Triggers of Ventricular Fibrillation in Patients With Inferolateral J-Wave Syndrome.

BACKGROUND: There are few data on ventricular fibrillation (VF) initiation in patients with inferolateral J waves. OBJECTIVES: This multicenter study investigated the characteristics of triggers initiating spontaneous VF in inferolateral J-wave syndrome. METHODS: A total of 31 patients (age 37 ± 14 years, 24 male) with spontaneous VF episodes associated with inferolateral J waves were evaluated to determine the origin and characteristics of triggers. The J-wave pattern was recorded in inferior leads in 11 patients, lateral leads in 3, and inferolateral leads in 17. RESULTS: The VF triggers (n = 37) exhibited varying QRS durations (176 ± 21 milliseconds, range 119-219 milliseconds) and coupling intervals (339 ± 46 milliseconds, range 250-508 milliseconds) with a right (70%) or left (30%) bundle branch block (BBB) pattern. Trigger patterns were associated with J-wave location: left BBB triggers with inferior J waves and right BBB triggers with lateral J waves. Electrophysiologic study was performed for 22 VF triggers in 19 patients. They originated from the left or right Purkinje system in 6 and from the ventricular myocardium in 10 and were undetermined in 6. Purkinje vs myocardial triggers showed distinct electrocardiographic characteristics in coupling interval and QRS-complex duration and morphology. Abnormal epicardial substrate associated with fragmented electrograms was identified in 9 patients, with triggers originating from the same region in 7 patients. Catheter ablation resulted in VF suppression in 15 patients (79%). CONCLUSIONS: VF initiation in inferolateral J-wave syndrome is associated with significant individual heterogeneity in trigger characteristics. Myocardial triggers have electrocardiographic features distinct from Purkinje triggers, and their origin often colocalizes with an abnormal epicardial substrate.

The Value of Programmed Ventricular Extrastimuli From the Right Ventricular Basal Septum During Supraventricular Tachycardia.

BACKGROUND: The difference between the right ventricular (RV) apical stimulus-atrial electrogram (SA) interval during resetting of supraventricular tachycardia (SVT) versus the ventriculoatrial (VA) interval during SVT (ΔSA-VAapex) is an established technique for discerning SVT mechanisms but is limited by a significant diagnostic overlap. OBJECTIVES: This study hypothesized that the difference between the RV SA interval during resetting of SVTs versus the VA interval during SVTs (ΔSA-VA) would yield a more robust differentiation of atrioventricular nodal re-entrant tachycardia (AVNRT) from atrioventricular reciprocating tachycardia (AVRT) when using the RV basal septal stimulation (ΔSA-VAbase) as compared to the RV apical stimulation (ΔSA-VAapex). Moreover, it was predicted that the ΔSA-VAbase might distinguish septal from free wall accessory pathways (APs) effectively. METHODS: In this prospective study, 105 patients with AVNRTs (age 48 ± 20 years, 44% male) and 130 with AVRTs (age 26 ± 18 years, 54% male) underwent programmed ventricular extrastimuli delivered from both the RV basal septum and RV apex. The ΔSA-VA values were compared between the 2 sites. RESULTS: The ΔSA-VAbase was shorter than the ΔSA-VAapex during AVRT (44 ± 30 ms vs 58 ± 29 ms; P < 0.001), and the opposite occurred during AVNRT (133 ± 31 ms vs 125 ± 25 ms; P = 0.03). A ΔSA-VAbase of ≧85 milliseconds had a sensitivity of 97% and specificity of 96% for identifying AVNRT. Furthermore, a ΔSA-VAbase of 45-85 milliseconds identified AVRT with left free wall APs (sensitivity 86%, specificity 95%), 20-45 milliseconds for posterior septal APs (sensitivity 72%, specificity 96%), and <20 milliseconds for right free wall or anterior/mid septal APs (sensitivity 86%, specificity 98%). CONCLUSIONS: The ΔSA-VAbase during programmed ventricular extrastimuli produced a robust differentiation between AVNRT and AVRT regardless of the AP location with ≧85 milliseconds as an excellent cutoff point. This straightforward technique further allowed localizing 4 general AP sites.

