Yasuhiro Yoshiga

Catheter Ablation of Long-Standing Persistent Atrial Fibrillation: 5-Year Outcomes of the Hamburg Sequential Ablation Strategy

OBJECTIVES This study describes the 5-year efficacy of catheter ablation for long-standing persistent atrial fibrillation (LS-AF). BACKGROUND Long-term outcome data after catheter ablation for LS-AF are limited. METHODS Long-term follow-up of 56 months (range 49 to 67 months) was performed in 202 patients (age 61 ± 9 years) who underwent the sequential ablation strategy for symptomatic LS-AF. Initial ablation strategy was circumferential pulmonary vein isolation (PVI). Additional ablation was performed only in acute PVI nonresponder, if direct current cardioversion failed after PVI. RESULTS After the first ablation procedure, sinus rhythm was documented in 41 of 202 (20.3%) patients. After multiple procedures, sinus rhythm was maintained in 91 of 202 (45.0%) patients, including 24 patients receiving antiarrhythmic drugs. In 105 patients, PVI was the sole ablative therapy, 49 (46.7%) of those patients remained in sinus rhythm during follow-up. Patients with a total AF duration of <2 years had a significantly higher ablation success rate than patients whose AF duration was >2 years (76.5% vs. 42.2%, respectively; p = 0.033). Persistent AF duration (hazard ratio: 1.09 [95% confidence interval: 1.04 to 1.13]; p < 0.001) independently predicted arrhythmia recurrences, and acute PVI responders had a reduced risk of relapse (hazard ratio: 0.57 [95% confidence interval: 0.41 to 0.78]; p < 0.001) after the first ablation. CONCLUSIONS During 5-year follow-up, single- and multiple ablation procedure success was 20% and 45%, respectively, for patients with LS-AF. For patients with a total AF duration of <2 years, the outcomes were favorable.

Comparison of expression of connexin in right atrial myocardium in patients with chronic atrial fibrillation versus those in sinus rhythm

An abnormal distribution of the gap junction occurs in chronic atrial fibrillation (AF). There are conflicting data regarding changes in connexins (Cxs) in experimental models of AF. We examined whether patients with chronic AF have alterations in atrial Cxs. We analyzed the expression of Cx40 and Cx43 in the right atrial myocardium from 10 patients with mitral valvular disease (MVD) who had AF (MVD/AF), 10 patients with MVD who were in normal sinus rhythm (MVD/NSR), and 10 control patients in NSR (tissue obtained during coronary artery bypass surgery). Hemodynamic and echocardiographic data were obtained before surgery, and an electrophysiologic examination was performed during the operation. An immunohistochemical study was performed on atrial tissue. The relative expression level of Cx40 protein was significantly lower in MVD/AF patients (6.5 +/- 4.6) than in either MVD/NSR patients (17.7 +/- 8.9, p <0.05) or controls (24.7 +/- 11.1, p <0.01). The relative expression level of Cx40 messenger ribonucleic acid was also significantly lower in MVD/AF patients (0.23 +/- 0.13) than in MVD/NSR patients (0.47 +/- 0.26, p <0.01) or controls (0.47 +/- 0.17, p <0.01). For Cx43 protein and messenger ribonucleic acid, there was no significant difference in relative expression levels among the 3 groups. Interestingly, the level of serine-phosphorylated Cx40 was approximately 52% greater in MVD/AF patients than in controls. In MVD/AF patients, the immunoreactive signal of Cx40 was significantly lower than in controls. There was no significant difference in the connective tissue-volume fraction among the groups. Thus, downregulation of Cx40 and abnormal phosphorylation of Cx40 may result in abnormal cell-to-cell communication and alteration in the electrophysiologic properties of the atrium, leading to the initiation and/or perpetuation of AF.

Urinary 8-hydroxy-2′-deoxyguanosine reflects symptomatic status and severity of systolic dysfunction in patients with chronic heart failure

Oxidative stress is known to play a crucial role in the pathogenesis of heart failure (HF). We investigated whether urinary 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG), a product of oxidative DNA damage, is a clinically useful biomarker of the severity of chronic heart failure (CHF) and oxidative stress levels in failing hearts.

