Robotic ablation of atrial fibrillation with a new remote catheter system

Purpose

Pulmonary vein isolation (PVI) is widely established as a curative treatment option for atrial fibrillation (AF). A wide range of techniques to improve catheter manipulation and steerability has been developed over the past years. A new remote catheter system (RCS) has recently become available (Amigo Remote Catheter System, Catheter Robotics, Budd Lake, NJ, USA). Here, we present a dual-center study on the RCS for left atrial mapping and PVI in patients with paroxysmal AF compared to a control group undergoing conventional PVI.

Methods

One hundred nineteen patients who underwent PVI for paroxysmal AF were studied. Forty patients underwent PVI with the use of the RCS. Seventy-nine patients, who underwent conventional PVI, served as control group. Procedural data were compared between the two groups.

Results

PVI was achieved in all patients. In the RCS group compared to standard ablation group, there were no significant differences in procedure duration (159.1?±?45.4 vs. 146?±?30.1 min, p?=?0.19), total energy delivery (78,146.3?±?26,992.4 vs. 87,963.9?±?79,202.1 Ws, p?=?0.57), and total fluoroscopy time (21.2?±?8.6 vs. 23.9?±?5.4 min, p?=?0.15). Operator fluoroscopy exposure was significantly reduced in the RCS group (13.4?±?6.1 vs. 23.9?±?5.4 min, p?Conclusions These initial results suggest that left atrial mapping and PVI are feasible with the use of the Amigo RCS. Acute procedural efficacy is comparable to the standard approach. The use of the Amigo RCS leads to a significant reduction of operator fluoroscopy exposure.     

Predictive value of left atrial volume measured by non-invasive cardiac imaging in the treatment of paroxysmal atrial fibrillation

Purpose

We investigate the role of left atrial volume (LAV) as a predictor of outcome following pulmonary vein isolation (PVI) in patients with exclusive paroxysmal atrial fibrillation (AF).

Methods

PVI was performed in 213 patients (80 females, aged 60?±?10?years) with paroxysmal AF using either the pulmonary vein ablation catheter (PVAC, n?=?78) or conventional single-tip ablation (n?=?135). LAV was assessed by multi-detector computed tomography (n?=?39) or cardiac magnetic resonance imaging (n?=?174) prior to ablation. LA diameter (LAD) and LA area were determined by echocardiography. Patients were followed up for 12?months clinically and with 72-h Holter ECG.

Results

The mean LAV was 85?±?28?ml (range, 22?C189?ml). Mean LAD and mean LA area were 43?±?6?mm and 23?±?6?cm2. After a follow-up period of 18?±?5?months, 202 patients were analyzed. AF recurrence was documented in 50 (23%) patients. Univariate analysis showed age (59?±?11 vs. 65?±?6?years, p?=?0.049), LA area (23?±?5 vs. 27?±?6?cm2, p?=?0.03), and LAV (80?±?27 vs. 96?±?28?ml, p?=?0.04) to be significantly associated with the outcome. Multivariate analysis revealed that none of these parameters were statistically significant (hazards ratio LAV, 0.52?C1.12, p?=?0.058; LA area, 0.63?C1.14, p?=?0.069; and age, 0.90?C1.09, p?=?0.41). In the case of AF recurrence, patients with LAV >95?ml showed a significantly higher probability for the occurrence of persistent AF (24% vs. 8%, p?=?0.02).

Conclusions

The assessment of LA size should not be incorporated as a main factor with regard to predicted ablation success in patients with paroxysmal AF being considered for PVI, as PVI may be successful even with considerable LA enlargement. Ablation should be performed promptly in patients with LAV ??95?ml to prevent further LA dilatation, as patients with LAV >95?ml have an increased probability to develop persistent AF in the case of ablation failure.     

Electrocardiographic P wave changes after thoracoscopic pulmonary vein isolation for atrial fibrillation

Background

Changes in P wave duration (PWD) and P wave area (PWA) have been described following catheter ablation for atrial fibrillation (AF). We hypothesize that video-assisted thoracoscopic pulmonary vein isolation (VATS-PVI) for AF results in decrease of PWD, PWA and P wave dispersion, which may resemble reverse electrical remodeling of the atrium after restoration of sinus rhythm.

Methods

VATS-PVI consisted of PVI and ganglionic plexus ablation in 29 patients (mean age, 59?±?7 years; 23 males; 17 paroxysmal AF) and additional left atrial lesions in patients with persistent AF. PWD and PWA were measured in ECG lead II, aVF and V2 of ECGs during sinus rhythm before, directly after, and 6 months postprocedure. P wave dispersion was derived from the 12 lead ECG.

