomes HIRS rates relate to physical and mental health, community severance, and “completeness” of intersections. Results HIRS facilitates pedestrian and cyclists’ use of intersections so intersections serve the dual needs of meaningful travel and good health while improving drivers experience and neighborhood livability and quality of life. The HIRS index may be constructed using common intersection travel efficiency and public health and community well-being indicators or indicators. The indicators can be weighed using two methodologies: the Relative Importance Index (RII) and the Analytical Hierarchy Process (AHP). The proposed system will be validated using an interdisciplinary industry panel of experts, and with empirical theoretical data runs. Conclusions Physical and operational design of roadway intersections, and the rating of sufficiency of such designs, are both necessary and possible for the well-functioning and use of urban transport systems and their users irrespective of modality. Tools that are dynamic and accommodating of changing designs and community values and priorities are necessary.

Most atrial fibrillation (AF) ablation studies have consisted predominantly of males; accordingly, there is a paucity of information on the safety and efficacy of catheter ablation in a large cohort of female AF patients.The purpose of this study was to evaluate catheter ablation for AF in female patients.From January 2005 to May 2008, 3265 females underwent pulmonary vein antrum isolation. Success rates, patient profiles, and complications were collected.Approximately 16% of our population was female (P.001). Females were older (59 +/- 13 vs. 56 +/- 19 years; P.01) and had a lower prevalence of paroxysmal atrial fibrillation (PAF; 46% vs. 55%; P.001). Females failed more antiarrhythmics (4 +/- 1 vs. 2 +/- 3; P = .04) and were referred later for catheter ablation (6.51 +/- 7 vs. 4.85 +/- 6.5 years; P = .02) than males. More females failed ablation (31.5% vs. 22.5%; P = .001) and had nonantral sites of firing than males (P.001). Female patients had 11 (2.1%) hematomas versus 27 (0.9%) in males.Five times as many males underwent catheter ablation than females. Females failed more ablations possibly because of a higher prevalence of nonantral firing, non-PAF, and longer history of AF. Females had more bleeding complications than males.

Background The best periprocedural anticoagulation strategy at the time of pulmonary vein isolation (PVI) is not known. Most centers stop administering warfarin (Coumadin) and use bridging with heparin or enoxaparin. Objective The purpose of this study was to evaluate the efficacy and safety of PVI under therapeutic international normalized ratio (INR). Methods Between January 2005 and December 2008, PVI was performed in 3,052 patients with therapeutic INR (≥1.8) at the time of ablation. All patients were evaluated for ischemic strokes and bleeding complications. Results Mean INR was 2.53 ± 0.62. Only 3 (0.098%) patients had ischemic strokes. One patient had a hemorrhagic stroke on the third day postablation but recovered completely by 1-week follow-up. Bleeding complications occurred in 34 (1.11%) patients; most were minor (0.79%). Major hemorrhagic complications occurred in 10 (0.33%) patients (tamponade in 5, hematomas requiring intervention in 2, transfusion necessary in 3). Conclusion In a large patient population, continuation of Coumadin at a therapeutic INR at the time of PVI without use of heparin or enoxaparin for bridging is a safe and efficacious periprocedural anticoagulation strategy. It is an acceptable and potentially better alternative to strategies that use bridging with heparin or enoxaparin.

