bluuebunny/crossref_metadata_2025 huggingface dataset:
Sluggish Upstroke of Signal‐Averaged QRS Complex. An Arrhythmogenic Sign in Patients with Anteroseptal Myocardial Infarction
Authors: Kanemura Masafumi , Katoh Takao , Tanaka Takashi , Kamei Shin‐ichiro , Kuroki Shin‐ichi , Takano Teruo , Hayakawa Hirokazu
Published: August 2012

Non‐invasive recording of the late potential (LP) by signal‐averaging technique is useful in predicting ventricular tachycardia (VT), especially in patients with myocardial infarction (MI). However, the rate of positive LP is much lower in anterior or anteroseptal MI than inferior MI since the LP is sometimes masked by QRS complex. The purpose of the present study is firstly, to detect local conduction delay in initial portion of QRS complex and secondarily, to evaluate the clinical significance of the initial delay in patients with MI. Eighty patients with MI were analyzed in 4 groups as follows: AS: anteroseptal, n = 18, including 6 VT; A: anterior, n = 22, 7 VT; I: inferior, n = 28, 9 VT; and P: posterior, n = 12, noVT. Twenty non‐MI patients were used as normal controls (N). A signal processor (NEC 7T 18) was used to record signal‐averaged electrocardiograms and each 10 msec integral value of filtered QRS complex from the initial upstroke to the 60 msec point was automatically measured.

The integral values of groups AS and A were lower than those of groups I, P, and N. AS patients with VT showed a lower integral value than AS patients without VT, but no differences were observed between A patients with VT and A patients without VT.

We conclude that there is a much more sluggish upstroke in the signal‐averaged initial QRS complex in anteroseptal MI patients with VT, suggesting that the local conduction delay at the ventricular septum plays an important role in the mechanism of VT in these patients.
Right Bundle Branch Block Like Pattern Recorded in Right Ventricular Endocardial Pacing
Authors: Ohnuki Masahiro , Miyataka Kazuhiko , Nakamura Takehiko , Ohnishi Yoshinobu , Kohnoike Yoshizumi , Tsujimoto Masayuki , Shiroyama Reirou
Published: August 2012

Right bundle branch block (RBBB) pattern recorded during right ventricular (RV) endocardial pacing should be given special attention in terms of safe RV pacing or lead malposition, e.g. left ventricular pacing or coronary venous pacing, even for patients with no symptoms. Paced electrocardiograms from 47 consecutive patients with a pacemaker implanted were studied. Four patients (8.5%) were found to have RBBB pattern recorded in precordial V1 and V2 leads in the usual 4th intercostal space. All of these patients showed left bundle branch block (LBBB) pattern in limb leads. When precordial V1 and V2 leads in the 5th space were recorded, RBBB pattern changed to LBBB pattern. Biplane chest X‐ray film and echocardiogram, especially 3D echo mode, confirmed that tips of pacing leads of the 4 patients were located in the distal RV septum or the apex. RBBB pattern observed during RV endocardial pacing usually represents safe RV endocardial pacing rather than perforation or malposition of pacing leads.
Ventricular Arrhythmias in the Elderly
Authors: Minor Stephen , Akiyama Toshio
Published: August 2012