Results

Prior to VATS-PVI, PWD did not correlate with left atrial size and no difference in left atrial size was found between patients with paroxysmal or persistent AF (p?=?0.27). Following VATS-PVI, PWD initially prolonged in all patients from 115?±?4.6 ms to 131?±?3.6 ms (p?<?0.01) but shortened to 99?±?3.2 ms after 6 months (p?<?0.01). PWA was 5.60?±?0.32 mV*ms at baseline, 6.44?±?0.32 mV*ms post-VATS-PVI (P?=?NS), and 5.40?±?0.28 mV*ms after 6 months (p?=?NS vs. baseline, p?<?0.05 vs. post-VATS-PVI). P wave dispersion decreased in the persistent AF group from baseline 67?±?3.3 to 64?±?2.5 ms post-VATS-PVI (p?=?0.30) and to 61?±?3.4 ms after 6 months (p?<?0.05).

Conclusions

PWD increases significantly directly after successful VATS-PVI in both groups. There was significant decrease in PWD after 6 months. Similarly, P wave dispersion decreased in the persistent group. These changes suggest an immediate procedure related effect, but the later changes may represent reverse electrical atrial remodeling following cessation of AF.     

Left atrial pressure as predictor for recurrence of atrial fibrillation after pulmonary vein isolation

Purpose

Identification of reliable risk factors for recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) has important implications. Left atrial (LA) pressure is a largely observator-independent parameter that can easily be determined after transseptal puncture. The purpose of this study was to investigate the predictive value of LA pressure for AF recurrence after PVI.

Methods

Two hundred five consecutive patients with paroxysmal or persistent AF scheduled for first PVI were included. Baseline clinical data were collected. During PVI, LA pressure was determined invasively after transseptal puncture. PVI was performed with radiofrequency or cryoenergy, and patients were followed for 25?±?7 months.

Results

One hundred five (51 %) patients had AF recurrence. Patients with persistent AF prior to ablation had significantly more recurrences than patients with paroxysmal AF (70.1 vs. 42.0 %, p?<?0.001). Mean LA pressure was significantly higher in patients with recurrence of AF (13.4?±?7.1 vs. 11.0?±?5.2 mmHg, p?=?0.007), as was mean LA volume index (40.1?±?18.5 vs. 33.0?±?11.2 mL/m², p?<?0.001). In the multivariate analysis, mean LA pressure was predictive in patients with normal or mildly enlarged LA, while AF type was not predictive. For each 1-mmHg increase in LA pressure, the risk of AF recurrence increased by 11 % in this subgroup. In patients with moderately or severely enlarged LA, AF type was predictive whereas LA pressure was not.

Conclusion

LA pressure, AF type, and LA volume index are independent predictors for recurrence of AF after PVI. LA pressure may be helpful especially in patients with small atria, where AF type is not predictive.     

Left atrial reverse remodeling and prevention of progression of atrial fibrillation with atrial resynchronization device therapy utilizing dual-site right atrial pacing in patients with atrial fibrillation refractory to antiarrhythmic drugs or catheter ablation

Introduction

Dual-site right atrial pacing (DAP) produces electrical atrial resynchronization but its long-term effect on the atrial mechanical function in patients with refractory atrial fibrillation (AF) has not been studied.

Methods

Drug-refractory paroxysmal (PAF) and persistent AF (PRAF) patients previously implanted with a dual-site right atrial pacemaker (DAP) with minimal ventricular pacing modes (AAIR or DDDR mode with long AV delay) were studied. Echocardiographic structural (left atrial diameter [LAD] and left ventricular [LV] end diastolic diameter [EDD], end systolic diameter [ESD]) and functional (ejection fraction [EF]) parameters were serially assessed prior to, after medium-term (n?=?39) and long-term (n?=?34) exposure to DAP.

Results

During medium-term follow-up (n?=?4.5 months), there was improvement in left atrial function. Mean peak A wave flow velocity increased with DAP as compared to baseline (75?±?19 vs. 63?±?23 cm/s, p?=?0.003). The long-term impact of DAP was studied with baseline findings being compared with last follow-up data with a mean interval of 37?±?25 (range 7–145) months. Mean LAD declined from 45?±?5 mm at baseline to 42?±?7 mm (p?=?0.003). Mean LVEF was unchanged from 52?±?9 % at baseline and 54?±?6 % at last follow-up (p?=?0.3). There was no significant change in LV dimensions with mean LVEDD being 51?±?6 mm at baseline and 53?±?5 mm at last follow-up (p?=?0.3). Mean LVESD also remained unchanged from 35?±?6 mm at baseline to 33?±?6 mm at last follow-up (p?=?0.47). During long-term follow-up, 30 patients (89 %) remained in sinus or atrial paced rhythm as assessed by device diagnostics at 3 years.

Conclusions

DAP can achieve long-term atrial reverse remodeling and preserve LV systolic function. DAP when added to antiarrhythmic drug (AAD) and/or catheter ablation (ABL) maintains long-term rhythm control and prevents AF progression in elderly refractory AF patients. Reverse remodeling with DAP may contribute to long-term rhythm control.     

