Last Entrainment Sequence: A Novel Diagnostic Technique for Atrial Tachycardia Mimicking Other Supraventricular Tachycardias.

BACKGROUND: Adenosine-sensitive re-entrant atrial tachycardia (AT) originating from near the atrioventricular (AV) node or AV annulus resembles other supraventricular tachycardias (SVTs), and the differential diagnosis is sometimes challenging. OBJECTIVES: This study sought to develop a novel technique to distinguish adenosine-sensitive re-entrant AT from AV nodal re-entrant tachycardia (AVNRT) and orthodromic reciprocating tachycardia (ORT). METHODS: The study retrospectively studied 117 re-entrant SVTs that were successfully entrained by atrial overdrive pacing (AOP) (27 adenosine-sensitive re-entrant ATs, 63 AVNRTs, 27 ORTs). If the second atrial electrogram after AOP (A2) at the earliest atrial activation site (EAAS) accelerated to the pacing cycle length, the EAAS was considered orthodromically activated. Then, we compared the sequence of A2 and the last entrained His bundle (H∗) and QRS complex (V∗). The study hypothesized that the last entrained impulse would activate the EAAS before it enters the AV node, His bundle, and ventricle during AT (A2-H∗-V∗) but would activate the EAAS after the His bundle activation during AVNRT and ORT (H∗-V∗-A2 or H∗-A2-V∗). RESULTS: Orthodromic EAAS activation was documented during AOP in 84 SVTs (72%) when performing AOP from sites proximal to the entrance of SVTs. A2-H∗-V∗ responses were observed in 21 of 25 ATs, but were never for AVNRTs or ORTs. All ORTs and fast-slow AVNRTs had H∗-V∗-A2 responses. Eleven of 21 slow-fast AVNRTs had H∗-A2-V∗ responses. The sensitivity, specificity, and positive and negative predictive values of the A2-H∗-V∗ response for diagnosing AT were 84%, 100%, 100%, and 94%, respectively. CONCLUSIONS: The last entrainment sequence was useful for differentiating ATs with diagnostic difficulties.

Improvement in Quality of Life via Catheter Ablation for Atrial Fibrillation in Patients Undergoing Hemodialysis Therapy.

Background: Atrial fibrillation (AF) is the most common arrhythmia in patients undergoing hemodialysis (HD); AF lowers quality of life (QoL) and increases the risk of dialysis-related complications. The present study aimed to evaluate the effectiveness of AF ablation on the QoL in patients undergoing HD. Methods: Nineteen patients undergoing HD (14 men, age 68 ± 8 years; 15 with paroxysmal AF) who underwent catheter ablation (CA) of AF were enrolled in the study. The Kidney Disease Quality of Life Short Form (KDQOL-SF) was assessed to evaluate the QoL of the HD patients at baseline and 6 months after the ablation. Ablation outcomes and procedural complications were evaluated and compared to those of 1053 consecutive non-HD patients who underwent AF ablation. Results: The KDQOL-SF of the HD patients 6 months after the ablation showed an improvement in physical functioning (54 ± 23 to 68 ± 28, P < 0.01), general health perceptions (38 ± 17 to 48 ± 15, P < 0.01), and symptoms/problems (75 ± 21 to 84 ± 13, P = 0.02), compared to baseline. For intradialytic symptoms, dyspnea during HD significantly improved after the CA in the HD patients without AF recurrence (43% to 7%, P = 0.04), whereas the atrial tachyarrhythmias and hypotension during HD remained unchanged. During the follow-up period of 17 ± 13 months after the last procedure, the incidence of being arrhythmia-free was similar (HD patients, 79% vs non-HD patients, 86%, log-rank P = 0.82). No life-threatening complications occurred in any of the patients. Conclusions: CA of AF improves QoL in patients undergoing chronic HD therapy.

