Mina Chung

Ventricular tachycardias arising from the aortic sinus of valsalva: an under-recognized variant of left outflow tract ventricular tachycardia.

OBJECTIVESnTo 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.nnnBACKGROUNDnWhether these VTs are epicardial and can be identified by a specific electrocardiographic pattern is unclear.nnnMETHODSnTwelve 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.nnnRESULTSnNo 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 V2 or 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.nnnCONCLUSIONSnNormal 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.

Empirical pulmonary vein isolation in patients with chronic atrial fibrillation using a three-dimensional nonfluoroscopic mapping system: Long-term follow-up

KANAGARATNAM, L., et al.: Empirical Pulmonary Vein Isolation in Patients with Chronic Atrial Fibrillation Using a Three‐Dimensional Nonfluoroscopic Mapping System: Long‐Term Follow‐Up. The purpose of this study was to assess the feasibility and long‐term results of empirical isolation of both superior pulmonary veins in patients with chronic AF. Although localizing and ablating the focal triggers of AF has been proven an effective approach, this strategy is time consuming, often requires multiple procedures, and carries the risk of pulmonary vein stenosis. Whether ostial electrical isolation of the superior pulmonary veins, without initial detailed mapping, is a more efficient approach is not known. The study included 71 consecutive patients who had chronic AF. Using a nonfluoroscopic electroanatomic mapping system, the left and right superior pulmonary veins were ablated circumferentially at the venoatrial junction, with the aim of achieving electrical isolation of the veins. Following ablation, if frequent atrial ectopies were present, mapping and ablation were considered. The patients were periodically followed with 48‐hour Holter and loop recorder monitoring. After the ablation of the right and left superior pulmonary veins 59 (83%) of 71 patients maintained sinus rhythm without premature atrial beats. The remaining 12 patients underwent further mapping and ablation including 5 patients who required isolation of the left inferior pulmonary veins. True electrical isolation could be achieved only in 45 (31%) of the 147 targeted veins. At the latest follow‐up (mean 29 ± 8 months), 80% of the patients with upper vein isolation remained in sinus rhythm off medications, 62% of the patients maintained sinus rhythm on previously ineffective medications, and 17% continued to be in AF. Fourteen (20%) patients developed intermittent episodes of left atrial flutter, and mapping in these patients revealed large electrically silent areas in the left atrium. Empirical isolation of pulmonary veins appeared to be an effective approach to help maintain sinus rhythm in patients with chronic AF. True electrical isolation of the pulmonary veins was associated with a higher likelihood of long‐term success. Left atrial flutter was seen in a significant number of patients at long‐term follow‐up.

Use of dabigatran for periprocedural anticoagulation in patients undergoing catheter ablation for atrial fibrillation

Background—Pulmonary vein isolation (PVI) for atrial fibrillation is associated with a transient increased risk of thromboembolic and hemorrhagic events. We hypothesized that dabigatran can be safely used as an alternative to continuous warfarin for the periprocedural anticoagulation in PVI. Methods and Results—A total of 999 consecutive patients undergoing PVI were included; 376 patients were on dabigatran (150 mg), and 623 patients were on warfarin with therapeutic international normalized ratio. Dabigatran was held 1 to 2 doses before PVI and restarted at the conclusion of the procedure or as soon as patients were transferred to the nursing floor. Propensity score matching was applied to generate a cohort of 344 patients in each group with balanced baseline data. Total hemorrhagic and thromboembolic complications were similar in both groups, before (3.2% versus 3.9%; P=0.59) and after (3.2% versus 4.1%; P=0.53) matching. Major hemorrhage occurred in 1.1% versus 1.6% (P=0.48) before and 1.2% versus 1.5% (P=0.74) after matching in the dabigatran versus warfarin group, respectively. A single thromboembolic event occurred in each of the dabigatran and warfarin groups. Despite higher doses of intraprocedural heparin, the mean activated clotting time was significantly lower in patients who held dabigatran for 1 or 2 doses than those on warfarin. Conclusions—Our study found no evidence to suggest a higher risk of thromboembolic or hemorrhagic complications with use of dabigatran for periprocedural anticoagulation in patients undergoing PVI compared with uninterrupted warfarin therapy.

