The Relationship Between Endocardial Voltage and Regional Volume in Electroanatomical Remodeled Left Atria in Patients with Atrial Fibrillation: Comparison of Three‐Dimensional Computed Tomographic Images and Voltage Mapping

Background: Long‐standing atrial fibrillation (AF) changes left atrial (LA) morphology, and the LA size is related to recurrence after radiofrequency catheter ablation (RFCA). We hypothesize that LA morphology, based on embryological origin, affects the outcome of RFCA. Methods: We analyzed 3D computed tomographic (CT) images of LA in 70 patients with AF (54 males, 55.6 ± 10.5 years old, paroxysmal AF (PAF):persistent AF (PeAF) = 32:38) who underwent RFCA. Each LA image was divided into venous atrium (VA), anterior LA (ALA), LA appendage (LAA), and both antrum. Absolute and relative volumes were calculated, and the lengths of linear ablation sites were measured. Results: (1) In patients with the mean LA voltage ≤ 2.0 mV, LA volume, especially ALA, was larger (P < 0.01) compared to those with LA voltage > 2.0 mV. (2) The total LA volume was significantly larger (P < 0.01) and LAA voltages (P < 0.05) and conduction velocities (P < 0.05) were lower in patients with PeAF than in those with PAF. (3) In patients with recurrence, LA volume was generally larger (P < 0.01) than in those without recurrence. In PAF patients with recurrence, the relative volume of ALA was significantly larger (P < 0.01) than those without recurrence. Conclusions Morphologically remodeled LA has low endocardial voltage, and enlargement of ALA is more significant in electroanatomically remodeled LA. The disproportional enlargement of ALA was observed more often in PAF patients with recurrence after ablation than those without recurrence.     

The prognostic significance of left atrial appendage peak flow velocity in the recurrence of persistent atrial fibrillation following first radiofrequency catheter ablation

BackgroundAtrial fibrillation (AF) relapse following radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (PeAF) continues to be a concern. This study establishes a connection between left atrial appendage peak flow velocity (LAAV) and recurrence of AF in individuals having PeAF following first RFCA.MethodsWe retrospectively studied 164 successive PeAF patients who had first RFCA between January 2018 and December 2019. Before the ablation, the LAAV was recorded using transesophageal echocardiography (TEE). The demographic and clinical data of the individuals were gathered. Participants were monitored at regular intervals to monitor for recurrence of AF. We employed Cox proportional hazards regression to determine if LAAV, as well as other clinical indicators, were predictive of AF recurrence in follow-up.ResultsIn this study, AF relapse was seen in 43 patients (26.2%) following a median follow-up of 15 [interquartile range (IQR): 12–18] months. It was shown that the LAAV was decreased in individuals who had recurrences of AF (0.36±0.05 vs. 0.45±0.17 m/s, P=0.004). Using Kaplan-Meier analysis, it was discovered that the low LAAV (0.37 m/s) group had a poorer event-free survival rate compared to the high LAAV (>0.37 m/s) group (17.6 vs. 21.2 months, log-rank P=0.002) group. Based on the results of the multivariate Cox regression analysis, a LAAV of fewer than 0.37 m/s [hazard ratio (HR): 2.32; 95% confidence interval (CI): 1.177–4.227; P=0.014] was shown to be an independent predictor of AF recurrence following RFCA.ConclusionsA low LAAV is associated with AF relapse, and it is a predictor of AF relapse following the first RFCA for PeAF. This discovery may be useful in the optimization of treatment strategies and the care of patients with PeAF.     

Hybrid Therapy of Radiofrequency Catheter Ablation and Percutaneous Transvenous Mitral Commissurotomy in Patients With Atrial Fibrillation and Mitral Stenosis

AF Ablation and PTMC. Background: The rhythm control of atrial fibrillation (AF) associated with mitral stenosis (MS) is often difficult using antiarrhythmic drugs (AADs), even after a percutaneous transvenous mitral commissurotomy (PTMC). Few studies have examined the efficacy and safety of simultaneously performing radiofrequency catheter ablation (RFCA) and a PTMC in patients with MS and AF. Methods: Twenty consecutive patients with drug‐resistant AF and rheumatic MS underwent RFCA combined with a PTMC (n = 10; persistent AF‐8, long‐lasting [>1 year] persistent AF‐2; RFCA group) or transthoracic direct cardioversion (DC) following a PTMC (n = 10; persistent AF‐7, long‐lasting persistent AF‐3; DC group). In all patients, the mitral valve morphology was amenable to a PTMC, and more than 2 AADs had been ineffective in maintaining sinus rhythm (SR). In the RFCA group, a segmental pulmonary vein isolation (PVI) was performed in the initial 5 patients, and an extensive PVI was performed in the remaining 5. Results: During a mean follow‐up period of 4.0 ± 2.7 years, 8 patients (80%) in the RFCA group were maintained in SR, as compared to 1 (10%) in the DC group (hazard ratio, 0.16; 95% confidence interval, 0.03 to 0.75; P = 0.008 by the log‐rank test). The prevalence of the concomitant use of class I and/or class III AADs was comparable between the 2 groups (P = 0.70). No complications occurred during the procedure or follow‐up period in either group. Conclusions: The hybrid therapy using RFCA and a PTMC was safe and feasible, and significantly improved the AF free survival rate compared to DC following a PTMC. (J Cardiovasc Electrophysiol, Vol. 21, pp. 284–289, March 2010)     