Contexte: La fibrillation auriculaire (FA), la forme d'arythmie la plus fréquente chez les patients sous hémodialyse (HD), entraîne une diminution de la qualité de vie (QdV) et une augmentation des risques de complications liées à la dialyse. La présente étude visait à évaluer l'effet de l'ablation de la FA sur la QdV des patients sous HD. Méthodologie: Dix-neuf patients sous HD (âgés de 68 ± 8 ans, dont 14 étaient des hommes et 15 étaient atteints de FA paroxystique) ayant subi une ablation par cathéter de la FA ont été admis dans l'étude. Le questionnaire KDQOL-SF (Kidney Disease Quality of Life Short Form) a été utilisé pour évaluer la QdV des patients sous HD avant l'intervention et six mois après l'ablation. L'issue de l'ablation et les complications liées à l'intervention ont été évaluées et comparées à celles de 1 053 patients consécutifs n'étant pas hémodialysés et ayant subi une ablation de la FA. Résultats: La comparaison des résultats initiaux au KDQOL-SF des patients hémodialysés avec les résultats obtenus six mois après l'ablation a montré des améliorations de la fonction physique (de 54 ± 23 à 68 ± 28, p < 0,01), de la perception de l'état de santé global (de 38 ± 17 à 48 ± 15, p < 0,01), et des symptômes/problèmes de santé (de 75 ± 21 à 84 ± 13, p = 0,02). En ce qui concerne les symptômes survenant lors des séances d'HD, une amélioration significative de la dyspnée a été observée après l'ablation par cathéter chez les patients sous HD sans récurrence de la FA (de 43 % à 7 %, p = 0,04), alors qu'aucun changement n'a été constaté pour les tachyarythmies auriculaires et l'hypotension. Durant la période de suivi de 17 ± 13 mois après la dernière intervention, le nombre de patients sans arythmie était comparable dans les deux groupes (79 % chez les patients hémodialysés et 86 % chez les patients non hémodialysés, test du log-rank = 0,82). Aucun patient n'a subi de complication menaçant le pronostic vital. Conclusions: L'ablation par cathéter de la FA permet d'améliorer la QdV des patients qui subissent un traitement par HD de longue durée.

Structural heart disease, not the right ventricular pacing site, determines the QRS duration during right ventricular pacing.

Right ventricular (RV) pacing causes changes in the heart's electrical and mechanical activation patterns. The QRS duration is a useful surrogate marker of electrical dyssynchrony; a longer QRS duration during RV pacing indicates poor prognosis. However, the mechanisms underlying a longer QRS duration during RV pacing remain unclear; hence, we investigated factors predicting QRS prolongation during RV pacing. We enrolled 211 patients who underwent catheter ablation for supraventricular tachyarrhythmia and showed no bundle branch block. Three-dimensional mapping for the QRS duration during RV pacing from the RV outflow to RV apex was performed, and differences in the QRS duration were analyzed. The predisposing factors causing QRS > 160 ms during RV apical pacing were also analyzed. The QRS durations at baseline and during RV pacing from the RV outflow and at the RV apex were 85.0 ± 7.5 ms, 163.7 ± 17.1 ms, and 156.2 ± 16.1 ms, respectively. With respect to the QRS duration, there was a significant correlation between RV outflow and RV apical pacing (r = 0.658, p < 0.001). Difference in the QRS duration between the RV outflow and RV apex in each patient was only 12.5 ± 10.4 ms. Logistic multivariable regression analysis identified baseline QRS duration [odds ratio (OR) 1.24, 95% confidence interval (CI) 1.15-1.33, p < 0.01], interventricular septum thickness (OR 1.20, 95% CI 1.02-1.40, p = 0.025), left atrial diameter (OR 1.08, 95% CI 1.01-1.16, p = 0.024), and E/e' (OR 1.23, 95% CI 1.12-1.35, p < 0.01) as significant predictors of QRS prolongation during RV apical pacing. The QRS duration during RV pacing largely depends not on the pacing site, but on the underlying structural heart diseases.

Esophageal pressure monitoring for airway management during catheter ablation of atrial fibrillation.

BACKGROUND: Respiratory management during catheter ablation of atrial fibrillation (AF) is important for the efficacy and safety of the procedure. Obstructive apnea due to an upper airway obstruction might cause serious complications including air embolisms and cardiac tamponade. However, real time monitoring of upper airway obstructions during catheter ablation has not been established. The purpose of the present study was to evaluate esophageal pressure monitoring for respiratory management during catheter ablation of AF. METHODS AND RESULTS: Twenty-four consecutive patients (20 men and 4 women; mean age, 61 ± 13 years) with AF who underwent esophageal pressure monitoring during catheter ablation of AF were retrospectively analyzed. The patients were divided into 2 groups. One was the obstructive apnea (OA) group (n = 17), which required airway management tools including nasal airways and/or non-invasive positive airway pressure (NPPV) and the other was the control group (n = 7), which did not require airway management. Esophageal pressure measurements were obtained in all patients, and the OA group exhibited a substantial negative esophageal pressure as compared to the control group (-41.48 ± 19.58 vs. -12.42 ± 5.77 mmHg, p < 0.001). Airway management in the OA group immediately improved the negative esophageal pressure and returned to a normal range (-41.48 ± 19.58 vs. -16 ± 8.1 mmHg, 0 < 0.001) along with a recovery from desaturation. CONCLUSIONS: Esophageal pressure monitoring was a simple and effective method for the evaluation and management of obstructive apnea during AF catheter ablation.