Correlation between substrate location and ablation strategy in patients with ventricular tachycardia late after myocardial infarction

BACKGROUND The requirement for epicardial radiofrequency ablation (RFA) is still undefined in ventricular tachycardia (VT) late after myocardial infarction (MI). OBJECTIVE The purpose of this study was to evaluate the correlation between the need for epicardial RFA and the clinical and electrophysiologic characteristics of VT late after MI. METHODS Endocardial mapping and RFA were performed for VT late after MI, followed by epicardial mapping and RFA if no endocardial substrate was present or endocardial RFA failed. RESULTS Seventy patients with VT late after MI (30 anterior MI [A-MI] and 40 posteroinferior MI [PI-MI]) were included in the study. Forty-one VTs in patients with A-MI and 64 VTs in patients with PI-MI were targeted for RFA. Epicardial mapping and ablation were attempted in 6 patients and performed successfully in only 4 patients. All 6 (100%) patients requiring epicardial access had PI-MIs. Patients with epicardial RFA had endocardial low-voltage areas of smaller size compared to patients without epicardial RFA (21 ± 13 cm(2) vs 68 ± 40 cm(2); P <.01). During 25 ± 19 months of follow-up, recurrence after the initial procedure was noted in 12 of 30 patients (40%) with A-MI and in 18 of 40 patients (45%) with PI-MI. There was no significant difference between groups. CONCLUSION In the majority of patients, clinical and slower VTs late after MI can be abolished using endocardial RFA. Rarely indicated, epicardial RFA is more commonly required in patients with small-sized PI-MI. During follow-up, VT recurrence after successful RFA is common.

Successful cryoballoon pulmonary vein isolation in a patient with situs inversus and dextrocardia

A 79‐year‐old man with situs inversus and dextrocardia underwent catheter ablation of symptomatic paroxysmal atrial fibrillation. Pulmonary vein isolation (PVI), using second‐generation cryoballoon under Ensite NavX system guidance, was performed successfully in a reverse manner, which required short procedure and fluoroscopy times, as required in a PVI performed on a normal heart without any complications. Cryoballoon‐based PVI under Ensite NavX guidance was feasible and safe to achieve a favorable outcome in this patient with abnormal anatomy.

What variables were associated with the inducibility of ventricular fibrillation during electrophysiologic stimulation test in patients without apparent organic heart disease

OBJECTIVE The purpose of our study was to determine what variables were associated with ventricular fibrillation (VF) induced during electrophysiological stimulation test in patients without apparent organic heart disease. METHODS Our study evaluated 77 patients (51+/-15 years) who underwent electrophysiological stimulation test, signal averaging, and Na+ channel-blocker challenge test (pilsicainide test). The subjects were divided into two groups, the Brugada group and non-Brugada group. Further, the patients were divided into three subgroups on the base of symptoms (8, 7 symptomatic; 9, 13 syncope; 28, 12 asymptomatic group; in the Brugada and non-Brugada groups, respectively). Multivariate analyses evaluated the association between baseline clinical factors and the induction of VF. RESULTS The inducibility of VF was significantly (p<0.0001) higher in the Brugada group (n=33, 73%) than the non-Brugada group (n=4, 13%). The multivariate analysis demonstrated that symptoms (odds ratio (OR) 31.6; 95% confidence interval (CI): 2.3-430.6; p<0.01), type 1 electrocardiogram after pilsicainide test (OR 21.3; CI: 1.7-272.2; p<0.02), and syncope (OR 13.5; CI: 1.2-158.8; p<0.05) were strongly associated with the inducibility of VF, but not with family history, type 1 electrocardiogram in control, positive in late potential, maxDeltaST elevation (>==200microV) after pilsicainide test. CONCLUSIONS The symptoms, syncope, and type 1 electrocardiogram after pilsicainide test were independently associated with the electrophysiological substrate of VF in patients without apparent heart disease.

Strict sequential catheter ablation strategy targeting the pulmonary veins and superior vena cava for persistent atrial fibrillation

BACKGROUND An effective catheter ablation strategy, beyond pulmonary vein isolation (PVI), for persistent atrial fibrillation (AF) is necessary. Pulmonary vein (PV)-reconduction also causes recurrent atrial tachyarrhythmias. The effect of the PVI and additional effect of a superior vena cava (SVC) isolation (SVCI) was strictly evaluated. METHODS Seventy consecutive patients with persistent AF who underwent a strict sequential ablation strategy targeting the PVs and SVC were included in this study. The initial ablation strategy was a circumferential PVI. A segmental SVCI was only applied as a repeat procedure when patients demonstrated no PV-reconduction. RESULTS After the initial procedure, persistent AF was suppressed in 39 of 70 (55.7%) patients during a median follow-up of 32 months. After multiple procedures, persistent AF was suppressed in 46 (65.7%) and 52 (74.3%) patients after receiving the PVI alone and PVI plus SVCI strategies, respectively. In 6 of 15 (40.0%) patients with persistent AF resistant to PVI, persistent AF was suppressed. The persistent AF duration independently predicted persistent AF recurrences after multiple PVI alone procedures [HR: 1.012 (95% confidence interval: 1.006-1.018); p<0.001] and PVI plus SVCI strategies [HR: 1.018 (95% confidence interval: 1.011-1.025); p<0.001]. A receiver-operating-characteristic analysis for recurrent persistent AF indicated an optimal cut-off value of 20 and 32 months for the persistent AF duration using the PVI alone and PVI plus SVCI strategies, respectively. CONCLUSIONS The outcomes of the PVI plus SVCI strategy were favorable for patients with shorter persistent AF durations. The initial SVCI had the additional effect of maintaining sinus rhythm in some patients with persistent AF resistant to PVI.

