Takanori Arimoto

Prevention of atrial fibrillation recurrence with corticosteroids after radiofrequency catheter ablation: a randomized controlled trial.

OBJECTIVES We sought to clarify the efficacy of corticosteroid therapy for preventing atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). BACKGROUND The inflammatory process may cause acute AF recurrence after PVI. However, no studies have examined the relationship between corticosteroid administration and AF recurrence after PVI. METHODS A total of 125 patients with paroxysmal AF were randomized to receive either corticosteroids (corticosteroid group) or a placebo (placebo group). In the corticosteroid group, intravenous hydrocortisone (2 mg/kg) was given the day of the procedure, and oral prednisolone (0.5 mg/kg/day) was administered for 3 days after the PVI. The body temperature and high-sensitivity C-reactive protein level were measured before and on each of the first 3 days after ablation. RESULTS The prevalence of immediate AF recurrence (≤3 days after the PVI) was significantly lower in the corticosteroid group (7%) than in the placebo group (31%). The maximum body temperature and C-reactive protein during the initial 3 days after ablation and the increase in the body temperature and C-reactive protein level from baseline were significantly lower in the corticosteroid group than in the placebo group. Corticosteroid treatment did not decrease AF recurrences between 4 and 30 days after ablation. The AF-free rate at 14 months post-ablation was greater in the corticosteroid group (85%) than in the placebo group (71%, p=0.032 by the log-rank test). CONCLUSIONS Transient use of small amounts of corticosteroids shortly after AF ablation may be effective and safe for preventing not only immediate AF recurrences but also AF recurrences during the mid-term follow-up period after PVI.

Comparison of Characteristics and Significance of Immediate Versus Early Versus No Recurrence of Atrial Fibrillation After Catheter Ablation

Atrial fibrillation (AF) recurrences after catheter ablation are common within the first month after AF ablation, and inflammatory processes may be related to AF genesis. This study aimed to clarify the relation between inflammatory processes and recurrence of AF after ablation and to characterize AF recurring within 3 days after ablation (immediate AF recurrence).The study included 186 patients with drug-refractory paroxysmal AF who underwent extensive pulmonary vein isolation. Body temperature and C-reactive protein level were measured before and consecutively on the first 3 days after ablation. Signs of pericarditis or atrial arrhythmias within 3 days after ablation were also monitored. Forty-five patients (24%) had immediate AF recurrence (immediate-AF-recurrence group), 27 (14%) had early recurrence 4 to 30 days after ablation (early-AF-recurrence group), and the remaining 114 (61%) had no AF recurrence within 1 month after ablation (no-AF-recurrence group). Increases in body temperature and C-reactive protein level from baseline in the immediate-AF-recurrence group were the highest among the 3 groups, and signs of pericarditis were observed in 15 of the 45 patients (33%) in the immediate-AF-recurrence group. Atrial premature contractions and nonsustained AF occurred most frequently in the early-AF-recurrence group. After 6-month follow-up, the AF-free rate was greater in the immediate-AF-recurrence group (76%) than in the early-AF-recurrence group (30%). In conclusion, immediate AF recurrence has an apparently different mechanism and impact on midterm outcomes than does early AF recurrence. Acute inflammatory changes after ablation may be responsible for immediate AF recurrence.

Prevalence and characteristics of asymptomatic excessive transmural injury after radiofrequency catheter ablation of atrial fibrillation.