The management of malignant ventricular arrhythmias will become gradually more important as life expectancy continues to increase. The incidence of sudden cardiac death and overall cardiac mortality is more pronounced in the elderly mainly as a reflection of the higher prevalence of ischemic heart disease. With the exception of beta‐blocker therapy, antiarrhythmic drug therapy has not proven to be effective in the prevention of sudden cardiac death. Implantable cardioverter‐defibrillator therapy has been shown to reduce both overall mortality and arrhythmic death when following current guidelines for implantation and appears to be applicable to any age group when sensible patient selection is implemented. The greater efficacy of this therapy relative to antiarrhythmic therapies supports its expanded use in the elderly population. Such therapy has a similar cost‐effectiveness to other accepted interventions and does not appear to be associated with reduced quality of life or age‐specific complications. The clinical approach to elderly patients at risk of sudden death from ventricular arrhythmias will continue to evolve as new technologies are developed, but the future of ventricular arrhythmia treatment in the elderly will likely emphasize an increasing utilization of both implantable cardioverter‐defibrillator and beta‐blocker therapies.
Conduction Velocity around the Tricuspid Valve Annulus during Typical Atrial Flutter by Electro‐anatomic Mapping System
Authors: Sawa Akira , Shimizu Akihiko , Ueyama Takeshi , Yoshiga Yasuhiro , Suzuki Shinsuke , Sugi Naoki , Matsuaki Masunori
Published: August 2012

Objective: Conduction velocity around the tricuspid valve annulus (TA. during typical atrial flutter (AFL. has been shown to be slowest in the inferior vena cava‐tricuspid valve (IVC‐TV. isthmus when compared to the septal or free wall segments of the TA. We investigated the conduction velocity in IVC‐TV isthmus, dividing into three areas. Methods: We evaluated conduction velocity around the TA during typical AFL in 10 patients, using an electro‐anatomic mapping system (CARTO™). Conduction velocity was calculated at six areas around the TA including the septal wall, upper wall, lateral wall, and isthmus wall, which was further divided into three areas, lateral isthmus, mid isthmus, and septal isthmus. Results: Conduction velocity around the TA during typical AFL was slowest in the IVC‐TV isthmus. Further, conduction velocities (m/sec. in the mid isthmus (0.44±0.17. and septal isthmus (0.45±0.22. were significantly slower (p < 0.05. than that in the upper wall (0.67±0.26). Conclusions: The relatively slower conduction in IVC‐TV isthmus resulted from the relatively slower conduction in the area from mid to septal isthmus.
Changes of Sympathetic Activity in Patient with Chronic Atrial Fibrillation and Severe Congestive Heart Failure Treated with Biventricular Pacing
Authors: Matsushita Kohei , Ishikawa Toshiyuki , Sumita Shinichi , Kobayashi Tsukasa , Ogawa Hideyuki , Inoue Noriko , Matsumoto Katsumi , Taima Minoru , Nakazawa Ichirou , Sugano Teruyasu , Ishigami Tomoaki , Uchino Kazuaki , Kimura Kazuo , Umemura Satoshi
Published: August 2012

The patient was a 64‐year‐old man with chronic atrial fibrillation with bradycardia. Left ventricular ejection fraction was 34%. He was treated with biventricular pacing. Heart failure improved from NYHA class III to II. Sympathetic nerve activity (SNA. was recorded during 6 minutes of biventricular (BV), right ventricular apical (RVA. and left ventricular (LV. pacing. SNA was significantly lower during biventricular pacing (49.5 ± 4.0/min. compared with RVA (58.8 ±6:9/min, p = 0.016. and LV (63.3 ± 4.3/min, p = 0.002. pacing. BV pacing improves hemodynamics and decreases SNA compared with RVA or LV pacing.
Slow‐fast Form of Atrioventricular Nodal Reentrant Tachycardia with Unusual Retrograde Activation in the Right Atrium —Possible Conduction Disturbance across the Tendon of Todaro Related to the Genesis of Positive Component of Biphasic Retrograde P Wave—
Authors: Ishibashi Kazuya , Hirasaki Satoshi , Matsuo Ryohei , Tsukamoto Masaki , Kawata Koichi , Suzuki Fumio
Published: August 2012

