Yukio Sekiguchi

University of Tsukuba, Tsukuba, Ibaraki, Japan

Are you Yukio Sekiguchi?

Claim your profile

Publications (82)313.2 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: -Septal atrial tachycardia (AT) can occur in patients without structural heart disease and in patients with prior catheter ablation of atrial fibrillation. We aimed to assess septal AT that occurs after open-heart surgery. -This study comprised 20 consecutive patients undergoing catheter ablation of macroreentrant AT after open-heart surgery. Relevance to surgical approach, mechanisms, anatomical and electrophysiological characteristics, and outcomes were assessed. Septal AT was identified in 7 patients who had all undergone mitral valve surgery. All septal ATs were localized in the left atrial septum, whereas 10 of 13 non-septal ATs originated from the right atrium. Patients with left septal AT had a thicker fossa ovalis (median: 4.0, 25(th)-75(th) percentile: 3.6-4.2 vs 2.3, 1.6-2.6 mm, p=0.006) and broader area of low voltage (<0.3 mV) in the septum than patients with non-septal AT (82, 76-89 vs 31, 28-36%, p=0.02). Repeated gradual prolongations of the tachycardia cycle length without change of the septal circuit was observed in all patients with septal AT (70, 63-100 vs 15, 10-40 ms, p=0.0008). Although ablation terminated all ATs, recurrence of targeted ATs was more frequent in patients with left septal AT during 30-month follow-up (71 vs 0%, p=0.001). -Left septal AT after open-heart surgery was characterized by a thicker septum, more scar burden in the septum, and repeated prolongations of the tachycardia cycle length during ablation. Such an arrhythmogenic substrate may interfere with transmural lesion formation by ablation and may account for higher likelihood of recurrence of left septal AT.
    Circulation Arrhythmia and Electrophysiology 11/2014; · 5.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The long-term prognosis of subjects with supraventricular premature complexes (SVPCs) remains unclear in the general population. The aim of this study was to examine the prognostic significance of SVPCs in community-based health checkups.
    European heart journal. 10/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although several reports address characteristic 12-lead ECG findings of outflow tract ventricular arrhythmias (OT-VAs), accuracy of the ECG algorithms to predict OT-VA origin is sometimes limited.
    Heart rhythm: the official journal of the Heart Rhythm Society 05/2014; · 4.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: -We recently showed that the presence of early repolarization (ER) increases the risk of ventricular fibrillation occurrences in the early phase of acute myocardial infarction (AMI). This study aimed to clarify whether an association exists between ER and occurrences of ventricular tachyarrhythmias (VT/VF) or sudden death in the chronic phase of AMI.
    Circulation Arrhythmia and Electrophysiology 05/2014; · 5.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: -Fatal arrhythmia is commonly observed in cardiac sarcoidosis, but clinical effects of a systematic treatment approach are still uncertain. This study sought to describe both clinical and electrophysiologic characteristics and outcomes of systematic treatment approach to ventricular tachycardia (VT) associated with cardiac sarcoidosis.
    Circulation Arrhythmia and Electrophysiology 05/2014; · 5.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although radiofrequency ablation creates myocardial necrosis leading to troponin T (TnT) release into the systemic circulation, the significance of TnT elevation after atrial fibrillation (AF) ablation is unknown. To demonstrate a possible mechanism of reverse structural remodeling in the left atrium (LA) by evaluating post-procedure TnT elevation. This study included 106 patients with an enlarged LA (paroxysmal AF, n=43; persistent AF, n=63). All patients underwent pulmonary vein isolation alone in the index procedure. LA volume indexed to body surface area (LAVi) was measured by echocardiography before ablation and 6 months after sinus rhythm restoration. Patients were divided into responders (n=53) or nonresponders (n=53) based on a cut-off value of 23% reduction in LAVi. TnT was measured 12 hours post procedure. LAVi decreased from 43±13 to 33±12 mL/m(2) (P<0.0001). TnT level was higher in responders than in nonresponders (1.31±0.34 vs 0.88±0.29 μg/L, P<0.0001) and correlated linearly with % reduction in LAVi (R=0.54, P<0.0001). Also in multivariate analysis, TnT level was the only independent predictor for responders (OR, 90.1; 95% CI 14.95-543.3; P<0.0001). TnT level in patients who required a repeat procedure (n=30) was lower than that in patients who did not only in the persistent AF group (0.92±0.38 vs 1.16±0.37 μg/L, P=0.01). Greater elevation of TnT level was related both to favorable outcomes after ablation and to greater reversal of structural remodeling. Post-procedure TnT level may be reflective of the preservation of healthy LA myocardium.
