Michio Nagashima

Importance of nonpulmonary vein foci in catheter ablation for paroxysmal atrial fibrillation.

BACKGROUND Pulmonary vein (PV) isolation is an established treatment strategy for paroxysmal atrial fibrillation (PAF). However, the recurrence rate of PAF is 8% to 37%, despite repeated procedures, and the catheter ablation strategy for PAF with non-PV foci is unclear. OBJECTIVE The purpose of this study was to assess the PAF ablation strategy for non-PV foci. METHODS The study included 304 consecutive patients undergoing PAF ablation (209 males, age 63.0 ± 10.4 years) divided into 3 groups: group 1 (245 patients) with no inducible non-PV foci; group 2 (34 patients) with atrial fibrillation (AF) originating from non-PV foci and all the foci successfully ablated; and group 3 (25 patients) with AF originating from non-PV triggers, but without all foci being ablated or with persistently inducible AF. RESULTS Mean follow-up period was 26.9 ± 11.8 months, and AF recurrence rates since the last procedure were 9.8%, 8.8%, and 68.0% in groups 1, 2, and 3, respectively. There was no statistically significant difference in recurrence rate between groups 1 and 2 (P = .89); however, there were statistically significant differences between groups 3 and 1 (P <.0001) and groups 3 and 2 (P <.0001). The patients in group 2 had an AF-free outcome to equivalent to those who had PV foci in group 1 (P = .83). CONCLUSION Success rates can be improved for PAF ablation if non-PV foci are detected and eliminated.

Effect of class Ia antiarrhythmic agents on fasciculoventricular fibers

In four patients with fasciculoventricular (FV) fibers, the electrocardiographic and electrophysiologic characteristics were studied based on their response to class Ia antiarrhythmic agents. Three patients had paroxysmal atrial fibrillation, and one showed atrioventricular nodal Wenckebach-type block with dual pathways. Three of the four patients showed complete block of FV fibers after administration of disopyramide 0.28-0.60 mg/kg, procainamide 1.7-2.6 mg/kg, and ajmaline 0.18-0.26 mg/kg, respectively. Normalization in the remaining patient was not seen after disopyramide 2 mg/kg or procainamide 10 mg/kg, but was achieved by ajmaline 0.86 mg/kg. Ventricular preexcitation beats showed initial q waves (3 patients) or a decrease in the height of the r wave (1 patient) in V1, no initial q wave in V6 (4 patients), and ST-T changes (1 patient). Since these findings resemble ischemic change or intraventricular conduction disturbance, drug testing is necessary for precise diagnosis and proper clinical management.

Long-term outcomes of catheter ablation of ventricular tachycardia in patients with structural heart disease

Catheter ablation of ventricular tachycardia (VT) is feasible. However, the long‐term outcomes for different underlying diseases have not been well defined.

Impact of Catheter Ablation for Paroxysmal Atrial Fibrillation in Patients With Sick Sinus Syndrome – Important Role of Non-Pulmonary Vein Foci –

BACKGROUND The clinical efficacy of catheter ablation (CA) for paroxysmal atrial fibrillation (PAF) in patients with sick sinus syndrome (SSS) and the mechanism and predictors of recurrence are not yet completely elucidated. METHODSANDRESULTS Of 963 consecutive patients who underwent PAF ablation during the study period, a total of 108 patients with SSS (SSS group) and 108 matched controls without SSS (non-SSS group) were followed up. During the follow-up period (mean, 32.8±17.5 months), the SSS group had significantly higher AF recurrence rate since the last procedure than the non-SSS group (26.9% vs. 12.0%; P=0.02). The SSS group had significantly higher prevalence of non-pulmonary vein (non-PV) foci than the non-SSS group (25.9% vs. 13.9%; P=0.027). On multivariate analysis congestive heart failure (HR, 13.7; 95% CI: 1.57-119; P=0.02) and non-PV foci (HR, 5.75; 95% CI: 1.69-19.6; P=0.005) were independent predictors of recurrence following CA in the SSS group. In the SSS group, 88 patients had bradycardia-tachycardia syndrome without prior permanent pacemaker implantation. Of these, 6 required pacemaker implantation because of AF and sinus pause recurrence. CONCLUSIONS Patients with SSS are at higher risk of AF recurrence after CA. Non-PV foci are associated with AF recurrence following PAF with SSS.

Lead extractions in patients with cardiac implantable electronic device infections: Single center experience.

Lead extraction using laser sheaths is performed mainly for cardiac implantable electronic device (CIED) infections. However, there are few reports concerning the management of CIED infections in Japan.