Objectives We report on the initiation of ventricular fibrillation (VF) storm in patients with ischemic cardiomyopathy (ICM) and the results of targeted ablation to treat VF storm. Background Monomorphic premature ventricular contractions (PVCs) have been shown to initiate VF in patients without structural heart disease. Methods A total of 29 patients with ICM and documented VF initiation were identified. In 21 patients, VF storm was controlled with antiarrhythmic drugs and/or treatment of heart failure. Eight patients with VF (mean 52 ± 25 episodes) refractory to medical management required ablation. All patients underwent three-dimensional electroanatomical mapping using CARTO (Biosense-Webster Inc., Diamond Bar, California), and PVCs were mapped when present. Scarred areas were identified using voltage mapping. Results Monomorphic PVCs initiated VF in all 29 identified patients. Five of eight patients requiring ablation had frequent PVCs that allowed PVC mapping. The earliest activation site was consistently located in the scar border zone. The PVCs were always preceded by a Purkinje-like potential (PLP). Ablation was successfully performed at these sites. In three patients, infrequent PVCs prevented mapping, but PLPs were recorded around the scar border. Ablation targeting these potentials along the scar border was successfully performed. During follow-up (10 ± 6 months), one patient had a single VF episode and another developed sustained, monomorphic ventricular tachycardia. There was no recurrence of VF storm. Conclusions Ventricular fibrillation in ICM is triggered by monomorphic PVCs originating from the scar border zone with preceding PLPs; targeting these PVCs may prevent VF recurrence. In the absence of PVCs, both substrate mapping and ablation appear to be equally effective.

We read with much interest the recently published study by Di Biase et al. [(1)][1]. This multicentric trial makes an important contribution to the expanding field of ventricular tachycardia (VT) ablation in which randomized trials are rare. Di Biase et al. [(1)][1] reported on better procedural

Objectives We conducted this study to assess long-term results of three-dimensional (3-D) mapping-guided radiofrequency ablation (RFA) of inappropriate sinus tachycardia (IST). Change in activation after the administration of esmolol was also assessed and compared to the shift documented with successful sinus node (SN) modification. Background The long-term results after RFA of IST have been reported to vary between 27% and 66%. Methods Thirty-nine patients (35 women, mean age 31 ± 9 years) with debilitating IST were included in the study. The area around the earliest site of activation recorded using the 3-D mapping system was targeted for ablation. The shift in the earliest activation site after administration of esmolol was compared with the shift after RFA. Results The heart rate at rest and in drug-free state ranged between 95 and 125 beats/min (mean 99 ± 14 beats/min). Sinus node was successfully modified in all patients. Following ablation, the mean heart rate dropped to 72 ± 8 beats/min, p Conclusions Three-dimensional electroanatomical mapping seems to facilitate and improve the ablation results of IST. The difference in caudal shift seen after esmolol administration and following SN modification suggests that adrenergic hypersensitivity is not the only mechanism responsible for the inappropriate behavior of the SN.

OBJECTIVES To describe a normal heart left bundle branch block, inferior axis ventricular tachycardia (VT), that could not be ablated from the right or left ventricular outflow tracts. BACKGROUND Whether these VTs are epicardial and can be identified by a specific electrocardiographic pattern is unclear. METHODS Twelve patients with normal heart left bundle branch block, inferior axis VT and previously failed ablation were included in this study. Together with mapping in the right and left ventricular outflow tracts, we obtained percutaneous epicardial mapping in the first five patients and performed aortic sinus of Valsalva mapping in all patients. RESULTS No adequate pace mapping was observed in the right and left ventricular outflow tracts. Earliest ventricular activation was noted in the epicardium and the aortic cusps. All patients were successfully ablated from the aortic sinuses of Valsalva (95% CI 0% to 18%). The electrocardiographic pattern associated with this VT was left bundle branch block, inferior axis and early precordial transition with Rs or R in V2or V3. Ventricular tachycardia from the left sinus had rS pattern in lead I, and VT from the noncoronary sinus had a notched R wave in lead I. None of the patients had complications and all remained arrhythmia-free at a mean follow-up of 8 ± 2.6 months. CONCLUSIONS Normal heart VT with left bundle branch block, inferior axis and early precordial transition can be ablated in the majority of patients from either the left or the noncoronary aortic sinus of Valsalva.