We report a rare case of slow‐fast form of atrioventricular nodal reentrant tachycardia with delayed activation in the low septal right atrium (His bundle area). During supraventricular tachycardia (SVT), electrocardiogram showed “pseudo‐positive P waves” in II, III, and aVF leads. SVT was induced by atrial extrastimulus with marked AH prolongation (i.e., jump phenomenon). Ventricular pacing showed a decremental retrograde conduction without jump phenomenon. Double atrial potentials were observed in the His bundle area during SVT and during ventricular pacing. The first electrogram of these split potentials, which was the earliest activation during SVT and during ventricular pacing, showed a dull and small deflection, whereas the second electrogram was sharp and clear. The interval of these discrete potentials was 70 msec during SVT. After a standard slow pathway ablation, SVT could never be induced by any programmed stimuli. It was concluded that in this case, the conduction disturbance across the tendon of Todaro was likely to cause the delayed atrial activation in the His bundle area, which created the pseudo‐positive (biphasic. retrograde P wave.
Idiopathic Premature Ventricular Contraction Originating from Left Epicardial Outflow Tract —Effects of Antiarrhythmic Drugs, Autonomic Provocation and Radiofrequency Catheter Ablation—
Authors: Miyaji Kotaro , Nishizaki Mitsuhiro , Ogawa Toru , Sugawara Shinji , Fujii Hiroyuki , Ashikaga Takashi , Yamawake Noriyoshi , Sakurada Harumizu , Hiraoka Masayasu
Published: August 2012

We present a patient with frequent episodes of palpitation who had idiopathic premature ventricular contraction (PVC. with QRS morphology exhibiting a right bundle branch block pattern with an inferior axis. Neither administration of procainamide, propranolol, lidocaine or verapamil could inhibit PVC, whereas administration of adenosine triphosphate, carotid sinus massage and Valsalva maneuver could effectively eliminate PVC. The earliest activation preceding the QRS complex by 25 msec at occurrence of the PVC was recorded at the distal site of the coronary sinus and within the left coronary cusp. Pacemapping in the supravalvular site during sinus rhythm produced a QRS complex more similar to PVC than that produced in the infravalvular site of the left ventricular outflow tract (LVOT). Radiofrequency catheter ablation was performed at the supravalvular site close to the epicardial LVOT, which resulted in successful elimination of PVCs.
Coronary Sinus Morphology in Patients with Posteroseptal Atrioventricular Accessory Pathways
Authors: Takenaka Sou , Nakano Yukiko , Hirao Hidekazu , Teragawa Hiroki , Shingu Tetsuji , Chayama Kazuaki
Published: August 2012

Background: There have been numerous reports about coronary sinus (CS) anomalies related to posteroseptal accessory pathways (APs). The purpose of this study was to explore the diameter and morphology of CS in patients with posteroseptal APs.

Methods: We performed direct CS angiography in 105 patients with 22 posteroseptal APs and 83 APs in other regions, and 25 control subjects. We compared the diameter of the CS ostium in all subjects, and assessed the correlation of the local activation time in the patients with posteroseptal APs.

Results: The proximal size (diameter) of the CS in the patients with posteroseptal APs (13:6 ± 1:1 mm) was larger than that in the patients with other types of APs (10:2 ± 1:8 mm [p < 0:001]) and that in the control subjects (9:6 ± 1:5 mm [p < 0:001]). Dilatation of the CS in the patients with posteroseptal APs extended up to 20 mm inside the CS. In 15 (68%) of the patients with posteroseptal APs, the proximal site of the CS demonstrated a windsock appearance.

Conclusions: We concluded that the larger size and the wind cone appearance of proximal CS were unique structural characteristics in most patients with posteroseptal APs.
Effects of Music Therapy on Heart Rate Variability in Elderly Patients with Cerebral Vascular Disease and Dementia
Authors: Kurita Akira , Takase Bonpei , Okada Kaoru , Horiguchi Yuji , Abe Shinya , Kusama Yoshiki , Atarasi Hirotsugu
Published: August 2012

Objective: In Japan, the number of elderly people with cerebral vascular disease (CVD) and dementia is increasing, resulting in increased expenditures to treat such patients. Reports indicate that music therapy can reduce anxiety in patients with myocardial infarction. However, it is unclear whether music therapy can have beneficial effects on very elderly patients with CVD and dementia, as these conditions may influence cardiac autonomic nerve functions. Therefore, we investigated the effects of music therapy on the autonomic nerve system in elderly patients with CVD and dementia, using an ambulatory Holter ECG system.