Mid-term feasibility and safety of downgrade procedure from defibrillator to pacemaker with cardiac resynchronization therapy.

BACKGROUNDS: Some patients who undergo implantation of cardiac resynchronization therapy with defibrillator (CRT-D) survive long enough, thus requiring CRT-D battery replacement. Defibrillator therapy might become unnecessary in patients who have had significant clinical improvement and recovery of left ventricular ejection fraction (LVEF) after CRT-D implantation. METHODS: Forty-nine patients who needed replacement of a CRT-D battery were considered for exchange of CRT-D for cardiac resynchronization therapy with pacemaker (CRT-P) if they met the following criteria: LVEF >45%; the indication for an implantable cardioverter defibrillator was primary prevention at initial implantation and no appropriate implantable cardioverter defibrillator therapy was documented after initial implantation of the CRT-D. RESULTS: Seven patients (14.2%) were undergone a downgrade from CRT-D to CRT-P without any complications. No ventricular tachyarrhythmic events were observed during a mean follow-up of 39.7 ±â€¯21.1 months and there was no significant change in LVEF between before and 1 year after device replacement (53.5% ±â€¯6.2% vs. 56.4% ±â€¯7.3%, P = 0.197). CONCLUSIONS: This study confirmed mid-term feasibility and safety of downgrade from CRT-D to CRT-P alternative to conventional replacement with CRT-D.

Noninvasive evaluation of reverse atrial remodeling after catheter ablation of atrial fibrillation by P wave dispersion.

Atrial fibrillation (AF) itself creates structural and electrophysiological changes such as atrial enlargement, shortening of refractory period and decrease in conduction velocity, called "atrial remodeling", promoting its persistence. Although the remodeling process is considered to be reversible, it has not been elucidated in detail. The aim of this study was to assess the feasibility of P wave dispersion in the assessment of reverse atrial remodeling following catheter ablation of AF. Consecutive 126 patients (88 males, age 63.0 ± 10.4 years) who underwent catheter ablation for paroxysmal AF were investigated. P wave dispersion was calculated from the 12 lead ECG before, 1 day, 1 month, 3 months and 6 months after the procedure. Left atrial diameter (LAD), left atrial volume index (LAVI), left ventricular ejection fraction (LVEF), transmitral flow velocity waveform (E/A), and tissue Doppler (E/e') on echocardiography, plasma B-type natriuretic peptide (BNP) concentrations, serum creatinine, and estimated glomerular filtration rate (eGFR) were also measured. Of all patients, 103 subjects remained free of AF for 1 year follow-up. In these patients, P wave dispersion was not changed 1 day and 1 month after the procedure. However, it was significantly decreased at 3 and 6 months (50.1 ± 14.8 to 45.4 ± 14.4 ms, p < 0.05, 45.2 ± 9.9 ms, p < 0.05, respectively). Plasma BNP concentrations, LAD and LAVI were decreased (81.1 ± 103.8 to 44.8 ± 38.3 pg/mL, p < 0.05, 38.2 ± 5.7 to 35.9 ± 5.6 mm, p < 0.05, 33.3 ± 14.2 to 29.3 ± 12.3 mL/m2, p < 0.05) at 6 months after the procedure. There were no significant changes in LVEF, E/A, E/e', serum creatinine, and eGFR during the follow up period. P wave dispersion was decreased at 3 and 6 months after catheter ablation in patients without recurrence of AF. P wave dispersion is useful for assessment of reverse remodeling after catheter ablation of AF.

Blanking Period Phenomenon After a Second Atrial Fibrillation Ablation Session: The Application and Factors Related to It.

