Yoshinari Enomoto

Left Axillary Pacemaker Generator Implantation with a Direct Puncture of the Left Axillary Vein

Pacemaker generators are routinely implanted in the anterior chest. However, where to place the generator may need to be considered from the mental, functional, and cosmetic standpoints.

Outcomes of Ventricular Tachycardia Ablation Using Percutaneous Left Ventricular Assist Devices

Background— Although percutaneous left ventricular assist devices (pLVADs) facilitate mapping and ablation of hemodynamically unstable ventricular tachycardia (VT), there is limited data whether clinical outcomes are improved. We sought to retrospectively compare the outcomes of patients undergoing scar-related VT ablation with and without pLVAD support. Methods and Results— The study population comprised 194 patients (109 pLVAD and 85 non-pLVAD). The pLVAD group more often had dilated cardiomyopathy (33% versus 13%; P=0.001), New York Heart Association heart failure class ≥III (51% versus 25%; P<0.001), lower left ventricular ejection fractions (26±10% versus 39±16%; P<0.001), and electrical storm (49% versus 34%; P=0.04). Procedure times (422±112 versus 330±92 minutes; P<0.001), postablation VT inducibility (20% versus 7%; P=0.02), and length of subsequent hospitalization (median 6 versus 4 days; P=0.001) were all higher in the pLVAD group. During median follow-up of 215 days, the primary end point (recurrent VT, heart transplantation, or death) occurred in 36% of the pLVAD versus 26% of the non-pLVAD groups (P=0.14). After propensity matching for differences between groups, no differences were seen between groups for both acute procedural outcomes and the primary end point. Conclusions— In this large single-center scar-related VT ablation experience, despite the worse clinical status of the patients selected for pLVAD support, clinical outcomes were better than expected and were similar to healthier patients not receiving hemodynamic support. Patients with dilated cardiomyopathy presenting with electrical storm, advanced heart failure, and severe left ventricular dysfunction most frequently received hemodynamic support during VT ablation.

Efficacy and Myocardial Injury With Subcutaneous Implantable Cardioverter Defibrillators – Computer Simulation of Defibrillation Shock Conduction –

BACKGROUND Subcutaneous implantable cardiac defibrillator (S-ICD) systems have a lower invasiveness than traditional ICD systems, and expand the indications of ICD implantations. The S-ICD standard defibrillation shock output energy, however, is approximately 4 times that of the traditional ICD system. This raises concern about the efficacy of the defibrillation and myocardial injury. In this study, we investigated the defibrillation efficacy and myocardial injury with S-ICD systems based on computer simulations. METHODS AND RESULTS First, computer simulations were performed based on the S-ICD system configurations proposed in a previous study. Furthermore, simulations were performed by placing the lead at the left or right parasternal margin and the pulse generator in the superior and inferior positions (0-10 cm) of the recommended site. The simulated defibrillation threshold (DFT) for the 4 S-ICD system configurations were 30.1, 41.6, 40.6, and 32.8 J, which were generally similar to the corresponding clinical results of 33.5, 40.4, 40.1, and 34.3 J. CONCLUSIONS The simulated DFT were generally similar to their clinical counterparts. In the simulation, the S-ICD system had a higher DFT but relatively less severe myocardial injury compared with the traditional ICD system. Further, the lead at the right parasternal margin may correspond to a lower DFT and cause less myocardial injury.