Efficacy of SubcutAneous implantable cardioVErter-defibrillators in ≤18 year-old CHILDREN: SAVE-CHILDREN registry.

BACKGROUND: In adult patients, subcutaneous implantable cardioverter defibrillators (S-ICDs) have been reported to be non-inferior to transvenous ICDs with respect to the incidence of device-related complications and inappropriate shocks. Only a few reports have investigated the efficacy of S-ICDs in the pediatric field. This study aimed to investigate the utility and safety of S-ICDs in patients ≤18 years old. METHODS: This study was a multicenter, observational, retrospective study on S-ICD implantations. Patients <18 years old who underwent S-ICD implantations were enrolled. The detailed data on the device implantations and eligibility tests, incidence of appropriate- and inappropriate shocks, and follow-up data were assessed. RESULTS: A total of 62 patients were enrolled from 30 centers. The patients ranged in age from 3 to 18 (median 14 years old [IQR 11.0-16.0 years]). During a median follow up of 27 months (13.3-35.8), a total of 16 patients (26.2%) received appropriate shocks and 13 (21.3%) received inappropriate shocks. The common causes of the inappropriate shocks were sinus tachycardia (n = 4, 30.8%) and T-wave oversensing (n = 4, 30.8%). In spite of the physical growth, the number of suitable sensing vectors did not change during the follow up. No one had any lead fractures or device infections in the chronic phase. CONCLUSIONS: Our study suggested that S-ICDs can prevent sudden cardiac death in the pediatric population with a low incidence of lead complications or device infections. The number of suitable sensing vectors did not change during the patients' growth.

Novel Diagnostic Observations of Nodoventricular/Nodofascicular Pathway-Related Orthodromic Reciprocating Tachycardia Differentiating From Atrioventricular Nodal Re-Entrant Tachycardia.

OBJECTIVES: This study sought to assess the performance of current diagnostic criteria and identify additional electrophysiological features differentiating orthodromic reciprocating tachycardia (ORT) with a concealed nodoventricular/nodofascicular (NV/NF) pathway from atrioventricular nodal re-entrant tachycardia (AVNRT). BACKGROUND: Diagnosing sustained supraventricular tachycardia (SVT) despite the occurrence of ventriculoatrial block (VAB) is challenging. METHODS: We analyzed electrograms of 25 sustained SVTs (9 NV/NF-ORTs [n = 7/2] and 16 AVNRTs) with VAB and 91 AVNRTs without VAB (for reference). RESULTS: More than 1 SVT, each with a different ventriculoatrial interval, was commonly induced in AVNRT cases (75%) but not in NV/NF-ORT cases (0%; p = 0.0005). Wenckebach VAB was common in NV/NF-ORTs (78%), but VAB patterns varied in AVNRTs. The His-His interval transiently prolonged in the following beat after the VAB in most AVNRTs but rarely did in NV/NF-ORTs (79% vs. 22%; p = 0.01). NV/NF-ORT was diagnosed by His-refractory premature ventricular contractions (n = 5) and the findings during right ventricular overdrive pacing showing an uncorrected/corrected post-pacing interval (PPI)-tachycardia cycle length (TCL) ≤115/110 ms (n = 5/5), orthodromic His capture (n = 6), and V-V-A (ventricle-ventricle-atrial response) response (n = 3). A single form of induced SVT (positive predictive value [PPV]: 69%; negative predictive value [NPV]: 100%), Wenckebach VAB (PPV: 70%; NPV: 87%), stable His-His interval despite VAB (PPV: 70%; NPV: 85%), orthodromic His capture (PPV: 100%; NPV: 97%), and V-V-A response (PPV: 100%; NPV: 95%) characterized NV/NF-ORT, and a PPI-TCL of ≤125 ms (PPV: 100%; NPV: 100%) characterized NV-ORT. CONCLUSIONS: Induction of a single SVT form, Wenckebach VAB, stable His-His interval despite VAB, orthodromic His capture, and V-V-A response appeared to discriminate NV/NF-ORT from AVNRT, with a PPI-TCL of ≤125 ms discriminating NV-ORT from NF-ORT and AVNRT.

