Continuous rhythm monitoring for ventricular arrhythmias after alcohol septal ablation for hypertrophic cardiomyopathy.

OBJECTIVE: The purpose of the present study was to determine the incidence of ventricular arrhythmias before and after alcohol septal ablation (ASA). BACKGROUND: In patients with hypertrophic obstructive cardiomyopathy (HOCM), gradient reduction by ASA is an alternative for surgical myectomy. However, concerns exist about whether the induction of a myocardial scar during ASA may create substrate for ventricular arrhythmias. METHODS: The study group consisted of 44 patients in whom ASA was performed for symptomatic, drug-refractory hypertrophic cardiomyopathy. Continuous rhythm monitoring was obtained by implantable loop recorder (n=30) or pacemaker (n=14). Occurrence of ventricular and supraventricular arrhythmias before and after ASA was noted, retrospectively. RESULTS: The ASA procedure was considered successful (resting gradient <30 mm Hg, and provoked gradient <50 mm Hg at 4 months in combination with NYHA Class functional status ≤2) in 30 (68%) patients. Rhythm monitoring before ASA was available in 28 patients. The median duration of rhythm monitoring after ASA was 3.0 years (IQR 1.3-4.3). Sustained VT/VF within 30 days after ASA occurred in three patients (7%), including 2 cases of procedural VF, while no VT/VF was observed before ASA (p=0.10). No sustained VT/VF was observed >30 days after ASA. No cardiac deaths occurred during follow-up. CONCLUSIONS: In a low-risk cohort of patients who underwent ASA, in which continuous rhythm monitoring was performed, sustained VT or VF within 30 days occurred in 3 patients (7%) while no VT/VF was observed before ASA. During long-term follow-up, no sustained VT or VF was observed >30 days after ASA.

Early recurrence of atrial fibrillation as a predictor for 1-year efficacy after successful phased RF pulmonary vein isolation: evaluation of complaints and multiple Holter recordings.

BACKGROUND: Early arrhythmia recurrences after pulmonary vein isolation (PVI) for atrial fibrillation (AF) are accepted as part of the blanking period. Their relevance for long-term efficacy is not well-known. We evaluated patients, who came to hospital with a documented recurrence of AF, or had a registered episode of AF on the 24-hour Holter 6 weeks after PVI and compared it with long-term outcome. METHODS: One hundred consecutive patients with paroxysmal AF were treated with the PVAC. In the 3-month blanking period patients who came to hospital with a documented recurrence of AF on ECG were recorded. 6 weeks after procedure a 24-hour Holter was performed. After 3 months patients were asked if they felt a relapse. Follow-up was performed at 3, 6, and 12 months with ECG, 7-day Holter at 6 and/or 12 months, and event recording if needed. RESULTS: Within the blanking period, 25/100 (25%) patients had a documented recurrence of AF while 46/100 (46%) patients felt a relapse. After the blanking period up to 12 months, 53/100 (53%) patients were free of AF without anti-arrhythmic drugs. Multivariate regression analyses revealed that absence of AF in the blanking period (OR 0.22 95%CI [0.05-0.98]) and absence of a relapse of symptoms suspect for AF during the blanking period (OR 0.21 95%CI [0.06-0.52]) were independent predictors of successful long-term outcome. CONCLUSIONS: Poor long-term outcome is strongly related to patients who experienced palpitations with ECG documented AF, AF on the 24-hour Holter at 6 weeks after PVI and a relapse in the blanking period.

Safety of pulmonary vein isolation and left atrial complex fractionated atrial electrograms ablation for atrial fibrillation with phased radiofrequency energy and multi-electrode catheters.

