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 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.     

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.     

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.     

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.     

Assessment of atrial conduction time in patients with polycystic ovary syndrome

Background

Polycystic ovary syndrome (PCOS) is closely related to increased cardiovascular risk in women of reproductive age. Atrial conduction abnormalities in these patients have not been investigated in terms of atrial electromechanical delay measured by tissue Doppler imaging (TDI) as an early predictor of atrial fibrillation development. The aim of this study was to evaluate whether TDI-derived atrial conduction time is prolonged in PCOS.

Methods

The study included 51 patients with PCOS and 48 age-matched healthy controls. P-wave dispersion (PWD) was calculated on the 12-lead surface electrocardiogram. Systolic and diastolic left ventricular (LV) functions, atrial electromechanical coupling, intraatrial and interatrial electromechanical delays were measured with conventional echocardiography and TDI.

Results

PWD was higher in PCOS women (50.45?±?3.7 vs 34.73?±?6.7 ms, p?=?0.008). Interatrial and intraatrial electromechanical delay were found longer in patients with PCOS compared to controls (41.9?±?9.0 vs 22.2?±?6.6 ms, p?p?r?=?0.54, p?C-reactive protein levels (r?=?0.68, p?r?=?0.53, p?r?=?0.31, p?=?0.04; r?=?0.37, p?=?0.021, respectively) and negatively correlated with flow propagation velocity (r?=??0.38, p?=?0.014).

Conclusion

This study shows that atrial electromechanical delay is prolonged in PCOS patients. Atrial electromechanical delay prolongation is related to low-grade inflammation, insulin resistance, and LV diastolic dysfunction in PCOS.     

Predictors of left atrium appendage clot detection despite on-target warfarin prevention for atrial fibrillation

Background and purpose

The antithrombotic management of atrial fibrillation (AF) is currently based on clinical scores (CHADS₂ or CHA₂DS₂VASc). The prevalence of left atrium (LA) thrombi in effectively anticoagulated AF patients has been reported as being up to 7.7 %. We tried to correlate LA/LA appendage (LAA) thrombus detection with possible clinical predictors in warfarin-treated patients.

Methods

We performed trans-esophageal echocardiography on 430 patients (mean age, 60.3?±?9.8 years) receiving oral anticoagulant (OAC) therapy and undergoing pulmonary vein isolation. In 10/430 (2.3 %), an LA thrombus was found despite therapeutic OAC (mean INR 2.6?±?0.6; range, 2.0–3.8) over the previous 4 weeks.

Results

Two study groups were identified:

1. T-positive group?=?with LAA thrombus (10 patients)
2. T-negative group?=?without LAA thrombus (420 patients)

The T-positive patients had a higher CHADS₂ score (1.5?±?0.7 versus 0.7?±?0.8; p?=?0.004), a lower LVEF (54.7?±?9.5 % versus 60.2?±?7.4; p?=?0.02), and a larger LA size (LA diameter, 56?±?12.2 mm versus 46?±?6.5 mm; p? <?0.001and normalized LA volume: 140.2?±?66 ml/m² vs. 67?±?39 ml/m²; p?<?0.05). On multivariate analysis, a larger LA diameter and normalized LA volume (OR, 1.14; 95 % C.I., 1.04–1.26; p?=?0.006 and OR, 1.02; 95 % C.I., 1.01–1.03; p?=?0.001, respectively) and a higher CHA₂DS₂VASc score (OR, 2.4; 95 % C.I., 1.4–4.2; p?=?0.001) predicted left atrium appendage (LAA) thrombus. In another 42/430 (9.8 %) patients, an LA spontaneous echo-contrast (SEC) was detected. Thus, cumulatively, 52/430 (12.1 %) patients had either LAA thrombi (10 patients) or SEC (42 patients). LA diameter continued to predict the presence of either thrombi or SEC (OR, 1.14; 95 % C.I., 1.07–1.2; p?<?0.05).

Conclusions

We found a 2.3 % prevalence of LA thrombus (12.1 % when SEC was also considered). The thrombus was present despite on-target warfarin prevention. In addition to a higher CHA₂DS₂VASc score, a larger LA size was a strong predictor of clot detection.     

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.     

Mitral regurgitation recovery and atrial reverse remodeling following pulmonary vein isolation procedure in patients with atrial fibrillation: a clinical observation proof-of-concept cardiac MRI study

Background

Reverse remodeling of the left atrium (LA) following successful pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) has been well documented. However, mitral regurgitation (MR) recovery after successful PVI has never been demonstrated systematically. The objective of our study was to retrospectively analyze the effectiveness of PVI in patients with AF on recovery of MR using cardiac magnetic resonance (CMR) imaging.

