Coincidental ganglionated plexus modification during radiofrequency pulmonary vein isolation and post-ablation arrhythmia recurrence.

AIMS: Vagal responses (VR) during left atrial ablation for atrial fibrillation (AF) treatment have been reported to be associated with less recurrences, presumably because they are a sign of ganglionated plexi modification. Our objective was to evaluate whether coincidentally elicited VR during left atrial ablation are associated with lower AF recurrence rates. METHODS AND RESULTS: This is a post hoc analysis of a prospective study of 291 patients with paroxysmal AF undergoing radiofrequency pulmonary vein isolation (PVI). Vagal responses were defined as episodes of heart rate <40 bpm or asystole lasting >5 s elicited during energy application. Sixty-eight patients (23.4%) had a VR during ablation. In Kaplan-Meier analysis, mean recurrence-free survival was 449 days (95% confidence interval 411-488) in patients with VR when compared with 435 days (95% confidence interval 415-455) in those without (P = 0.310). The 12-month recurrence rate estimates were 25 and 27%, respectively. In an unadjusted Cox model, VR was associated with an odds ratio for recurrence of 0.77 (95% confidence interval 0.46-1.28). CONCLUSION: Coincidentally elicited VR during radiofrequency PVI in patients with paroxysmal AF do not appear to be related to lower risk of arrhythmia recurrence. This may mean that, even if a VR is truly a sign of coincidental ablation of a ganglionated plexus, this does not necessarily mean that a therapeutic modification has been effected, at least to a degree associated with clinical benefit.

Permanent pacing after transcatheter aortic valve implantation of a CoreValve prosthesis as determined by electrocardiographic and electrophysiological predictors: a single-centre experience.

AIM: The most frequent conduction complications with transcatheter aortic valve implantation (TAVI) are complete atrioventricular (AV) block and new bundle branch block (BB). The purpose of this study was to assess clinical, electrocardiographic, and electrophysiological predictors of conduction abnormalities in patients (pts) undergoing TAVI with the CoreValve prosthesis. The secondary end points were the long-term rhythm follow-up and the recovery of conduction. METHODS AND RESULTS: Forty-five consecutive pts with severe aortic stenosis, New York Heart Association II/III, and normal or slightly impaired left ventricular function who underwent CoreValve transcatheter implantation were randomized 2:1 to electrocardiographic and electrocardiographic plus electrophysiological evaluations. Pacemakers were implanted in pts with complete AV block. Follow-up was performed at 1, 6, 12, and 24 months. Conduction was affected in the total group of pts undergoing TAVI. The PR lengthened compared with the baseline but did not exceed the normal cut-off of 200 ms, and the QRS widened, basically due to new left bundle branch blocks (LBBBs). Within 1 month of follow-up, 10 pts (22%) developed complete AV block (9 peri-procedurally-20%) and 15 pts (33%) developed a new bundle BB, with LBBBs being the most common (14-31%). In the 30 pts who underwent an electrophysiological study, analysis showed that prolonged HV intervals were prognostic for pacemaker implantation. Follow-up in the total study group revealed that only 4 of the 10 (9%) initial implantations remained completely pacemaker dependent. CONCLUSION: Conduction was affected in all pts undergoing TAVI, but serious complications that required permanent pacing generally occurred in pts with pre-existing conduction abnormalities.

Central sympathetic inhibition to reduce postablation atrial fibrillation recurrences in hypertensive patients: a randomized, controlled study.

BACKGROUND: The autonomic system is an important determinant of atrial arrhythmogenesis. Current evidence indicates that a combined sympathovagal drive is most commonly responsible for eliciting atrial fibrillation (AF) episodes. The purpose of this study was to test whether moxonidine, a centrally acting sympathoinhibitory agent, can lead to a reduction in postablation AF recurrence. METHODS AND RESULTS: This was a prospective, double-blinded, randomized study of 291 hypertensive patients with symptomatic paroxysmal AF who were scheduled to undergo pulmonary vein isolation. Patients were randomly assigned to receive either moxonidine (0.2-0.4 mg daily) or placebo, along with standard antihypertensive treatment. No significant differences in blood pressure levels were observed between the 2 groups. In the primary outcome analysis, mean recurrence-free survival was 467 days (95% CI, 445-489 days) in the moxonidine group as compared with 409 days (95% CI, 381-437 days) in control subjects (log rank test, P=0.006). The calculated 12-month recurrence rate estimates were 36.9% in the control group and 20.0% in the moxonidine group (P=0.007). Moxonidine treatment was associated with lower recurrence risk after adjustment for age, body mass index, number of AF episodes in the previous year, and left atrial diameter (adjusted hazard ratio, 0.35 [95% CI, 0.22-0.55]; P<0.001). CONCLUSIONS: Treatment with moxonidine is associated with less AF recurrences after ablation treatment for drug-refractory AF in patients with hypertension. The observed effect does not appear to depend on the antihypertensive action of this agent. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01791699.