    Heart rhythm: the official journal of the Heart Rhythm Society 04/2014; · 4.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Radiofrequency catheter ablation of an atrial tachycardia (AT) and atrial fibrillation (AF) was performed in a patient with a history of pulmonary vein isolation for paroxysmal AF. The AT exhibited a centrifugal pattern with the posterolateral LA as the earliest activation site. The AT was not terminated by ablation at the endocardial earliest site, but its cycle length was prolonged by ablation at an opposite site within the Vein of Marshall. Finally, the AT was terminated by an energy application at a site 7 mm posteroinferior to the initial earliest activation site. We analyzed the local potentials of each energy delivery site in detail.
    Heart and Vessels 04/2014; · 2.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The present case report describes a 53-year-old man with drug-resistant heart failure. Electrocardiogram showed complete right-bundle branch block and left anterior fascicular block. A cardiac resynchronization therapy (CRT) device was implanted in him because echocardiography showed obvious left ventricular dyssynchrony between septal and lateral walls. After CRT implantation, dyssynchrony was improved and ejection fraction was increased. Evaluation of coexisting left hemiblock and left ventricular dyssynchrony may be needed in patients with atypical indications for CRT. <Learning objective: Cardiac resynchronization therapy (CRT) for patients with complete right-bundle branch block (CRBBB) is still controversial. Presence of hemiblock and left ventricular dyssynchrony between the pacing sites may be essential to determine CRT indication even in patients with CRBBB.
    Journal of Cardiology Cases 04/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Linear ablation of atrial flutter usually targets a 6 o'clock position on the cavotricuspid isthmus on left anterior oblique view, but the difficulty of the ablation often requires a variation in successful ablation line position from 5 to 7 o'clock. Methods and Results: This study included 94 patients without structural heart disease. A linear lesion was created in turn at the 6, 7, and 5 o'clock positions until bidirectional block of the isthmus was completed; the final lesion was defined as the successful ablation line. The degree of counterclockwise heart rotation (CCW-HR) was evaluated in a blinded fashion according to the angle between the vertical line crossing the His bundle catheter and the line connecting the His bundle catheter and coronary sinus ostium. Successful ablation lines were obtained at the 6 o'clock position in 59 patients (63%); the 7 o'clock position in 19 patients (20%; the oldest group with a moderate radiofrequency burden); and the 5 o'clock position in the remaining 16 (17%; the youngest group with the largest radiofrequency burden). Age-related increase in CCW-HR was the only independent predictor of a more septal successful ablation line (OR, 7.1; 95% CI: 3.3-14.3; P<0.01). Conclusions: Variation in successful ablation line position was affected by age-related CCW-HR; its evaluation might reduce radiofrequency burden, especially in the young and elderly.
    Circulation Journal 02/2014; · 3.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Stereoselective analyses of flecainide enantiomers were performed using reversed-phase high-performance liquid chromatography (HPLC) equipped with a polysaccharide-based chiral column (Chiralpak AS-RH) and fluorescence detector. Excitation and emission wavelengths were set at 300 and 370 nm, respectively. Flecainide enantiomers in serum and urine were extracted using diethyl ether. The mobile phase solution, comprising 0.1 m potassium hexafluorophosphate and acetonitrile (65:35, v/v), was pumped at a flow rate of 0.5 mL/min. The recoveries of flecainide enantiomers were greater than 94%, with the coefficients of variation (CVs) <6%. The calibration curves of flecainide enantiomers in serum and urine were linear in the concentration range 5-500 ng/mL and 0.75-15 µg/mL (r > 0.999), respectively. CVs in intra-day and inter-day assays were 1.8-5.8 and 3.4-7.5%, respectively. In a pharmacokinetic study, the ratios of (S)- to (R)-flecainide (S/R ratio) in the area under the curve and the amount of flecainide enantiomers excreted in urine were lower in a subject carrying CYP2D6*10/*10 than in subjects carrying CYP2D6*1/*2. The S/R ratio of trough serum flecainide concentration ranged from 0.79 to 1.16 in patients receiving oral flecainide. The present HPLC method can be used to assess hepatic flecainide metabolism in a pharmacokinetic study and therapeutic drug monitoring. Copyright © 2014 John Wiley & Sons, Ltd.