Outcomes of Brugada Syndrome Patients with Coronary Artery Vasospasm

Objective To evaluate the outcomes of patients with concomitant Brugada syndrome and coronary artery vasospasm. Methods Patients diagnosed with Brugada syndrome with an implantable cardiac defibrillator were retrospectively investigated, and the coexistence of vasospasm was evaluated. The clinical features and outcomes were evaluated, especially in patients with coexistent vasospasm. A provocation test using acetylcholine was performed in patients confirmed to have no organic stenosis on percutaneous coronary angiography to confirm the presence of vasospasm. Implantable cardiac defibrillator shock status was checked every three months. Statistical comparisons of the groups with and without vasospasm were performed. A univariate analysis was also performed, and the odds ratio for the risk of implantable cardiac defibrillator shock was calculated. Patients Thirty-five patients with Brugada syndrome, of whom six had coexistent vasospasm. Results There were no significant differences in the laboratory data, echocardiogram findings, disease, or the history of taking any drugs between patients with and without vasospasm. There were significant differences in the clinical features of Brugada syndrome, i.e. cardiac events such as resuscitation from ventricular fibrillation or appropriate implantable cardiac defibrillator shock. Four patients with vasospasm had cardiac events such as resuscitation from ventricular fibrillation and/or appropriate defibrillator shock; three of them had no cardiac events with calcium channel blocker therapy to prevent vasospasm. The coexistence of vasospasm was a potential risk factor for an appropriate implantable cardiac defibrillator shock (odds ratio: 13.5, confidence interval: 1.572-115.940, p value: 0.035) on a univariate analysis. Conclusion Coronary artery vasospasm could be a risk factor for cardiac events in patients with Brugada syndrome.

The Efficacy and Safety of Oral Rivaroxaban in Patients with Non-Valvular Atrial Fibrillation Scheduled for Electrical Cardioversion.

Objective Electrical cardioversion (EC) is associated with an increased risk of thrombotic events in patients with non-valvular atrial fibrillation (NVAF). Patients who experience AF for a period of >48 hours therefore require adequate anticoagulation therapy for at least 3 weeks before and 4 weeks after EC. While the guidelines address the management of vitamin K antagonists (VKAs), there are limited data on the use of novel oral anticoagulants (NOAC). One NOAC, rivaroxaban, has a rapid onset of action and might therefore shorten the time for which anti-coagulant treatment is required before a patient undergoes EC. Methods This study included 91 patients with NVAF of >48 hours in duration or in whom the time of onset was unknown who were undergoing EC after pretreatment with rivaroxaban. All of the patients were pretreated with rivaroxaban for at least 2 hours before EC and the same dose of rivaroxaban was prescribed for 4 weeks after EC. The primary endpoint was a successful EC without any thrombotic events or bleeding complications within 30 days after EC. The secondary endpoint was the time to EC. Results The mean age was 63±12 years and 70 of the 91 patients were male. The CHADS2 and HAS-BLED scores were 1.0±1.0 and 1.7±1.3, respectively. Although there were no thrombotic events, minor bleeding (gingival hemorrhage) occurred 20 days after the initiation of rivaroxaban treatment in one patient. The average time to EC was 11.9±11.1 days. Conclusion Rivaroxaban is safe and effective drug for NVAF patients who are scheduled for an EC. Furthermore, since VKAs take a substantial amount of time to establish adequate anticoagulation, pretreatment with rivaroxaban could shorten the time to the EC.

Decreased Defibrillation Threshold and Minimized Myocardial Damage With Left Axilla Implantable Cardioverter Defibrillator Implantation

BACKGROUND To reduce myocardial damage caused by implantable cardioverter defibrillator (ICD) shock, the left axilla was studied as an alternative pulse generator implantation site, and compared with the traditional implantation site, the left anterior chest. METHODSANDRESULTS Computer simulation was used to study the defibrillation conduction pattern and estimate the simulated defibrillation threshold (DFT) and myocardial damage when pulse generators were placed in the left axilla and left anterior chest, respectively; pulse generators were also newly implanted in the left axilla (n=30) and anterior chest (n=40) to compare the corresponding DFT. On simulation, when ICD generators were implanted in the left axilla, compared with the left anterior chest, the whole heart may be defibrillated with a lower defibrillation energy (left axilla 6.4 J vs. left anterior chest 12.0 J) and thus the proportion of cardiac myocardial damage may be reduced (2.1 vs. 4.2%). Clinically, ventricular fibrillation was successfully terminated with a defibrillation output ≤5 J in 86.7% (26/30) of the left axillary group, and in 27.5% (11/40) of the left anterior group (P<0.001). CONCLUSIONS Clinically and theoretically, the left axilla was shown to be an improved ICD implantation site that may reduce DFT and lessen myocardial damage due to shock. Lower DFT also facilitates less myocardial damage, as a result of the lower shock required.