Inner lumen mapping catheter-facilitated big cryoballoon treatment for atrial fibrillation shortens procedural duration and fluoroscopic exposure with comparable mid-term efficacy

Purpose

This study aims to investigate whether the use of a novel inner lumen circular mapping catheter (IMC) can shorten the procedural duration and fluoroscopic exposure of the single transseptal big cryoballoon (CB) pulmonary vein isolation (PVI) procedures in patients with atrial fibrillation (AF).

Methods

This is a prospective non-randomized case–control study. Forty-two patients (28 men, mean age 55.7?±?12.1) with drug-refractory paroxysmal or persistent AF and underwent CB PVI procedures were divided into Group A (conventional single transseptal big CB approach, n?=?21) and Group B (IMC-facilitated approach, n?=?21). They were compared in the co-primary endpoints: (1) procedural duration and (2) fluoroscopic exposure and secondary endpoints: (1) 6-month AF-free survival and (2) number of cryo-applications.

Results

Both the procedural duration (162?±?26 vs. 215?±?25 min; p?<?0.001) and fluoroscopic exposure (44.1?±?10.4 vs. 56.8?±?11.7 min; p?=?0.001) were significantly shorter in Group B than Group A patients. With multivariate stepwise regression, only the use of IMC was an independent predictor for procedural duration (β?=??59; 95 % CI, ?84.1 to ?33.8; p?<?0.001) and fluoroscopic exposure (β?=??16.9; 95 % CI, ?28.4 to ?5.4; p?=?0.006). The number of cryo-applications was significantly fewer in Group B than Group A patients (median 8 vs. 11; p?=?0.001). There was no significant difference in the 6-month AF-free survival between the two approaches (57 % vs. 71 %; p?=?0.351).

Conclusions

Compared to conventional single transseptal big CB PVI procedures, the use of IMC may reduce procedural duration, fluoroscopic exposure and the number of cryo-applications with comparable mid-term efficacy.     

Outcome of pulmonary vein isolation ablation for paroxysmal atrial fibrillation: predictive role of left atrial mechanical dyssynchrony by speckle tracking echocardiography

Introduction

Although few clinical variables have been associated with recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) the role of left atrial (LA) mechanical function in the outcome of catheter ablation of AF is not adequately defined. The aim of our study was to determine whether LA mechanical dyssynchrony as evaluated by speckle tracking echocardiography can predict outcome of PVI ablation procedure in patients with paroxysmal AF.

Methods

Twenty-five patients (age 58?±?11 years, [mean ± standard deviation], 17 males) with paroxysmal AF who met specific enrollment criteria pertaining to clinical presentation and follow-up, assessment of LA mechanical dyssynchrony, and strategy of catheter ablation procedure were enrolled. For LA mechanical dyssynchrony assessment, the time to peak longitudinal strain (TPk) in opposing walls in the midportion of the LA walls at peak atrial contraction in standard two- and four-chamber echocardiographic views by vector velocity imaging (VVI) was measured. Outcome of PVI procedure, whether no recurrence (NR) or AF recurrence (AFR) after 3 months of post-procedural blanking period, was evaluated based on AF-related symptoms and documentation of AF by electrocardiogram, continuous 24-h Holter, and intermittent event monitor recordings.

Results

During a follow-up period of 20.3?±?8.6 months, 18 out of 25 (72 %) patients had no recurrence (NR group), and 7 out of 25 (28 %) patients had recurrence of AF (AFR group). Significant gender difference was observed in terms of outcome such that all AFR patients were men and no woman had recurrence of AF. Between the NR and AFR groups, neither the left atrial diameter, 4.0?±?0.3 and 4.2?±?0.2 cm, respectively (p?=?0.2), nor the left atrial volume indexes, 45?±?15 and 48?±?20 ml/m², respectively (p?=?0.56), were statistically significantly different. For LA mechanical function, compared to the patients in NR group who had maximum opposing wall TPk delay of 39.9?±?12.0 ms, those in the AFR group demonstrated significantly more LA mechanical dyssynchrony with maximum opposing wall TPk delay of 64.4?±?17.0 ms prior to ablation (p?=?0.007). Using receiver operative characteristic analyses of the data that had an area under the curve of 0.865, we identified a maximum opposing wall delay cutoff value of 51 ms which predicted AF recurrence with sensitivity and specificity values of 89 and 72 %, respectively (p?=?0.005).

Conclusions

Speckle tracking strain analysis echocardiography can evaluate the LA mechanical dyssynchrony quantitatively. The severity of LA mechanical dyssynchrony by VVI can predict the outcome of PVI catheter ablation for paroxysmal AF.     

Improvement of left ventricular diastolic function and left atrial reverse remodeling after catheter ablation of premature ventricular complexes

Aims

Catheter ablation of premature ventricular complexes (PVC) improves left ventricular (LV) systolic performance in certain patients; however, the effect on diastolic function and left atrial (LA) remodeling is unclear. We assessed the effects of catheter ablation of PVCs on parameters of LV diastolic function and LA remodeling.