Is Pursuit of Termination of Atrial Fibrillation During Catheter Ablation of Great Value in Patients with Longstanding Persistent Atrial Fibrillation?

Termination of Atrial Fibrillation During Catheter Ablation Predicts Better Outcome . Background: The reliable endpoint for ablation of longstanding persistent atrial fibrillation (LPAF) has not been clearly established. Methods and Results: This study included 140 patients who underwent catheter ablation for drug‐refractory LPAF. A stepwise ablation approach included circumferential pulmonary vein isolation followed by left atrial and right atrial complex fractionated electrogram‐guided ablation. Atrial fibrillation (AF) was terminated by radiofrequency application during catheter ablation in 95 patients (67.9%). Among them, 33 patients (23.6%) converted to sinus rhythm directly, whereas 62 patients (44.3%) via atrial tachycardias (ATs). Patients in whom AF terminated during the index procedure had a lower recurrence rate of atrial arrhythmia than patients in whom AF did not terminate (45.3% vs 68.9%, P = 0.009, follow‐up 18.7 ± 7.6 months). Among patients in whom AF terminated, there was no significant difference in recurrence rate according to the termination mode, whether converted to AT or not (P = NS). However, patients who converted to AT had a higher recurrence rate of AT (54.8% vs 81%; P = 0.016). Multivariable logistic regression analysis demonstrated that termination of AF during ablation (HR 0.440; 95% CI: 0.200–0.969, P = 0.041) and structural heart disease (HR 2.633; 95% CI: 1.211–5.723; P = 0.015) were significant independent factors predicting the recurrence of atrial arrhythmia. Conclusions: Termination of AF during catheter ablation is associated with a better clinical outcome in patients with LPAF. (J Cardiovasc Electrophysiol, Vol. 23 pp. 1051‐1058, October 2012)     

Electroanatomic characteristics of atrial premature beats triggering atrial fibrillation in patients with persistent versus paroxysmal atrial fibrillation

APBs in Persistent Versus Paroxysmal AF. BACKGROUND: Although the electrical disconnection between the left atrium (LA) and pulmonary veins (PVs) by radiofrequency catheter ablation has been proven to be effective in controlling atrial fibrillation (AF), the recurrence rate is higher in patients with persistent AF (PeAF) than with paroxysmal AF (PAF). We hypothesized that the origin of the atrial premature beats (APBs) that trigger AF and the pattern of their breakthrough into the LA differ between PAF and PeAF. METHODS: We mapped 75 APBs (53 APBs triggering AF, 22 isolated APBs) from the LA and PVs in 26 patients with AF (age: 49.5 +/- 9.6, males: 23, PAF = 17, PeAF = 9), using a noncontact endocardial mapping (NCM) system. The location of the preferential conduction (PC) sites and their conduction velocity (CV) were compared. RESULTS: In patients with PeAF, the earliest activation (EA) site and exit of the PC were more frequently located on the LA side of the LA-PV junction as compared with PAF (P < 0.001). Eighty-one percent of the PCs were located in the area between the left and right superior PVs. The incidence of PCs was similar between the PeAF and PAF patients (P = NS). PCs were more commonly found with APBs inducing AF (63.3%) than with those not inducing AF (35.2%, P = 0.01). The CV of the PC was slower for PeAF than PAF (P < 0.001). The CV in the LA during sinus rhythm was also slower for PeAF than PAF (P < 0.01). CONCLUSION: PeAF was more frequently triggered by APBs from the LA side of the LA-PV junction than PAF and resulted in slower conduction than did PAF. These findings may help explain the higher potential for recurrence after electrical PV isolation in patients with PeAF.     