AIMS: Recently, a multi-electrode catheter system using phased radiofrequency (RF) energy was developed specifically for atrial fibrillation (AF) ablation: the pulmonary vein ablation catheter (PVAC), the multi-array septal catheter (MASC), and the multi-array ablation catheter (MAAC). Initial results of small trials have been promising: shorter procedure times and low adverse event rates. In a large single-centre registry, we evaluated the adverse events associated with multi-electrode ablation catheter procedures with PVAC alone, or combined with MASC and MAAC. METHODS AND RESULTS: In all, 634 consecutive patients with AF had 663 procedures with multi-electrode ablation catheters, 502 patients with the PVAC alone, 128 patients with PVAC/MASC/MAAC, 29 redo procedures with the PVAC or PVAC/MASC/MAAC, and 4 patients had a complicated transseptal puncture. Major and minor adverse events during 6 month follow-up were registered. In 15 cases (2.3%), major adverse events were seen within the first month after the procedure. These included complicated transseptal puncture (4), stroke (2), transient ischaemic attack (5), acute coronary syndrome (2), femoral pseudoaneurysm (1), and arteriovenous fistulae (1). Minor adverse events were seen in 10.7% at 6 months, mostly due to femoral haematoma (3.9%), and non-significant PV stenosis (5.2%). There was no difference in the occurrence of major adverse events between PVAC alone, or PVAC/MASC/MAAC ablation. CONCLUSION: Ablation with phased RF and multi-electrode catheters is accompanied by a major adverse event rate of 2.3% within 1 month and a minor event rate of 10.7% at 6 months.

Freedom from paroxysmal atrial fibrillation after successful pulmonary vein isolation with pulmonary vein ablation catheter-phased radiofrequency energy: 2-year follow-up and predictors of failure.

AIMS: In patients with paroxysmal atrial fibrillation (PAF) the pattern of atrial fibrillation (AF) episodes and the total AF burden, may be related to the efficacy of pulmonary vein isolation (PVI). We evaluated (pre)-procedural factors explaining the long-term outcome after PVI, using a ring-shaped multielectrode ablation catheter [pulmonary vein ablation catheter (PVAC)]. METHODS AND RESULTS: A total of 120 consecutive patients with PAF were treated with the PVAC. The patients' histories were obtained by a questionnaire and the clinical charts. Follow-up was performed at 3, 6, 12, 18, and 24 months with serial electrocardiogram, and multiple day Holter at 6, 12, and 24 months, as well as event recording in case of unexplained palpitations. At 1 year, 66 of 120 (55%, 95% confidence interval (CI) [46-63%]) patients were free of any left atrial (LA) arrhythmia without class I or III anti-arrhythmics after a single procedure. At 2 years, freedom from LA arrhythmia slightly declined further to 58 of 119 (49%, 95% CI [40-58%]). The only pre-procedural predictor of long-term success was a shorter duration of the longest episode of AF (hazard ratio (HR) 0.77 95% CI [0.64-0.92]). The only procedural predictor of long-term success was no need for direct current cardioversion (DCCV) for AF (HR 0.36 95% CI [0.21-0.61]). Since other characteristics in these PAF patients were very homogeneous, no further clinical predictors were observed. CONCLUSION: Freedom from LA arrhythmia after PVI for PAF with PVAC is 49% after 2-year follow-up, with little decline between year 1 and 2. Predictors of long-term failure were a longer duration of the longest episode of AF in the pre-procedural questionnaire, and a procedural DCCV for AF.

Arrhythmia detection after atrial fibrillation ablation: value of incremental monitoring time.

BACKGROUND: After pulmonary vein isolation (PVI), patients need to be followed to analyze the effect of the treatment. We evaluated the influence of the duration of Holter monitoring on the detection of arrhythmia recurrences after a single PVI at 12 months. METHODS: Consecutive patients with paroxysmal atrial fibrillation (AF) underwent successful PVI with phased radiofrequency and pulmonary vein ablation catheter. Follow-up was performed with electrocardiogram at 3, 6, and 12 months and 7-day Holter at 12 months. Symptomatic patients received additional event recording. The 7-day Holters at 12 months were evaluated for documented left atrial tachyarrhythmia recurrences, and each individual day with AF was categorized. RESULTS: At 12 months after the procedure, 21 of the 96 (22%) patients had AF on their 7-day Holter. In the patients with AF recurrence, there was an increase in sensitivity from 53% of a 1-day Holter up to 88% with 4-day Holter, and 100% of a 7-day Holter. Monitoring with duration of less than 4 days resulted in significantly less detection of patients with AF compared to 7-day Holter. CONCLUSIONS: A 4-day Holter at 12 months has an 88% sensitivity for arrhythmia detection, and appears to provide a sufficient monitoring time. Prolonging the monitoring time to 7 days does not significantly increase the yield.

Pulmonary vein anatomy and long-term outcome after multi-electrode pulmonary vein isolation with phased radiofrequency energy for paroxysmal atrial fibrillation.