Methods and Results: The subjects were 12 elderly patients aged ≥75 years, hospitalized for CVD and dementia. We measured their heart rate variability (HRV) indices of power domain and frequency domain analysis. The mean RR significantly increased during music therapy, from 842 ± 174 to 1022 ± 284 (p < 0:05), and decreased to 820 ± 284 ms after music therapy. HF significantly increased during music therapy, from 59 ± 41 to 127 ± 97 ms2 (p < 0:01), and decreased to 77 ± 60 ms2 after music therapy. LF/HF decreased from 2:2 ± 1:3 to 1:7 ± 1:3 during music therapy (p < 0:10), and increased to 2:0 ± 1:1 after music therapy. Time domain (HRV) indices increased during music therapy and decreased after music therapy: RMSSD increased from 19:4 ± 11 to 39:8 ± 17 ms, and then decreased to 19:4 ± 8:3 ms; pNN50 increased from 3:6 ± 3:2 to 16:1 ± 13:3%(p < 0:01), and then decreased to 4:3 ± 4:2%.

Conclusions: Music therapy enhanced parasympathetic activity and decreased sympathetic activity in elderly patients with CVD and dementia. These findings suggest that music therapy is useful for alleviating anxiety, increasing comfort and facilitating relaxation for elderly patients with CVD and dementia.
The Rho/Rho‐kinase Systems Are Involved in Rapid Pacing‐induced Changes of Atrial Refractory Period in a Canine Model
Authors: Furusho Hiroshi , Sakagami Satoru , Takamura Masayuki , Kitano Katsunori , Abe Tsuyoshi , Hirazawa Motoaki , Usui Soichiro , Okajima Masaki , Saeki Takahiro , Maruyama Michiro , Kaneko Shuichi , Takata Sigeo
Published: August 2012

Introduction: The Rho/Rho‐kinase pathway has been related to various physiological responses of the cardiovascular system. Previous reports have suggested a significant effect of Rho signals on the electrophysiological characteristics of the heart. We hypothesized that the Rho/Rho‐kinase system would contribute to the rapid pacing‐related change of atrial effective refractory period (AERP).

Methods and Results: In 17 dogs, AERP was measured at the right atrial appendage (RAA) and posterior left atrium (LA) before, during, and after 6‐hours rapid atrial pacing at 500 bpm. Saline control (n = 5), verapamil (n = 5), or fasudil (n = 7) were infused throughout the protocol. The shortening of AERP after rapid pacing was abrogated by the administration of verapamil, as reported in previous studies. Furthermore, fasudil (Rho/Rho‐kinase inhibitor) influenced the change of AERP in a manner similar to the infusion of verapamil throughout the experiments.

Conclusions: Since the AERP was attenuated by fasudil, rapid pacing‐related atrial electrophysiological changes might involve the Rho/Rho‐kinase pathway.
Use of Catheter Ablation in the Treatment of Ventricular Tachycardia Triggered by Premature Ventricular Contraction
Authors: Kato Isao , Iwa Toru , Suzuki Yasushi , Ito Takayuki
Published: August 2012