Importance of Sinus Rhythm as Endpoint of Persistent Atrial Fibrillation Ablation

Endpoint of Persistent AF Ablation . Background: The endpoint of persistent atrial fibrillation (AF) ablation is still a matter of debate. The purpose of this study was to evaluate if sinus rhythm (SR) as endpoint of persistent AF ablation has a better long‐term outcome compared to atrial tachycardia (AT) or AF at the end of the procedure. Methods and Results: Between 2008 and 2011, 191 consecutive patients undergoing de novo catheter ablation for symptomatic persistent and long‐standing persistent AF using a sequential ablation approach (including pulmonary vein isolation, ablation of complex fractionated electrograms and linear lesions) were included in the study. According to the result at the end of ablation procedure, patients were classified into 3 groups: patients with termination of AF into SR (Group 1, n = 62), patients with AT undergoing cardioversion (CV) (Group 2, n = 47), or patients with AF undergoing CV (Group 3, n = 82). The primary endpoint was freedom from any atrial tachyarrhythmia off antiarrhythmic drugs at 12 months. At 12 months, estimated proportions of patients free from any arrhythmia recurrence were 42% for Group 1, 13% for Group 2, and 25% for Group 3 (P = 0.002). In a Cox regression analysis only termination into SR was associated with a lower risk of arrhythmia recurrence (HR: 0.62; P = 0.04). Conclusion: If SR is achieved as endpoint of persistent and long‐standing persistent AF ablation using a sequential ablation approach it is associated with the highest long‐term single procedure success rate compared to AT or AF at the end of the procedure. (J Cardiovasc Electrophysiol, Vol. 24, pp. 388‐395, April 2013)     

Effects of late regain of sinus rhythm on pulmonary artery pressure and functional status in patients with mitral valve replacement surgery and atrial fibrillation

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the effects of regaining sinus rhythm (SR) on pulmonary artery pressure (PAP) and NYHA class in patients undergoing mitral valve replacement (MVR) surgery and in atrial fibrillation (AF). METHODS: Forty patients (mean age 50.7+/-8.2 years) with previous MVRS and chronic AF were included in the study; the mean postoperative interval was 54.7+/-31.8 months. Among these 40 patients, 22 (the study group) were treated with amiodarone (600 mg/day) and direct current (DC) cardioversion (CV), while 18 (control group) underwent normal treatment. RESULTS: In the study group, two patients regained SR with amiodarone loading, while 20 proceeded with DC CV at 21 days after amiodarone loading. SR was regained in 20 patients. The amiodarone dosage was lowered to 200 mg/day in the sixth postoperative week. Patients were followed for a mean of 18.0+/-4.4 months (range: 12-22 months). In the study group, recurrence of AF occurred in only one patient, at four months after DC CV. SR was maintained in 19 patients. At a clinical control examination, the mean NYHA class of study patients was decreased from 2.6+/-0.5 to 1.8+/-0.6 in two months, and to 1.5+/-0.6 in 12 months (p <0.01). Doppler echocardiographic follow up in the study group showed PAP to be significantly reduced, from 44.2+/-12.3 mmHg to 32.8+/-8.1 mmHg (p <0.01). CONCLUSION: In patients with MVR and AF, amiodarone treatment and DC CV achieved good early and mid-term success in regaining and maintaining SR. Regulation of rhythm was concomitant with a reduction in PAP and improved NYHA functional class. Hence, a special effort should be made to correct arrhythmia in patients with MVR and AF.     

Intravenous administration of magnesium and potassium solution lowers energy levels and increases success rates electrically cardioverting atrial fibrillation

Intravenous Electrolytes Increase Success Rate of Cardioversion . Background: External biphasic electrical cardioversion (CV) is a standard treatment option for patients suffering from acute symptoms of atrial fibrillation (AF). Nevertheless, CV is not always successful, and thus strategies to increase the success rate are desirable. Objective: The purpose of this study was to evaluate the effect of intravenously administered K/Mg solution on the biphasic CV energy threshold and success rate to restore sinus rhythm (SR) in patients with AF. Methods: The study consisted of 170 patients with persistent AF. The patients were randomly assigned to undergo biphasic CV either with (n = 84) or without (n = 86) pretreatment with K/Mg solution. An energy step‐up protocol of 75, 100, and 150 W (J) was used. Results: Biphasic CV of AF was effective in 81 (96.4%) patients in the pretreatment and 74 (86.0%) patients in the control group (P = 0.005). The effective energy level required to achieve SR was significantly lower in the pretreated group (140.8 ± 26.9 J vs 182.5 ± 52.2 J, P = 0.02). No K/Mg‐solution‐associated side effects such as hypotension or bradycardia were observed. Conclusion: Administration of K/Mg solution positively influences the success rate of CV in patients with persistent AF. Furthermore, significantly less energy is required to successfully restore SR and therefore K/Mg pretreatment may facilitate SR restoration in patients undergoing CV for AF. (J Cardiovasc Electrophysiol, Vol. 23, pp. 54‐59, January 2012)     

Clinical efficacy of irrigated catheter application of amiodarone during ablation of persistent atrial fibrillation

Background

Pharmacological treatment during ablation of persistent atrial fibrillation (AF) is common, but utility of irrigated catheter application of amiodarone during ablation of persistent AF remains unclear.