The Role of Colchicine in Treating Postoperative and Post-catheter Ablation Atrial Fibrillation.

PURPOSE: The goal of this review was to summarize, analyze, and compare trials studying the efficacy of colchicine in the prevention of atrial fibrillation (AF) post-operatively (POAF) and post-catheter ablation. Ongoing studies and current guidelines are also presented and reviewed. METHODS: Published studies on the field were identified through a literature search of the PubMed and clinicaltrials.gov databases. FINDINGS: Four original studies regarding POAF, two original studies regarding post-catheter ablation AF, and six meta-analyses were identified. In addition, the 3 most recent guidelines/expert consensus documents were scrutinized. IMPLICATIONS: AF occurs frequently after cardiac surgery (POAF) and catheter pulmonary vein isolation (postablation AF) and is associated with increased cardiovascular morbidity. A number of trials over the last few years have investigated the role of colchicine in the prevention of POAF and postablation AF targeting the local and systemic inflammatory process that leads to initiation and maintenance of AF. Available data imply that colchicine may have a preventive role in POAF and/or postablation AF. However, certain limitations of these studies underline the need for further investigation.

Permanent pacemaker implantation in octogenarians with unexplained syncope and positive electrophysiologic testing.

BACKGROUND: Syncope is a common problem in the elderly, and a permanent pacemaker is a therapeutic option when a bradycardic etiology is revealed. However, the benefit of pacing when no association of symptoms to bradycardia has been shown is not clear, especially in the elderly. OBJECTIVE: The aim of this study was to evaluate the effect of pacing on syncope-free mortality in patients aged 80 years or older with unexplained syncope and "positive" invasive electrophysiologic testing (EPT). METHODS: This was an observational study. A positive EPT for the purposes of this study was defined by at least 1 of the following: a corrected sinus node recovery time of >525 ms, a basic HV interval of >55 ms, detection of infra-Hisian block, or appearance of second-degree atrioventricular block on atrial decremental pacing at a paced cycle length of >400 ms. RESULTS: Among the 2435 screened patients, 228 eligible patients were identified, 145 of whom were implanted with a pacemaker. Kaplan-Meier analysis determined that time to event (syncope or death) was 50.1 months (95% confidence interval 45.4-54.8 months) with a pacemaker vs 37.8 months (95% confidence interval 31.3-44.4 months) without a pacemaker (log-rank test, P = .001). The 4-year time-dependent estimate of the rate of syncope was 12% vs 44% (P < .001) and that of any-cause death was 41% vs 56% (P = .023), respectively. The multivariable odds ratio was 0.25 (95% confidence interval 0.15-0.40) after adjustment for potential confounders. CONCLUSION: In patients with unexplained syncope and signs of sinus node dysfunction or impaired atrioventricular conduction on invasive EPT, pacemaker implantation was independently associated with longer syncope-free survival. Significant differences were also shown in the individual components of the primary outcome measure (syncope and death from any cause).

Colchicine for prevention of atrial fibrillation recurrence after pulmonary vein isolation: mid-term efficacy and effect on quality of life.