INTRODUCTION: The concept of a 3-month blanking period is widely accepted after the first radiofrequency catheter ablation (RFCA) session for atrial fibrillation (AF). We sought to investigate whether this phenomenon was also observed after a 2nd session, and which factors were related to it. METHODS AND RESULTS: We conducted a prospective observational study including all AF patients who underwent RFCA since 2010. The patients who underwent a second RFCA were followed without any antiarrhythmic drugs. Their clinical background, laboratory data, echocardiographic parameters, ablation procedures, and arrhythmia recurrences were analyzed. Recurrences were classified into early period recurrences (EPRs) and late period recurrences (LPRs) recorded within and after the first 3 months postablation, respectively. Among 925 patients who underwent an initial AF ablation, 2nd sessions were performed in 250 patients, and EPRs and LPRs occurred in 53 (21.2%) and 54 (21.6%) patients, respectively. Although EPRs were an independent predictor of LPRs (hazard ratio [HR], 8.01; 95% confidence interval [CI] 4.03-15.93, P < 0.001), 20 of the patients with EPRs (37.7%) did not experience LPRs, supporting the concept of a blanking period. Among 53 patients with EPRs, the E/E' ratio on echocardiography (HR, 1.156; 95% CI 1.00-1.33, P = 0.04) was an independent predictor of LPRs, while other parameters including the maximum serum C-reactive protein level after the session and the ablation procedure details were not. CONCLUSION: A 3-month blanking period was also applicable after the 2nd AF ablation session. This phenomenon was related to a lower left atrial pressure demonstrated by the E/E' ratio.

Massive Right Atrial Thrombus Formation Followed by an Atrial Flutter with 1:1 Atrioventricular Conduction in a Patient with Arrhythmogenic Right Ventricular Cardiomyopathy.

A 46-year-old man was admitted to our hospital for near syncope and palpitations. An electrocardiogram showed a common type of atrial flutter (AFL) with 1:1 atrioventricular conduction. Transthoracic echocardiography revealed a massive right atrial (RA) thrombus with a huge RA and right ventricle. The patient was diagnosed with arrhythmogenic right ventricular cardiomyopathy. It was difficult to control the heart rate with beta-blockers during AFL, which resulted in the deterioration of right-sided heart failure. The effect of anticoagulation therapy for the RA thrombus was also limited. Restoration to sinus rhythm by catheter ablation effectively improved the right-sided heart failure, and the massive RA thrombus eventually disappeared.

Urgent Catheter Ablation in Octogenarians with Serious Tachyarrhythmias.

BACKGROUND: Urgent catheter ablation is often required for various tachyarrhythmias; however, its efficacy and safety in elderly patients have not been fully elucidated. METHODS: This study included consecutive octogenarians who underwent urgent radiofrequency catheter ablation (RFCA) for various serious tachyarrhythmias (urgent group, n=28) that were life-threatening, hemodynamically deleterious, or provoking ischemia, and consecutive octogenarians who underwent elective RFCA (control group, n=36). The rate of a successful RFCA, complications, later arrhythmia recurrences, and mortality were compared between the groups. RESULTS: There was no significant difference in the breakdown of the targeted arrhythmias between the groups, and common-type atrial flutter was most often targeted in both the urgent group (57%) and the elective group (56%). Compared with the control group patients, the patients of the urgent group were older (84±3 vs. 82±2 years P=0.001), with a higher frequency of baseline heart disease (68% vs. 17%, P<0.001) and lower left ventricular ejection fraction (45%±15% vs. 68%±10%, P<0.001). The rates of acute success (100% vs. 100%, P=1.00) and later arrhythmia recurrences (4% vs. 14%, P=0.22) were comparable between the groups. Two patients in the urgent group and 2 in the elective group had procedure-related nonlethal complications (7% vs. 6%, P=1.00): groin hematoma in 2, pressure ulcer in 1, and CO2 narcosis in 1. There were no in-hospital deaths, and mortality during follow-up did not differ between the urgent and elective groups (6.0% vs. 3.9% per year, log-rank P=0.38). CONCLUSION: Even in octogenarian patients, urgent catheter ablation for serious tachyarrhythmias can be safely performed with a high success rate and acceptable prognosis.

Mechanisms of postoperative atrial tachycardia following biatrial surgical ablation of atrial fibrillation in relation to the surgical lesion sets.

