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Objectives This randomized study compared uninterrupted rivaroxaban therapy with warfarin therapy as prophylaxis against catheter ablation (CA)-induced asymptomatic cerebral infarction (ACI) and identified the risk factors of rivaroxaban. Background The reported incidence of ACI during CA for atrial fibrillation (AF) remains at 10% to 30%, and periprocedural oral anticoagulation could affect this incidence. Methods Patients with nonvalvular AF undergoing radiofrequency CA were randomly assigned to receive either uninterrupted rivaroxaban or warfarin as periprocedural anticoagulation therapy. CA was performed after at least 1 month of adequate anticoagulation. Cerebral magnetic resonance imaging (MRI) was performed within 2 weeks before and 1 day after CA to detect ACI. Results A total 132 patients were enrolled; 127 (median: 60.0 years of age; 83.5% males; 64.6% incidence of paroxysmal AF) complied with the study protocol and were analyzed; 64 patients received rivaroxaban, and 63 patients received warfarin. The rates of CA-induced ACI in the rivaroxaban group (15.6% [10 of 64 patients]) were similar to those in the warfarin group (15.9% [10 of 63 patients]; p = 1.000). No thromboembolic events developed; no differences in major or nonmajor bleeding rates were observed between the 2 drug groups (3.1% vs. 1.6%, respectively, or 18.8% vs. 19.0%, respectively). Multiple regression analysis indicated that the presence of deep and subcortical white matter hyperintensity (p = 0.002; odds ratio [OR]: 5.323) and the frequency of cardioversions (p = 0.016; OR: 1.250) were associated with the incidence of ACI. Conclusions No notable differences were found between the incidence of CA-induced ACI in the rivaroxaban group and that in the warfarin group in this randomized study.

Background We aimed to clarify the cost-effectiveness of an expensive combination therapy for atrial fibrillation (AF) using both catheter ablation and dabigatran compared with warfarin at each CHADS2 score for patients in Japan. Methods A Markov model was constructed to analyze costs and quality-adjusted life years associated with AF therapeutic options with a time horizon of 10 years. The target population was 60-year-old patients with paroxysmal AF. The indication for anticoagulation was determined according to the Japanese guideline. Anticoagulation-related data were derived from the RE-LY study and the AF recurrence rate was set at 2.7% per month during the first 12 months and at 0.40% per month afterwards. Stroke risk was determined according to AF recurrence, anticoagulation, and CHADS2 score. The risks for stroke recurrence and stroke death were also considered. Costs were calculated from the healthcare payer's perspective, and only direct medical costs were included. Results Warfarin was the most preferred option for patients with a CHADS2 score of 0 from a health economics aspect. Ablation under warfarin was preferred for a CHADS2 score of 1–3, while ablation under dabigatran was preferred for a CHADS2 score ≥4. The quality of life score for AF had the largest impact on the incremental cost-effectiveness ratios in the analysis between the anticoagulation arm and the anticoagulation + ablation arm for a CHADS2 score of 2. Within the range of the Japanese willingness-to-pay threshold (¥5,000,000), the ablation + warfarin arm became the best option with its probability of 81.7% for a CHADS2 score of 2; the dabigatran + ablation arm was the most preferred option with its probability of 56.1% for a CHADS2 score of 4. Conclusions Ablation under dabigatran therapy is an expensive therapeutic option, but it might benefit patients with a low quality of life and a high CHADS2 score.

Differences in the methodologies for evaluating atrial fibrillation (AF) ablation outcomes should be evaluated. In the present study, we compared the AF ablation outcomes among periodic clinic electrocardiography (ECG), 24-h Holter ECG, and telemonitoring ECG to evaluate the differences among these methods. In addition, we evaluated the AF-free survival rate for each method with different durations of the blanking period. A total of 30 AF patients were followed up for 6 months after initial catheter ablation, with clinic ECG on every clinic visit, monthly 24-h Holter ECG, and telemonitoring ECG twice daily and upon symptoms. AF relapse was defined as AF or atrial tachycardia detected with any of the methods. Two patients dropped out of the study, and 28 patients were followed up for 8.8 ± 2.7 months. Patients underwent 3.6 ± 0.8 clinic ECG, 5.1 ± 0.8 Holter ECG, and 273 ± 68 telemonitoring ECG examinations. During the first, second, third, fourth, fifth, and sixth months of follow-up, Holter ECG detected relapses in 11.1, 8.3, 11.5, 15.4, 4.2, and 4.8 % of patients and telemonitoring ECG detected relapses in 32.1, 25.0, 25.0, 17.9, 28.6, and 17.9 % of patients, respectively. When no duration was set for the blanking period, the AF-free survival rate was significantly lower with telemonitoring ECG (46.4 %) than with Holter ECG (78.6 %, P = 0.013) or clinic ECG (85.7 %, P = 0.002). In addition, when the duration of the blanking period was set to 3 months, the AF-free survival rate was significantly lower with telemonitoring ECG than with clinic ECG (92.9 vs. 71.4 %, P = 0.041). The AF ablation outcomes with twice-daily telemonitoring ECG might differ from those with clinic ECG when the duration of the blanking period is 0-3 months. A follow-up based solely on clinic ECG might underestimate AF recurrence.

In patients with Brugada syndrome (BS), VF occurred predominantly during the nocturnal period. Some patients also developed ESs. In addition to the circadian rhythm, patients showed weekly and seasonal patterns. The patients with ESs had peak episodes of VF on Saturday and in the winter and spring, while episodes of VF in patients with single VF events occurred most often on Monday with smaller seasonal variation. Except for age, there was no difference in the clinical or ECG characteristics between the patients with ESs and those with single VF episodes.