BACKGROUND: Our group previously showed that colchicine treatment is associated with decreased early recurrence rate after ablation for atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to test the mid-term efficacy of colchicine in reducing AF recurrences after a single procedure of pulmonary vein isolation in patients with paroxysmal AF. Assessment of quality-of-life (QOL) changes was a secondary objective. METHODS: Patients with paroxysmal AF who were scheduled for ablation were randomized to a 3-month course of colchicine 0.5 mg twice daily or placebo and were followed for a median of 15 months (with a 3-month blanking period). QOL was assessed with a general-purpose health-related QOL tool (26-item World Health Organization QOL questionnaire) at baseline and after 3 and 12 months. RESULTS: Two hundred twenty-three randomized patients underwent ablation, and 206 patients were available for analysis (144 male, age 62.2 ± 5.8 years). AF recurrence rate in the colchicine group was 31.1% (32/103) vs 49.5% (51/103) in the control group (P = .010), translated in a relative risk reduction of 37% (odds ratio 0.46, 95% confidence interval 0.26-0.81). The number needed to treat was 6 (95% confidence interval 3.2-19.8). Physical domain QOL scores at 12 months were 63.6 ± 13.8 in the colchicine group and 52.5 ± 18.1 in controls, whereas psychological domain scores were 56.1 ± 13.7 vs 44.7 ± 17.3, respectively (P <.001, for both). CONCLUSION: Colchicine treatment after pulmonary vein isolation for paroxysmal AF is associated with lower AF recurrence rates after a single procedure. This reduction is accompanied by corresponding improvements in physical and psychological health-related QOL scores.

Interatrial conduction time and incident atrial fibrillation: a prospective cohort study.

BACKGROUND: Atrial electrical conduction properties have been implicated in atrial fibrillation (AF) pathogenesis. OBJECTIVE: The purpose of this study was to prospectively assess the potential association of interatrial conduction time (IACT) with incident AF. METHODS: The study included persons referred for invasive electrophysiologic study (EPS), aged ≥50 years, without AF history or valvular disease. IACT was defined as the interval between the high right atrium electrogram and the distal coronary sinus atrial electrogram. RESULTS: Six hundred twelve subjects were included (median follow-up 43 months, interquartile range 40-47). AF incidence was 21.7 cases per 1000 person-years. IACT was a significant predictor of AF with a c-statistic of 0.770 (95% confidence interval 0.702-0.838). In time-dependent analysis, IACT was a significant stratifier of AF risk (log-rank 28.0, P <.001). The corresponding incidences of AF in each tertile of IACT were 3, 17, and 46 per 1000 person-years, respectively (all differences between tertiles were significant). IACT remained significant in multivariable Cox regression analysis, after adjustment for age, sex, hypertension, and left atrial diameter, with each millisecond of prolonged IACT corresponding to 7% (95% confidence interval 2%-12%) higher adjusted risk of incident AF. CONCLUSION: IACT is independently associated with incident AF. The invasive nature of the measurement is a limitation for its use as a clinical risk stratifier (although it could be used in patients referred for EPS), but these results are of interest in themselves because they suggest a strong pathophysiologic connection between atrial conduction times and substrate alterations ultimately leading to AF.

Feasibility and procedure-related patient discomfort of peripheral venous access for coronary sinus cannulation during electrophysiology procedures.

BACKGROUND: Placement of an electrode catheter in the coronary sinus (CS) through the jugular or subclavian vein, as part of electrophysiology (EP) procedures, increases patient discomfort and the possibility of adverse events. We studied the hypothesis that peripheral venous access for CS cannulation, as part of EP procedures, is feasible and can reduce patient discomfort, eliminating central venous access-associated risks. METHODS: Consecutive patients submitted to EP procedures were randomly assigned to peripheral or central venous access for CS cannulation. If after 30 min from initial needle insertion the CS was still not catheterized, the attempt was considered unsuccessful. Patient level of discomfort was assessed with a visual analog scale (VAS). RESULTS: Success rate was 90% in the peripheral versus 95% in the central venous access group (p = 1.00). No complications related to venous access were observed in the peripheral venous access group, whereas one case of pneumothorax and one case of extensive hematoma in the anterior cervical area were recorded in the central venous access group. Patients submitted to central vein catheterization reported higher VAS scores, 46.8 ± 16.3 versus 36.8 ± 12.9 (p = 0.04). No significant difference was observed in fluoroscopy time needed for CS cannulation (51.1 ± 9.2 s versus 51.4 ± 7.9 s; p = 0.71) between the two groups. CONCLUSION: This small, randomized study indicates that peripheral venous access for CS catheter placement during EP procedures is feasible, with equivalent success rate to the central venous access approach, and associated with lower levels of self-reported patient discomfort.

Integration of intracardiac echocardiographic imaging of the left atrium with electroanatomic mapping data for pulmonary vein isolation: first-in-Greece experience with the CartoSound™ system and brief literature review.