AIMS: We evaluated the effect of pulmonary vein (PV) anatomical characteristics on PV isolation (PVI) and long-term efficacy of ablation with phased radiofrequency (RF) energy and pulmonary vein ablation catheter (PVAC) multi-electrode catheter. METHODS AND RESULTS: Before the procedure, PV anatomy was visualized by magnetic resonance imaging (MRI). Consecutive patients with paroxysmal atrial fibrillation were treated with the PVAC with successful acute isolation. Follow-up was performed at 3, 6, and 12 months with electrocardiogram and 7-day Holter recording at 6 and/or 12 months. Symptomatic patients received additional event recording. In 110 patients a pre-procedure cardiac MRI was performed. Ninety-seven (88%) had a separate left superior PV and separate left inferior PV, all patients had a separate right superior PV and separate right inferior PV. Fourteen (13%) had a left PV with common trunk and 27 (25%) had a separate right middle PV (RMPV). After a follow-up of 1 year, 57 of 110 (52%) patients were free of AF without anti-arrhythmic drug. No specific anatomical variable that was related to long-term failure could be found. There was a trend for patients with larger veins (>24 mm) or separate RMPV to have a lower efficacy. The number of applications per vein or procedure did not influence long-term outcome. CONCLUSIONS: In patients who have undergone PVI with phased RF energy and PVAC multi-electrode ablation, long-term efficacy is not significantly affected by PV anatomy or number of applications, although a trend for reduced efficacy is seen for PV with diameter >24 mm, and presence of RMPV.

Pulmonary vein isolation and left atrial complex-fractionated atrial electrograms ablation for persistent atrial fibrillation with phased radio frequency energy and multi-electrode catheters: efficacy and safety during 12 months follow-up.

AIMS: Ablation for persistent atrial fibrillation (AF) remains a difficult and time-consuming procedure with varying degrees of success. We evaluated the long-term effects of a novel approach for ablation of persistent AF using multi-electrode catheters. METHODS AND RESULTS: In 89 patients with longstanding persistent AF (>1 year), multi-electrode ablation was performed with a pulmonary vein ablation catheter (PVAC), a multi-array septal catheter (MASC), and a multi-array ablation catheter (MAAC) for ablation of complex-fractionated atrial electrograms (CFAE) at the septum, left atrial (LA) roof, floor, posterior wall, and mitral isthmus. Follow-up was performed at 6 and 12 months with electrocardiogram, 7 days Holter, and occasionally ambulant event recordings. Average procedure and fluoroscopy times were 112 ± 32 and 21 ± 10 min. The pre-specified endpoint of pulmonary vein isolation and LA CFAE ablation was reached in all patients. No procedural complications were observed. At 12 months after a single treatment 44 of 89 (49%) remained in sinus rhythm, including direct current cardioversion in 12 patients. At 12 months, after a redo PVAC/MASC/MAAC, an additional 6 of 15 patients (40%) were free of AF. In 18 of 89 (20%) patients AF was changed to paroxysmal. CONCLUSIONS: In this single centre study, ablation for longstanding persistent AF with the PVAC/MASC/MAAC resulted in 56% freedom of AF at 1 year after 1.2 ± 0.4 procedures. This approach is time efficient and has a favourable safety profile.

Left atrial pressure reduction for mitral stenosis reverses left atrial direction-dependent conduction abnormalities.

AIMS: Left atrial (LA) stretch-associated electrophysiological changes in patients with mitral stenosis (MS) predispose to atrial fibrillation. We hypothesized that the normalization of the pressure gradient by percutaneous transvenous mitral balloon valvotomy (PTMV) affects LA but not right atrial (RA) conduction, depending on the site of stimulation. Because direction-dependent (asymmetric) changes of conduction may contribute to arrhythmogenesis, we assessed conduction symmetry in MS patients and tested whether it is restored by PTMV. METHODS AND RESULTS: In nine patients with MS, atrial effective refractory period and local activation times (ATs) were determined during stimulation before and after PTMV, with up to four decapolar catheters (LA and RA). Eight patients with ventricular pre-excitation served as controls. ATs at basic cycle length were similar before and after PTMV. With stimulation from either atrium, they were about 45 ms in the ipsilateral atrium and about 115 ms in the contralateral atrium. With premature stimulation, ATs increased dramatically. The shortest ATs were found in the RA with RA stimulation (78 +/- 9 and 80 +/- 6 ns, before and after PTMV). PTMV caused a shortening in LA-ATs (following LA stimulation) from 118 +/- 14 to 82 +/- 5 ms (before and after; P < 0.05). Asymmetry in conduction properties was therefore normalized by PTMV. PTMV led to a decrease in RA-ATs (following LA stimulation) from 196 +/- 11 to 174 +/- 13 ms (P < 0.02). In addition, following RA stimulation, the dispersion in ATs in the LA decreased significantly by PTMV (from 66 +/- 10 to 34 +/- 7 ms; P < 0.02). CONCLUSION: MS is associated with LA conduction delay, increased LA dispersion of conduction, and conduction asymmetry. These changes are immediately reversible by PTMV.