The aims of this study were to: 1) use a novel method of late gadolinium enhancement (LGE) quantification that uses normalized intensity measures to confirm the association between LGE extent and atrial fibrillation (AF) recurrence following ablation; and 2) examine the presence of interaction and effect modification between LGE and AF persistence.Recurrent AF after catheter ablation has been reported to associate with the baseline extent of left atrial LGE on cardiac magnetic resonance. Traditional methods for measurement of intensity lack an objective threshold for quantification and interpatient comparisons of LGE.The cohort included 165 participants (mean age 60.0 ± 10.2 years, 77% men, 57% with persistent AF) who underwent initial AF ablation. The association of baseline LGE extent with AF recurrence was examined using multivariable Cox proportional hazards models. Multiplicative and additive interactions between AF type and LGE extent were examined.During 10.2 ± 5.7 months of follow-up, 63 patients (38.2%) experienced AF recurrence. Baseline LGE extent was independently associated with AF recurrence after adjusting for confounders (hazard ratio: 1.5 per 10% increased LGE; p 0.001). The hazard ratio for AF recurrence progressively increased as a function of LGE. The magnitude of association between LGE35% and AF recurrence was greater among patients with persistent AF (hazard ratio: 6.5 [p = 0.001] vs. 3.6 [p = 0.001]); however, there was no evidence for statistical interaction.Regardless of AF persistence at baseline, participants with LGE ≤35% have favorable outcomes, whereas those with LGE35% have a higher rate of AF recurrence in the first year after ablation. These findings suggest a role for: 1) patient selection for AF ablation using LGE extent; and 2) substrate modification in addition to pulmonary vein isolation in patients with LGE extent exceeding 35% of left atrial myocardium.

Aims The left atrial appendage (LAA) represents the major source of cardiac thrombus formation in patients with atrial fibrillation (AF). Phased-array intracardiac echocardiography (ICE) has become available and frequently used during catheter ablation of AF. We attempted to study the feasibility of using ICE for the visualization and evaluation of the LAA from the pulmonary artery (PA) in patients with AF. Methods and Results Eighty patients with AF undergoing catheter ablation (70 males, 57.5 ± 9.1 years) were included. Transoesophageal echocardiography was performed on the prior day before the catheter ablation, and ICE was performed just before the transseptal puncture during the catheter ablation. The ICE catheter was advanced up into the PA from the femoral vein, where the LAA was clearly and entirely visualized by manipulating the ICE catheter. We compared the degree of spontaneous echo contrast, and the correlation was obtained between the ICE and TEE ( κ = 0.534, P < 0.001). Furthermore, the LAA flow velocity (LAA emptying and filling velocities) measured by ICE had a good correlation to that measured by TEE ( R = 0.872, P < 0.01 and R = 0.753, P < 0.01, respectively). No patients developed any complications. Conclusion The utilization of ICE in the PA is feasible for the observation and evaluation of the LAA.

Background We investigated various serum inflammatory markers to predict ablation responders who have no atrial fibrillation (AF) relapse after the initial ablation. Methods Forty-four consecutive AF patients (age: 59 ± 8 years, paroxysmal: 31, CHADS 2 : 1.1 ± 1.1) who underwent an initial pulmonary vein isolation were investigated. Various serum inflammatory markers, such as adiponectin, ANP, BNP, 1CTP, F1+2, hs-CRP, IL-6, intact P1NP, MDA-LDL, MMP-2, TGF-β, TIMP-2, and TNF-α, were evaluated prior to ablation. AF relapse was defined as AF documented in telemonitoring electrocardiograms twice a day during 9.7 ± 2.4 months of follow-up with three months of a blanking-period. Results A total of 29 patients (paroxysmal: 21) maintained sinus rhythm after the initial catheter ablation. These ablation responders had significantly lower MMP-2 (Sinus vs. Relapsed: 748 ± 132.7 vs. 841.2 ± 152.4 ng/mL, P=0.042) and TNF-α (1.1 ± 0.4 vs. 1.8 ± 1.7 pg/mL, P=0.046) levels prior to ablation. A BNP-adjusted Cox multivariate regression analysis revealed that the independent predictive factor for AF recurrence was high MMP-2 levels (>766 ng/mL) accompanied by high TNF-α levels (>1.2 pg/mL). Conclusions The levels of MMP-2 and TNF-α might be useful for predicting initial AF catheter ablation responders.

Electrophysiological Properties of the Superior Vena Cava and Venoatrial Junction Background Although the superior vena cava (SVC) has been well known to be one of the important foci triggering atrial fibrillation (AF), its electrophysiological characteristics have received little research attention. The aim of this study was to investigate the electrophysiological properties of the SVC and venoatrial junction (VAJ). Methods Twenty-five consecutive AF patients without structural heart disease undergoing electrical SVC isolation were included in this study. After pulmonary vein isolation, a circular decapolar catheter and 2 multipolar catheters were emplaced in the VAJ, right atrial appendage (RAA), and SVC, respectively. Burst pacing and single extrastimulus were applied from the RAA and SVC. The atrial and caval potentials on the circular catheter in the VAJ were investigated. Results Intracaval conduction delay and various degrees of conduction block over the VAJ were observed with burst pacing from both the RAA and SVC. A single extrastimulus from the RAA and SVC with a basic cycle length of 600 milliseconds prolonged the conduction time via the VAJ by 81 ± 49.7 milliseconds and 61 ± 58.7 milliseconds, respectively. The atrial and caval electrograms at the VAJ, which were separated from each other by pacing applications, facilitated mapping of the earliest activation site at the VAJ. Conclusions Intracaval conduction delay and decremental conduction property via the VAJ were demonstrated using pacing maneuvers. Pacing applications from the RAA or SVC can help distinguish the atrial and caval potentials and can facilitate mapping of the optimal ablation sites to isolate the SVC.

Background— The characteristic ECG of Brugada syndrome (BS) can be masked by complete right bundle-branch block (CRBBB) and exposed by resolution of the block or pharmacological or pacing maneuvers. Methods and Results— The study consisted of 11 patients who had BS and CRBBB. BS was diagnosed before the development of CRBBB, on the resolution of CRBBB, or from new characteristic ST-segment changes that could be attributable to BS. Structural heart diseases were excluded, and coronary spasm was excluded on the basis of a provocation test at catheterization. In 7 patients, BS was diagnosed before the development of CRBBB. BS was diagnosed when CRBBB resolved spontaneously (n=1) or by right ventricular pacing (n=3). The precipitating cause for the spontaneous resolution of CRBBB, however, was not apparent. On repeated ECGs, new additional upward-convex ST-segment elevation was found in V 2 or V 3 in 3 patients. In 2 patients, new ST-segment elevation was induced by class I C drugs. The QRS duration was more prolonged in patients with BS and CRBBB compared with age- and sex-matched controls: 170±13 versus 145±15 milliseconds in V 1 and 144±19 versus 128±7 milliseconds in V 5 (both P 1 was larger in the BS patients than in the control subjects ( P =0.0323), but that of R′ was similar ( P =0.0560). Conclusions— BS can coexist behind CRBBB, and CRBBB can completely mask BS. BS might be demonstrated by relief of CRBBB or by spontaneous or drug-induced ST-segment elevation. The prevalence, mechanism, and clinical significance of a combination of CRBBB and BS are yet to be determined.