Relationship between device-detected subclinical atrial fibrillation and heart failure in patients with cardiac resynchronization therapy defibrillator.

BACKGROUND: Atrial fibrillation (AF) is a leading preventable cause of heart failure (HF) for which early detection and treatment is critical. Subclinical-AF is likely to go untreated in the routine care of patients with cardiac resynchronization therapy defibrillator (CRT-D). HYPOTHESIS: The hypothesis of our study is that subclinical-AF is associated with HF hospitalization and increasing an inappropriate therapy. METHODS: We investigated 153 patients with an ejection fraction less than 35%. We divided into three groups, subclinical-AF (n = 30), clinical-AF (n = 45) and no-AF (n = 78). We compared the baseline characteristics, HF hospitalization, and device therapy among three groups. The follow-up period was 50 months after classification of the groups. RESULTS: The average age was 66 ± 15 years and the average ejection fraction was 26 ± 8%. Inappropriate therapy and biventricular pacing were significantly different between subclinical-AF and other groups (inappropriate therapy: subclinical-AF 13% vs clinical-AF 8.9% vs no-AF 7.7%: P = .04, biventricular pacing: subclinical-AF 81% vs clinical-AF 85% vs no-AF 94%, P = .001). Using Kaplan-Meier method, subclinical-AF group had a significantly higher HF hospitalization rate as compared with other groups. (subclinical-AF 70% vs clinical-AF 49% vs no-AF 38%, log-rank: P = .03). In multivariable analysis, subclinical-AF was a predictor of HF hospitalization. CONCLUSIONS: Subclinical-AF after CRT-D implantation was associated with a significantly increased risk of HF hospitalization. The loss of the biventricular pacing and increasing an inappropriate therapy might affect the risk of HF hospitalization.

Anomalous origin of the coronary artery coursing between the great vessels presenting with a cardiovascular event (J-CONOMALY Registry).

AIMS: Anomalous origin of the coronary artery (AOCA) with an inter-arterial course (IAC) between the great vessels poses a risk for a life-threatening cardiovascular event. We assessed, in a registry-based study, the clinical features, treatment strategies, and prognoses of life-threatening cardiovascular events ensuant to AOCA. METHODS AND RESULTS: Included were 65 AOCA patients (48 men/17 women, aged 41 ± 23 years) from 40 clinical centres who had experienced sudden cardiac arrest (SCA) (n = 30), acute myocardial infarction (AMI) (n = 5), angina (n = 23), or syncope (n = 7). The anomalous vessel was the right coronary artery in 72% of patients and left coronary artery in 28%; the ostium was slit-like in 42%. Coronary luminal narrowing ≥75% was absent in patients with SCA or syncope (86% and 57%, respectively), but occlusion or narrowing was seen in those with AMI (100%) or angina (52%). Age ≤40 years, male sex, sporting activity, absence of prodromal symptoms, acutely angled (≤30°) take-off from the aorta, and absence of luminal narrowing of the IAC segment were associated with SCA in this patient group. Coronary vasospasm was inducible in 12 of 17 patients without coronary narrowing. Management included surgical revascularization (n = 26) percutaneous coronary intervention (n = 9), and medical treatment (n = 26). Four SCA patients died while hospitalized; no others died during the median 5.0 (range, 1.8-7.0)-year follow-up period. CONCLUSIONS: In patients with AOCA, age ≤40 years, male sex, sporting activity, and an acute take-off angle appear to be risk factors for SCA. Appropriate management can be beneficial. Confirmation in a large-scale study is warranted.