BACKGROUND Even with a low energy setting, radiofrequency energy applications on the left atrial (LA) posterior wall may cause excessive transmural injury (ETI) during catheter ablation of atrial fibrillation (AF). OBJECTIVE The purpose of this study was to clarify the prevalence and characteristics of ETI. METHODS This study included 104 patients with AF who underwent extensive encircling pulmonary vein isolation (EEPVI) followed by an endoscopic examination (≤48 hours after EEPVI). EEPVI was performed under conscious sedation, and the ablation settings at the LA posterior wall were a maximum energy of 20 to 25 W and duration of ≤30 seconds. The ETI was defined as any injury that resulted from EEPVI, including esophageal damage or periesophageal nerve injury. RESULTS ETIs were found in 10 (9.6%) patients and were all asymptomatic; esophageal damage in 4 patients and periesophageal nerve injury in the remaining 6. All patients with ETI were below normal weight (body mass index [BMI] < 24.9 kg/m(2)), and consisted of 17% of those below normal weight. The procedural parameters such as the type of energy source, total duration of energy applications to the LA posterior wall, additional LA linear ablation, and biochemical markers were not related to the ETI. In the logistic multiadjusted model, the BMI (per 1 kg/m(2)) was the only independent predictor of ETI (odds ratio = 0.76; 95% confidence interval = 0.59 to 0.97, P < .05). CONCLUSION Asymptomatic ETIs were not rare even with a low energy setting in patients below normal weight. Tailored energy settings based on the patients BMI may be required when performing EEPVI.

High Washout Rate of Iodine-123-Metaiodobenzylguanidine Imaging Predicts the Outcome of Catheter Ablation of Atrial Fibrillation

123 I‐MIBG and Ablation for Atrial Fibrillation. Introduction: Excessive sympathetic nervous activity may contribute to atrial fibrillation (AF) recurrences after ablation, but its precise role remains controversial. The goals of this study were to assess the effects of AF on the iodine‐123‐metaiodobenzylguanidine (123I‐MIBG) findings and to elucidate its impact on the procedural outcome in patients undergoing a first‐time catheter ablation to treat AF.

Effect of Restoration of Sinus Rhythm by Extensive Antiarrhythmic Drugs in Predicting Results of Catheter Ablation of Persistent Atrial Fibrillation

In patients with persistent atrial fibrillation (AF), an extensive antiarrhythmic drug (AAD) therapy using class III AADs and class I AADs might be more effective in restoring sinus rhythm than class I or III AADs alone. However, the significance and efficacy of this treatment before radiofrequency catheter ablation is unclear. The present study included 51 consecutive patients with long-lasting persistent AF (>12 months) in whom > or =2 previous AADs had failed to restore sinus rhythm (SR). Before performing extensive pulmonary vein isolation, extensive AAD therapy for >3 months was attempted. Before ablation, AF had converted to SR in 33 patients (65%; SR group) and had continued in 18 (35%; AF group). The left ventricular ejection fraction had increased (p <0.01) in association with the improved left atrial diameter (p <0.05) and brain natriuretic peptide plasma level (p <0.001) in the SR group. However, these parameters had not improved in the AF group. The AF-free rate without any AADs at 14 months after a single ablation procedure was greater in the SR group (61%) than in the AF group (22%; hazard ratio 2.62, 95% confidence interval 1.22 to 5.63; p = 0.013). No restoration of SR with extensive AAD therapy (odds ratio 4.493, 95% confidence interval 1.143 to 17.658; p <0.05) and sustained AF lasting for >3 years (odds ratio 4.574, 95% confidence interval 1.027 to 20.368; p <0.05) before ablation were associated with AF recurrence after ablation. In conclusion, restoration of SR with improved cardiac function and structural remodeling after extensive AAD therapy might predict favorable outcomes after ablation in patients with long-lasting, persistent AF.