A substantial number of patients with idiopathic ventricular fibrillation (IVF) present with no specific electrocardiographic (ECG) findings.To evaluate complete right bundle branch block (RBBB) in patients with IVF.Patients with IVF showing complete RBBB were included in the present study. Structural and primary electrical diseases were excluded, and provocation tests were performed to exclude the presence of spastic angina or Brugada syndrome (BrS). The prevalence of complete RBBB and the clinical and ECG parameters were compared either in patients with IVF who did not show RBBB or in the general population and age and sex comparable controls with RBBB.Of 96 patients with IVF, 9 patients were excluded for the presence of BrS. Of 87 patients studied, 10 (11.5%) patients showed complete RBBB. None had structural heart diseases, BrS, or coronary spasms. The mean age was 44 ± 15 years, and 8 of 10 patients were men. Among the ECG parameters, only the QRS duration was different from that of the other patients with IVF who did not show complete RBBB. Ventricular fibrillation recurred in 3:2 in the form of storms, which were well suppressed by isoproterenol. Complete RBBB was found less often in control subjects (1.37%; P.0001), and the QRS duration was more prolonged in patients with IVF: 139 ± 10ms vs 150 ± 14ms (P = .0061).Complete RBBB exists more often in patients with IVF than in controls. A prolonged QRS complex suggests a conduction abnormality. Our findings warrant further investigation of the role of RBBB in the development of arrhythmias in patients with IVF.

Background Strokes develop even in patients with low CHADS 2 scores, and the left atrial appendage (LAA) is the embolic source 90% of the time. We focused on the LAA morphology as a new predictor of strokes. Objective To clarify the anatomical characteristics of the LAA for risk stratification of strokes in patients with nonvalvular atrial fibrillation (AF) who have low CHADS 2 scores. Methods Among 80 patients who underwent catheter ablation of AF with contrast-enhanced computed tomography, the LAA characteristics were compared between 30 patients with histories of strokes and 50 age-matched controls. The LAA anatomy was classified into 4 types—"cactus," "cauliflower," "chicken wing," and "windsock"—discriminated by the computed tomography measurements of the length, angle, and number of lobes of the LAA. Results The average CHADS 2 score did not differ significantly between patients with stroke and controls (0.8±0.8 vs 0.6±0.7; P = .277). Eight (26.7%) patients with stroke had CHA 2 DS 2 -VASc scores of 0. The left atrial size, LAA flow velocity, left ventricular function, and serum brain natriuretic peptide level were also unable to predict strokes. However, a "cauliflower" LAA, defined as a main lobe of less than 4 cm long without forked lobes, was significantly more common in patients with stroke (odds ratio 3.857; 95% confidence interval 1.482–10.037; P = .005). The CHA 2 DS 2 -VASc score-adjusted logistic regression analysis revealed the cauliflower LAA as an independent predictor of a stroke (odds ratio 3.355; 95% confidence interval 1.243–9.055; P = .017). Conclusions The LAA anatomy might be useful for predicting strokes in patients with nonvalvular AF who have low CHADS 2 scores.

Ridge-Related Reentry Introduction The ridge between the left pulmonary veins (PV) and the left atrial appendage composes part of the lateral mitral isthmus (LMI). Following circumferential PV isolation and LMI linear ablation for the treatment of atrial fibrillation (AF), a critical pathway might develop over the ridge leading to a ridge-related reentry (RRR). Methods and Results Out of 61 patients who underwent circumferential PV isolation appended by LMI ablation, 5 patients developed RRR. The diagnosis of RRR was based on (1) macro-reentrant atrial tachycardia involving the septum, anterior and inferior wall of the left atrium; (2) slow conduction along the ridge; (3) wide-split double potentials in the ventricular aspect of the LMI were identified with the coronary sinus (CS) electrodes. RRR was investigated with electroanatomical mapping and entrainment mapping and catheter ablation was carried out in all patients. The mean cycle length (CL) of RRR was 312 ± 82 milliseconds and the PPIs at the left atrial septum, inferior and anterior wall during RRR were 10 ± 6, 12 ± 8, 9 ± 5 milliseconds longer than the RRR CL. The interval of the double potentials recorded in the CS electrodes crossing the LMI was 164 ± 38 milliseconds during RRR and the PPI on the LMI near the mitral annulus was 57 ± 10 milliseconds longer than the RRR CL. Catheter ablation was performed anatomically by targeting the ridge and successfully terminated RRR. Conclusion After circumferential PV isolation and ablation for LMI in patients with AF, RRR can develop by utilizing the surviving myocardial tissue of the ridge as a critical pathway.

Patients with coronary spasm generally have a good prognosis, although it can result in sudden cardiac arrest (SCA) and syncope. We hypothesized that the nature of coronary spasm triggering lethal arrhythmias may be different from that which induces angina-only.Clinical characteristics were examined in patients who had experienced SCA (n = 18) or syncope (n = 28) triggered by coronary spasm. These characteristics were compared to those of patients who had coronary spastic angina-only (n = 52).SCA and syncope occurred frequently during daytime in 57% and 68%, respectively. Spontaneous ST-segment changes during daytime were recorded more often in patients with SCA (50%) and syncope (39%) than angina-only patients (4%, p0.01 for each). Nocturnal angina occurred less frequently in patients with SCA (33%) and syncope (32%) than angina-only patients (83%, p0.01 for each). Severe multivessel spasm, daytime ST-segment changes, and younger age were significant predictors of SCA. Daytime ST-segment changes and active smoking were related to syncope.The circadian variance of coronary spasm triggering SCA or syncope may be different from that inducing typical coronary spastic angina. The coronary spasm should be evaluated for patients with aborted SCA or recurrent syncope of unknown cause, even though the patients have not experienced the typical nocturnal angina.