A 50‐year‐old man who had suffered from old myocardial infarction presented with an episode of syncope. DC shock was required for the interruption of frequent pleomorphic ventricular tachycardia (VT). Although the treatment for heart failure decreased the frequency of VT attacks, hemodynamically unstable VT occurred several times. A 12‐lead Holter electrocardiogram was used to determine the triggering premature ventricular contraction (PVC) and catheter ablation was performed by targeting this PVC. The site of origin of the triggering PVC was considered to be located between damaged cardiac muscle and intact Purkinje's fiber. No episode of PVC and VT was observed after a few days of ablation. An implantable cardioverter defibrillator was implanted but VT did not recur for more than 20 months.
Ablation of Idiopathic Ventricular Tachycardia with a Left Bundle‐Branch Block Morphology Originating from the Pulmonary Artery
Authors: Ogi Hiroshi , Nakano Yukiko , Oda Noboru , Miyoshi Miwa , Chayama Kazuaki , Ishibashi Ken , Hirai Yuko , Okimoto Tomokazu
Published: August 2012

We successfully performed radiofrequency catheter ablation (RFCA) in 2 cases involving patients with idiopathic ventricular tachycardias (VTs) and premature ventricular contractions (PVCs) originating from the pulmonary artery (PA). The QRS morphology of the VTs and PVCs in the two cases exhibited a left bundle‐branch block (LBBB) morphology with an inferior axis. Activation and pace mappings were performed in the right ventricular outflow tract (RVOT) and above the pulmonary valve to determine the origin of the VTs and PVCs. In both cases, the earliest ventricular activation was recorded in the PA above the pulmonary valve. Applications of radiofrequency current at those sites in the PA resulted in the elimination and noninducibility of the VT and PVC. During the follow‐up, the VT or PVC did not recur without any antiarrhythmic drug administration.
Sinus Bradycardia with Heart Rate Lower than the Programmed Lower Rate Limit in a Patient with an Implanted VDD Pacemaker
Authors: Suzuki Satoru , Hashizume Kenichi , Kanki Hideaki , Harada Shigeru
Published: August 2012

The authors present a case report of a patient with an implanted VDD pacemaker whose postoperative ECG revealed sinus bradycardia, showing the heart rate remarkably lower than the programmed lower rate limit. Upon assessing some pacemaker manufacturers' mechanisms to set the lower rate limit in VDD mode, it was found that they can be classified into four types. The mechanisms are based on keeping atrioventricular (AV) synchronous pacing in VDD mode or maintaining the lower rate limit in VVI mode. AV synchronous pacing results in producing an actual heart rate which is lower than the programmed lower rate limit. The classification also depends on whether the pacemakers are operating on either atrial‐based or ventricular‐based lower rate timing. Therefore, the actual heart rate can be lower than the programmed lower rate limit, depending on the VDD pacemaker model.
Diagnosis and Treatment of Syncope
Authors: Kobayashi Youichi
Published: August 2012

Accurate diagnosis of syncope is essential because it ranges from cardiac syncope with a very poor prognosis to neurally‐mediated syncope (NMS) with a relatively favorable prognosis. Diagnosis of syncope, however, is difficult in many patients even by HUT, so a new loading method for HUT or implanted Holter ECG monitoring will be required in the future. The prognosis of NMS itself may be favorable, but it may cause the aggravation of complications.
Long‐Term Follow‐Up of Endocardial Pacing Leads Implanted with Extrathoracic Subclavian Venous Approach
Authors: Ohnuki Masahiro , Miyataka Kazuhiko , Nakamura Takehiko , Ohnishi Yoshinobu , Kohnoike Yoshizumi , Tsujimoto Masayuki , Shirayama Reirou
Published: August 2012

The extrathoracic subclavian venous approach is a new approach with the aim to exclude the disadvantages of the conventional subclavian venous approach that carries a risk of pneumothorax and may result in lead damage. We investigated long‐term survival of the leads implanted by this new approach between May 1995 and June 2005. A total of 482 leads implanted in 309 patients were analyzed. In cases of patient death, meeting criteria for lead failure or difficulty of continuing follow‐up for other reasons, the follow‐up was terminated at that time. Therefore, the follow‐up was complete for 358 leads (74.3%) and the mean followup time was 55.0 ± 32.1 months (range 1–122 months). The overall lead survival rate was 100% at 5 years and 98.3% at 7 years. This finding suggested that this approach might reduce the incidence of lead failure.
Common Trunk of the Inferior Pulmonary Veins in a Patient with Paroxysmal Atrial Fibrillation
Authors: Miyanaga Satoru , Date Taro , Yamane Teiichi , Inada Keiichi , Shibayama Kenri , Matsuo Seiichiro , Miyazaki Hidekazu , Kanzaki Yasuko , Sugimoto Ken‐ichi , Mochizuki Seibu
Published: August 2012