C reactive protein concentration and recurrence of atrial fibrillation after electrical cardioversion

Background: To test the hypothesis that a high C reactive protein (CRP) concentration would predict recurrence of atrial fibrillation (AF) after cardioversion in patients taking antiarrhythmic drugs. Methods: 111 patients who underwent direct current cardioversion for symptomatic AF were enrolled. Blood was drawn for CRP determination before cardioversion on the same day. All patients were taking antiarrhythmic drugs before and after electrical cardioversion. Results: After a mean follow up of 76 days, 75 patients had recurrence of AF. In univariate analysis, the median CRP concentration was significantly higher in patients with AF recurrence (3.95 mg/l v 1.81 mg/l, p u200a=u200a 0.002). Among the 55 patients with CRP in the upper 50th centile, 44 (80%) experienced recurrence of AF over a total follow up of 8.98 patient years, whereas among the 56 patients with CRP in the lower 50th centile, 31 (55%) experienced recurrence of AF over a total follow up of 14.3 patient years (p < 0.001). The adjusted hazard ratio comparing the upper 50th centile of CRP with the lower 50th centile of CRP was 2.0 (95% confidence interval 1.2 to 3.2, p u200a=u200a 0.007). Conclusions: CRP is independently associated with recurrence of AF after electrical cardioversion among patients taking antiarrhythmic drugs. These results suggest that inflammation may have a role in the pathogenesis of AF resistant to antiarrhythmic drugs.

Plasma B-Type Natriuretic Peptide Levels and Recurrent Arrhythmia After Successful Ablation of Lone Atrial Fibrillation

Background— Plasma B-type natriuretic peptide (BNP) is abnormally elevated in patients with lone atrial fibrillation (AF). The exact significance and prognostic implications of this elevation have yet to be determined. Little is known about BNP in lone AF patients undergoing arrhythmia ablation. We sought to determine the relationship between BNP levels and the risk of recurrent arrhythmia after ablation of lone AF. Methods and Results— We followed up 726 patients with lone AF undergoing first-time arrhythmia ablation. All had BNP levels measured on the day of ablation with of the point-of-care Triage Meter assay (Biosite Diagnostics, San Diego, CA). At baseline, factors associated with elevated BNP levels in multivariable linear regression analysis (with log BNP being the dependent variable) were older age (&bgr; regression coefficient for +1-year change, 0.025; P<0.0001), longer duration of AF (&bgr; for +1-year change, 0.031; P=0.01), nonparoxysmal AF (versus paroxysmal; &bgr;, 0.52; P<0.0001), and larger left atrial size (&bgr; for +1-cm2 change, 0.040; P<0.0001). The BNP levels were strongly associated with arrhythmia recurrence in univariate- (hazard ratio for +1-log-BNP change, 2.32; 95% confidence interval, 2.11 to 2.74; P<0.001) and covariate- (hazard ratio for +1-log-BNP change, 2.13; 95% confidence interval, 2.06 to 2.38; P<0.001) adjusted Cox proportional hazards analysis. The covariate-adjusted hazard ratios for recurrent arrhythmia were 1.6, 2.7, 4.3, and 5.7 for the second, third, fourth, and fifth quintiles, respectively, compared with patients in the lowest quintile (P for trend across quintiles <0.001). Conclusions— B-type natriuretic peptide levels correlate with AF burden (chronicity, altered hemodynamics, and anatomic remodeling) in patients with lone AF and are strong predictors of recurrent arrhythmia after ablation. Elevated BNP levels may reflect increased cardiac chamber wall stress and/or intrinsic atrial disease, thus increasing the risk of arrhythmia recurrence.