Methods

Forty-seven patients (age 65?±?10 years, 46 men) who underwent catheter ablation for symptomatic PVCs were evaluated using two-dimensional echocardiography before and 6?±?2 months after ablation. The measured diastolic indices included mitral inflow parameters (E wave, A wave, E/A ratio, and deceleration time (DT)), mitral lateral annulus early diastolic velocity (Ea), and E/Ea ratio. The LA volume was measured using modified biplane Simpson's method. We also compared the changes in the left atrial volumes and left atrial volume index (LAVI) after PVC ablation.

Results

After catheter ablation of PVCs, the mean LV ejection fraction (EF) increased significantly (49.9?±?10.3 vs. 42.8?±?11.8, p?<?0.01). Significant improvement was also seen in A wave velocity (71.3?±?17.1 vs. 59.5?±?15.1 cm/s, p?=?0.039), E/A ratio (1.42?±?0.6 vs. 1.07?±?0.5 ml, p?=?0.034), Ea (8.9?±?3.9 vs. 6.8?±?2.9 cm/s, p?=?0.04), and E/Ea ratio (15.4?±?5.8 vs. 10.6?±?3.4, p?=?0.027), whereas mitral E and DT did not show significant change. LAVI decreased significantly after ablation (44.4?±?14.8 vs. 36.7?±?12.5, p?<?0.001). Significant improvement in LAVI was also seen in patients with normal baseline LVEF (p?=?0.04).

Conclusion

Catheter ablation of PVCs improved LV diastolic function and resulted in left atrial reverse remodeling.     

Predictive value of total atrial conduction time measured with tissue Doppler imaging for postoperative atrial fibrillation after coronary artery bypass surgery

Objective

Postoperative atrial fibrillation (POAF) complicating coronary artery bypass grafting surgery (CABG) increases morbidity and stroke risk. Total atrial conduction time (PA-TDI duration) has been identified as an independent predictor of new-onset atrial fibrillation (AF). We aimed to assess whether PA-TDI duration is a predictor of AF after CABG.

Methods

In 128 patients who had undergone CABG, preoperative clinical and echocardiographic data were compared between patients with and without POAF. The PA-TDI duration was assessed by measuring the time interval between the beginning of the P wave on the surface ECG and point of the peak A wave on TDI from left atrium (LA) lateral wall just over the mitral annulus.

Results

Patients with POAF (38/128, 29.6 %) were older (68.1?±?11.1 vs. 59.3?±?10.2 years; p?<?0.001), had higher LA maximum volume, had prolonged PA-TDI duration, and had lower ejection fraction compared with patients without POAF. PA-TDI duration was found to be significantly increased in POAF group (134.3?±?19.7 vs. 112.5?±?17.7 ms; p?=?0.01). On multivariate analysis, age (95 % CI?=?1.03–1.09; p?=?0.003), LA maximum volume (95 % CI?=?1.01–1.06; p?=?0.03), and prolonged PA-TDI duration (95 % CI, 1.02–1.05; p?=?0.001) were found to be the independent risk factors of POAF.

Conclusions

In this study, LA maximum volume and PA-TDI duration were found to be the independent predictors of the development of POAF after CABG. Echocardiographic predictors of left atrial electromechanical dysfunction may be useful in risk stratifying of patients in terms of POAF development after CABG.     

Fibrosis and electrophysiological characteristics of the atrial appendage in patients with atrial fibrillation and structural heart disease

Purpose

This study was conducted to investigate the degree of fibrosis in atrial appendages of patients with and without atrial fibrillation (AF) undergoing cardiac surgery. In addition, we hypothesized that areas of atrial fibrosis can be identified by electrogram fractionation and low voltage for potential ablation therapy.

Methods

Interstitial fibrosis from right (RAA) and/or left atrial appendages (LAA) was studied in patients with sinus rhythm (SR, n?=?8), paroxysmal (n?=?21), and persistent AF (n?=?20) undergoing coronary artery bypass and/or aortic or mitral valve surgery. Atrial fibrosis quantification was performed with Masson trichrome staining. Intraoperative bipolar epicardial electrophysiological measurements were performed to correlate fibrosis to electrogram fractionation, voltage, and AF cycle length.

Results

The average degree of fibrosis was 11.2?±?7.2 % in the LAA and 22.8?±?7.6 % in the RAA (p?<?0.001). Fibrosis was not significantly higher in paroxysmal AF patients compared to SR subjects (18.2?±?8.7 versus 20.7?±?5.3 %). Persistent AF patients had a higher degree of LAA and RAA fibrosis compared to paroxysmal AF patients (LAA 14.6?±?8.7 versus 8.6?±?4.7 %, p?=?0.02, and RAA 28.2?±?7.9 versus 18.2?±?8.7 %, respectively, p?=?0.04). The left atrial end diastolic volume index was higher in persistent AF patients compared to SR controls (38.3?±?16.4 and 28?±?11 ml/m², respectively, p?=?0.04). No correlation between atrial fibrosis and electrogram fractionation or voltage was found.