Background— Prior studies have demonstrated regional left atrial late gadolinium enhancement (LGE) heterogeneity on magnetic resonance imaging. Heterogeneity in regional conduction velocities is a critical substrate for functional reentry. We sought to examine the association between left atrial conduction velocity and LGE in patients with atrial fibrillation. Methods and Results— LGE imaging and left atrial activation mapping were performed during sinus rhythm in 22 patients before pulmonary vein isolation. The locations of 1468 electroanatomic map points were registered to the corresponding anatomic sites on 469 axial LGE image planes. The local conduction velocity at each point was calculated using previously established methods. The myocardial wall thickness and image intensity ratio defined as left atrial myocardial LGE signal intensity divided by the mean left atrial blood pool intensity was calculated for each mapping site. The local conduction velocity and image intensity ratio in the left atrium (mean±SD) were 0.98±0.46 and 0.95±0.26 m/s, respectively. In multivariable regression analysis, clustered by patient, and adjusting for left atrial wall thickness, conduction velocity was associated with the local image intensity ratio (0.20 m/s decrease in conduction velocity per increase in unit image intensity ratio, P Conclusions— In this clinical in vivo study, we demonstrate that left atrial myocardium with increased gadolinium uptake has lower local conduction velocity. Identification of such regions may facilitate the targeting of the substrate for reentrant arrhythmias.

Background: Phrenic nerve (PN) injury is a potential complication that can occur during superior vena cava (SVC) isolation to cure atrial fibrillation (AF). Avoiding radiofrequency (RF) energy delivery is the safer alternative but may result in failed isolation. High-output PN pacing above the ablation site (upstream PN pacing) to confirm whether the PN is intact is a promising technique to avoid PN injury. This study was conducted to elucidate the safety of delivering RF energy at the site of capture of the right PN using upstream high-output pacing during electrical SVC isolation. Methods: SVC isolation was conducted in 41 drug-resistant AF patients. When high-output pacing (25 mA) from the distal tip of the ablation catheter captured the PN at the right atrial-SVC junction, upstream PN pacing (cycle length: 1000–1500 ms) was applied during RF delivery. The application of RF energy was stopped upon the failure or weakness of diaphragmatic twitching. The feasibility of SVC isolation using upstream PN pacing was investigated. Results: In all 41 patients, SVC isolation was successfully achieved. RF energy was delivered at the PN capture site in 26 patients (154 ± 138 second, 18 ± 5 W), and upstream PN pacing was successfully applied in all of the patients. Out of 46 SVC isolations, including five repeated sessions, PN injury occurred in one patient, who recovered spontaneously within 2 weeks. Conclusions: Upstream PN pacing may be effective for the safe completion of SVC isolation and to reduce the severity of PN injury. (PACE 2012; 35:1053–1060)

Background and Objective This study proposes photosensitization reaction for non-thermal cardiac ablation in arrhythmia therapy. Acute and chronic phase experiments were conducted in exposed porcine hearts to demonstrate the photosensitization reaction-induced myocardial electrical conduction block in vivo. Study Design/Materials and Methods The porcine left atrial appendage was exposed under an open-chest procedure. Then, a water-soluble chlorin photosensitizer, NPe6, was injected into the pigs intravenously at 5 or 10 mg/kg. About 15 or 30 minutes after the injection, a 663-nm continuous-wave diode laser was irradiated on the surface of the atrial appendage through a silica optical fiber. The laser energy was delivered to the tissue point by point at an energy density of 50–208 J/cm2. Results Acute and chronic tissue damages as a result of the photosensitization reaction were determined by electrophysiology and histology, respectively. The change in the myocardial conduction time between two electrodes was measured immediately after the completion of the 35-mm irradiation line between the electrodes. The conduction delay of 35.5 milliseconds might be due to the change in the conduction pathway induced by transmural acute conduction block with the photosensitization reaction. The tissue temperature increase in the irradiated area was approximately 12.8°C. Azan-staining revealed about 1-mm transmural fibrosis of the atrial appendage at 2 weeks after the irradiation (50 J/cm2). Conclusions The results suggest that the photosensitization reaction might induce acute and chronic myocardial electrical conduction block. Cardiac ablation with the photosensitization reaction might be a non-temperature-mediated methodology for arrhythmia therapy. Lasers Surg. Med. 43:984–990, 2011. © 2011 Wiley Periodicals, Inc.

Objective A nonsurgical approach from the epicardial surface is useful for various cardiac interventions, such as positioning of the left ventricular lead for cardiac resynchronization therapy and epicardial ablation. Stem cell delivery on the epicardial surface can be considered in the future if good quality of visualization can be obtained. However, because the pericardial space is limited, hemodynamic conditions may deteriorate with pericardial endoscopy. Therefore, the feasibility and efficacy of pericardial endoscopy were examined by using ready-made endoscopes. Methods Anesthetized swines (26–61 kg; n = 6) were used for the experiment. Electrocardiogram, femoral artery blood pressure, and oxygen saturation by pulse oximetry were continuously monitored during the procedures. Guided by the fluoroscopy, sheaths were advanced to the pericardial space using the modified Seldinger technique from the subxyphoid space. Results After insertion of an endoscope with a maximum diameter of 6.9 mm, hemodynamic parameters were stable during the procedure with atropine. Stable and acceptable endoscopic images were obtained. Minor operations can be performed with pericardial endoscopic-guided laparoscopic forceps with no complications. Conclusions The endoscopic pericardial procedure is effective and feasible. This procedure can increase the possibility and efficacy of nonsurgical treatment for cardiac diseases.

Background Recent evidence suggests that left atrial (LA) dysfunction may be mechanistically contributing to cerebrovascular events in patients with atrial fibrillation (AF). We investigated the association between regional LA function and a prior history of stroke during sinus rhythm in patients referred for catheter ablation of AF. Methods and Results A total of 169 patients (59 ± 10 years, 74% male, 29% persistent AF) with a history of AF in sinus rhythm at the time of pre‐ablation cardiac magnetic resonance (CMR) were analyzed. The LA volume, emptying fraction, strain (S), and strain rate (SR) were assessed by tissue‐tracking cardiac magnetic resonance. The patients with a history of stroke or transient ischemic attack (n=18) had greater LA volumes (V max and V min ; P =0.02 and P P max and S preA ; P P =0.01, respectively), and lower absolute values of LA SR during left ventricular (LV) systole and early diastole (SR s and SR e ; P =0.005 and 0.03, respectively) than those without stroke/transient ischemic attack (n=151). Multivariable analysis demonstrated that the LA reservoir function, including total emptying fraction, S max , and SR s , was associated with stroke/transient ischemic attack (odds ratio 0.94, 0.91, and 0.17; P =0.03, 0.02, and 0.04, respectively) after adjusting for the CHA 2 DS 2 ‐VASc score and LA V min . Conclusions Depressed LA reservoir function assessed by tissue‐tracking cardiac magnetic resonance is significantly associated with a prior history of stroke/transient ischemic attack in patients with AF. Our findings suggest that assessment of LA reservoir function can improve the risk stratification of cerebrovascular events in AF patients.