BACKGROUND: Atrial tachycardia (AT) may develop after biatrial surgical ablation of atrial fibrillation. However, the mechanism has not been determined in detail. OBJECTIVE: We aimed to determine the mechanism and treatment of postoperative AT following biatrial surgical ablation in relation to the design and durability of the surgical lesion sets. METHODS: An electrophysiologic study and radiofrequency ablation were performed in 34 consecutive patients (23 male, mean age of 63 ± 9.4 years) who were referred for AT that developed late after biatrial surgical ablation. RESULTS: The mechanism of a total of 53 ATs was macroreentry in 30, a focal mechanism in 20, and localized reentry in 1, and could not be determined in 2. The cause of the macroreentrant AT was residual conduction across a surgical lesion, most of which was located at the annular end of the mitral (n = 18) or tricuspid isthmus incision (n = 7), where cryoablation was applied during the surgery. We did not find any gaps across the cut-and-sew lesions. Radiofrequency (RF) applications to the gap, or an alternative site to transect the circuit, or the earliest activation site of the focus was effective for 48 ATs (91%). After a total of 1.3 ± 0.6 RF sessions, 27 patients (79%) were free of AT (n = 2) or AF (n = 5) during a follow-up period of 50 ± 49 months. CONCLUSIONS: Macroreentry due to a gap in a surgical lesion and focal AT were the major mechanisms of AT in patients after biatrial surgical ablation. Radiofrequency ablation of those ATs is feasible.

Clinical and Electrocardiographic Characteristics of Electrical Storms Due to Monomorphic Ventricular Tachycardia Refractory to Intravenous Amiodarone.

BACKGROUND: Few reports are available on the characteristics of electrical storms of ventricular tachycardia (VT storm) refractory to intravenous (IV) amiodarone. METHODS AND RESULTS: IV-amiodarone was administered to 60 patients with ventricular tachyarrhythmia between 2007 and 2012. VT storms, defined as 3 or more episodes of VT within 24 h, occurred in 30 patients (68±12 years, 7 female), with 12 having ischemic and 18 non-ischemic heart disease. We compared the clinical and electrocardiographic characteristics of the patients with VT storms suppressed by IV-amiodarone (Effective group) to those of patients not affected by the treatment (Refractory group). IV-amiodarone could not control recurrence of VT in 9 patients (30%). The Refractory group comprised 5 patients with acute myocardial infarctions. Although there was no difference in the VT cycle length, the QRS duration of both the VT and premature ventricular contractions (PVCs) followed by VT was narrower in the Refractory group than in the Effective group (140±30 vs. 178±25 ms, P<0.01; 121±14 vs. 179±22 ms, P<0.01). In the Refractory group, additional administration of IV-mexiletine and/or Purkinje potential-guided catheter ablation was effective. CONCLUSIONS: IV-amiodarone-refractory VT exhibited a relatively narrow QRS tachycardia. The narrow triggering PVCs, suggesting a Purkinje fiber origin, may be treated by additional IV-mexiletine and endocardial catheter ablation.

Detection and Evaluation of Pulmonary Hypertension by a Synthesized Right-Sided Chest Electrocardiogram.

BACKGROUND: Current standard 12-lead electrocardiogram (ECG) criteria for diagnosing pulmonary hypertension (PH) have a low sensitivity. Although the right-sided chest ECG (V3R-V5R) increases the diagnostic accuracy, these additional leads are not routinely recorded. The aim of the present study was to assess the usefulness of the synthesized right-sided chest ECG (Syn-ECG), generated from 12-lead ECG information, in the detection and evaluation of PH. PATIENTS AND METHODS: The Syn-ECG waveforms in 30 patients with PH, defined as an estimated pulmonary arterial systolic pressure (PASP) >35 mmHg, were compared to those in 30 age- and gender-matched normal subjects. RESULTS: The R wave amplitude and R/S ratio in the Syn-ECGs were significantly (P<0.01) greater in patients with PH than in the controls. The R wave amplitude in the Syn-ECGs exhibited a significant and better correlation (correlation coefficient 0.513-0.596, P<0.001) with the PASP than lead V1 (correlation coefficient 0.375, P=0.02). A receiver-operating characteristic curve analysis showed that the R wave amplitude (AUC 0.802, P<0.001) and R/S ratio (AUC 0.823, P<0.001) in the synthesized V5R was a good predictor of PH. New criteria, including 1) an R in V5R>0.12 mV, and 2) R/S ratio in V5R>0.42, had an improved sensitivity (0.63 and 0.73, respectively) and comparable specificity (0.93 and 0.87, respectively) to the conventional criteria (sensitivity 0.10-0.43, specificity 0.90-1.00). CONCLUSION: The diagnostic criteria derived from the Syn-ECG provided better diagnostic accuracy than the known conventional criteria from the standard 12-lead ECG. This technique described in the present study may be useful for diagnosing and evaluating PH.