J-Wave Elevation in the Inferior Leads Predicts Lethal Ventricular Arrhythmia Initiated by Premature Ventricular Contractions With Right Bundle Branch Block and Superior Axis.

BACKGROUND: Lethal ventricular arrhythmia (VA) can be initiated by idiopathic premature ventricular contractions (PVCs) originating from the left ventricular (LV) inferior wall. Furthermore, J-wave elevation in the inferior leads on ECG is sometimes associated with lethal VA. However, the relationship between these PVCs and J-wave elevation in patients with lethal VA is unclear, so we investigated it in the present study.Methods and Results:We studied 32 consecutive patients who underwent radiofrequency (RF) ablation of idiopathic PVCs with right bundle branch block (RBBB) and superior axis. Thee PVCs were originating from the inferior wall of the LV. Lethal VA was defined as ventricular fibrillation (VF) or ventricular tachycardia (VT) with loss of consciousness (LOC). Among 32 patients, 3 had VF and 2 had VT with LOC. Other 27 had non-lethal VA. Baseline clinical characteristics were not significantly difference between lethal and non-lethal VA. The ratio of J-wave elevation in lethal VA was significantly higher as compared with non-lethal VA (100% vs. 11.1%, P<0.0001). Furthermore, no patients with J-wave elevation in the inferior leads had recurrence of lethal VA after RF ablation of the PVCs. CONCLUSIONS: We speculate that J-wave elevation in the inferior leads might be a predictor of lethal VA initiated by PVCs with RBBB and superior axis. RF ablation of these PVCs was a useful method of treating lethal VA.

Idiopathic basal crux ventricular arrhythmias with left bundle branch block and superior axis: A comparison with inferior-septal valvular arrhythmias.

INTRODUCTION: Left bundle branch block (LBBB) with superior axis is common in patients with idiopathic-ventricular arrhythmia (VA) originating from the tricuspid annulus (TA) and rarely from the cardiac basal crux and mitral annulus (MA). We described the electrocardiography and electrophysiological findings of idiopathic-VA presenting with LBBB and superior axis. METHODS AND RESULTS: We described 42 idiopathic-VA patients who had an LBBB and superior axis; 15 basal crux-VA, 17 TA-VA, and 10 MA-VA. No patient had a structural heart disease. Among patients with idiopathic-VA referred for ablation, we investigated the electrocardiogram and clinical characteristics of basal crux-VA as compared with other LBBB and superior axis-VA. The left ventricular ejection fraction with MA-VA was significantly lower in comparison with basal crux-VA (P = .01). All patients had a positive R wave in lead I and aVL. The maximum deflection index with basal crux-VA was significantly higher in comparison with TA-VA or MA-VA (P = .01). Patients with basal crux-VA presented with QS wave in lead II more frequently as compared with TA-VA or MA-VA (P = .001). All MA-VA patients had Rs wave in V6, and basal crux-VA, and TA-VA patients had a monophasic R wave or Rs wave in V6. Basal crux-VA patients underwent ablation in the middle cardiac vein (MCV) or coronary sinus (success rate: 94%, recurrence rate: 6%). CONCLUSIONS: We could distinguish basal crux-VA, TA-VA, and MA-VA, using a combination of clinical and electrocardiographic findings. These findings might be useful for counseling patients about an ablation strategy. Ablation via the MCV is effective for eliminating basal crux-VA.

Intracardiac Thrombosis and Heart Failure in a Patient with Hepatocellular Carcinoma and Cardiac Amyloidosis and an Implanted Cardiac Resynchronization Therapy Device.