Introduction Lead failures (LFs) are one of the most common complications in patients implanted with cardiovascular implantable electronic devices. LFs often cause serious secondary complications such as inappropriate ICD shocks or asystole. This study aimed to identify the clinical factors associated with the occurrence of LFs. Methods A total of 735 consecutive device implantations (mean age 67±15years, males 64%) performed at a single university hospital setting from 1997 to 2014 were included. The implanted devices consisted of 421 pacemakers, 250 implantable cardioverter defibrillators (ICD), 9 cardiac resynchronization therapy pacemakers (CRT-P), and 55 CRT defibrillators (CRT-D). The primary endpoint was the development of an LF. Results During a mean duration of 5.8±4.3years, 38 LFs developed in 31 patients (mean age 56±14years). LFs included 32 ICD (7 Sprint Fidelis, 2 Riata), and 6 pacing leads. Nine patients received inappropriate ICD shocks and 1 had syncope due to an LF. All patients underwent lead reinsertions with device replacements. Eight patients required opposite site implantations due to venous occlusions. The predictive factors of LFs were the age, male sex, taller body length, ICD vs. pacemaker, lesser lead number, extra-thoracic puncture of the axillary vein vs. a cut-down of the cephalic vein, use of recalled leads and patients with idiopathic ventricular fibrillation (IVF) and Brugada syndrome (BrS). Conclusion LFs occurred mainly with ICD leads. A lesser age, the puncture method, lead model, and diagnosis of IVF/BrS were associated with the development of LFs.

A 45-year-old male was admitted to our hospital after successful resuscitation of cardiac arrest. Ventricular fibrillation (VF) had occurred during breakfast and was defibrillated by an automated external defibrillator operated by emergency medical service staff. On admission, his ECG demonstrated complete right bundle branch block as the sole abnormality. Intensive examination could not detect any structural disease leading to a diagnosis of idiopathic VF and implantation of an ICD. VF storm occurred one month after hospital discharge and beta-blocker, amiodarone, and sedative administration had no effect on VF. Likewise, catheter ablation for triggering premature ventricular beats failed to control the VF storm. The VF storm then subsided in the following weeks and the patient was discharged on amiodarone. A half month later VF storm recurred and the patient was admitted again. This time, isoproterenol infusion was effective in suppressing VF, and thereafter the patient was administered bepridil and followed up without recurrence of VF for 1.5 years. From these beneficial effects, the VF of the patient was suggested to share common arrhythmogenic characteristics to those of Brugada syndrome or J-wave associated VF.

Background— Atrial fibrillation (AF) is associated with left atrial (LA) structural and functional changes. Cardiac magnetic resonance late gadolinium enhancement (LGE) and feature-tracking are capable of noninvasive quantification of LA fibrosis and myocardial motion, respectively. We sought to examine the association of phasic LA function with LA enhancement in patients with AF. Methods and Results— LA structure and function was measured in 90 patients with AF (age 61±10 years; 76% men) referred for ablation and 14 healthy volunteers. Peak global longitudinal LA strain, LA systolic strain rate, and early and late diastolic strain rates were measured using cine–cardiac magnetic resonance images acquired during sinus rhythm. The degree of LGE was quantified. Compared with patients with paroxysmal AF (60% of cohort), those with persistent AF had larger maximum LA volume index (56±17 versus 49±13 mL/m 2 ; P =0.036), and increased LGE (27.1±11.7% versus 36.8±14.8%; P P P P Conclusions— Increased LA enhancement is associated with decreased LA reservoir, conduit, and booster pump functions. Phasic measurement of LA function using feature-tracking cardiac magnetic resonance may add important information about the physiological importance of LA fibrosis.

Postablation atrial fibrillation recurrence is positively associated with the extent of preexisting left atrial (LA) late gadolinium enhancement (LGE) on magnetic resonance imaging (MRI), but negatively associated with the extent of postablation LGE regardless of proximity to the pulmonary vein antra. The characteristics of pre- vs postablation LA LGE may provide insight into this seeming paradox and inform future strategies for ablation.The purpose of this study was to define the characteristics of preexisting vs ablation-induced LA LGE.LGE-MRI was prospectively performed before and ≥3 months after initial ablation in 20 patients. The intracardiac locations of ablation points were coregistered with the corresponding sites on axial planes of postablation LGE-MRI. The image intensity ratio (IIR), defined as the LA myocardial MRI signal intensity divided by the mean LA blood pool intensity, and LA myocardial wall thickness were calculated on pre- and postablation images.Imaging data from 409 pairs of pre- and postablation axial LGE-MRI planes and 6961 pairs of pre- and postablation image sectors were analyzed. Ablation-induced LGE revealed a higher IIR, suggesting greater contrast uptake and denser fibrosis, than did preexisting LGE (1.25 ± 0.25 vs 1.14 ± 0.15; P.001). In addition, ablation-induced LGE regions had thinner LA myocardium (2.10 ± 0.67 mm vs 2.37 ± 0.74 mm; P.001).Regions with ablation-induced LGE exhibit increased contrast uptake, likely signifying higher scar density, and thinner myocardium as compared with regions with preexisting LGE. Future studies examining the association of postablation LGE intensity and nonuniformity with ablation success are warranted and may inform strategies to optimize ablation outcome.