Pulmonary vein isolation by duty-cycled bipolar and unipolar radiofrequency energy with a multielectrode ablation catheter.

BACKGROUND: Pulmonary vein (PV) isolation for ablation of atrial fibrillation (AF) remains a complex and lengthy procedure. OBJECTIVE: The purpose of this study was to evaluate the feasibility and safety of a novel multielectrode catheter that delivers duty-cycled bipolar and unipolar radiofrequency (RF) energy. METHODS: Patients eligible for catheter ablation of paroxysmal AF after screening with magnetic resonance imaging and transesophageal echocardiography were included in the study. A decapolar (3-mm electrode, 3-mm spacing, 25-mm diameter), circular, over-the-wire mapping and ablation catheter was deployed in the antrum of each PV. Ablation was performed with 60-second, 60 degrees C applications of duty-cycled bipolar/unipolar RF in a 4:1 ratio simultaneously at all selected electrode pairs until local activity was no longer observed. At 6 months, 7-day Holter monitoring was performed to determine freedom from AF without use of antiarrhythmic drugs. RESULTS: In 98 patients (mean age 59 +/- 9 years), the PV ablation catheter was used for ablation of 369 veins (20 common left antra). All targeted veins (100%) were isolated as confirmed by the absence of potentials in the ostium either by PV ablation catheter or Lasso mapping. Mean number of RF applications was 27 +/- 7, total procedural time 84 +/- 29 minutes, and fluoroscopy time 18 +/- 8 minutes. Follow-up after 6 months without antiarrhythmic drugs showed freedom from AF in 83% of patients. No procedure-related complications were observed. CONCLUSION: PV isolation by duty-cycled bipolar/unipolar low-power RF energy through a circular, decapolar catheter can be achieved safely and efficiently, with good efficacy at 6 months.

Freedom from atrial arrhythmias after classic maze III surgery: a 10-year experience.

OBJECTIVES: We studied the persistence of favorable outcome, the occurrence of new atrial arrhythmias, and sinus node dysfunction in patients who underwent the maze III procedure. METHODS: Preoperative, in-hospital, and follow-up data of 203 patients who underwent the maze III procedure between June 1993 and June 2003 were collected. A total of 139 patients underwent the maze procedure for lone atrial fibrillation, and 64 patients underwent the maze procedure and concomitant cardiac surgery. RESULTS: There was no 30-day postoperative mortality. During a mean follow-up of 4.0 +/- 2.6 years, 12 patients (6%) died (2 cardiac related). At the end of follow-up, freedom from supraventricular arrhythmias was 80% for the lone atrial fibrillation group and 64% for the concomitant atrial fibrillation group. Freedom from stroke during follow-up was 100% in the lone atrial fibrillation group and 97% in the concomitant group. Multivariate analysis revealed that rhythm at 1-year follow-up (P < .001; odds ratio 9.56, 95% confidence limits 3.92-23.31) and preoperative left atrium dimension (P = .028; odds ratio 1.06 for every millimeter, 95% confidence limits 1.01-1.12) were predictors of success at the end of follow-up. CONCLUSIONS: This study shows that the favorable results of the maze III procedure in terms of freedom from supraventricular arrhythmias persist in most patients for at least 4 years.

Effect of fish oil on ventricular tachyarrhythmia and death in patients with implantable cardioverter defibrillators: the Study on Omega-3 Fatty Acids and Ventricular Arrhythmia (SOFA) randomized trial.