INTRODUCTION: Intracardiac echocardiography (ICE) offers the ability to image the left atrium in order to reconstruct a three-dimensional model that can be integrated with electroanatomic data to guide pulmonary vein isolation. We report a case series representing the first-in-Greece experience with the CartoSound module. METHODS: Patients with paroxysmal or persistent atrial fibrillation (AF) referred for pulmonary vein isolation were included in this case-series. The SoundStar ICE catheter was used to trace left atrial and pulmonary vein contours from the right atrium, the right ventricular outflow tract and the coronary sinus. RESULTS: Eight patients (age 66.3 ± 1.6 years) are presented in this case-series report. Six of them (75%) had paroxysmal AF and the rest were in persistent AF for less than one year. The time for ICE imaging and left atrium three-dimensional reconstruction decreased from a median of 20.5 minutes (interquartile range 19.3-23.3) for the chronologically first four cases to a median of 16.5 minutes (interquartile range 14.517.0) for the chronologically last four cases (p=0.02). The procedure was completed in all cases. No significant periprocedural complications were encountered. Acute success, with restoration of sinus rhythm, was achieved in both patients with persistent AF. Seven of the eight patients (87.5%) were AF-free in 48-hour Holter recordings one week after the procedure. CONCLUSION: ICE integration into three-dimensional electroanatomic reconstruction of the left atrium provides reliable guidance for pulmonary vein isolation. It appears that this modality is a sound alternative to magnetic resonance and computed tomography image data registration, although randomized comparisons are lacking.

Feasibility of peripheral venous access for temporary right ventricular pacing.

INTRODUCTION: In this brief report, we present our experience from placing temporary pacing electrodes through peripheral venous access sites, at bedside, in a series of patients needing temporary pacing. METHODS: Consecutive patients requiring temporary pacing were selected. The median cubital or the basilic vein of the left upper extremity were used for catheterization at the bedside in all cases. RESULTS: 25 patients (17 men, age 64.6 ± 11.8) were included. The procedure was successful in 21 cases (84%), 18 of which were completed without the need for fluoroscopic guidance. The pacing leads remained for 4.2 ± 2.2 days. As expected, no serious complications related to venous puncture were observed. Although patients were allowed to be mobilized within the ward and engage in limited movements of the catheterized arm, in only one case was the lead displaced, requiring repositioning. CONCLUSIONS: We provide observational evidence that the use of peripheral venous access for temporary pacing lead insertion (with no fluoroscopic guidance, as default strategy) is a safe and feasible choice that might be considered as an alternative to central vein catheterization.

Colchicine for prevention of early atrial fibrillation recurrence after pulmonary vein isolation: a randomized controlled study.

OBJECTIVES: The purpose of the present study was to test the potential of colchicine, an agent with potent anti-inflammatory action, to reduce atrial fibrillation (AF) recurrence after pulmonary vein isolation in patients with paroxysmal AF. BACKGROUND: Proinflammatory processes induced by AF ablation therapy have been implicated in postablation arrhythmia recurrence. METHODS: Patients with paroxysmal AF who received radiofrequency ablation treatment were randomized to a 3-month course of colchicine 0.5 mg twice daily or placebo. C-reactive protein (CRP) and interleukin (IL)-6 levels were measured on day 1 and on day 4 of treatment. RESULTS: In the 3-month follow-up, recurrence of AF was observed in 27 (33.5%) of 80 patients of the placebo group versus 13 (16%) of 81 patients who received colchicine (odds ratio: 0.38, 95% confidence interval: 0.18 to 0.80). Gastrointestinal side-effects were the most common symptom among patients receiving active treatment. Diarrhea was reported in 7 patients in the colchicine group (8.6%) versus 1 in the placebo group (1.3%, p = 0.03). Colchicine led to higher reductions in CRP and IL-6 levels: the median difference of CRP and IL-6 levels between days 4 and 1 was -0.46 mg/l (interquartile range: -0.78 to 0.08 mg/l) and -0.10 mg/l (-0.30 to 0.10 pg/ml), respectively, in the placebo group versus -1.18 mg/l (-2.35 to -0.46 mg/l) and -0.50 pg/ml (-1.15 to -0.10 pg/ml) in the colchicine group (p < 0.01 for both comparisons). CONCLUSIONS: Colchicine is an effective and safe treatment for prevention of early AF recurrences after pulmonary vein isolation in the absence of antiarrhythmic drug treatment. This effect seems to be associated strongly with a significant decrease in inflammatory mediators, including IL-6 and CRP.