Herein we report a case of a patient presenting with paroxysmal atrial fibrillation (PAF) in whom the pulmonary veins (PVs) had a common inferior trunk and PV isolation at the common inferior trunk was successfully performed to prevent recurrence of PAR A 58‐year‐old man with drug‐resistant PAF was referred to undergo curative treatment at our institution. A three‐dimensional image of the PVs re‐constructed by contrast‐enhanced multi‐detector computed tomography before the operation revealed a common inferior trunk of the PVs (24mm diameter). Segmental ostial PV isolation with the guidance of a circular mapping catheter was performed for both superior PVs and the common inferior PV trunk. All three PV ostia were successfully isolated from the LA, and the patient has been free from PAF thereafter for 18 months. Preprocedural multi‐detector computed tomography or magnetic resonance imaging to evaluate the anatomy of PVs (the number, size, and shape) is thus considered to be useful for performing safe and smooth catheter ablation in patients with PAR
Detecting Restenosis after Percutaneous Coronary Intervention Using Exercise‐Stress Electrocardiogram Findings Including QT Dispersion
Authors: Takase Bonpei , Kusama Yoshiki , Nishizaki Mitsuhiro , Koide Yasushi , Li Syoudai , Kawakubo Kiyoshi , Saito Satoshi , Tanabe Teruhisa , Kodama Kazuhisa , Kishida Hiroshi
Published: August 2012

Despite the advent of drug‐eluting stents in Japan, bare metal stents or conventional balloon angioplasty are still indicated in some patients needing elective percutaneous coronary intervention (PCI) and in patients with acute coronary syndrome if these patients develop side effects while taking ticlopidine. In such patients, restenosis is a problem that is difficult to diagnose. To investigate the comparative diagnostic accuracy of the exercise‐stress electrocardiogram (ECG) for detecting restenosis after PCI, we measured conventional ST‐segment changes and QT dispersion during exercise‐stress testing in 173 patients with elective PCI (63 ± 10 years old). Exercise‐stress testing was performed 3 to 6 months after successful PCI, and restenosis was confirmed by follow‐up coronary angiogram. There were 98 patients with a prior myocardial infarction (prior MI group and 76 patients with no prior myocardial infarction (no MI group). Restenosis was found in 45 patients (46% in the prior MI group and 26 patients (34%) in the no MI group. Conventional ST‐segment depression (>1:0 mm, J 60 ms indicating exercise‐induced myocardial ischemia had a sensitivity of around 50% and a specificity of around 70% for diagnosing restenosis in both groups. In the prior MI group, QT dispersion was increased by exercise‐stress testing in both patients with and without restenosis, whereas in the no MI group, QT dispersion increased only in patients with restenosis. With a cut‐off value of >60 ms, QT dispersion had a sensitivity of 54% and a specificity of 68% for detecting restenosis in the no MI group; these values were comparable to those seen with conventional ST‐segment changes. In conclusion, due to its low cost, exercise‐stress ECG remains useful for diagnosing restenosis following PCI if the clinician understands its limited sensitivity and specificity. The presence of a prior MI must be considered when QT dispersion during exercise‐stress testing is used for detecting restenosis.
A Combined Therapy Using Encircling Pulmonary Vein Isolation and Supplemental Segmental Ostial Isolation for the Treatment of Atrial Fibrillation
Authors: Tsuboi Naoya , Yoshida Yukihiko , Masaya Matsumoto , Yamamoto Takashi , Aoyama Yutaka , Ishikawa Makoto , Ogura Yasuhiro , Suzuki Hirohiko , Yamashita Kentaro , Muramatsu Takashi , Nanasato Mamoru , Hirayama Haruo , Itoh Teruo , Okada Taro , Yamada Takumi , Murakami Yoshimasa , Kondo Takahisa , Inden Yasuya , Murohara Toyoaki , Kodama Itsuo , Toyama Junji
Published: August 2012