Aims Accumulating data show the efficacy of catheter ablation (CA) for atrial fibrillation (AF); however, postoperative recurrence is not uncommon. The aim of this study was to identify predictors of AF recurrence in patients undergoing CA. Methods and results We studied 100 patients with symptomatic paroxysmal (68) or persistent (32) AF who underwent CA preceded by transthoracic echocardiographic examination. Of these, 50 had sinus rhythm during echocardiography (Group NSR) and 50 had AF rhythm (Group AF). The left atrial (LA) strain was measured by two-dimensional speckle tracking echocardiography. Echocardiographic parameters were compared between the patients with AF recurrence and no recurrence. During 12 months of follow-up, 26 of 100 patients (11 in Group NSR and 15 in Group AF) had AF recurrence; these patients had significantly longer AF duration, a lower LA global strain (LA-GS), lower LA lateral total strain (LA-LS), and larger maximum LA volume index (LAVImax) than those who maintained sinus rhythm. Multivariate logistic regression identified basal LA-LS and LAVImax as independent predictors of AF recurrence. Furthermore, receiver operating characteristic analyses revealed that basal LA-LS was the most useful parameter for predicting AF recurrence [area under the curve (AUC): 0.84 vs. 0.74 in LAVImax]. Subanalyses showed that LAVImax was another independent predictor of AF recurrence in Group AF, but not in Group NSR, while basal LA-LS was a significant predictor in both groups. Conclusion LA myocardial function assessed by basal LA-LS could predict AF recurrence after CA. Notably, such an assessment could be applicable even during AF rhythm, suggesting its convenience in the clinical setting without defibrillation before analysis.

We present a patient with ventricular fibrillation (VF) associated with J-wave manifestation following pericarditis after catheter ablation of paroxysmal atrial fibrillation (AF). The premature ventricular contraction induced VF with J-waves in the inferior leads 2 days after the procedure. The patient's juvenile onset of AF and a family history of sudden cardiac death strongly suggested an underlying hereditable channelopathy. The late gadolinium enhancement in the posterior wall, viewed by cardiac magnetic resonance imaging, matched the leads of the J-waves. VF might develop in juvenile onset of AF especially in individuals with a family history of sudden cardiac death.

A 79 year-old male without structural heart disease suffered from drug refractory ventricular tachycardia (VT). VTs and premature ventricular complexes (PVCs) with the same morphology occurred incessantly with a concordant R pattern in chest leads and a tall R in Lead II, III, and aVF. The origin was expected to be near the left epicardial ventricular outflow tract (LVOT), which was termed the left ventricular summit area. Pace-mapping from the LVOT and the left coronary cusp (LCC) did not match well with the QRS morphology of the PVC. A good match was obtained from the distal great cardiac vein (GCV), and radiofrequency (RF) delivery eliminated the PVC and VT. However, the PVC recurred four times upon cessation of RF delivery. By placing an ablation catheter at the LCC, we obtained pace-mapping showing two different types of QRS morphologies; one was an rS pattern in V1, and the other was an R pattern in V1 with a longer stimulus to QRS interval, which was a nearly perfect match to the PVC. RF application to the LCC permanently eliminated PVCs and VTs. Several VTs from the epicardial LVOT can be cured by RF application from both the distal GCV and the LCC.

We investigated electrophysiological and histological effect on canine anatomical isthmus in right atrium by photosensitization reaction (PR) of talaporfin sodium operated via a manipulative 7 Fr. laser catheter to establish a nonthermal tachyarrhythmia treatment. We continuously administrated talaporfin sodium via a left femoral vein to maintain photosensitizer concentration of 25-35 μg/ml in blood plasma, which is within the range of clinical use in human. Fifteen-minute after kickoff of the photosensitizer administration, a 663 nm laser was irradiated via the laser catheter for 30 s/point with irradiance of 10 W/cm2. After 17 times irradiations, a 23 ms delay of the electrical signal propagation along tricuspid annulus was observed. This result might demonstrate the acute electrical conduction delay induced by PR. The canine heart was extracted 10 days after PR and Azan staining specimen was histologically evaluated to investigate the myocardial damage by PR. The transmural fibrosis in anatomical isthmus was found. We demonstrated the PR-induced electrical conduction delay in acute phase in vivo using continuous photosensitizer dosed canine model, which maintain the clinical photosensitizer concentrat

complaining of palpitation Yoshiyasu Aizawa ⁎, Seiji Takatsuki , Yuko Suenaga , Takehiro Kimura , Nobuhiro Nishiyama , Kotaro Fukumoto , Yoko Tanimoto , Kojiro Tanimoto , Shun Kohsaka , Yukiko Fukuda , Mitsushige Murata , Shunichiro Miyoshi , Toshiaki Sato , Shiro Iwanaga , Satoshi Ogawa , Keiichi Fukuda a a Keio University School of Medicine, Tokyo, Japan b Kyorin University, Tokyo, Japan c Tokyo Medical University, Tokyo, Japan d International University of Health and Welfare, Mita Hospital, Tokyo, Japan

Aims Phrenic nerves (PNs) can be damaged during interventional cardiovascular therapy because of the nerves' proximity to the heart. This study aimed to analyse the anatomy of the PN by performing three-dimensional (3-D) imaging and pace mapping. Methods and results Forty consecutive patients with atrial fibrillation referred for catheter ablation were enrolled in this study and underwent preoperative cardiovascular computed tomography (CT). In 10 patients with sinus rhythm during tomography, 3-D images of the right and left pericardiophrenic bundles (PBs), consisting of the ipsilateral PN and accompanying vessels, were reconstructed from the CT data. During the electrophysiological study, PN pace mapping was performed from both atria. The course of the PBs generated by CT imaging and the PN pace map generated by the 3-D mapping system were compared. By electrical pacing, the PNs were captured in 40 individuals (100%) from the superior vena cava and the right atrium, and in 17 patients (43%) from the left atrial appendage. Clear 3-D images of PBs were reconstructed in all cases in which CT-reconstruction was performed. The distance between the locations of the right PB generated by CT imaging and those of the right PN-capture sites in the right-sided heart on the mapping system was 8.7 ± 5.8 mm. Conclusions The 3-D routes of the bilateral PNs passing near the heart were verified by pace mapping. The preoperatively reconstructed 3-D course of the PB succeeded in locating the PN, which may facilitate the comprehension of PN anatomy to avoid its injury during interventional cardiovascular therapy.