Hypothesis

Irrigated catheter application of amiodarone improves quality of ablation and long‐term outcomes.

Methods

We enrolled 90 persistent AF patients who underwent catheter ablation. Patients were randomized to the amiodarone group (n = 45) or control group (n = 45). All patients underwent stepwise ablation beginning with isolation of the pulmonary veins. Next, we performed ablation of linear lesions and focal triggers until sinus rhythm (SR) was achieved. The primary endpoint was documented atrial arrhythmia during follow‐up. The secondary endpoint was cardioversion to SR during ablation.

Results

All pulmonary veins were successfully isolated. Conversion of AF to SR occurred more frequently in the amiodarone group than in the control group (33 vs 23 [73.3% vs 51.1%]; P = 0.03). The amiodarone group had lower procedure, radiofrequency, and fluoroscopy times than the control group (167.4 ± 22.5 min vs 186.7 ± 25.3 min; 78.3 ± 14.2 min vs 90.4 ± 15.5 min; and 6.5 ± 1.9 min vs 8.6 ± 2.4 min, respectively; P < 0.05). More importantly, the atrial arrhythmia recurrence‐free survival rates were 80% in the amiodarone group and 60% in the control group during the 14.7 ± 7.5‐month follow‐up (P = 0.043).

Conclusions

Irrigated catheter application of amiodarone during ablation for persistent AF resulted in higher cardioversion rates and lower procedure times and significantly reduced rates of atrial arrhythmia recurrence.

     

Effect of amiodarone on dispersion of atrial refractoriness and cycle length in patients with atrial fibrillation

INTRODUCTION: Amiodarone is effective in preventing the recurrence of atrial fibrillation (AF) after cardioversion (CV). Dispersion of atrial refractoriness may be relevant to the generation of AF. We designed a study to determine the electrophysiologic effects of amiodarone in patients with previous early recurrence of AF after CV. METHODS AND RESULTS: Fifteen patients with previous AF recurrence (without antiarrhythmic drugs) after CV (CV1) were selected for amiodarone therapy and repeat CV (CVamio). Prior to CV1, mean AF cycle length (AFCL) had been recorded at four atrial sites (right atrial appendage [RAA], distal coronary sinus [DCS], right atrial lateral wall [LAT], and interatrial septum [IAS]) and dispersion of AFCL had been calculated. These patients were treated with amiodarone and, prior to CVamio, AFCL was recorded at the four atrial sites as for CV1. Between CV1 and CVamio, AFCL increased at all atrial sites: 153 +/- 13 msec to 179 +/- 14 msec at RAA, 144 +/- 12 msec to 174 +/- 18 msec at DCS, 158 +/- 13 msec to 182 +/- 16 msec at LAT, and 161 +/- 18 msec to 181 +/- 17 msec at IAS. Dispersion of AFCL decreased from 24 +/- 10 msec at CV1 to 15 +/- 11 msec at CVamio (P = 0.01). The median time in sinus rhythm increased from 3.12 hours post CV1 to 28 days post CVamio, (P < 0.02). CONCLUSION: Amiodarone causes a reduction in the dispersion of AFCL. This action may be relevant to the beneficial effects of amiodarone in patients with AF.     

Catheter ablation of atrial fibrillation in octogenarians: safety and outcomes

AF Ablation in Octogenarians. Introduction: Radiofrequency catheter ablation (RFCA) is an effective treatment for atrial fibrillation (AF), although studies evaluating the role of RFCA have largely excluded elderly patients. We report the safety and outcomes of RFCA of AF in octogenarians. Methods and Results: From 2008 to 2011, out of 2,754 consecutive patients undergoing RFCA of AF, 103 (3.7%) had ≥80 years (age 85 ± 3 years, 4 with >90 years). Pulmonary vein (PV) antrum isolation was performed in paroxysmal AF. In nonparoxysmal AF, ablation was extended to the entire left atrial posterior wall and to complex fractionated electrograms. Non‐PV triggers were disclosed by isoproterenol challenge at the end of the procedure and targeted for ablation. Octogenarians presented a high rate of non‐PV triggers (84% vs 69%, P = 0.001), especially in patients with paroxysmal AF (62% vs 19%, P < 0.001); non‐PV triggers were most commonly mapped in the coronary sinus (54%), left atrial appendage (32%), interatrial septum and superior vena cava (14%). After a mean follow‐up of 18 ± 6 months, 71 (69%) octogenarians remained free from AF recurrence off antiarrhythmic drugs after a single procedure (vs 71% in patients <80 years, P = 0.65). The success rate reached 87% after 2 procedures. Total periprocedural complication rates also did not differ between the 2 age groups. Conclusions: RFCA of AF is safe and effective in octogenarians. A high rate of non‐PV triggers is present in these patients, and targeting multiple structures other than the pulmonary veins is often necessary to achieve long‐term success. (J Cardiovasc Electrophysiol, Vol. 23, pp. 687‐693, July 2012)     