Percutaneous Antegrade Mitral Paravalvular Leak Closure Through Porcelain Atrial Septum – First Percutaneous Paravalvular Leak Closure in Japan –

Received August 24, 2014; revised manuscript received December 21, 2014; accepted December 23, 2014; released online January 26, 2015 Time for primary review: 29 days Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo (H.H., G.H., T.A., Y.N., K.Y., M.T., Y.E., F.H., Y.Y., R.I., M.S., K.S., M.N.); Department of Cardiovascular Surgery, National Hospital Organization Kanazawa Medical Center, Kanazawa (Y.M.), Japan; and Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (T.M., S.K.), USA Mailing address: Hidehiko Hara, MD, PhD, Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, 2-17-6 Ohashi, Meguro-ku, Tokyo 153-8515, Japan. E-mail: harahide@oha.toho-u.ac.jp ISSN-1346-9843 doi: 10.1253/circj.CJ-14-0940 All rights are reserved to the Japanese Circulation Society. For permissions, please e-mail: cj@j-circ.or.jp Percutaneous Antegrade Mitral Paravalvular Leak Closure Through Porcelain Atrial Septum – First Percutaneous Paravalvular Leak Closure in Japan –

Evaluation of defibrillation safety and shock reduction in implantable cardioverter-defibrillator patients with increased time to detection: A randomized SANKS study

The need for ways to minimize the number of implantable cardioverter‐defibrillator (ICD) shocks is increasing owing to the risk of its adverse effects on life expectancy. Studies have shown that a longer detection time for ventricular tachyarrhythmia reduces the safety of therapies, in terms of syncope and mortality, but not substantially in terms of the success rate. We aimed to evaluate the effects of increased number of intervals to detect (NID) VF on the safety of ICD shock therapy and on the reduction of inappropriate shocks.

Congenital Absence of Left Atrial Appendage Diagnosed by Multimodality Imaging

A 70-years-old male with a history of hypertension and drug resistant paroxysmal atrial fibrillation (AF) presented to our hospital for catheter ablation to his symptomatic AF. He had no prior surgical or percutaneous procedure to close or exclude the left atrial appendage (LAA). A transesophageal echocardiography (TEE) was performed to rule out intra-cardiac thrombus prior to the ablation procedure. Although the TEE imaging at multiple acquisition angles was obtained, the LAA could not be visualized and an absence of the LAA was suspected. An absence of the LAA was confirmed using cardiac computed tomography (CT), which included 3D reconstruction. Additionally, the LAA was not visualized with left atrium (LA) angiography. During the ablation procedure, 3D voltage mapping in LA was created and no low voltage area or abnormal potential was recorded around the usual root location of the LAA. Successful electrical pulmonary vein isolation was achieved with no major complications. After six months of follow-up, the patient remained in sinus rhythm without any antiarrhythmic drugs and showed no related clinical symptoms. He stopped his anticoagulation therapy due to lack of evidence of AF recurrence and an absence of LAA. Multimodality imaging allowed us to identify the congenital absence of LAA.

Leadless Pacemaker and Subcutaneous Implantable Cardioverter Defibrillator Combination in a Hemodialysis Patient

Received March 2, 2018; revised manuscript received April 25, 2018; accepted May 7, 2018; released online June 6, 2018 Time for primary review: 12 days Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo (Y.E., H.H., R.I., S.T., K.N., M.M., M. Nakamura); Division of Cardiovascular Center, Toho University Sakura Medical Center, Sakura (M. Noro); and Division of Cardiology, Odawara Cardiovascular Hospital, Odawara (K.S.), Japan Mailing address: Yoshinari Enomoto, MD, Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, 2-17-6 Ohashi Meguro-ku, Tokyo 153-8515, Japan. E-mail: yenomo1225@oha.toho-u.ac.jp ISSN-1346-9843 All rights are reserved to the Japanese Circulation Society. For permissions, please e-mail: cj@j-circ.or.jp Leadless Pacemaker and Subcutaneous Implantable Cardioverter Defibrillator Combination in a Hemodialysis Patient