Masayuki Ishimura

Estimation of the origin of ventricular outflow tract arrhythmia using synthesized right-sided chest leads

AIMS For successful ablation of ventricular outflow tract arrhythmia, estimation of its origin prior to the procedure can be useful. Morphology and lead placement in the right thoracic area may be useful for this purpose. Electrocardiography using synthesized right-sided chest leads (Syn-V3R, Syn-V4R, and Syn-V5R) is performed using standard leads without any additional leads. This study evaluated the usefulness of synthesized right-sided chest leads in estimating the origin of ventricular outflow tract arrhythmia. METHODS AND RESULTS This retrospective study included 63 patients in whom successful ablation of ventricular outflow tract arrhythmia was performed. Numbers of arrhythmias originating from the left ventricle, the septum of the right ventricle, and the free wall of the right ventricle were 11, 40, and 13, respectively. In one patient, two different left ventricular outflow tract origins were found. Electrocardiographic recordings from right-sided chest leads were divided into three types as follows: those in which an R > S concordance, a transitional zone, or an R < S concordance were detected. In all left arrhythmia cases, R > S concordance was observed. A transitional zone was evident in 34 of 40 cases of right ventricular outflow tract arrhythmia originating in the ventricular septum, and an R < S concordance was observed in 6 of the 40 cases. However, an R < S concordance was found in all cases of right ventricular outflow tract arrhythmia originating in the free wall. CONCLUSION Synthesized right-sided chest lead electrocardiography may be useful for estimating the origin of ventricular outflow tract arrhythmia.

Evaluation of periesophageal nerve injury after pulmonary vein isolation using the 13C-acetate breath test

Pulmonary vein isolation (PVI) has become an important option for treating patients with atrial fibrillation (AF). Periesophageal nerve (PEN) injury after PVI causes pyloric spasms and gastric hypomotility. This study aimed to clarify the impact of PVI on gastric motility and assess the prevalence of gastric hypomotility after PVI.

Identification of Left Atrial Ganglionated Plexi by Dense Epicardial Mapping as Ablation Targets for the Treatment of Concomitant Atrial Fibrillation

Autonomic ganglionated plexi (GPs) play a significant role in the initiation and maintenance of atrial fibrillation (AF). GPs are key targets for a maze procedure. The purpose of this study was to identify the location of the left atrial GPs based on dense epicardial mapping during a maze procedure in patients with concomitant AF.

Unexpected and unmanageable malfunctions of current co-radial pacemaker leads

We read with interest the paper by Reinhart Dorman et al. 1 regarding the high failure rate of 5 Fr Sorin Hepta 4B pacemaker leads with a co-radial structure. Its entity was similar to our experience regarding another co-radial transvenous pacemaker lead available for sale. We experienced six cases of failures with Petite™ 58ERB (OSCOR, Inc.) leads which are co-radial ventricular leads with a multi-wound coil structure like the Hepta™ 4B (Sorin CRM). Between July 2010 and December 2012, 124 patients (67 men and 57 women, age 73.6 ± 10.8) underwent pacemaker implantations at our institution with the Petite™ 58ERB for ventricular pacing through an …

A novel technique for ligation of the cephalic vein reduces hemorrhaging during a two-in-one insertion of dual cardiac device leads

The cutdown technique for the cephalic vein is a common access route for transvenous cardiac device leads (TVLs), and sometimes one cephalic vein can accomodate two TVLs. We examined a novel ligation technique to balance the hemostasis and lead maneuverability for this two-in-one insertion. A total of 22 patients scheduled for cardiac device implantations with two or more leads were enrolled. The ipsilateral cephalic vein was identified for inserting the TVLs with a cutdown. If two TVLs could be introduced into one cephalic vein, hemostasis was established by ligating the venous wall between the TVLs. We measured the amount of hemorrhaging per minute and the operators assessed the lead maneuverability before and after the ligation. We successfully implanted cardiac devices in 15 patients (68%) with this novel method, whereas only one TVL could be introduced via the cephalic vein in 7 patients. As for the successful patients, hemorrhaging from the gap was significantly reduced (5.6 ± 7.3 to 0.41 ± 0.36g/min, p = 0.016) after the novel ligation. The lead maneuverability was well maintained so there was no difficulty placing the leads into the cardiac chambers in all cases. No major complications were observed. In the present study, the novel ligation method provided significant hemostasis as well as a preserved maneuverability. It could be an optional choice for insertion of multiple TVLs.

Shortening of the atrial-His bundle interval during atrial pacing as a predictor of successful ablation for typical atrioventricular nodal re-entrant tachycardia

Aims Shortening of the atrial-His bundle (AH) interval during the sinus rhythm is occasionally observed after slow pathway ablation for atrioventricular nodal re-entrant tachycardia (AVNRT). In addition, high-rate atrial pacing is useful for avoiding atrioventricular block. We hypothesized that shortening of the AH interval during slow pathway ablation under high-rate atrial pacing would lead to successful ablation of typical AVNRT. Methods and results This retrospective study included 37 patients in whom successful ablation of typical AVNRT was performed under atrial pacing. The AH interval was measured immediately before the first radiofrequency (RF) application and immediately after the last RF application, prior to the first induction. Twenty-five of 37 patients achieved procedural success at the first induction (i.e. successful group). No patients developed a prolonged AH interval or atrioventricular block. The AH interval was shortened by an average of 14.6 ± 7.7 and 1.8 ± 1.2 ms in the successful and other patient groups, respectively (P < 0.01). An AH interval decrease of > 10 ms was observed in 23 of 27 (85%) patients in the successful group, whereas all other patients had an AH interval decrease of < 5 ms. Conclusion Shortening of the AH interval during high-rate atrial pacing is a predictor of the successful ablation for typical AVNRT.

Successful intermuscular implantation of subcutaneous implantable cardioverter defibrillator in a Japanese patient with pectus excavatum

The entirely subcutaneous implantable cardioverter‐defibrillator (ICD) system was developed to provide a life‐saving defibrillation therapy that does not affect the heart and vasculature. The subcutaneous ICD is preferred over the transvenous ICD for patients with a history of recurrent infection presenting major life‐threatening rhythms. In this case report, we describe the first successful intermuscular implantation of a completely subcutaneous ICD in a Japanese patient with pectus excavatum. There were no associated complications with the device implantation or lead positioning. Further, the defibrillation threshold testing did not pose any problem with the abnormal anatomy of the patient.