Left atrial deformation imaging with ultrasound based two-dimensional speckle-tracking predicts the rate of recurrence of paroxysmal and persistent atrial fibrillation after successful ablation procedures

Predict AF. Objective: Since predictors of recurrence of atrial fibrillation (AF) after ablation procedures are poorly defined, this prospective study was conducted to assess the value of left atrial (LA) deformation imaging with two‐dimensional speckle‐tracking (2D‐ST) to predict AF recurrences after successful ablation procedures. Methods and results: One hundred and three consecutive patients (age 58.1 ± 16.6 years, 72.8% male) with AF (76 paroxysmal, 27 persistent) and 30 matched controls underwent transthoracic echocardiography and 2D‐ST‐LA‐deformation analysis with assessment of LA‐radial and LA‐longitudinal strain (Sr, Sl), and velocities derived from the apical 4‐ and 2‐chamber views (4CV, 2CV). AF recurrence was assessed during 6 months of follow‐up. For determination of AF‐related LA changes, AF patients were compared to controls and patients with AF recurrences after ablation procedures (n = 30, 29.1%) were compared with patients who maintained sinus rhythm (n = 73, 70.9%). Atrial deformation capabilities were significantly reduced (P < 0.0005) in patients with AF (4CVSl 17.8 ± 13.5%; 4CVSr 22.3 ± 14.9%; 4CV‐velocities 2.53 ± 0.97 seconds) when compared with controls (4CVSl 31.3 ± 12.4%; 4CVSr 30.3 ± 9.1%; 4CV‐velocities 3.48 ± 1.01 cm/s). Independent predictors for AF recurrence after ablation procedures were 2CV‐LA‐global‐strain (Sr, P = 0.03; Sl, P = 0.003), 4CV‐LA‐gobal‐strain (Sr, P = 0.03; Sl, P = 0.02), and regional LA‐septal wall‐Sl (P = 0.008). LA‐global‐strain parameters were superior to regional LA function analysis for the prediction of AF recurrences, with cutoff values (cov), hazard ratios (HR), positive and negative predictive values (PPV, NPV) were: 4CVSl cov, 10.79% (HR 27.8, P < 0.0005; PPV 78.8%, NPV 93.9%), 4CVSr cov, ?16.65% (HR 24.8, P < 0.0005; PPV 69.4%, NPV 96.6%), 2CVSl cov, 12.31% (HR 22.7, P < 0.0005; PPV 75.8%, NPV 95.3%), and 2CVSr cov, ?14.9% (HR 12.9, P < 0.0005; PPV 64.3%, NPV 93.2%). Conclusion: Compared with controls, AF itself seems to decrease LA deformation capabilities. The assessment of global LA strain with 2D‐ST identifies patients with high risk for AF recurrence after ablation procedures. This imaging technique may help to improve therapeutic guiding for patients with AF. (J Cardiovasc Electrophysiol, Vol. 23 p. 247‐255, March 2012.)     

Clinical Significance of Induced Atrial Tachycardia After Termination of Longstanding Persistent Atrial Fibrillation Using a Stepwise Approach

Induced Atrial Tachyarrhythmia During Atrial Fibrillation Ablation. Introduction: The utility of inducibility test of atrial tachycardia (AT) in patients with longstanding persistent atrial fibrillation (AF; LPAF) is unclear. This study aimed to evaluate the significance of induced AT and the impact of their ablation on the clinical outcome. Methods: In 194 patients with LPAF (>1 year) who underwent catheter ablation (pulmonary vein isolation with substrate ablation), an inducibility test was performed after AF termination. Results: AT was induced in 108 (56%) patients (induced AT group); neither AT nor AF was inducible in 37 (19%, noninduction group). During 39 ± 21 months, AT recurred in 30 patients (28%), AF in 19 (17%), and no arrhythmia in 56 (52%) among induced AT group, although there was a recurrence of AT in 9 (24%, P = 0.68), AF in 6 (16%, P = 0.85), and no arrhythmia in 22 (60%, P = 0.42) among noninduction group (P = NS). Note that 10 patients with repeated ablation in induced AT group revealed 8 different and 2 similar recurrent ATs compared to the induced ATs at first session. The mean cycle length of induced AT that terminated by ablation (271 ± 64 ms) was longer than that without (249 ± 58 ms, P < 0.05). In induced AT group, AT recurrence rate in patients who achieved AT termination by ablation was lower than those without termination (5% vs 36%, P < 0.05). Conclusions: ATs that are inducible after LPAF termination do not necessarily become clinical AT. However, patients who achieved noninducibility of AT by ablating slower cycle length of AT had better outcomes. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1171–1178, November 2012)     