Clinical and Procedural Characteristics of Acute Hemodynamic Responders Undergoing Triple-Site Ventricular Pacing for Advanced Heart Failure

The advantages of triple-site ventricular pacing (Tri-V) compared to conventional biventricular site pacing (Bi-V) have been reported. We sought to identify the predictors of acute hemodynamic Tri-V responders. Acute hemodynamic studies were performed in 32 patients with advanced heart failure during Tri-V implantation. After the right ventricular (RV) and left ventricular (LV) leads were implanted for a conventional Bi-V system, an additional pacing lead was implanted in the RV outflow tract for Tri-V. The LV peak +dP/dt and tau were measured during AAI, Bi-V, and Tri-V pacing. A Tri-V responder was defined as a patient whose percentage of increase in the peak +dP/dt during Tri-V was >10% compared to of that during Bi-V. The baseline clinical variables and RV outflow tract lead location were analyzed to identify the characteristics of the Tri-V responders. Of the 32 patients, 10 (31%) were classified as Tri-V responders. The LV end-diastolic volume was greater (246 ± 48 vs 173 ± 53 ml, p <0.01), and the RV outflow tract lead was implanted at a greater outflow tract portion (p <0.05) in the Tri-V responders. Multivariate analysis revealed that only the baseline LV end-diastolic volume (per 50-ml greater) predicted the Tri-V response (odds ratio 2.87, 95% confidence interval 1.03 to 8.00, p <0.05). The area under the receiver operating characteristic curve for the LV end-diastolic volume was 0.84 (p <0.01) and an LV end-diastolic volume of >212 ml had a sensitivity of 80% and specificity of 77% to distinguish Tri-V responders. In conclusion, Tri-V provides greater hemodynamic effect for patients with a larger LV end-diastolic volume owing to its resynchronization effects on the LV anterior wall.

Epicardial Ablation of Ventricular Tachycardia with Manual Controlled External Irrigation in a Patient with Nonischemic Cardiomyopathy

We describe a patient with nonischemic cardiomyopathy who underwent radiofrequency (RF) catheter ablation for a drug‐refractory ventricular tachycardia (VT). RF ablation from a left ventricular (LV) endocardial site failed to eliminate the VT. Using a conventional ablation catheter with the temperature‐controlled mode, RF ablation from the LV epicardium resulted in failed ablation because of low power due to a temperature limitation function. However, by using a pericardial pigtail catheter for manual infusion and removal of saline within the pericardial space, adequate energy could be delivered, and the ablation overlying the lowvoltage area successfully eliminated the VT.

Implantable Cardioverter Defibrillator in a Patient with Eisenmenger Syndrome after Senning Repair for Transposition of the Great Arteries

An implantation of a cardioverter‐defibrillator was attempted in a 32‐year‐old man with atrial tachycardia, ventricular tachycardia and sinus node dysfunction. He had undergone a Senning operation and half closure of ventricular septal defect in order to correct a transposition of the great arteries. Cardiac catheterization revealed severe pulmonary hypertension and Eisenmenger syndrome. Prior knowledge of the complex cardiac anatomy obtained by magnetic resonance imaging helped in determining the suitable site for implanting the leads and planning the procedural strategy. With repletion of a large amount of saline and oral anticoagulation with warfarin, no complications related to thromboembolism occurred during a 10‐month follow‐up period.

Coronary Venous Lead Implantation after an Evaluation by Virtual Histology Intravascular Ultrasound and Stenting of a Stenosis

We describe a patient who developed coronary vein (CV) stenosis shortly (<3 months) after an initial left ventricular (LV) lead implantation with significant fibrous tissue. The virtual histological intravascular ultrasound analysis was useful for characterizing the plaque component of the stenotic lesion and formulating the strategy. A summarized review of the CV angioplasty for LV lead implantations disclosed that CV stenosis was often found in patients who had a previous history of cardiac surgery or an LV lead implantation and that a stent implantation was required to deploy the LV lead in the targeted CV in some (9.3%) patients. (PACE 2013; 36:e59–e63)

Efficacy and Safety of Strict Voltage-based Substrate Mapping and Radiofrequency Catheter Ablation in Electrical Storms—Review of Substrate-mapping Guided Ablation in Frequent Appropriate Shocks

Background: We investigated the efficacy and safety of strict voltage‐based substrate mapping and radiofrequency catheter ablation (SV‐substrate‐map ablation) in patients with electrical storm.