Matching approved nondedicated hardware to obtain biventricular pacing and defibrillation: Feasibility and troubleshooting

KANAGARATNAM, L., et al.: Matching Approved “Nondedicated” Hardware to Obtain Biventricular Pacing and Defibrillation: Feasibility and Troubleshooting. Biventricular ICDs may offer increased benefit for patients with severe congestive heart failure and ventricular arrhythmia. Currently there are no approved dedicated biventricular ICDs available. Twenty‐one consecutive patients who had approved nondedicated hardware implanted for biventricular pacing and defibrillation were included in this study. All device therapies were evaluated using stored electrograms. During mean follow‐up at 13 ± 7 months, 8 (36%) patients had inappropriate shocks. Ventricular fibrillation therapy was delivered for slow ventricular tachycardia because of double counting in two patients. In one patient, AV nodal reentrant tachycardia below detection rate cut off triggered device therapy because of ventricular double counting. Sinus tachycardia or premature atrial contraction initiating AV conduction and ventricular double counting resulted in shocks in five patients. The number of shocks per patient ranged from 1 to 64. Two patients required transient disconnection of the LV lead and subsequent ICD generator replacement for premature battery depletion. Two patients required AV junction ablation and three needed slow pathway ablation. Two patients were treated by upgrading to a device that was capable of a higher atrial tracking rate. The patients with impaired AV conduction or constant ventricular pacing did not have inappropriate therapy for sinus tachycardia or supraventricular arrhythmia. Use of conventional nondedicated hardware for biventricular pacer/defibrillator is feasible but should be considered only in patients with poor AV node function or less likely to require antitachycardic therapy, to avoid ICD double counting of ventricular sensed events and consequent high incidence of inappropriate therapies.

Radiofrequency Ablation of Persistent Atrial Fibrillation Diagnosis-to-Ablation Time, Markers of Pathways of Atrial Remodeling, and Outcomes

Background—Various ablation strategies of persistent atrial fibrillation (PersAF) have had disappointing outcomes, despite concerted clinical and research efforts, which could reflect progressive atrial fibrillation–related atrial remodeling. Methods and Results—Two-year outcomes were assessed in 1241 consecutive patients undergoing first-time ablation of PersAF (2005–2012). The time intervals between the first diagnosis of PersAF and the ablation procedures were determined. Patients had echocardiograms and measures of B-type natriuretic peptide and C-reactive protein before the procedures. The median diagnosis-to-ablation time was 3 years (25th–75th percentiles 1–6.5). With longer diagnosis-to-ablation time (based on quartiles), there was a significant increase in recurrence rates in addition to an increase in B-type natriuretic peptide levels (P=0.01), C-reactive protein levels (P<0.0001), and left atrial size (P=0.03). The arrhythmia recurrence rates over 2 years were 33.6%, 52.6%, 57.1%, and 54.6% in the first, second, third, and fourth quartiles, respectively (Pcategorical<0.0001). In Cox Proportional Hazard analyses, B-type natriuretic peptide levels, C-reactive protein levels, and left atrial size were associated with arrhythmia recurrence. The diagnosis-to-ablation time had the strongest association with the ablation outcomes which persisted in multivariable Cox analyzes (hazard ratio for recurrence per +1Log diagnosis-to-ablation time 1.27, 95% confidence interval 1.14–1.43; P<0.0001; hazard ratio fourth versus first quartile 2.44, 95% confidence interval 1.68–3.65; Pcategorical<0.0001). Conclusions—In patients with PersAF undergoing ablation, the time interval between the first diagnosis of PersAF and the catheter ablation procedure had a strong association with the ablation outcomes, such as shorter diagnosis-to-ablation times were associated with better outcomes and in direct association with markers of atrial remodeling.

Safety of Catheter Ablation for Atrial Fibrillation in Patients With Prior Cerebrovascular Events