Conclusion

Patients with structural heart disease undergoing cardiac surgery have more fibrosis in the RAA than in the LAA. Furthermore, RAA fibrosis is increased in persistent AF but not paroxysmal AF patients compared to control subjects. Electrogram fractionation and low voltage did not provide accurate identification of the fibrotic substrate.     

Hemodynamic impact of percutaneous left atrial appendage closure in patients with paroxysmal atrial fibrillation

Purpose

Percutaneous left atrial appendage (LAA) closure has become a valid alternative to anticoagulation therapy for the prevention of thromboembolic events in patients with atrial fibrillation (AF). However, scarce data exist on the impact of LAA closure on left atrial and ventricular function. We sought to assess the acute hemodynamic changes associated with percutaneous LAA closure in patients with paroxysmal AF.

Methods

The study population consisted of 31 patients (mean age 73?±?10 years; 49% women) with paroxysmal AF who underwent successful percutaneous LAA closure. All patients were in sinus rhythm and underwent 2D transthoracic echocardiography at baseline and the day after the procedure. A subset of 14 patients underwent preprocedural cardiac computed tomography (CT) with 3D LA and LAA reconstruction.

Results

Left ventricular systolic function parameters and LA volumetric indexes remained unchanged after the procedure. No significant changes in left ventricular stroke volume (72.4?±?16.0 vs. 73.3?±?15.7 mL, p?=?0.55) or LA stroke volume (total 15.6?±?4.2 vs. 14.6?±?4.2 mL, p?=?0.21; passive 9.0?±?2.8 vs. 8.3?±?2.6 mL, p?=?0.31; active 10.3?±?5.6 vs. 10.0?±?6.4 mL, p?=?0.72) occurred following LAA closure. Mean ratio of LAA to LA volume by 3D CT was 10.2?±?2.3%. No correlation was found between LAA/LA ratio and changes in LA stroke volume (r?=?0.35, p?=?0.22) or left ventricular stroke volume (r?=?0.28, p?=?0.33).

Conclusions

The LAA accounts for about 10% of the total LA volume, but percutaneous LAA closure did not translate into any significant changes in LA and left ventricular function.

     

Left atrial wall thickness and outcomes of catheter ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy

Purpose

Catheter ablation of atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) is still challenging, and it is unclear whether the difficulty is caused by the hypertrophy of left atrial (LA) myocardial wall thickness. The objective of the study was to compare the LA wall thickness and AF ablation outcomes between patients with HCM and those without structural heart disease.

Methods

The present study enrolled 17 consecutive HCM patients (63?±?12 years) with drug-refractory AF and 34 control patients without any detectable heart disease, whose age, gender, type of AF, and LA dimension were matched to the HCM patients. The myocardial wall thickness of 11 distinct LA locations, measured using 64-slice computed tomography images, and AF ablation outcomes were compared between the two groups.

Results

The LA wall thickness did not differ at 9 of the 11 locations and was significantly thinner in the HCM patients than in the control patients at the mid-posterior wall (1.44?±?0.17 vs. 1.58?±?0.22, p?=?0.04) and infero-posterior wall (1.62?±?0.16 vs. 1.74?±?0.18, p?=?0.03). Although antiarrhythmic drugs were used more frequently in the HCM patients (p?=?0.008), the rate of maintaining sinus rhythm during the follow-up did not differ between the HCM and control patients (53 vs. 56 % after the initial ablation [log-rank p?=?0.78] and 82 and 88 % after the repeat procedure [log-rank p?=?0.35]).

Conclusions

The LA wall in the HCM patients with AF was not thicker than that of the matched patients without structural heart disease. Catheter ablation of AF showed favorable outcomes in both patient groups.     

Left atrial mechanics predict the success of pulmonary vein isolation in patients with atrial fibrillation

Background

Atrial fibrillation (AF) is a common arrhythmia with relevant impact on mortality and morbidity. Pulmonary vein isolation (PVI) is an established therapy in patients who remain symptomatic under optimal medical therapy. However, up to 70 % of patients present with recurrence of AF after PVI. Therefore, identifying ideal candidates is an unmet clinical need. Left atrial (LA) fibrosis is associated with reduced LA function. Analysis of LA mechanics using 2D speckle tracking echocardiography (STE) might give more insight into LA substrates and be therefore of predictive value.