Background The efficacy and safety of rigid pericardial endoscopy as the promising minimally invasive approach to the pericardial space was evaluated. Techniques for cell transplantation, epicardial pacemaker lead implantation, and epicardial ablation were developed. Methods Two swine and 5 canines were studied to evaluate the safety and efficacy of rigid pericardial endoscopy. After a double pericardiocentesis, a transurethral rigid endoscope was inserted into the pericardial space. The technique to obtain a clear visual field was examined, and acute complications such as hemodynamic changes and the effects on intra-pericardial pressure were evaluated. Using custom-made needles, pacemaker leads, and forceps, the applications for cell transplantation, epicardial pacemaker lead implantation, and epicardial ablation were also evaluated. Results The use of air, the detention of a stiff guide wire in the pericardial space, and the stretching of the pericardium with the rigid endoscope were all useful to obtain a clear visual field. A side-lying position also aided observation of the posterior side of the heart. As a cell transplantation methodology, we developed an ultrasonography-guided needle, which allows for the safe visualization of transplantation without major complications. Pacemaker leads were safely and properly implanted, which provides a better outcome for cardiac resynchronizing therapy. Furthermore, the success of clear visualization of the pulmonary veins enabled us to perform epicardial ablation. Conclusions Rigid pericardial endoscopy holds promise as a safe method for minimally invasive cell transplantation, epicardial pacemaker lead implantation, and epicardial ablation by allowing clear visualization of the pericardial space.

Background and Objective Contact laser irradiation is generally used in therapeutic laser procedures such as plastic surgery and laser catheter lead removal. However, it may induce blood charring on the surface of the optical window in blood circumstance so that the laser beam might be blocked. Various charring detection methods have been proposed, but they detect charring only after charring has occurred. This study investigates the transient behavior of red blood cells (RBCs) prior to the charring on the surface of an optical window during red laser irradiation in blood circumstance. Materials and Methods The backscattering light power was continuously measured to investigate the transient behavior of a 1-mm-thick porcine blood model (hematocrit: 40%) during continuous laser irradiation (center wavelength: 663 nm; irradiance: 81 W/cm2). A rabbit blood model was microscopically observed after irradiation. The absorption coefficient (µa) and the reduced scattering coefficient () were measured using a double integrating sphere setup and the inverse adding–doubling method. The backscattering light power was continuously measured in vivo during contact laser irradiation via a laser catheter in a porcine heart cavity. Results The results reveal that it may be possible to detect a precursory state of charring from a time course of the backscattering light power. µa increased monotonically by 15% until charring occurred. decreased by 10% followed a broad peak until charring occurred. These changes in the optical property correspond to changes in the morphology of RBCs. Changes in the backscattering light power measured in vivo were similar to those measured ex vivo. Conclusions The transient optical changes in blood prior to charring may be caused by changes in the morphology of RBCs on the optical window surface. Backscattering light power measurements may be a practical method to detect the precursor state of charring. Lasers Surg. Med. 44: 508–513, 2012. © Wiley Periodicals, Inc.

We have studied a new type of myocardial catheter ablation with photosensitization reaction to realize non-thermal therapy for atrial arrhythmia, such as atrial fibrillation. Photochemically-generated reactive oxygen species may induce myocardial electrophysiological damage without heat generation. In this study, to demonstrate photosensitization reaction-induced myocardial electrical conduction block, the inferior vena cava to tricuspid annulus (IVC-TA) isthmus linear ablation was conducted with photosensitization reaction in porcine heart in vivo, using a newly developed laser catheter (7 Fr.). The end point of the procedure was the production of IVC-TA isthmus block under the electrophysiological analysis by diagnostic catheter with 10-bipole electrodes placed in right atrium along the isthmus. Talaporfin sodium (NPe6) as a photosensitizer was injected intravenously to pigs at 2.5-5.0 mg/kg. About 15 min after the injection, the laser light at the wavelength of 663 nm with a catheter output power density of 40-60 W/cm2 in about 1.4 mm spot size was irradiated through the laser catheter point by point in line crossing the isthmus under the fluoroscopic guidance. Before the photosensitization procedure, pacing signal from the distal electrodes of the diagnostic catheter, propagated through the isthmus in order. During the irradiation, electrical potential at the irradiated area was diminished. After the completion of the irradiation line, the bidirectional conduction block on the IVC-TA isthmus was validated by pacing from the distal and proximal bipole. These results indicated that photosensitization reaction could achieve the electrical conduction block of myocardial tissue immediately after the irradiation. We think that photosensitization reaction could become a novel therapy for atrial arrhythmia.

A 72-year-old man with drug-refractory paroxysmal atrial fibrillation (AF) was referred for catheter ablation. Written informed consent was obtained, and electrode catheters were introduced to the right ventricle and the coronary sinus (CS), allowing the proximal electrodes to cover the area around the superior vena cava (SVC) (CS-SVC catheter). A circular mapping catheter was also placed at the right superior pulmonary vein (PV) and a saline-irrigated ablation catheter was inserted into the left atrium (LA). Circumferential right PV isolation was conducted using the CARTO system (Biosense Webster, Diamond Bar, CA, USA) with 30 W of radiofrequency energy. Energy was applied from the bottom of the right inferior PV in the left lateral view as the ablation catheter was dragged in the clockwise direction. When the ablation catheter came to the anterior side of the right superior PV, the SVC potential (arrows) recorded by the CS-SVC catheter inadvertently disappeared (Figures 1A and 1B). The ablation procedure was continued, and the right and left PVs were circumferentially isolated. Sinus rhythm was then restored by intracardiac electrical cardioversion with 10 J. To reveal dormant conduction between the LA and PVs, 2 g isoproterenol and 20 mg adenosine triphosphate (ATP) were injected. Interestingly, the SVC potentials then reappeared (Figure 1C) for a few seconds with the development of transient atrioventricular block. The rapid firing from the SVC also initiated transient AF that terminated spontaneously, although there was no dormant conduction between the LA and PVs. The circular mapping catheter was then placed at the SVC-RA junction. ATP was repeatedly infused to reveal the dormant conduction between the RA and

The coronary sinus (CS) including the great cardiac vein is an important anatomic structure that is considered a landmark for the mitral annulus (MA) and also a target for catheter ablation.This study evaluated the anatomical relationship between the CS and its surrounding structures visualized by multi-detector computed tomography (MDCT).We performed MDCT on 42 patients, and the ranges of the coronary arteries (CAs) and esophagus that ran closest (5 mm) to the CS were examined. In addition, the distances between the CS and the MA and left ventricle and left atrium were compared with the amplitudes of the local atrial and ventricular electrograms in the CS at the most lateral point (3 o'clock) and the inferior point (6 o'clock) in the CS.The distal portion of the right CA ran near the antero-inferior side of the CS ostium in 92% of the patients. The esophagus and the left circumflex CA proximity to the CS ran from 15 to 41 mm and from 53 to 104 mm from the ostium in all patients. At the 3 o'clock and 6 o'clock position of the MA, the distance between the center of the CS and MA was 12 and 13 mm, respectively, and showed negative correlation with the ratio of atrial and ventricular electrograms.The right CA, the left circumflex CA, and the esophagus were frequently located near the CS. The CS was shifted away from the MA, and the CS-MA distance could be predicted with intracardiac electrograms.