A novel finding of the atrial substrate properties and long-term results of catheter ablation in chronic atrial fibrillation patients with left atrial spontaneous echo contrast

Atrial Substrate Properties in Chronic AF Patients with LASEC. Background: The atrial substrate in chronic atrial fibrillation (AF) patients with a left atrial spontaneous echo contrast (LASEC) has not been previously reported. The aim of this study was to investigate the atrial substrate properties and long‐term follow‐up results in the patients who received catheter ablation of chronic AF. Methods: Of 36 consecutive patients with chronic AF who received a stepwise ablation approach, 18 patients with an LASEC (group I) were compared with 18 age‐gender‐left atrial volume matched patients without an LASEC (group II). The atrial substrate properties including the weighted peak‐to‐peak voltage, total activation time during sinus rhythm (SR), dominant frequency (DF), and complex fractionated electrograms (CFEs) during AF in the bi‐atria were evaluated. Result: The left atrial weighted bipolar peak‐to‐peak voltage (1.0 ± 0.6 vs 1.6 ± 0.7 mV, P = 0.04), total activation time (119 ± 20 vs 103 ± 13 ms, P < 0.001) and DF (7.3 ± 1.3 vs 6.6 ± 0.7 Hz, P < 0.001) differed between group I and group II, respectively. Those parameters did not differ in the right atrium. The bi‐atrial CFEs (left atrium: 89 ± 24 vs 92 ± 25, P = 0.8; right atrium: 92 ± 25 vs 102 ± 3, P = 0.9) did not differ between group I and group II, respectively. After a mean follow‐up of 30 ± 13 month, there were significant differences in the antiarrhythmic drugs (1.1 ± 0.3 vs 0.7 ± 0.5, P = 0.02) needed after ablation, and recurrence as persistent AF (92% vs 50%, P = 0.03) between group I and group II, respectively. After multiple procedures, there were more group II patients that remained in SR, when compared with group I (78% vs 44%, P = 0.04). Conclusion: There was a poorer atrial substrate, lesser SR maintenance after catheter ablation and need for more antiarrhythmic drugs in the chronic AF patients with an LASEC when compared with those without an LASEC. (J Cardiovasc Electrophysiol, Vol. pp. 1‐8)     

Statin therapy for the prevention of atrial fibrillation trial (SToP AF trial)

Statins for Prevention of Atrial Fibrillation . Background: Inflammation and oxidative stress are associated with atrial fibrillation (AF). Statins have antioxidant and anti‐inflammatory properties. We tested if atorvastatin reduced AF recurrence after DC cardioversion (CV) by modifying systemic oxidative stress and inflammation (NCT00252967). Methods and Results: In a randomized, double‐blinded, placebo‐controlled trial, patients with atrial fibrillation/flutter (AF) were randomized to receive either atorvastatin 80 mg (n = 33) or placebo (n = 31) before CV. Treatment was continued for 12 months or until AF recurred. Serum oxidative stress markers (ratios of oxidized to reduced glutathione and cysteine, derivatives of reactive oxygen species, isoprostanes) and inflammatory markers (high‐sensitivity C‐ reactive protein [hs‐CRP], interleukin‐6 [IL‐6], interleukin‐1β[IL‐1β], tumor necrosis factor alpha [TNFα]) were measured at baseline and on follow‐up. AF recurred in 22 (66.7%) of atorvastatin and 26 (83.9%) of placebo group (P = 0.2). The adjusted hazard ratio of having recurrence on atorvastatin versus on placebo was 0.99 (95% CI: 0.98–1.01, P = 0.3). There was no significant difference in the time to recurrence using Kaplan–Meier survival estimates (median [IR]: 29 [2–145] days versus 22 [7–70] days, P = 0.9). Although no significant effect was seen on oxidative stress, 2 of 4 inflammatory markers, IL‐6 (adjusted OR: 0.59, 95% CI: 0.35–0.97, P = 0.04) and hs‐CRP (adjusted OR: 0.59, 95% CI: 0.37–0.95, P = 0.03) were significantly lowered with atorvastatin. Cholesterol levels significantly decreased with atorvastatin (P = 0.03). Conclusions: High‐dose atorvastatin did not reduce the recurrence of AF after CV. It reduced selective markers of inflammation without affecting systemic oxidative stress. Failure of atorvastatin to prevent AF recurrence may be due to its failure to affect oxidative stress. (J Cardiovasc Electrophysiol, Vol. 22, pp. 414‐419)     

Stunning of the Left Atrium after Conversion of Atrial Fibrillation: Predictor for Maintenance of Sinus Rhythm?