Efficacy and safety of flecainide for ventricular arrhythmias in patients with Andersen-Tawil syndrome with KCNJ2 mutations.

BACKGROUND: Andersen-Tawil syndrome (ATS) is an autosomal dominant genetic or sporadic disorder characterized by ventricular arrhythmias (VAs), periodic paralyses, and dysmorphic features. The optimal pharmacological treatment of VAs in patients with ATS remains unknown. OBJECTIVE: We evaluated the efficacy and safety of flecainide for VAs in patients with ATS with KCNJ2 mutations. METHODS: Ten ATS probands (7 females; mean age 27 ± 11 years) were enrolled from 6 institutions. All of them had bidirectional VAs in spite of treatment with ß-blockers (n = 6), but none of them had either aborted cardiac arrest or family history of sudden cardiac death. Twenty-four-hour Holter recording and treadmill exercise test (TMT) were performed before (baseline) and after oral flecainide therapy (150 ± 46 mg/d). RESULTS: Twenty-four-hour Holter recordings demonstrated that oral flecainide treatment significantly reduced the total number of VAs (from 38,407 ± 19,956 to 11,196 ± 14,773 per day; P = .003) and the number of the longest ventricular salvos (23 ± 19 to 5 ± 5; P = .01). At baseline, TMT induced nonsustained ventricular tachycardia (n = 7) or couplets of premature ventricular complex (n = 2); treatment with flecainide completely (n = 7) or partially (n = 2) suppressed these exercise-induced VAs (P = .008). In contrast, the QRS duration, QT interval, and U-wave amplitude of the electrocardiogram were not altered by flecainide therapy. During a mean follow-up of 23 ± 11 months, no patients developed syncope or cardiac arrest after oral flecainide treatment. CONCLUSION: This multicenter study suggests that oral flecainide therapy is an effective and safe means of suppressing VAs in patients with ATS with KCNJ2 mutations, though the U-wave amplitude remained unchanged by flecainide.

Anatomical factors associated with periesophageal vagus nerve injury after catheter ablation of atrial fibrillation.

BACKGROUND: The periesophageal vagus nerve plexus controls the kinetics of the stomach, digestive tract, and gallbladder, and catheter ablation of atrial fibrillation (AF) can cause vagus nerve injury (VNI). We sought to clarify the incidence, clinical course, and anatomical factors related to periesophageal VNI. METHODS: The present study included 257 consecutive patients with AF (mean age, 62±11 years) who underwent catheter-based pulmonary vein isolation. With 64-slice computed tomographic images, the left atrium (LA)-esophageal contact length, LA diameter, and distances between each mediastinal structure were compared between patients with VNI and those without VNI. RESULTS: VNI occurred in 5 patients (1.9%), gastric hypomotility in 3 patients, and acalculous cholecystitis in 2 patients, within 3 days after ablation, and all patients recovered completely within 2 weeks. Compared with patients without VNI, those with VNI more frequently underwent ablation at the mitral isthmus (p=0.03) and inside the coronary sinus (p=0.03). On computed tomographic images, the esophagus was closer to the aorta than to the spine in 67% of patients and was defined as an aorta-sided esophagus. In patients with VNI, the distance from the LA to the spine or the descending aorta (in patients with an aorta-sided esophagus) was shorter (p=0.03), and the transverse LA-esophageal contact length was longer (p=0.01). CONCLUSION: Acalculous cholecystitis, as well as gastric hypomotility, can develop as a result of periesophageal VNI in patients undergoing AF ablation. The anatomical relationships among the LA, esophagus, spine, and descending aorta may influence the occurrence of VNI.

Three-month lower-dose flecainide after catheter ablation of atrial fibrillation.