Methods

Prior to PVI, patients underwent a clinically indicated CMR imaging. Post-PVI (6?±?2 months), patients underwent a follow-up MRI and were classified into two groups—responders (R) and non-responders (NR) to PVI—as assessed by cessation of AF at the end of the prespecified 6-month (14-day “P” sensitive event monitor defined) follow-up period. Furthermore, CMR was used to evaluate the severity of MR (0 to 4+) and to relate changes in MR to LA volumes as well as mitral apparatus geometry. Patients who had mild and higher MR (2+) on baseline CMR and had a post-PVI CMR were selected for final analysis.

Results

Out of the consecutive 122 patients with AF who underwent PVI, 74 patients that had mitral regurgitation on initial CMR were included in the study. Of these74 patients with AF with MR, 52 (70 %) were classified as R and 22 (30 %) were classified as NR. Baseline demographics were similar between the groups. In the subgroup with mild to severe MR, pre vs. post in the R group MR severity significantly improved (mean?=?2.3, median?=?2.0 vs. mean?=?1.0, median?=?1.0, p?<?0.0001) and was matched by favorable reverse remodeling of the mitral apparatus geometry (annulus?=?35?±?4 vs. 33?±?3 mm, p?<?0.002; tenting area?=?175?±?56 vs.137?±?37 mm², p?<?0.003; tenting height?=?8?±?2 vs.7?±?2 mm, p?<?0.02; and tenting angle?=?129?±?10° vs. 131?±?11°, p?=?0.1). However, in the NR subgroup, MR failed to improve (mean?=?2.2, median?=?2.0 vs. mean?=?1.5, median?=?1.0, p?=?NS) and paralleled general failure of mitral geometry reverse remodeling (annulus?=?35?±?4 vs. 35?±?4 mm, p?=?0.2; tenting area?=?153?±?39 vs. 152?±?34 mm², p?=?NS; tenting height?=?7?±?1 vs. 7.0?±?2, p?=?0.1; and tenting angle?=?131?±?11° vs. 133?±?10°, p?=?NS). In those with lesser degrees of MR, favorable remodeling was predicated on responder status to PVI. Similarly, other cardiac dimensions pre- to post-PVI favorably improved in the R group, but not in the NR group.

Conclusion

In those with durable maintenance of normal sinus rhythm (NSR), cardiac reverse remodeling demonstrated by 3D CMR occurs and is matched by marked improvements in MR and mitral apparatus, likely contributing to continued maintenance of NSR.     

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.     

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.     

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.     

Why atrial fibrillation recurs in patients who obtained current ablation endpoints with longstanding persistent atrial fibrillation

Purpose

Although several techniques for modification of atrial fibrillation (AF) substrate, such as linear ablation and complex fractionated atrial electrograms (CFAEs) ablation, have been proposed for longstanding persistent AF (LS-AF) and improved the outcome, there was still a certain recurrence rate, even if current ablation endpoints of these techniques were completely achieved. The purpose of this study was to describe the determinants of recurrent AF in patients who obtained current ablation endpoints with LS-AF.

Methods and results

In all, 208 consecutive patients who obtained current ablation endpoints with LS-AF were studied. The current ablation endpoints were defined as complete pulmonary vein isolation, bidirectional block of lines, and disappearance of CFAEs. After a follow-up of 19.9?±?4.1 months, the patients were classified as AF recurrence group and non-AF recurrence group (including patients with sinus rhythm and atrial tachycardia), and 34 (16 %) patients were in the AF recurrence group. The patients in AF recurrence group had higher rates of right atrium (RA) enlargement (67.7 vs. 45.4 %, p?=?0.018) and ≥2 procedure times (58.8 vs. 27.0 %, p?<?0.001), longer AF duration (82.4?±?44.8 vs. 50.8?±?42.8 months, p?<?0.001), and larger left atrium (LA) diameter (49.4?±?6.2 vs. 46.5?±?5.3 mm, p?=?0.007). In the multivariate analysis, RA enlargement, ≥2 procedure times, and AF duration were independent predictors of AF recurrence.

Conclusion

RA enlargement, ≥2 procedure times, and AF duration played important roles in AF recurrence in patients who obtained current ablation endpoints. For these patients with AF recurrence who had already underwent ≥2 procedure times, enlarged RA may contribute to other AF foci and/or substrate, and the ablation strategy may be transformed from LA to RA in the next ablation procedures.     

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.     

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.     

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.     

Reverse atrial electrical remodelling induced by continuous positive airway pressure in patients with severe obstructive sleep apnoea

Background

Obstructive sleep apnoea (OSA) is associated with cardiovascular morbidity and mortality, including atrial arrhythmias. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA; its impact on atrial electrical remodelling has not been fully investigated. Signal-averaged p-wave (SAPW) duration is an accepted marker for atrial electrical remodelling.

Objective

The objective of this study is to determine whether CPAP induces reverse atrial electrical remodelling in patients with severe OSA.