Recurrence of atrial fibrillation (AF) after cardioversion (CV) to sinus rhythm (SR) is determined by various clinical and echocardiographic parameters. The aim of this study was to determine the value of mitral inflow A-wave velocity, performed at 24 hours after CV in estimation of AF recurrence. The study group consisted of 187 consecutive patients with nonvalvular atrial fibrillation, who had been cardioverted to SR from 1998 to 2000. Transthoracic echocardiography was performed in all cases recruited for the study 24 hours after CV. Left atrial (LA) diameter, left ventricular ejection fraction, and mitral inflow A-wave velocity were measured. The patients were evaluated in five groups according to their recurrence time (<30 days, 31-90 days, 91-180 days, 181-365 days, and >365 days). Maintenance of SR was determined to have a negative linear correlation with age (r =-0.97, P = 0.006), LA diameter (r =-0.93, P = 0.02), and AF duration (r =-0.93, P = 0.02), while having a positive linear correlation with mitral inflow A-wave velocity (r = 0.96, P = 0.008). In the maintenance of sinus rhythm, age, LA diameter, and AF duration were not affected from the method of CV, while mitral inflow A-wave velocity was found to be affected with the method of CV. No relationship was determined between mitral inflow A-wave velocity and the maintenance of sinus rhythm in those performed electrical cardioversion, while frequency of recurrence was found to be higher in those with slow mitral inflow A-wave velocity who were performed pharmacological cardioversion (r = 0.89, P = 0.004). In conclusion, age, duration of AF, LA diameter, and the mitral inflow A-wave velocity can be used to predict the maintenance of SR after CV.     

Long‐Term Results of Transcatheter Atrial Fibrillation Ablation in Patients with Impaired Left Ventricular Systolic Function

AF Ablation and Impaired Left Ventricular Function. Introduction: Long‐term outcome of AF ablation in patients with impaired LVEF is unknown. The aim of this study is to evaluate sinus rhythm (SR) maintenance, clinical status, and echocardiographic parameters over a long‐term period following atrial fibrillation (AF) transcatheter ablation in patients with left ventricular ejection fraction (LVEF) <50%. Methods and Results: A total of 196 patients (87.2% males, age 60.5 ± 10.2 years) with LVEF <50% underwent radiofrequency transcatheter ablation for paroxysmal (22.4%) or persistent (77.6%) AF. Patients were followed up for 46.2 (16.4–63.5) months regarding AF recurrences, functional class, and echocardiographic parameters. All patients underwent pulmonary vein isolation, while 167 (85.2%) required additional atrial lesions. Eleven (5.6%) patients suffered procedural complications. During follow‐up, 58 (29.6%) patients required repeated ablations. At the follow‐up end, 15 (7.7%) patients died, while 74 (37.8%) documented at least one episode of AF, atrial flutter, or atrial ectopic tachycardia. Eighty‐three (47.2%) patients maintained antiarrhythmic drugs. During follow‐up, NYHA class improved by at least one class more frequently among patients maintaining SR compared to those experiencing relapses (70.6% vs 47.9%, P = 0.003). LVEF showed a broader relative increase in patients maintaining SR (32.7% vs 21.4%; P = 0.047) and mitral regurgitation grading significantly decreased (P <0.001) only within these patients. At multivariable analysis SR maintenance emerged as an independent predictor (odds ratio 4.26, 95% CI 1.69–10.74, P = 0.002) of long‐term clinical improvement (reduction in NYHA class ≥1 and relative increase in LVEF ≥10%). Conclusions: Although not substantially worse than in patients with preserved LVEF, AF ablation in patients with impaired LVEF is affected by high long‐term recurrence rate. Among these patients SR maintenance is associated with greater clinical improvement. (J Cardiovasc Electrophysiol, Vol. 24, pp. 24‐32, January 2013)     

A Short‐Term,Randomized, Double‐Blind,Parallel‐Group Study to Evaluate the Efficacy and Safety of Dronedarone versus Amiodarone in Patients with Persistent Atrial Fibrillation: The DIONYSOS Study

Dronedarone versus Amiodarone in Patients with AF. Introduction: We compared the efficacy and safety of amiodarone and dronedarone in patients with persistent atrial fibrillation (AF). Methods: Five hundred and four amiodarone‐naïve patients were randomized to receive dronedarone 400 mg bid (n = 249) or amiodarone 600 mg qd for 28 days then 200 mg qd (n = 255) for at least 6 months. Primary composite endpoint was recurrence of AF (including unsuccessful electrical cardioversion, no spontaneous conversion and no electrical cardioversion) or premature study discontinuation. Main safety endpoint (MSE) was occurrence of thyroid‐, hepatic‐, pulmonary‐, neurologic‐, skin‐, eye‐, or gastrointestinal‐specific events, or premature study drug discontinuation following an adverse event. Results: Median treatment duration was 7 months. The primary composite endpoint was 75.1 and 58.8% with dronedarone and amiodarone, respectively, at 12 months (hazard ratio [HR] 1.59; 95% confidence interval [CI] 1.28–1.98; P < 0.0001), mainly driven by AF recurrence with dronedarone compared with amiodarone (63.5 vs 42.0%). AF recurrence after successful cardioversion was 36.5 and 24.3% with dronedarone and amiodarone, respectively. Premature drug discontinuation tended to be less frequent with dronedarone (10.4 vs 13.3%). MSE was 39.3 and 44.5% with dronedarone and amiodarone, respectively, at 12 months (HR = 0.80; 95% CI 0.60–1.07; P = 0.129), and mainly driven by fewer thyroid, neurologic, skin, and ocular events in the dronedarone group. Conclusion: In this short‐term study, dronedarone was less effective than amiodarone in decreasing AF recurrence, but had a better safety profile, specifically with regard to thyroid and neurologic events and a lack of interaction with oral anticoagulants. (J Cardiovasc Electrophysiol, Vol. 21, pp. 597‐605, June 2010)     