Inferior J waves in patients with vasospastic angina might be a risk factor for ventricular fibrillation

BACKGROUND There is little information about the relationship between J waves and the occurrence of ventricular fibrillation (VF) in patients with vasospastic angina (VSA). The present study aimed to assess the incidence of J waves and the occurrence of VF in patients with VSA. METHODS The subjects consisted of 62 patients with VSA diagnosed by acetylcholine provocation tests in our institution from 2002 to 2014. We investigated the VF events, prevalence of J waves, and relationship between the VF events and J waves. RESULTS J waves were observed in 16 patients (26%) and VF events were documented in 11 (18%). The incidence of VF in the patients with J waves was significantly higher than that in those without J waves (38% vs 11%, p=0.026). J waves were observed in the inferior leads in 14 patients, lateral leads in 5, and anterior leads in 3. A univariate analysis indicated that the incidence of VF in the inferior leads of J wave positive patients (46%=6/14) was significantly (p=0.01) higher than that in the inferior leads of J wave negative patients (10%=5/48). The J waves in the anterior and/or lateral leads were not related to the incidence of VF. Notched type and slurred type J waves were not associated with VF. A multivariate analysis revealed that J waves in VSA patients were associated with VF [odds ratio (OR) 6.41, 95% confidence interval (CI) 1.37-29.93, p=0.02] and organic stenosis (OR 6.98, 95% CI 1.39-35.08, p=0.02). Further, J waves in the inferior leads were strongly correlated with VF (OR 11.85, 95% CI 2.05-68.42, p=0.006). CONCLUSIONS The results suggest that the existence of J waves, especially in the inferior leads, might be a risk factor for VF in VSA patients.

Differentiation of the electrophysiological effects on the atrial myocardium between the pure Na channel blocker, pilsicainide, and flecainide.

AbstractThe purpose of this study was to identify the difference between the pure Na channel blocker, pilsicainide and Ic-antiarrhythmic drug, flecainide, on the atrial electrophysiological characteristics. Methods: The subjects consisted of 24 patients (48 ± 12 years-old: P-group) in whom pilsicainide was administrated intravenously (1 mg/kg/10 min) and 31 patients (47 ± 15 years-old: F-group) in whom flecainide was administrated intravenously (2 mg/kg/10 min). The atrial effective refractory period (ERP-A), intra-atrial conduction time (CT), max intra-atrial conduction delay (Max CD), repetitive atrial firing zone (RAFZ), fragmented atrial activity zone (FAZ) and intra-atrial conduction delay zone (CDZ) were measured before and after the drugs. Results: Pilsicainide and flecainide significantly prolonged the ERP-A (211 ± 27 msec to 246 ± 39 msec; p < 0.001, 217 ± 25 msec to 244 ± 33 msec; p < 0.001, respectively) and CT (121 ± 33 msec to 149 ± 43 msec; p < 0.001, 122 ± 22 msec to 153 ± 27 msec; p < 0.001, respectively) to the same degree. However, the Max CD was shortened by pilsicainide, but not by flecainide. The RAFZ, FAZ and CDZ decreased in the P-group (21 ± 25 msec to 4 ± 10 msec; p < 0.01, 24 ± 24 msec to 14 ± 18 msec; p < 0.05, 56 ± 29 msec to 43 ± 32 msec, p < 0.05, respectively), but not in the F-group. Conclusions: The effects of atrial conduction delays may differ between pilsicainide and flecainide. Further examination will be needed to explain this mechanism.

Conduction Velocity around the Tricuspid Valve Annulus during Typical Atrial Flutter by Electro-anatomic Mapping System

Objective: Conduction velocity around the tricuspid valve annulus (TA. during typical atrial flutter (AFL. has been shown to be slowest in the inferior vena cava‐tricuspid valve (IVC‐TV. isthmus when compared to the septal or free wall segments of the TA. We investigated the conduction velocity in IVC‐TV isthmus, dividing into three areas. Methods: We evaluated conduction velocity around the TA during typical AFL in 10 patients, using an electro‐anatomic mapping system (CARTO™). Conduction velocity was calculated at six areas around the TA including the septal wall, upper wall, lateral wall, and isthmus wall, which was further divided into three areas, lateral isthmus, mid isthmus, and septal isthmus. Results: Conduction velocity around the TA during typical AFL was slowest in the IVC‐TV isthmus. Further, conduction velocities (m/sec. in the mid isthmus (0.44±0.17. and septal isthmus (0.45±0.22. were significantly slower (p < 0.05. than that in the upper wall (0.67±0.26). Conclusions: The relatively slower conduction in IVC‐TV isthmus resulted from the relatively slower conduction in the area from mid to septal isthmus.