Previous work had demonstrated a reduced specificity associated with head-up tilt protocols using high-dose isoproterenol in patients between 20 and 50 years of age. We evaluated the specificity of head-up tilt testing using different isoproterenol infusion doses and administration of nitroglycerin in patients aged >60 years. In addition, whether the same protocols have impact on the sensitivity of the test was also assessed. One hundred sixty subjects were included in this study. Seventy-six were volunteers randomized to either head-up tilt test with low-dose, 3- and 5-microg/min of isoproterenol (group I) or to a protocol including 0.4 mg of sublingual nitroglycerin (group II). In addition, after an upright tilt drug-free state, 58 patients with a history of syncope underwent repeat head-up tilt with increasing doses of isoproterenol infusion, followed by sublingual nitroglycerin if the test result remained negative. The remaining 33 patients were subjected to the nitroglycerin protocol after the drug-free state phase. In the control groups, the incidence of false-positive responses was 88% and 95%, respectively. In patients with syncope after a negative test result during 5 microg of isoproterenol infusion, nitroglycerin administration increased the number of positive responses from 45% to 79%. The percentage of positive tilt in patients undergoing nitroglycerin administration after the drug-free state part of the protocol was 78%. Administration of nitroglycerin was the most significant predictor of a positive upright tilt in patients with syncope. In subjects aged >60 years, head-up tilt protocols with high-dose isoproterenol infusion and nitroglycerin maintained an adequate specificity. In this subset of patients, nitroglycerin seemed to provide a better sensitivity than isoproterenol.

We report our experience with mapping and ablation of right and left atrial tachycardia using a 3-dimensional nonfluoroscopic mapping system. Twenty-nine ectopic atrial tachycardias were successfully ablated. This novel mapping system has the potential to increase a successful cure of this arrhythmia by catheter ablation.

Impact of catheter ablation on exercise performance, quality of life (QoL) and symptom perception in asymptomatic longstanding persistent AF (LSP-AF) patients has not been reported yet.Sixty-one consecutive patients (mean age 62 ±13 years, 71% males) with asymptomatic LSP-AF undergoing first catheter ablation were enrolled. Extended pulmonary vein antrum isolation plus ablation of complex fractionated atrial electrograms and nonpulmonary vein triggers was performed in all. QoL survey was taken at baseline and 12-months postablation, using Short Form-36 (SF-36). Information on arrhythmia perception was obtained using a standard questionnaire and corroborating symptoms with documented evidence of arrhythmia. Exercise tests were performed on 38 patients at baseline and 5 months after procedure. Recurrence was assessed using event recorder, cardiology evaluation, electrocardiogram, and 7-day holter monitoring. After 20 ± 5 months follow-up, 36 (57%) patients remained recurrence-free off-AAD. Of the 25 patients experiencing recurrence, 21 (84%) were symptomatic. Compared to baseline, follow-up SF-36 scores improved significantly in many measures. For patients with successful ablation, physical component summary (PCS) and mental component summary (MCS) demonstrated substantial improvement (64.2 ± 22.3 to 70.1 ± 18.6 [P = 0.041]; PCS: 62.6 ± 18.4 to 70.0 ± 14.4 [P = 0.032]). Postablation exercise study in recurrence-free patients showed significant reduction in resting and peak heart rate (75 ± 11 vs. 90 ± 17 and 132 ± 20 vs. 154.5 ± 36, respectively, P0.001), increase in peak oxygen pulse (13.4 ± 3 vs. 18.9 ± 16 mL/beat, Δ5.5 ± 15, P = 0.001), peak VO2 /kg (19.7 ± 5 to 23.4 ± 13 mL/kg/min [Δ 3.7 ± 10, P = 0.043]), and corresponding MET (5.6 ± 1 to 6.7 ± 4 [Δ1.1 ± 3, P = 0.03]). No improvement was observed in patients with failed procedures.Successful ablation improves exercise performance and QoL in asymptomatic LSP-AF patients.

In patients with persistent and long standing persistent (LSP) atrial fibrillation (AF) in addition to pulmonary vein isolation (PVI), extensive substrate modification and Non PV triggers ablation is important to achieve long term success. Whether AF termination during ablation should be considered

Catheter ablation of inappropriate sinus tachycardia (IST) is a challenging procedure due to the proximity of the sinus node to the phrenic nerve, and the predominant epicardial location of the sinus node structure. We report a consecutive series of patients undergoing ablation of IST and