Serial antiarrhythmic therapy: role of amiodarone in prevention of atrial fibrillation recurrence--a lesson from the HOT CAFE Polish Study

Antiarrhythmic drug prophylaxis is known to improve long-term success of electrical cardioversion (CV) in persistent atrial fibrillation (AF). This prospective study evaluates the efficacy of sequential antiarrhythmic drug therapy in sinus rhythm (SR) maintenance after successful elective CV in patients with persistent nonvalvular AF. MATERIALS AND METHODS: One hundred and twenty-eight patients (61+/-8 years old) with persistent AF underwent CV. Mean AF duration preceding CV was 268+/-99 days. Following SR restoration, patients were treated sequentially with either of the following antiarrhythmic drugs: propafenone, sotalol or disopyramide. Where arrhythmia recurred, patients received another CV and a new drug from the range defined above. Where such treatment failed, patients were loaded with 14.0- to 16.0-gram doses of amiodarone and a third CV was performed. If the first CV failed to restore SR, patients received a loading dose of amiodarone followed by another CV. When successful, amiodarone was administered on continuous basis. RESULTS: The first CV proved successful in 55.5% of patients. During 1-year of follow-up, 31 patients (43.7%) presented with SR were treated with one antiarrhythmic agent (median does not exist). Application of the second drug proved to be effective in 6 patients (15.0%; median 13 days). Amiodarone was administered as the third antiarrhythmic agent to patients who had AF recurrence on the first two antiarrhythmic agents (propafenone, sotalol or disopyramide). It proved to be effective in 18 patients (52.9%; median does not exist) remaining free from AF for a period of 1 year as of commencement of the sequential antiarrhythmic therapy. Fifty-seven patients, in whom the first CV was ineffective, received amiodarone. During the loading period, SR was restored in 7 patients (12.3%). The remaining 50 patients underwent repeated CV, with SR restored in 37 (74.0%) of them. Long-term amiodarone treatment maintained SR in 30 (68.2%) patients during the follow-up period. Amiodarone helped to maintain SR in a total of 56.5% of patients. CONCLUSIONS: Amiodarone seems to be the drug most effectively restoring and maintaining SR in patients with persistent AF resistant to CV and standard antiarrhythmic drug prophylaxis.     

Impaired transport function of the left atrium in patients with lone paroxysmal atrial fibrillation

Background: Although lone paroxysmal atrial fibrillation (LPAF) is clinically defined as an arrhythmia that occurs in the absence of structural heart disease, it has been suggested that the presence of anatomical substrate is related to LPAF. The aim of the present study is to determine whether structural and functional remodeling of the left atrium (LA) occurs in patients with LPAF, and to identify whether frequent episodes of atrial fibrillation (AF) contribute to LA remodeling. Methods and Results: Forty‐five patients who diagnosed as LPAF and age‐, gender‐, and body mass index‐matched healthy control subjects (n = 45) were enrolled. Patients were grouped based on the frequency of AF episodes. An echocardiography was performed >2 weeks after last episode of AF without antiarrhythmic drugs. There were no statistical differences in left ventricular (LV) diastolic and systolic functions as well as baseline characteristics between patients and controls, whereas, patients had significantly larger LA volume (LAV), lower active LA emptying fraction (LAEF_active, P = 0.009) and total LAEF (LAEF_total, P = 0.005) compared with controls. Passive LAEF (LAEF_passive) was not different between patients and controls (P = 0.664). LAEF_active was significantly depressed in patients with frequent episodes of AF than the others (P = 0.034). Conclusions: Compared with healthy controls, patients with LPAF had increased LAV and depressed LAEF_active and LAEF_total without accompanying compensatory increase in LAEF_passive. LAEF_active was influenced by frequent episodes of AF. These findings may support the hypothesis that LPAF is “not‐so‐lone AF” and related to the concealed cardiac dysfunctions. (Echocardiography 2011;28:44‐51)