Methods

This prospective single-center pilot study included 31 patients (mean age, 62.3?±?9.1 years; 19 males) with AF who underwent PVI and 20 matched healthy controls (mean age, 60.6?±?6.6 years; 10 males). 2D STE strain indices of LA reservoir (R_LA), conduit, and, if feasible, contractile function, were analyzed before and 6 months after PVI. Assessment of the LV diastolic function was based on standard indices. Responders to PVI were defined as being asymptomatic and free of AF in a 7-day Holter-ECG after 6 months.

Results

At baseline, all patients with AF had significantly lower reservoir and contractile function compared with controls. After 6 months, 17 patients (54.8 %) were identified as responders. At baseline, the reservoir function was significantly higher in responders compared with nonresponders (32.7?±?11.1 vs. 22.9?±?10.9 %; P?=?0.019). Only in responders, R_LA and contractile LA function improved and reached normal values whereas LA function remained unchanged in nonresponders. In a ROC analysis, a R_LA value of ≥19.5 % discriminated responders and nonresponders in patients with persistent AF with a sensitivity of 86 % and a specificity of 100 % (P?=?0.012; area under the curve 0.943; CI, 0.81–1.0).

Conclusions

LA reservoir function helps to predict efficacy of PVI after 6 months. Only in responders, reservoir, and contractile function normalized within 6 months after PVI indicating a lower level of atrial remodeling at baseline. No deleterious effects of ablation were detected in nonresponders.     

The acute effect of percutaneous mitral balloon valvuloplasty on atrial electromechanical delay and P-wave dispersion in patients with mitral stenosis

Background and aim of the study

The predisposition to atrial fibrillation (AF) in mitral stenosis (MS) has been demonstrated with several electrocardiographic (increased P-wave dispersion) and echocardiographic parameters (atrial electromechanical delay). Despite the improvement in P-wave dispersion after percutaneous mitral balloon valvuloplasty (PMBV), the changes in echocardiographic parameters related to AF risk are unknown. In this study we aimed to investigate the acute effect of PMBV on atrial electromechanical delay (EMD) assessed by tissue Doppler echocardiography in addition to electrocardiographic parameters.

Materials and methods

This single-center study consisted of 30 patients with moderate or severe MS (23 females and seven males, aged 36.5?±?8.5 years, with a mean MVA of 1.1?±?0.2 cm²) who underwent successful PMBV without complication at our clinic and 20 healthy volunteers from hospital staff as a control group (16 females and four males, aged 35.4?±?6 years). We compared the two groups in regard to clinical, electrocardiographic and echocardiographic features. The patients with MS were also evaluated after PMBV within 72 h of the procedure. The P-wave dispersion was calculated from12-lead ECG. Interatrial and intra-atrial EMDs were measured by tissue Doppler echocardiography. These ECG and echocardiographic parameters after PMBV were compared with previous values.

Results

The maximum P-wave duration (138?±?15 vs. 101?±?6 ms, p?<?0.01), PWD (58?±?18 vs 23?±?4, p?<?0.01), the interatrial (55?±?16 vs 36?±?11 ms, p?<?0.01) and left-sided intra-atrial EMD (40?±?11 vs 24?±?12 ms, p?<?0.01) were higher in patients with MS than in healthy subjects. The left atrial (LA) diameter, LA volume and LA volume index had positive association with the interatrial (r?=?0.5, p?<?0.01; r?=?0.5, p?<?0.01 and r?=?0.5, p?<?0.01, respectively) and left-sided intra-atrial EMD (r?=?0.5, p?<?0.01; r?=?0.4, p?<?0.01; r?=?0.4, p?<?0.01 respectively). After PMBV, the interatrial (55?±?16 vs. 40?±?11 ms, p?<?0.01) and left-sided intra-atrial EMD (40?±?11 vs 31?±?10, p?<?0.01) showed significant improvement compared to previous values. There was also a statistically significant difference in maximum P-wave duration and PWD between pre-and post-PMBV (138?±?15 vs 130?±?14, p?<?0.01, and 58?±?18 vs 49?±?16, p?<?0.01, respectively).

Conclusions

Our study shows that PMBV has a favorable effect on the electrocardiographic and echocardiographic parameters related with AF risk in patients with MS.     

Effect of pulmonary vein isolation on atrial fibrillation recurrence after ablation of paroxysmal supraventricular tachycardia in patients with high dispersion of atrial refractoriness

Purpose

This study aimed to assess pulmonary vein isolation (PVI) efficacy on atrial fibrillation (AF) recurrence and to determine a predictive dispersion of atrial refractoriness (dERP) value for performing PVI in paroxysmal supraventricular tachycardia (PSVT) patients.

Methods

Of 67 PSVT patients with past AF episodes who underwent accessory pathway (AP) or slow pathway of atrioventricular node ablation, 63 (4 lost to follow-up or death) were assigned into two groups (A and B; 29 and 34 patients, respectively) based on whether they underwent or not subsequent PVI, and all were followed-up up to 3 years. Atrial effective refractory period (AERP) and dERP were measured during the ablation procedure.