AIMS: Atrial tachyarrhythmias (AT) commonly recur within the first 3 months after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF), and the influence of antiarrhythmic drugs (AADs) on the recurrences has not been fully elucidated. We sought to evaluate the efficacy of a 3-month lower-dose flecainide regime on early and late recurrences of ATs. METHODS AND RESULTS: We randomly assigned 126 patients, who underwent RFCA for AF, to the flecainide group (150 or 100 mg/day according to their body weight) or to the control group receiving no AADs. The primary endpoint was any AT lasting for ≥30 s during the first 3 months and the secondary endpoint was a composite of ATs lasting for ≥24 h or requiring cardioversion or hospitalization during the same period. All AADs were stopped after the first 3 months and the late arrhythmia recurrences were also evaluated. The primary endpoint rates were 37 and 41% in the flecainide (143 ± 19 mg/day) and control groups, respectively (log-rank P = 0.76), and those of the secondary endpoint were 10 and 14%, respectively (log-rank P = 0.45). The estimated rates of maintaining sinus rhythm at 12 months after the first 3 months were 78 and 72%, in the flecainide and control groups, respectively (log-rank P = 0.68), and the rates were 51 and 90% in those with and without the primary endpoint, respectively (log-rank P < 0.001). CONCLUSION: The 3-month lower-dose flecainide therapy after AF ablation did not reduce the early and late arrhythmia recurrences. The clinically significant ATs were also not prevented.

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.

Urgent catheter ablation for sustained ventricular tachyarrhythmias in patients with acute heart failure decompensation.

AIMS: Ventricular tachycardia (VT) and ventricular fibrillation (VF) are not uncommon in patients hospitalized with acute heart failure (AHF). We sought to evaluate the efficacy of urgent radiofrequency catheter ablation (RFCA) for recurrent VT/VF during AHF decompensations. METHODS AND RESULTS: The present study retrospectively analysed the data of 15 consecutive patients (69 ± 9 years, ischaemic heart disease in 10), who underwent urgent RFCA for frequent drug-refractory VT/VF episodes during an AHF decompensation with pulmonary congestion. The target arrhythmias were clinically documented monomorphic VTs in 10 patients, frequent premature ventricular contractions (PVCs) triggering VF in 4, and both in 1. The mean left ventricular ejection fraction was 26 ± 8%. The maximum number of arrhythmia episodes over 24 h was 9.1 ± 11.7. All RFCA sessions were completed without any major complications except for a temporary deterioration of pulmonary congestion in three patients (20%). Elimination and non-inducibility of the target arrhythmias were achieved in 13 patients (87%). Successful ablation site electrograms showed Purkinje potentials for all 5 PVCs triggering VF and 4 of 14 clinically documented monomorphic VTs (29%). Five patients (33%) underwent second sessions 10 ± 4 days after the first session for acute recurrences. Sustained VT/VF was completely suppressed during admission in 12 patients (80%), and the AHF ameliorated in 13 patients (93%). Twelve patients (80%) were discharged alive. CONCLUSION: Urgent RFCA for drug-resistant sustained ventricular tachyarrhythmias during AHF decompensations would be an appropriate therapeutic option. Purkinje fibres can be ablation targets not only in those with PVCs triggering VF, but also in those with monomorphic VT.

Recovery of atrioventricular block following steroid therapy in patients with cardiac sarcoidosis.

BACKGROUND: Atrioventricular (AV) block is one of the main clinical manifestations in patients with cardiac sarcoidosis (CS). Although steroid therapy is considered to be effective for AV block, the efficacy has not been demonstrated in detail. METHODS AND RESULTS: Fifteen CS patients presenting with advanced or complete AV block were retrospectively investigated. All patients were treated with 30mg/day of prednisone after device implantation, which was tapered to a maintenance dosage of 5-10mg/day. During a mean follow-up of 7.1 years, AV block resolved to normal conduction or first-degree AV block in 7 patients (recovery group). The improvement was driven within the first week of steroid therapy in 4 patients, while 3 patients showed late recovery of AV conduction. The remaining 8 patients were classified as the non-recovery group. The recovery group showed a higher left ventricular ejection fraction (69.4±8.9% versus 44.1±19.3%, p=0.029) and higher prevalence of advanced AV block (87.5% versus 28.6%, p=0.040) compared with those of the non-recovery group. In patients with the recovery group, there was no late recurrence of AV block during the follow-up period. CONCLUSIONS: Early initiation of steroid therapy may be effective for AV block, and steroid therapy before device implantation is a possible therapeutic strategy for some selected patients.