BACKGROUND Intracardiac thrombosis has been known to be associated with not only hepatocellular carcinoma but also with amyloidosis and use of a cardiac implantable electronic device. We report a case of a continuous tumor thrombus with hepatocellular carcinoma from the portal vein and hepatic vein to the right atrium via the inferior vena cava in a patient with a cardiac amyloidosis and an implanted cardiac resynchronization therapy (CRT) device. CASE REPORT A 68-year-old female first admitted to our hospital because of heart failure with an AL type primary cardiac amyloidosis. After 3 years, she underwent an implantation of a CRT device for biventricular pacing following repeated episodes of heart failure and low left ventricular ejection fraction of 34% with NYHA class III. Again, she presented with symptoms of heart failure and cardiomegaly on chest x-ray at 7 years after the CRT device implantation. The echocardiography showed a huge echogenic mass occupying the right atrium, and 64 multi-detector computed tomography showed a lobulated heterogeneously enhancing mass of hepatocellular carcinoma in the right upper lobe of her liver and a continuous tumor thrombus from the portal vein and hepatic vein to the right atrium via the inferior vena cava. CONCLUSIONS Intracardiac thrombosis and heart failure occurred in a patient with hepatocellular carcinoma and cardiac amyloidosis, who had an implanted CRT device, which resulted not only in hypercoagulability by the hepatocellular carcinoma itself and the accumulation of various risk factors, but also the progression of myocardial damage with the development of amyloidosis.

Association left ventricular lead and ventricular arrhythmias after upgrade to cardiac resynchronization therapy in patients with implantable cardioverter defibrillators.

BACKGROUND: There are some controversial reports related to the pro-arrhythmic or anti-arrhythmic potential of cardiac resynchronization therapy (CRT) and little is known about the relationship between ventricular arrhythmia (VA) and left ventricular (LV)-lead threshold. HYPOTHESIS: Upgrade CRT is anti-arrhythmic effect of VA with implantable cardioverter-defibrillator (ICD) patients and has a relationship with the incident of VA and LV-lead threshold. METHODS: Among 384 patients with the implantation of CRT-defibrillator (CRT-D), 102 patients underwent an upgrade from ICD to CRT-D. We divided patients into three groups; anti-arrhythmic effect after upgrade (n = 22), pro-arrhythmic effect (n = 14), and unchanging-VA events (n = 66). The VA event was determined by device reports. We described the electrocardiography parameters, LV-lead characteristics, and clinical outcomes. RESULTS: Before upgrade, the numbers of VA were 305 episodes and the numbers of ICD therapy were 157 episodes. While after upgrade, the numbers of VA were 193 episodes and the number of ICD therapy were 74 episodes. Ventricular tachycardia cycle length (VT-CL) after upgrade was significantly slower as compared to those with before upgrade. Pro-arrhythmic group was significantly higher with delta LV-lead threshold (after 1 month-baseline) as compared to those with anti-arrhythmic group (0.74 vs -0.21 V). Furthermore, pro-arrhythmic group was significantly bigger with delta VT-CL (after 3 months-before 3 months) as compared to those with anti-arrhythmic group (P = .03). CONCLUSIONS: We described upgrade-CRT was associated with reduction of VA, ICD therapies and VT-CL. While 14 patients had a pro-arrhythmic effect and LV lead threshold might be associated with VA-incidents.

Catheter Ablation of Refractory Ventricular Fibrillation Storm After Myocardial Infarction.