Results

In receiver operating characteristic (ROC) curve analysis, dERP?=?74.5 ms effectively predicted AF recurrence in PSVT patients (p?=?0.003). Difference in AF recurrence rate between groups did not reach statistical significance (17.2 %, 5/29 vs. 29.4 %, 10/34, p?=?0.203). AF recurrence rate was lower in patients with dERP >74.5 ms who underwent AP or slow-pathway ablation with vs. without PVI (18.2 %, 2/11 vs. 77.8 %, 7/9, p?=?0.012).

Conclusions

PVI addition after successful AP or slow pathway of atrioventricular node ablation significantly reduced AF recurrence in PSVT patients with high atrial vulnerability (dERP >74.5 ms).     

High prevalence of obstructive sleep apnea in patients with resistant paroxysmal atrial fibrillation after pulmonary vein isolation

Objectives

To address the question whether obstructive sleep apnea (OSA) is associated with the recurrence of paroxysmal atrial fibrillation (AF) in patients treated with ≥2 pulmonary vein isolation procedures.

Patients and Methods

In this study, we included adults with therapy-resistant symptomatic paroxysmal AF, defined as AF recurring after ≥2 PV-isolation procedures (n?=?23). For comparison, we selected another cohort of patients being successfully treated by one PV isolation without AF recurrence within 6 months (n?=?23). PV isolation was performed by radiofrequency with an open irrigated tip catheter. Each of the 46 participants completed an overnight polygraphic study. The two groups were matched for age, gender, and ejection fraction. Patients were late middle-aged (65?±?7 vs 63?±?10 years, P?=?0.23), white (100%), and overweight (BMI 27.3?±?3.6 vs. 27.2?±?4.6 kg/m², P?=?0.97).

Results

The prevalence of sleep apnea, defined as an apnea–hypopnea index (AHI) of >5 per hour of sleep, was 87% in patients with therapy-resistant AF compared to 48% in the control cohort (P?=?0.005). In addition, OSA was more severe in the resistant AF group indicated by a significantly higher AHI (27?±?22 vs 12?±?16, P?=?0.01).

Conclusion

The extraordinarily high prevalence of sleep apnea in patients with recurrent paroxysmal AF supports its presumable role in the pathogenesis of AF and demands further controlled prospective trials. Moreover, OSA should inherently be considered in patients with therapy-resistant AF.     

Effect of periodic pacemaker optimization on left atrial reverse remodeling in long-term cardiac resynchronization therapy

Purpose

Few data exist about the effect of cardiac resynchronization therapy (CRT) on left atrial (LA) reverse remodeling and function, and whether echocardiographic (echo)-guide pacemaker optimization of atrioventricular and interventricular delays could beneficially affect LA reverse remodeling in long-term CRT therapy.

Methods

Effect of periodic pacemaker optimization on LA reverse remodeling induced by CRT was analyzed in 113 consecutive patients (mean age, 60?±?11 years) and stratified according to periodic pacemaker optimization (group 1) and nonperiodic pacemaker optimization (group 2). Left atrial volumes index percent changes were assessed at every continuing 6-month follow-up visit. The primary endpoint was LA reverse remodeling. The secondary endpoint included left ventricular reverse remodeling and left ventricular ejection fraction.

Results

There is no significant difference of follow-up duration in subgroups (42.43?±?18.94 months in group 1 vs 37.76?±?20.24 months in group 2, p?=?0.228). The responder’s rate of subgroups showed similar after follow-up of 12 months (60.0 vs 53.2 %, p?=?0.483). After 24-month follow-up, the mean reduction of LAV index was similar in two groups (10.34 vs 7.53 %, p?=?0.257). The improvement effect of LA reverse remodeling induced by CRT was sustained during 24-month follow-up to the end of current study in periodic pacemaker optimization group. The degree of LAV index percent reduction was directly correlated to periodic pacemaker optimization at end of current analysis (17.13 vs 10.35 %, p?=?0.047).

Conclusions

Periodic echo-guide pacemaker optimization of atrioventricular and interventricular delays plays a positive role on LA reverse remodeling in long-term CRT therapy.     

Long-term outcomes of adjunctive complex fractionated electrogram ablation to pulmonary vein isolation as treatment for non-paroxysmal atrial fibrillation

Purpose

The adjunctive ablation of areas of complex fractionated electrogram (CFE) to pulmonary vein isolation (PVI) is an emerging strategy for patients with non-paroxysmal atrial fibrillation (AF). We studied the long-term outcomes of this approach.

Methods

Sixty-six patients (mean age 58?±?9, 86.4 % male) with non-paroxysmal AF underwent ablation procedures consisting of PVI plus extensive CFE ablation. Post-ablation atrial tachycardia (AT) was also targeted if presented. All patients were followed up regularly on an ambulatory basis by means of ECG and Holter recordings.