Methods

Consecutive patients attending the Sleep Disorder Clinic at Kingston General Hospital underwent full polysomnography. OSA-negative controls and severe OSA were defined as apnoea–hypopnea index (AHI)?<?5 events/hour and AHI?≥?30 events/hour, respectively. SAPW duration was determined at baseline and after 4–6 weeks of CPAP in severe OSA patients or without intervention controls.

Results

Nineteen severe OSA patients and 10 controls were included in the analysis. Mean AHI and minimum oxygen saturation were 41.4?±?10.1 events/hour and 80.5?±?6.5 % in severe OSA patients and 2.8?±?1.2 events/hour and 91.4?±?2.1 % in controls. At baseline, severe OSA patients had a greater SAPW duration than controls (131.9?±?10.4 vs 122.8?±?10.5 ms; p?=?0.02). After CPAP, there was a significant reduction of SAPW duration in severe OSA patients (131.9?±?10.4 to 126.2?±?8.8 ms; p?<?0.001), while SAPW duration did not change after 4–6 weeks in controls.

Conclusion

CPAP induced reverse atrial electrical remodelling in patients with severe OSA as represented by a significant reduction in SAPW duration.     

Incidence,predictors, and clinical course of atrial tachyarrhythmias in patients with pulmonary hypertension

Background

The prevalence and predictors of atrial tachyarrhythmias (ATa) in patients with pulmonary hypertension (PH) is less well understood.

Methods

We performed a retrospective study including 311 patients with PH, confirmed by right heart catheterization in our center between 2007 and 2011. Baseline characteristics, clinical, echocardiographic, and hemodynamic data were collected and compared between patients with and without ATa.

Results

The mean age was 61?±?13 years with 64 % females. The mean pulmonary artery pressure (mPAP) was 46?±?20 mmHg, mean left ventricular ejection fraction (LVEF) was 55?±?13 %, and mean pulmonary capillary wedge pressure (PCWP) was 19?±?9 mmHg. Of the 311 patients with PH, 121 (39 %) patients had ATa. Patients with ATa were older (p?p?=?0.03), diabetes (p?=?0.015), coronary artery disease (p?p?p?=?0.001), impaired LVEF (p?=?0.02), and left atrial enlargement (p?p?=?0.022). In multivariate analysis using Cox-proportional hazard model, the independent predictors of mortality were age (HR 1.05; p?=?0.003), coronary artery disease (HR 2.34; p?=?0.047), LVEF (HR 0.793; p?=?0.023), and mPAP (HR 1.023; p?=?0.003).

Conclusion

ATa are common in patients with PH. Left heart disease, left atrial enlargement, and elevated PCWP but not right atrial enlargement or mPAP predict the occurrence of ATa in patients with PH.     

Comparative distribution of complex fractionated atrial electrograms, high dominant frequency (HDF) sites during atrial fibrillation and HDF sites during sinus rhythm

Purpose

Complex fractionated atrial electrograms (CFAEs) and high dominant frequency sites during atrial fibrillation (AF-HDF) are related to the maintenance of atrial fibrillation (AF). HDF sites in sinus rhythm (SR-HDF; as defined by frequencies of >70 Hz) are suggested to be abnormal atrial tissue. Relations between these electrophysiologic signals have not been elucidated.

Methods

We investigated the relations between SR-HDF and CFAE and AF-HDF sites during AF. NavX-based maps of CFAE and left atrium (LA)/pulmonary vein (PV) dominant frequency (DF) during AF and DF maps during SR were created for 23 patients with AF (paroxysmal AF (PAF), n?=?14; persistent AF (PerAF), n?=?9).

Results

The extent of overlap between SR-HDF and CFAE sites was 51?±?18 % (as calculated by the LA/PV segments containing both an SR-HDF site and a CFAE site/total LA/PV segments containing an CFAE site) and the extent of overlap between SR-HDF and AF-HDF sites was 50?±?35 % (P?=?0.7464). However, statistically poor agreement was noted for both (kappa values, 0.07?±?0.19 and 0.08?±?0.24, P?=?0.8794). The extent of overlap did not differ between PAF and PerAF patients (SR-HDF and CFAE, 52 % (interquartile range (IQR), 42–59) versus 57 % (IQR, 33–67), P?=?0.5842; SR-HDF and AF-HDF, 43 % (IQR, 25–85) versus 55 % (IQR, 13–83), P?=?0.9465). The bipolar voltage amplitudes of SR-HDF, CFAE, and AF-HDF sites revealed normal voltage areas (1.6 mV (IQR, 0.8–2.7), 1.9 mV (IQR, 1.1–2.8), and 1.5 mV (IQR, 1.7–2.7), respectively).

Conclusions

In both PAF and PerAF, most CFAE and AF-HDF sites did not correspond to the SR-HDF sites or low-voltage area during SR. Thus, most CFAE and DF signals during AF represent functional electrical activities rather than structural remodeling of the atria.