BACKGROUND: Ventricular fibrillation (VF) storm after myocardial infarction (MI) is a life-threatening condition that necessitates multiple defibrillations. Catheter ablation is a potentially effective treatment strategy for VF storm refractory to optimal medical treatment. However, its impact on patient survival has not been verified in a large population. METHODS: We conducted a multicenter, retrospective observational study involving consecutive patients who underwent catheter ablation of post-MI refractory VF storm without preceding monomorphic ventricular tachycardia. The target of ablation was the Purkinje-related ventricular extrasystoles triggering VF. The primary outcome was in-hospital and long-term mortalities. Univariate logistic regression and Cox proportional-hazards analysis were used to evaluate clinical characteristics associated with in-hospital and long-term mortalities, respectively. RESULTS: One hundred ten patients were enrolled (age, 65±11years; 92 men; left ventricular ejection fraction, 31±10%). VF storm occurred at the acute phase of MI (4.5±2.5 days after the onset of MI during the index hospitalization for MI) in 43 patients (39%), the subacute phase (>1 week) in 48 (44%), and the remote phase (>6 months) in 19 (17%). The focal triggers were found to originate from the scar border zone in 88 patients (80%). During in-hospital stay after ablation, VF storm subsided in 92 patients (84%). Overall, 30 (27%) in-hospital deaths occurred. The duration from the VF occurrence to the ablation procedure was associated with in-hospital mortality (odds ratio for each 1-day increase, 1.11 [95% CI, 1.03-1.20]; P=0.008). During follow-up after discharge from hospital, only 1 patient developed recurrent VF storm. However, 29 patients (36%) died, with a median survival time of 2.2 years (interquartile range, 1.2-5.5 years). Long-term mortality was associated with left ventricular ejection fraction <30% (hazard ratio, 2.54 [95% CI, 1.21-5.32]; P=0.014), New York Heart Association class ≥III (hazard ratio, 2.68 [95% CI, 1.16-6.19]; P=0.021), a history of atrial fibrillation (hazard ratio, 3.89 [95% CI, 1.42-10.67]; P=0.008), and chronic kidney disease (hazard ratio, 2.74 [95% CI, 1.15-6.49]; P=0.023). CONCLUSIONS: In patients with MI presenting with focally triggered VF storm, catheter ablation of culprit triggers is lifesaving and appears to be associated with short- and long-term freedom from recurrent VF storm. Mortality over the long-term follow-up is associated with the severity of underlying cardiovascular disease and comorbidities in this specific patient population.

Predictors of Mortality, Rehospitalization for Syncope and Cardiovascular Events in Patients With Cardiovascular Syncope.

BACKGROUND: Predictors of poor outcomes remain unknown for cardiovascular syncope patients after discharge.Methods and Results:We reviewed the medical records of consecutive patients admitted to hospital with cardiovascular syncope. We then performed Cox stepwise logistic regression analysis to identify significant independent factors for death, rehospitalization for syncope, and cardiovascular events. The study group was 206 patients with cardiovascular syncope. Of them, bradycardia was diagnosed in 50%, tachycardia in 27%, and structural disease in 23%. During a 1-year follow-up period, 18 (8%) and 45 (23%) patients, respectively, were rehospitalized for syncope or a cardiovascular event, and 10 (4%) died. Independent predictors of cardiovascular events were systolic blood pressure <100 mmHg (odds ratio [OR] 3.25; 95%confidence interval [CI] 1.41-7.51, P=0.006) and implantation of a pacemaker (OR 0.19; 95% CI 0.05-0.51, P=0.0005) (inverse association). Drug-induced syncope (OR 4.57; 95% CI 1.54-12.8, P=0.007) was an independent risk factor for rehospitalization. Finally, a history of congestive heart failure (OR 11.0; 95% CI 2.78-54.7, P=0.0006) and systolic blood pressure <100 mmHg (OR 5.40; 95% CI 1.30-22.7, P=0.02) were identified as significant independent prognostic factors for death. CONCLUSIONS: Drug-induced syncope, hypotension, no indication for a pacemaker, and a history of congestive heart failure are risk factors post-discharge for patients with cardiovascular syncope and careful follow-up of these patients for at least 1 year is recommended.

Immediate discontinuation of ablation during pulmonary vein isolation remarkably decreases the incidence of esophageal thermal lesions even when using steerable sheaths.