    Biomedical Chromatography 02/2014; · 1.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: -In patients with atrial fibrillation (AF), most thrombus forms in the left atrial appendage (LAA). However, the relation of LAA morphology with LAA thrombus is unknown. -We prospectively enrolled 633 consecutive patients who were candidates for catheter ablation for symptomatic drug-resistant AF. Transesophageal echocardiography (TEE) was performed to assess LAA thrombus. LAA structure was assessed by three-dimensional TEE. LAA orifice area, depth, volume, and number of lobes were measured on reconstructed three-dimensional images. Clinical characteristics and echocardiographic measures were compared to determine variables predicting LAA thrombus. Excluded were 69 (10.9%) patients who met the exclusion criteria. Finally, this study comprised 564 patients in whom LAA thrombus was observed in 36 (6.4%) patients. Multivariate analysis revealed CHADS2 score (P=0.002), left ventricular ejection fraction (P=0.01), degree of spontaneous echo contrast (P=0.02), left atrial volume (P=0.02), and number of LAA lobes (P<0.001) to be independently associated with thrombus formation. Most patients with LAA thrombus (32/34, 94.4%) had ≥3 LAA lobes, whereas LAA thrombus was observed in only 2 (0.7%) of 296 patients with 1 or 2 lobes. LAA volume significantly decreased in patients maintaining sinus rhythm after catheter ablation (P=0.0009). Number of LAA lobes did not change in any patient. -Complex LAA morphology characterized by an increased number of LAA lobes was associated with the presence of LAA thrombus, independently of clinical risk and blood stasis. This study suggests that LAA morphology might be a congenital risk factor for LAA thrombus formation in patients with AF.
    Circulation Cardiovascular Imaging 02/2014; · 5.80 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Although several reports address characteristic 12-lead ECG findings of outflow tract ventricular arrhythmias (OT-VAs), accuracy of the ECG algorithms to predict OT-VA origin is sometimes limited. Objective This study aimed to develop a magnetocardiography (MCG)-based algorithm using a novel adaptive spatial filter to differentiate between VAs originating from the aortic sinus cusp (ASC-VA) and those from the right ventricular OT (RVOT-VA). Methods This study comprised 51 patients with OT-VA as the target of catheter ablation. An algorithm was developed by correlating MCG findings with the successful ablation site. The arrhythmias were classified as RVOT-VA or ASC-VA. Three parameters were obtained from 3-D MCG imaging: depth of the origin of OT-VA in the anteroposterior direction, distance between the earliest atrial activation site, i.e., sinus node, and the origin of the OT-VA, and orientation of the arrhythmia propagation at the QRS peak. The distance was indexed to the patient’s body surface area (mm/m2). Results Origins of ASC-VAs were significantly deeper (81±6 vs 68±8 mm/m2, P<.01) and further from the sinus node (55±9 vs 41±9 mm/m2, P<.01) than those of RVOT-VAs. ASC-VA propagation had a tendency toward rightward axis. ROC analyses determined that the depth of origin was the most powerful predictor, with sensitivity of 90% and specificity of 73% (P<.01, AUC=.90). Discriminant analysis combining all 3 parameters revealed the accuracy of the localization to be 94%. Conclusion This MCG-based algorithm appeared to precisely discriminate ASC-VAs from RVOT-VAs. Further investigation is required to validate the clinical value of this technique.
    Heart Rhythm. 01/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Although radiofrequency ablation creates myocardial necrosis leading to troponin T (TnT) release into the systemic circulation, the significance of TnT elevation after atrial fibrillation (AF) ablation is unknown. Objective To demonstrate a possible mechanism of reverse structural remodeling in the left atrium (LA) by evaluating post-procedure TnT elevation. Methods This study included 106 patients with an enlarged LA (paroxysmal AF, n=43; persistent AF, n=63). All patients underwent pulmonary vein isolation alone in the index procedure. LA volume indexed to body surface area (LAVi) was measured by echocardiography before ablation and 6 months after sinus rhythm restoration. Patients were divided into responders (n=53) or nonresponders (n=53) based on a cut-off value of 23% reduction in LAVi. TnT was measured 12 hours post procedure. Results LAVi decreased from 43±13 to 33±12 mL/m2 (P<0.0001). TnT level was higher in responders than in nonresponders (1.31±0.34 vs 0.88±0.29 μg/L, P<0.0001) and correlated linearly with % reduction in LAVi (R=0.54, P<0.0001). Also in multivariate analysis, TnT level was the only independent predictor for responders (OR, 90.1; 95% CI 14.95–543.3; P<0.0001). TnT level in patients who required a repeat procedure (n=30) was lower than that in patients who did not only in the persistent AF group (0.92±0.38 vs 1.16±0.37 μg/L, P=0.01). Conclusion Greater elevation of TnT level was related both to favorable outcomes after ablation and to greater reversal of structural remodeling. Post-procedure TnT level may be reflective of the preservation of healthy LA myocardium.