A 68-year-old man who experienced ventricular fibrillation triggered by a vasospastic angina (VSA) was resuscitated by a lay-rescuer with an automated external defibrillator. He had been diagnosed with VSA on the basis of chest pain while at rest in the early morning, which had been treated successfully with nitrates and calcium channel blockers for 13 years. During hospitalization after the patient was resuscitated, he had VSA with ST elevation in the inferior leads after cessation of both medications. Ultrasound echocardiography showed no abnormal findings after the episode of VSA. The coronary angiograph and the left ventriculograph revealed the absence of both significant coronary stenosis and segmental asynergy (Figure 1A through 1C). Figure 1. Preoperative ( A through C ) and postoperative ( D through I ) coronary angiography and left …

A 58-year-old male was referred for catheter ablation for atrial fibrillation. He was incidentally diagnosed with cor triatriatum sinister by preoperative transesophageal echocardiography and cardiovascular computed tomography. The patient has since been free from atrial fibrillation for over 24 months following successful electrical pulmonary vein isolation. The rapidly soaring number of cases undergoing catheter ablation for atrial fibrillation and imaging investigation prior to the procedure may increase the incidental detection of asymptomatic congenital heart diseases.

Background: Visualization of the inner anatomical relationship of the pulmonary veins (PVs) and left atrium (LA) is important for achieving a better success rate and avoiding complications in circumferential LA ablation for atrial fibrillation (AF). Methods and Results: Twelve patients with AF underwent computed tomography and novel post-processing images that emphasized the boundaries of the PVs and LA were produced. Conclusions: The "Transparent View" images enabled visualization of the inner anatomical relationship of the PVs and LA in the same geometry as in pulmonary venography in all cases. (Circ J 2009; 73: 573 - 574)

An 83-year–old man with coronary artery disease was hospitalized for syncope due to sick sinus syndrome and underwent dual-chamber pacemaker implantation. An axillary vein was accessed using venography in the absence of a cephalic vein. A right ventricular screw-in lead (Medtronic 5076, Medtronic, Minneapolis, Minn) was inserted and placed easily in the right ventricular apex with a hydrophilic 0.038-inch guidewire retained. After positioning the right ventricular lead, an attempt to insert the sheath for the atrial lead over that wire proved challenging because of the narrow space beneath the clavicle. The guidewire became dislodged from the inferior vena cava to the superior vena cava and was readvanced into the right atrium using fluoroscopy in the anteroposterior view. A 7-French peel-away …

Background Before performing cardiac resynchronization therapy (CRT), it is useful to visualize the position of the coronary sinus (CS) orifice where the CS lead is inserted. Methods and Results A raysum image was created in which the outermost 1-voxel layer of the right atrium (RA) and CS was extracted. This image enabled visualization of the positional relationship between the RA and CS ostium using the same geometry as retrograde CS venography. Conclusion New post-processing imaging of the CS orifice will make the procedure of CRT safer. (Circ J 2008; 72: 487 - 488)

Purpose: Radiofrequency (RF) catheter ablation was revolutionary a decade ago, but operators still face the limitations to ablate arrhythmogenic foci because of ineffective heat conduction to deep tissue, high impedance, and the blood flow effect. A high output is then often required and may result in steam pop. Therefore, we aimed to determine a proper condition for photodynamic therapy (PDT), which induces a non-thermal oxidative injury only to an irradiated area. Methods: We developed a 1.4mm catheter which emits an irradiating laser from the distal tip (a). In 27 canines prepared with an open chest surgery, we commenced infusion of the photosensitizer (talaporfin sodium) and the laser was then irradiated to the heart. Canines were survived for 2 weeks and lesion depth was measured by HE stain to compare each condition; at a photosensitizer dose of 0, 2.5, and 5mg/kg, and laser output of 5, 10, and 20W/cm2 for duration of 0, 5, 10, 20, 30, 40, and 60sec (b). Catheter tip temperature was measured and compared with an open irrigated RF catheter. Results: A positive correlation was exhibited between lesion depth, photosensitizer concentration, laser output, and irradiation time. An output of 10W/cm2 under 5mg/kg of the photosensitizer for 60sec successfully created a lesion depth of 8.2±0.2mm (c). PDT catheter tip temperature rose to only 5.2±0.5oC without irrigation, whereas 23.3±8.9oC in RF ablation at 35W for 30sec with a 50oC cut-off under 27ml/min of saline irrigation. A maximum lesion depth of 8.7±0.8mm was acquired by 20W/cm2 for 60sec under 5mg/kg without a gross tissue edema. ![Figure][1] Figure 1 Conclusions: PDT mediated ablation proved to be a reliable non-thermal method to create a sufficient cardiac lesion, positively depending on photosensitizer concentration, laser output, and irradiation time. [1]: pending:yes

Background: Phrenic nerve (PN) injury is a potential complication during superior vena cava (SVC) isolation to cure atrial fibrillation (AF). Avoiding radiofrequency (RF) energy delivery is safer but may lead to a failed isolation. High-output PN pacing above the ablation site, upstream PN pacing, is a promising technique to avoid PN injury. This study was conducted to elucidate the safety of delivering RF energy at the site where high-output pacing captures PN.Methods and Results: SVC isolation was carried out in 41 drug-resistant AF patients. When high-output pacing (25 mA) from the ablation catheter captured PN, upstream PN pacing (cycle length: 1000–1500 msec) was applied during RF delivery. RF energy was ceased upon the failure or weakness of diaphragmatic twitching. The feasibility of SVC isolation using upstream PN pacing was investigated. In all 41 patients, SVC isolation was successfully achieved. RF energy was delivered at the PN capture site in 26 patients (154±138 sec, 18±5 W), and upstream PN pacing was successfully applied in all patients. Out of 46 SVC isolations, including 5 redo sessions, PN injury occurred in 2 patients, who recovered spontaneously within 2 weeks.Conclusions: Upstream PN pacing is effective in completing SVC isolation safely and reducing the severity of PN injury.