BACKGROUND: Left atrial-esophageal fistulas (LAEFs) are serious complications with high mortality after atrial fibrillation radiofrequency ablation (AFRA). Decreasing the incidence of esophageal thermal lesions (EsoTLs) that may lead to LAEFs is important. The aim of this study was to suppress EsoTL development and determine the appropriate alarm setting for a temperature-monitoring probe by using steerable sheath (STS) methods. METHODS: We enrolled 82 consecutive patients (mean, 61.9±11.7 years; 75.6% men) who underwent AFRA, including pulmonary vein isolation for symptomatic, drug-refractory atrial fibrillation with esophageal temperature monitoring by using STS between January 2011 and April 2014. All patients underwent upper gastrointestinal endoscopy (UGE) 1-3 days after AFRA. The timing of ablation discontinuation in the first 17 patients was determined by each physician during AFRA (only monitoring group, OM). In the next 65 patients, physicians were to immediately discontinue ablation when an alarm set at 39 °C went off (instruction group, INS). We compared two groups with respect to the incidence of EsoTLs. RESULTS: Among the 82 patients, 5 (6.1%) had EsoTLs after AFRA. EsoTLs occurred in 3 of 17 patients (17.6%) and 2 of 65 patients (3.1%) in the OM and INS groups, respectively. The incidence of EsoTLs in the INS group was significantly lower than that in the OM group (p=0.0254). EsoTL did not occur at maximal temperature less than 39 °C, measured by using esophageal temperature-monitoring probe. CONCLUSIONS: Immediate discontinuation of ablation during pulmonary vein isolation remarkably decreased the incidence of EsoTLs, even when using STS.

Comparison of remote magnetic navigation ablation and manual ablation of idiopathic ventricular arrhythmia after failed manual ablation.

PURPOSE: Catheter ablation for idiopathic ventricular arrhythmia (VA) is effective and safe, but efficacy is frequently limited due to an epicardial origin and difficult anatomy. The remote magnetic navigation (RMN) catheter has a flexible catheter design allowing access to difficult anatomy. We describe the efficacy of the RMN for ablation of idiopathic VA after failed manual ablation. METHODS: Among 235 patients with idiopathic VA referred for catheter ablation, we identified 51 patients who were referred for repeat ablation after a failed manual ablation. We analyzed the clinical characteristics, including the successful ablation site and findings at electrophysiology study, in repeat procedures conducted using RMN as compared with manual ablation. Among these patients, 22 (43 %) underwent repeat ablation with the RMN and 29 (57 %) underwent repeat ablation with a manual ablation. RESULTS: Overall, successful ablation rate was significantly higher using RMN as compared with manual ablation (91 vs. 69 %, P = 0.02). Fluoroscopy time in the RMN was 17 ± 12 min as compared with 43 ± 18 min in the manual ablation (P = 0.009). Successful ablation rate in the posterior right ventricular outflow tract (RVOT) plus posterior-tricuspid annulus was higher with RMN as compared with manual ablation (92 vs. 50 %, P = 0.03). Neither groups exhibited any major complications. CONCLUSIONS: The RMN is more effective in selected patients with recurrent idiopathic VA after failed manual ablation and is associated with less fluoroscopy time. The RMN catheters have a flexible design enabling them to access otherwise difficult anatomy including the posterior tricuspid annulus and posterior RVOT.

Effects of Aging on the Coagulation Fibrinolytic System in Outpatients of the Cardiovascular Department.

BACKGROUND: Although clinical trials demonstrate that the elderly with atrial fibrillation have risks of thrombosis and bleeding, the relationship between aging and coagulation fibrinolytic system in "real-world" cardiology outpatients is uncertain. METHODS AND RESULTS: We retrospectively evaluated 773 patients (mean age: 58 years; 52% men; Asian ethnicity). To thoroughly investigate markers of coagulation and fibrinolysis, we simultaneously measured levels of D-dimer, prothrombin-fragment1+2 (F1+2), plasmin-α2 plasmin inhibitor complex (PIC), and thrombomodulin (TM). There were correlations between aging and levels of F1+2, D-dimer, PIC, and TM (R=0.61, 0.57, 0.49, and 0.30, respectively). We compared 3 age groups, which were defined as the Y group (<64 years), M group (65-74 years), and the O group (>75 years). Levels of markers were higher in older individuals (D-dimer: 1.0±0.8 vs. 0.8±0.8 vs. 0.6±0.4 µg/ml, F1+2: 281.8±151.3 vs. 224.6±107.1 vs. 155.5±90.0 pmol/L, PIC: 0.9±0.3 vs. 0.8±0.3 vs. 0.6±0.5 µg/ml, and TM: 2.9±0.8 vs. 2.7±0.7 vs. 2.5±0.7FU/ml). We performed logistic regression analysis to determine F1+2 and PIC levels. Multivariate analysis revealed that aging was the most important determinant of high F1+2 and PIC levels. CONCLUSIONS: Hypercoagulable states develop with advancing age in "real-world" cardiology outpatients. (Circ J 2016; 80: 2133-2140).