    Heart Rhythm. 01/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background The HRS/EHRA/APHRS Expert Consensus Statement for implantable cardioverter defibrillator (ICD) in Brugada syndrome (BrS) has recently been published. The validity of the Class II indication for ICD is still unknown in BrS patients. Objective To evaluate the validity of the Class II indication for ICD implantation in the Consensus Statement with a large Japanese cohort of BrS. Methods Out of 410 patients with Brugada syndrome, a total of 213 consecutive BrS patients with the Class II indication for ICD implantation (mean age 53± 14 years, 199 men) were enrolled. Clinical outcomes were compared between patients with Class IIa (n = 66) and Class IIb (n = 147) indication according to the Consensus Statement. Results The incidence of cardiac events (documented ventricular tachycarrhythmias or sudden cardiac death) during follow-up of 62 ± 34 months was significantly higher in patients with Class IIa (n = 8, 2.2%/yr) than those with Class IIb indication (n = 4, 0.5%/yr) (p = 0.01). Conclusions We confirmed Class IIa indication identified a group of patients with increased risk compared to Class IIb indication for ICD in the Consensus Statement of 2013. In patients with Class II indication, the combination of a history of syncope and spontaneous type-1 ECG may be an important factor to distinguish intermediate- from low-risk patients with BrS in Japan.
    Heart Rhythm. 01/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background To determine an appropriate M-mode method in assessing left ventricular (LV) dyssynchrony in left bundle branch block (LBBB), and to assess feasibility of the method to predict cardiac resynchronization therapy (CRT) responses. Methods and results Fifty-one patients with LBBB were enrolled. Among them 31 patients underwent CRT. In addition to original septal to posterior wall motion delay (SPWMD), first peak-SPWMD was proposed as time of difference between the first septal displacement and the maximum displacement of the posterior. If an early septal point was not present, anatomical M-mode was used to visualize an early septal displacement spreading scan-area until inferoseptal wall. CRT responders were defined as LV end-systolic volume reduction (>15%) at 6 months after CRT. Twenty patients (65%) were identified as CRT responders. First peak-SPWMD in responders was significantly higher than those in nonresponders, although SPWMD did not differ between groups. Strong predicting ability of first peak-SPWMD was revealed (first peak-SPWMD: 80/90/83%; SPWMD: 35/100/58%), and area under the curve in receiver operating characteristic analysis of first peak-SPWMD (0.88) was significantly higher than that of SPWMD (0.61) (p < 0.05). Conclusion In patients with LBBB, time differences between early septal and delayed displacement of posterolateral wall on M-mode images were the appropriate dyssynchrony parameter, and could improve the predictive ability for CRT responses.
    Journal of Cardiology 01/2014; · 2.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study investigated the efficacy and safety of catheter ablation (CA) for atrial fibrillation (AF) in patients with heart failure with preserved ejection fraction (HFPEF). AF is a precipitating factor for clinical deterioration of HFPEF. CA for AF was performed in a consecutive 74 patients with compensated HFPEF (LV ejection fraction >50%). AF-free probability after CA and factors relating to maintenance of sinus rhythm (SR) were investigated. LV strain/strain rate were assessed by echocardiography at baseline and over 12 months postablation. During a 34±16-month follow-up period, single- and multiple-procedure drug-free success rates were 27% (n=20) and 45% (n=33), respectively. Multiple procedures and pharmaceutically assisted success rate was 73% (n=54). No major complications occurred during follow-up. Multivariate Cox regression analyses revealed that AF type (other than long-standing persistent AF) and lack of hypertension were independently associated with maintenance of SR (hazard ratio 1.81, 95% confidence interval 1.03 to 3.17, P=0.04; hazard ratio 0.49, 95% confidence interval 0.24 to 0.96, P=0.04, respectively). LV systolic indices (LV ejection fraction, LV strain/strain rate at systole) and diastolic indices (E/E', ratio of LV strain rate at diastole with early transmitral flow) were improved only in patients group maintaining SR at follow-up. Our results suggest that AF can be effectively and safely treated with a composite of repeat procedures and pharmaceuticals in patients with HFPEF. However, the current study was a single-arm analysis; therefore, larger randomized control studies are needed to verify the benefit of AF ablation in this cohort.