OBJECTIVESnThis study sought to report on the safety of catheter ablation for atrial fibrillation (AF) in patients with prior cerebrovascular events (CVEs), at a large-volume tertiary care center over the course of the past 15 years.nnnBACKGROUNDnMany patients with drug-refractory AF have a history of a prior CVE. These patients are considered to be at high procedural risk for catheter ablation but data are scant.nnnMETHODSnAll consecutive patients undergoing AF ablation at the Cleveland Clinic were enrolled in a prospectively maintained data registry, which was used to identify patients with a prior CVE. Strict periprocedural anticoagulation protocols were in place. Extreme care was taken with sheath and catheter manipulation to prevent thrombus formation or air embolism. All thromboembolic and hemorrhagic events occurring periprocedurally and up to 3 months of follow-up were identified.nnnRESULTSnOf 9,413 consecutive patients who underwent AF ablation, 247 patients with a prior CVE were identified (median age, 64 years; 40.1% female; median CHA2DS2-VASC score, 4). Anticoagulants used were warfarin (nxa0= 192), dabigatran (nxa0= 32), rivaroxaban (nxa0= 15), and apixaban (nxa0= 8). All patients received intravenous heparin before transseptal access (activated clotting time target during procedure, 350 to 400 seconds). The energy source was radiofrequency in 242 patients and cryoenergy in 5 patients. Acute procedural complications included 5 groin hematomas (1 requiring transfusion), 5 pericardial effusions with associated tamponade physiology in 2 (1 required pericardiocenthesis, 1 required surgery), and 1 arteriovenous fistula (managed conservatively). Importantly, none of the patients had a periprocedural thromboembolic event.nnnCONCLUSIONSnPatients with a prior history of cerebrovascular events do not seem to be predisposed to a significant risk of clinical CVE recurrence when undergoing catheter ablation for AF without interruption of therapeutic anticoagulation.

Recurrent Atrial Fibrillation After Initial Long-Term Ablation Success: Electrophysiological Findings and Outcomes of Repeat Ablation Procedures

Background: Atrial fibrillation recurrence after initial long-term success of catheter ablation has been described, yet not well studied. We assessed the electrophysiological findings and outcomes of repeat ablation procedures in this setting. Methods and Results: Between 2000 and 2015, 10u2009378 patients underwent atrial fibrillation ablation and were enrolled in a prospectively maintained data registry. From this registry, we included all 137 consecutive patients who had initial long-term success, defined as freedom from recurrent arrhythmia for >36 months off antiarrhythmics, then underwent repeat ablation for recurrent atrial fibrillation. The median arrhythmia-free period that defined long-term success was 52 months (41–68 months). In redo ablations, reconnection along at least one of the pulmonary veins (PVs) was found in 111 (81%) patients. Reconnection along a left superior, left inferior, right superior, and right inferior PV was found in 64%, 62%, 50%, and 54% of patients, respectively, and were reisolated. Additional non-PV ablations were performed in 127 (92.7%) patients: posterior wall (46%), septal to right PVs (49%), superior vena cava (35%), roof lines (52%), and cavotricuspid isthmus (33%). After a median follow-up of 17 months (5–36.9 months), 103 patients (75%) were arrhythmia free (79 off antiarrhythmics, 24 on antiarrhythmics). Conclusions: PV reconnection is the most common electrophysiological finding in patients with atrial fibrillation recurrence after long-term success, but with lower rates than what had been reported for early recurrences. In our experience, repeat ablations in this setting involve complex ablation approaches to reisolate the PVs and modify the atrial substrate and are associated with good success rates.

Transvenous lead extraction at the time of cardiac implantable electronic device upgrade: Complexity, safety, and outcomes

BACKGROUNDnThe practice of lead abandonment at the time of cardiac implantable electronic device upgrade remains a controversial topic but is affecting an increasing number of patients. Inherent risks include high-risk extractions of redundant leads when extraction is required at a later date.nnnOBJECTIVESnWe aimed to report our experience with transvenous lead extraction (TLE) at the time of device upgrade.nnnMETHODSnAll consecutive TLE procedures at the time of device upgrade at the Cleveland Clinic between January 1, 1996 and December 31, 2012 were included (n = 503). Success and complications were defined according to the Heart Rhythm Society consensus document on TLE.nnnRESULTSnThere were a total of 984 leads in place, and 719 were targeted with extraction (589 pacer and 130 defibrillator leads, 63 of them being dual-coil leads). In all patients, TLEs aimed to avoid abandoning leads. Concomitant lead management issues included lead malfunction (15%), previously abandoned leads (9%), vascular access occlusion (6%), or leads on advisory (3%). In most procedures (75.4%), special extraction tools were needed. The complete procedural and clinical success rates were 96.6% and 97.2%, respectively. During planned extractions, damage of coexisting leads occurred in 19 patients (3.8%), eventually requiring extraction. The major and minor complication rates were 1% and 1.4%, respectively.nnnCONCLUSIONnIn a high-volume center, TLEs at the time of device upgrade were successful in the vast majority of patients with a low complication rate.