Results

After a mean follow-up period of 40?±?14 months and 1.7?±?0.7 procedures, 38 patients (57.6 %) were free of arrhythmias, 15 (22.7 %) displayed clinical improvement and 13 (19.7 %) suffered recurrences of persistent AF/AT. Females displayed poorer long-term outcomes than males (arrhythmia-free 22.2 vs. 63.2 %, p?<?0.05). Multivariate analysis demonstrated that long duration of uninterrupted AF prior to the procedure was an additional predictor of long-term failure (odds ratio 1.49, p?<?0.01). ROC analysis (area under curve 0.80; p?<?0.001) estimated 3.5 years as the optimal cut-off point for predicting long-term failure (sensitivity 85 %, specificity 74 %). The cumulative data showed a significantly higher percentage of arrhythmia-free patients when the duration of AF had been ≤2 years (69.7 %) and ≤4 years (68.9 %) than when it was >4 years (33.3 %; p?<?0.01).

Conclusions

PVI?+?CFE ablation in non-paroxysmal AF appears to provide a reasonable proportion of arrhythmia-free patients during long-term follow-up. Poorer long-term results can be expected among female patients and those with an uninterrupted AF duration of >4 years.     

A combination of P wave electrocardiography and plasma brain natriuretic peptide level for predicting the progression to persistent atrial fibrillation: comparisons of sympathetic activity and left atrial size

Purpose

Development of atrial fibrillation (AF) is complexly associated with electrical and structural remodeling and other factors every stage of AF development. We hypothesized that P wave electrocardiography with an elevated brain natriuretic peptide (BNP) level would be associated with the progression to persistence from paroxysmal AF.

Methods

P wave electrocardiography such as a maximum P wave duration (MPWD) and dispersion by 12-leads ECG, heart/mediastinum (H/M) ratio by delayed iodine-123 metaiodobenzylguanidine scintigraphic imaging, left ventricular ejection fraction (LVEF), and left atrial dimension (LAD) by echocardiography, and plasma BNP level were measured to evaluate the electrical and structural properties and sympathetic activity in 71 patients (mean ± standard deviation, age: 67?±?13 years, 63.4 % males) with idiopathic paroxysmal AF.

Results

Over a 12.9-year follow-up period, AF developed into persistent AF in 30 patients. A wider MPWD (>129 ms) (p?=?0.001), wider P wave dispersion (>60 ms) (p?=?0.001), LAD enlargement (>40 mm) (p?=?0.001), higher BNP level (>72 pg/mL) (p?=?0.002), lower H/M ratio (≤2.7) (p?=?0.025), and lower LVEF (≤60 %) (p?=?0.035) were associated with the progression to persistent AF, and the wide MPWD was an independently powerful predictor of the progression to persistent AF with a hazard ratio (HR) of 5.49 [95 % confidence interval (CI) 2.38–12.7, p?<?0.0001] after adjusting for potential confounding variables, such as age and sex. The combination of wide MPWD and elevated BNP level was additive and incremental prognostic power with 13.3 [2.16–13, p?<?0.0001].

Conclusion

The wide MPWD with elevated BNP level was associated with the progression to persistent AF.     

Conduction recovery in patients with recurrent atrial fibrillation after pulmonary vein isolation using multi-electrode duty cycled radiofrequency ablation

Introduction

The pulmonary vein ablation catheter (PVAC) is designed for pulmonary vein isolation (PVI). Electrical reconnection of pulmonary veins is believed to result in AF recurrence. The purpose of this study was to establish the location and extent of PV reconnection after PVI with the PVAC catheter.

Methods and results

Eighty-two patients (79 % male, age 60?±?9 years) that underwent a redo procedure for recurrent AF after PVAC ablation were assessed for prevalence and location of reconnection. The number of reconnected PV’s was 0, 1, 2, 3, or 4 in 2 (2.4 %), 14 (17 %), 23 (28 %), 28 (34 %), and 15 (18 %) patients, respectively. Reconnection of left superior, left inferior, left common, right superior, and right inferior PV’s was found in 66, 63, 83, 57, and 67 %, respectively (p?=?0.48). In the left PV’s, reconnection was located significantly more anterior than posterior; LSPV anterior 32/70 vs posterior 13/70 (p?<?0.01), LIPV anterior 26/70 vs posterior 9/70 (p?<?0.01). In the right PV’s reconnection was distributed equally in all quadrants. Different modes of RF delivery during PVAC ablation (bipolar/unipolar 2:1 [n?=?35] vs. 4:1 [n?=?47]) yielded comparable rates of PV reconnection. During follow-up (median 296 days) no AF/AT was documented in 57 patients (70 %).

Conclusion

Almost all patients (98 %) with AF after PVAC ablation show reconnection of at least one PV. All PV’s are equally likely to show reconnection. In the left PV’s, reconnection was found more often anteriorly than posteriorly. During pulmonary vein isolation with the PVAC catheter, prevalent sites of reconnection deserve close attention to increase success.