Identification of causative organism in cardiac implantable electronic device infections

BACKGROUND The causative organism in cardiovascular implantable electronic device (CIED) infection is usually diagnosed with the cultures from blood, removed leads, and/or infected pocket material. The cultured organism, however, is sometimes different among these samples. METHODS Two hundred sixty patients with CIED infection, who underwent lead extraction between April 2005 and December 2014, were analyzed. More than two blood culture sets, all the extracted leads, and swab culture of the pocket were sent to the laboratory for culture. Among the patients all of whose microbiological examinations were available, we analyzed the causative organism defined as the species detected in at least two different sites. RESULTS All the culture results were available in the 208 patients, showing 69 systemic infections (including 30 cases of infectious endocarditis) and 139 local infections. Blood culture, lead culture, and swab culture were positive in 57 (27%), 169 (81%), and 152 (73%), respectively. Staphylococcus aureus [37% including methicillin-resistant S. aureus (MRSA) (12%)] and coagulase-negative staphylococci (CoNS, 36%) were the most common causative organism, followed by non-staphylococci (23%), and poly-microbial infection (4%). The detection of S. aureus from pocket or removed leads rendered higher predictive value of a causative organism than that of CoNS. The detection of Gram-negative bacteria, fungi, and mycobacteria indicated that it was most likely a causative organism. Gram-positive bacteria excluding Staphylococcus, such as Corynebacterium spp., tended to coexist as a benign organism. CONCLUSIONS The causative organism is mostly S. aureus and CoNS. Detection of S. aureus or Gram-negative bacteria means that it is more likely a causative organism.

Mortality and predictors of appropriate implantable cardioverter defibrillator therapy in Japanese patients with Multicenter Automatic Defibrillator Implantation Trial II criteria

Data regarding long‐term mortality and factors influencing appropriate therapies in Japanese patients with implantable cardioverter defibrillators (ICD), who satisfy the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) criteria for primary prevention, remain scarce.

Impact of catheter ablation of ventricular tachycardia in patients with prior myocardial infarctions

Catheter ablation can reduce episodes of ventricular tachycardia (VT) after myocardial infarction (MI). However, the optimal endpoint of the ablation procedure remains unclear.

Very long-term outcomes after percutaneous coronary intervention with bare metal stents for unprotected left main coronary artery disease.

AIMS The aim of this study was to evaluate very long-term clinical outcomes and potential predictors after percutaneous coronary intervention (PCI) with bare metal stents (BMS) for unprotected left main coronary artery disease (ULMCAD). METHODS AND RESULTS From March 1991 to August 2001, 151 patients who underwent PCI with BMS for ULMCAD were investigated retrospectively. The patient-oriented major adverse cardiac events (MACE) were defined as the occurrence of all-cause death, any MI, and any coronary revascularisation. The median follow-up duration was 10.5 years. The mean age was 69.9±11.5 years, and 106 patients (70.2%) were male. At 10 years, the incidences of cardiac death (CD), target lesion revascularisation (TLR) and patient-oriented MACE were 11.1%, 25.2% and 81.9%, respectively. In multivariate analysis, the pre-reference diameter of the left main trunk (LMT) was significantly associated with TLR (adjusted hazard ratio [HR] [95% confidence interval (CI)], 0.28 [0.14-0.54], p<0.001) and the SYNTAX score remained an independent predictor of patient-oriented MACE (adjusted HR [95% CI], 1.03 [1.007-1.05], p=0.009). CONCLUSIONS The pre-reference diameter of LMT was significantly associated with TLR, and the SYNTAX score significantly predicted the risk of patient-oriented MACE at 10 years. BMS implantation for larger size of ULMCAD with a lower SYNTAX score was feasible for up to 10 years.

Leadless Pacemaker Implantation Following Transcatheter Aortic Valve Implantation Using SAPIEN 3

https://e-kcj.org A 91-year-old male with symptomatic severe aortic stenosis underwent transcatheter aortic valve implantation (TAVI) using a 26-mm balloon-expandable SAPIEN 3 (Edwards Lifesciences, Irvine, CA, USA). The device was deployed via a transfemoral approach (Figure 1A). His pre-procedural electrocardiogram showed sinus rhythm without conduction disturbances (CDs). Within a few hours after TAVI, he suddenly experienced sinus arrest (Figure 1B) with syncope and required cardiac massage. There was no evidence of other complications after TAVI, and thus the event was thought to be an implant-related arrhythmia. The patients got cardiac arrest once, but he required cardiac massage, so we thought that he would need a permanent pacemaker, but he was very old and frail. We ultimately decided to implant a percutaneous leadless transcatheter pacemaker (MicraTM; Medtronic Inc., Minneapolis, MN, USA) to minimize the damage (Figure 1C). He was discharged from our hospital on foot without any complications.