CONTEXT: Very-long-chain n-3 polyunsaturated fatty acids (omega-3 PUFAs) from fish are thought to reduce risk of sudden death, possibly by reducing susceptibility to cardiac arrhythmia. OBJECTIVE: To study the effect of supplemental fish oil vs placebo on ventricular tachyarrhythmia or death. DESIGN, SETTING, AND PATIENTS: The Study on Omega-3 Fatty acids and ventricular Arrhythmia (SOFA) was a randomized, parallel, placebo-controlled, double-blind trial conducted at 26 cardiology clinics across Europe. A total of 546 patients with implantable cardioverter-defibrillators (ICDs) and prior documented malignant ventricular tachycardia (VT) or ventricular fibrillation (VF) were enrolled between October 2001 and August 2004. Patients were randomly assigned to receive 2 g/d of fish oil (n = 273) or placebo (n = 273) for a median period of 356 days (range, 14-379 days). MAIN OUTCOME MEASURE: Appropriate ICD intervention for VT or VF, or all-cause death. RESULTS: The primary end point occurred in 81 (30%) patients taking fish oil vs 90 (33%) patients taking placebo (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.64-1.16; P = .33). In prespecified subgroup analyses, the HR was 0.91 (95% CI, 0.66-1.26) for fish oil vs placebo in the 411 patients who had experienced VT in the year before the study, and 0.76 (95% CI, 0.52-1.11) for 332 patients with prior myocardial infarctions. CONCLUSION: Our findings do not indicate evidence of a strong protective effect of intake of omega-3 PUFAs from fish oil against ventricular arrhythmia in patients with ICDs. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00110838.

Sudden death in patients without structural heart disease.

Sudden unexpected cardiac death generally occurs in persons with known or previously unrecognized heart disease. However, it has become evident that it occurs often enough in patients without any identifiable structural abnormality to warrant the cardiologist's attention. Mostly, it concerns young, active, and otherwise healthy individuals. This paper focuses on various categories of patients with life-threatening events considered to have occurred on a solely "electrical" basis. Currently, several entities are recognized with distinct electrophysiological abnormalities, including Wolff-Parkinson-White syndrome, long QT syndrome, the Brugada syndrome, short-coupled torsade de pointes, and catecholamine-induced polymorphic ventricular tachyarrhythmia. The remaining patients without such distinct abnormalities are categorized as having idiopathic ventricular fibrillation. Although mechanical cardiac function may seem normal, such patients might have certain discrete anatomic abnormalities, unidentifiable with current investigational tools. Possibly in the future, with development of newer and more sophisticated tools (magnetic resonance imaging, positron emission tomography, genetic testing), some or all cases of idiopathic ventricular fibrillation must be redefined as having specific genetic and/or anatomic bases. All patients successfully resuscitated from cardiac arrest due to ventricular tachyarrhythmia without clear precipitating factors (acute myocardial infarction, severe electrolyte or metabolic disturbances) are at high risk of recurrences. Long-term prophylactic therapy is indicated. Contrasting with older belief, survivors of idiopathic ventricular fibrillation are now also considered high-risk patients. The implantable cardioverter-defibrillator appears to be the safest and most effective therapy.

Pulmonary vein ostium geometry: analysis by magnetic resonance angiography.

BACKGROUND: During a catheter ablation procedure for selective electrical isolation of pulmonary vein (PV) ostia, the size of these ostia is usually estimated using fluoroscopic angiography. This measurement may be misleading, however, because only the projected supero/inferior ostium diameters can be measured. In this study, we analyzed 3-dimensional magnetic resonance angiographic (MRA) images to measure the minimal and maximal cross-sectional diameter of PV ostia in relation to the diameter that would have been projected on fluoroscopic angiograms during a catheter ablation procedure. METHODS AND RESULTS: In 42 patients with idiopathic atrial fibrillation who were scheduled for selective electrical isolation of PV ostia, the minimal and maximal diameters of these ostia were measured from 3-dimensional MRA images. Thereafter, these images were oriented in a 45 degrees right or left anterior oblique direction and the projected diameter of the PV ostia were measured again. The average ratio between maximal and minimal diameter was 1.5+/-0.4 for the left and 1.2+/-0.1 for the right pulmonary vein ostia. Because of the orientation and oval shape of especially the left pulmonary vein ostia, their minimal diameters were significantly smaller than the projected diameters. CONCLUSION: Pulmonary vein ostia, especially those at the left, are oval with the short axis oriented approximately in the antero/posterior direction. Consequently, PV ostia may sometimes be very narrow despite a rather normal appearance on angiographic images obtained during a catheter ablation procedure.