    Journal of the American College of Cardiology 07/2013; · 14.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Activation imaging with 3-dimensional speckle-tracking echocardiography (3D-STE) aims to visualize the time required for the onset of regional contraction from QRS onset. We hypothesized that the optimal setting of activation imaging was associated with electrical activation. This study was designed to determine an optimal setting of activation imaging with 3D-STE in comparison with that of a voltage mapping system and to assess the feasibility of this imaging method. Methods and Results: We enrolled 7 patients who underwent electrical voltage mapping. Regional deformation was measured by area change ratio (ACR) with 3D-STE. Activation imaging data were obtained at 10%, 25%, 50%, and 100% of maximal ACR values as the threshold for onset of regional contraction. Duration of LV electrical intraventricular activation time (IVATelectrical) by voltage mapping and mechanical IVAT (IVATmechanical) by activation imaging was defined as the time difference between the first and latest endocardial activation sites. We obtained 21 data sets under various conduction patterns and pacing configurations. The strongest correlation between IVATmechanical and IVATelectrical was observed at 25% of maximal ACR values (IVATelectrical=0.47 * IVATmechanical+20, R=0.80, P<0.001). Concordance of the first and latest activated segments between activation imaging and voltage mapping was 90.5% at this setting (19 studies). Conclusions: Activation imaging with 3D-STE may be a feasible noninvasive method of dyssynchrony imaging based on electromechanical coupling.
    Circulation Journal 07/2013; · 3.58 Impact Factor
  • Circulation 05/2013; 127(21):e635-e636. · 15.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Prognosis and risk factors for patients age 35years or younger with Brugada syndrome (BrS) were prospectively explored in a sub-analysis of the Japan Idiopathic Ventricular Fibrillation Study (J-IVFS) registry. During the period from February 2002 to January 2011, 69 cases (mean age 30±6years, male=66) of the young (at or less than 35years old) BrS were enrolled in J-IVFS and the clinical course was followed for more than 1year. They were divided into 3 groups: documented ventricular fibrillation (VF) or aborted sudden cardiac death (SCD) (VF group, 12 cases), syncope without documentation of VF (Syncope group, 17 cases) and asymptomatic group (Asympt. group, 40 cases). During a mean follow-up period of 43±27months, cardiac events (VF and/or SCD) developed in 8 cases, with 5 of 12 cases in the VF (41.7%), 2 of 17 cases in the Syncope (11.8%) and 1 of 40 cases in the Asympt. group (2.5%). The VF group had a worse prognosis for cardiac events than the Syncope and Asympt. group. Multivariate analysis revealed symptoms as a risk factor for predicting cardiac events.
    Journal of electrocardiology 05/2013; · 1.08 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: INTRODUCTION: The presence of early repolarization (ER) recently has been considered as a prognostic marker for sudden cardiac death in patients with idiopathic ventricular fibrillation (IVF), but there are certain numbers of IVF patients lacking ER. We aimed to clarify the clinical and electrocardiographic characteristics of the patients with IVF in the presence and absence of ER. METHODS AND RESULTS: We studied 64 consecutive IVF patients from the Japan Idiopathic Ventricular Fibrillation Study (J-IVFS) registry, which subjected with at least one episode of documented VF in the absence of structural heart diseases and excluding Brugada syndrome. We assessed clinical and electrophysiological characteristics in the IVF patients with and without ER. ER was defined as J-point elevation of >0.1 mV in either inferior or lateral leads. Twelve-lead electrocardiogram (ECG) demonstrated 24 (38%) of 64 patients with ER (ER[+] group) and the remaining 40 (62%) patients without ER (ER[-] group ). ER[+] group had a male predominance (92% for males) and ER[-] group revealed nearly equal distribution in both sexes. While no patients in ER[+] group showed intraventricular conduction disturbance (CD) with abnormal axis deviation and/or bundle branch block in ECG, 9 in ER[-] group had signs of CD (ER[-]/CD[+] subgroup). ER[-]/CD[+] subgroup had prolonged P-R interval and QRS duration compared to other patient groups. CONCLUSION: We found 3 distinct ECG patterns in IVF patients. In addition to the presence and absence of ER, there is a subgroup without ER demonstrating intraventricular CD, which represents a distinct clinical entity of IVF.
    Journal of Cardiovascular Electrophysiology 04/2013; · 3.48 Impact Factor

Publication Stats

427 Citations
313.20 Total Impact Points

Institutions

  • 2006–2014
    • University of Tsukuba
      • • Department of Cardiovascular Surgery
      • • Institute of Clinical Medicine
      Tsukuba, Ibaraki, Japan
  • 2010–2013
    • Tokyo Medical and Dental University
      • Department of Cardiovascular Medicine
      Edo, Tōkyō, Japan
  • 2005–2006
    • Musashino Red Cross Hospital
      Edo, Tōkyō, Japan
    • Tohoku University
      • Department of Cardiovascular Medicine
      Sendai, Kagoshima-ken, Japan