Clinical and Electrophysiological Characteristics of Incessant Atrioventricular Nodal Re-Entrant Tachycardia.

OBJECTIVES: This study investigated clinical and electrophysiological findings in patients with incessant atrioventricular nodal reentrant tachycardia (AVNRT). BACKGROUND: AVNRT is the most frequent cause of paroxysmal supraventricular tachycardia (SVT) and, rarely, incessant SVT. There are a few case reports describing incessant AVNRT. METHODS: Among 342 patients treated using ablation for AVNRT, we identified 8 patients with incessant AVNRT (2.3%). We describe the clinical and electrophysiological features of patients with incessant AVNRT and compare them with those of patients with paroxysmal AVNRT (n = 334). RESULTS: This study population consisted of 5 men and 3 women with incessant AVNRT. Patients with incessant AVNRT presented more frequently with the fast-slow form than those with paroxysmal AVNRT (63% vs. 14%, respectively, p < 0.001). The ejection fraction in patients with incessant AVNRT was significantly lower than that in patients with paroxysmal AVNRT (49 ± 12% vs. 60 ± 8%, p = 0.03). The H-V interval in patients with incessant AVNRT was significantly longer than that in patients with paroxysmal AVNRT. A large circuit path length is inferred by spontaneous tachycardia induction in response to slight changes in sinus rate or random premature beats, suggesting that slight changes in rate produce changes in atrial or nodal refractoriness and provoke SVT. Catheter ablation in the conventional slow pathway region was successful in eliminating SVT. CONCLUSIONS: AVNRT can rarely present as incessant SVT, mimicking permanent junctional reciprocating tachycardia, and can be associated with tachycardia-associated cardiomyopathy. Catheter ablation in the slow pathway region leads to long-term success.

The Effect of Direct Current Stimulation versus T-Wave Shock on Defibrillation Threshold Testing.

INTRODUCTION: There are several methods to induce ventricular fibrillation (VF) during defibrillation threshold (DFT) testing. Delivering a shock at a critical time during the T wave (T-shock) is the conventional approach, while delivering a constant direct current voltage (DC stim) from the implantable cardioverter defibrillator is an alternative method. Only a few reports compare VF induction methods. The purpose of this study was to evaluate the effects and safety of DC stim versus T-shock. METHODS: We retrospectively investigated 414 consecutive patients undergoing DFT testing. We compared the two groups (DC stim and T-shock) with respect to clinical characteristics, electrocardiogram (ECG) changes, and complications. RESULTS: Ventricular arrhythmia, including ventricular tachycardia (VT) and VF, was induced by DC stim in 93 patients or T-shock in 321 patients. No more than three attempts were performed during one procedure. There was no significant difference in the baseline ECG, induced tachycardia cycle length (TCL), or complications between the two groups. However, the induced TCL was significantly shorter than the clinical TCL regardless of induction method (P = 0.001). Five patients suffered major complications (i.e., electromechanical dissociation or incessant VT). A history of atrial fibrillation was significantly greater in patients with major complications than the others (80% vs 24%, P = 0.004), and was an independent predictor on multivariate analysis. CONCLUSIONS: There is no significant difference in induced TCL or complications between the DC stim and T-shock. The induced TCL is significantly shorter than clinical TCL regardless of induction method.