Electrical isolation of the pulmonary veins (PV) has become a curative treatment for patients with atrial fibrillation (AF). Recently, there have been many reports that circumferential PV isolation (CPI) on the atrial side has a better outcome than segmental ostial PV isolation (SOPI). However, reports on the combination of CPI using electoroanatomic mapping and SOPI using a circular mapping catheter have been few. The aim of the present study was to investigate the efficacy and safety of a combined therapy using CPI and supplemental SOPI for the treatment of AF. We performed CPI in 120 patients with drugrefractory AF. In 27 of those patients CPI resulted in a disconnection between the left atrium (LA) and PVs. In the remaining patients, supplemental SOPI completed the LA‐PV disconnection. After an average follow‐up period of 10.4 months, 81.7%, 90.5% and 71.4% of the patients with paroxysmal, persistent and chronic AF, respectively, have been free of AF. In 14.1% of the patients with paroxysmal AF, a greatly reduced frequency and/or duration of the episodes of AF were observed after the ablation. No fatal complications were encountered. The present results suggest that the combination of CPI and supplemental SOPI is efficient and safe for the treatment of AF.
Arrangement of the Autonomic Nerves Around the Pulmonary Vein‐Left Atrial Junctions —Histologic and Immunohistochemical Analyses—
Authors: Matsuyama Taka‐aki , Inoue Shin , Kobayashi Youichi , Makino Mutsuki , Sakai Tetsuo , Saito Tsukasa , Asano Taku , Tanno Kaoru , Katagiri Takashi , Ota Hidekazu
Published: August 2012

Introduction: Imbalanced autonomic activity in the area of the pulmonary veins (PVs) can result in spontaneous atrial fibrillation (AF). Histologic characteristics of the PV sleeve musculature and associated autonomic nerve are not fully understood. We investigated the arrangement of autonomic nerve fibers around PV‐left atrium (LA) junctional musculature.

Methods: Thirteen autopsied adult hearts (9 men and 4 women; mean age at death, 66.2 years were studied. The atria were removed from each heart, along with all PV stalks, and cut longitudinally to each PV myocardial sleeve. After treatment with azan‐Mallory stain and immunohistochemical staining for S‐100 and tyrosine hydroxylase (TH), autonomic nerve distribution was assessed by counting the numbers of TH‐positive (adrenergic and ‐negative (non‐adrenergic) fibers within S‐100‐positive fibers (>50 mm in diameter) in the anterior, posterior, and septal junctions.

Results: TH‐positive adrenergic fibers, consisting of sympathetic nerves, were most predominant in the anterior and septal junctions. In the anterior junction, these fibers were packed tightly among myocardial sleeve fascicles. In the posterior junction, the numbers of adrenergic and non‐adrenergic fibers were fewer. In the septal junction, the number of THnegative non‐adrenergic fibers (predominantly parasympathetic nerves) was greater, concomitant diffuse ganglionic nodule distribution in the interatrial fat pad.

Conclusions: In each PV‐LA junction, autonomic nerves were localized on the anterior and septal walls. Heterogeneous distribution of TH‐positive and TH‐negative fibers and ganglion nodules around each PV opening appears to represent the major histologic characteristic in these areas.
Detection of Pacemaker Lead Infection by Fluorodeoxyglucose Positron Emission Tomography
Authors: Miura Takashi , Kinoshita Osamu , Horigome Mitsuaki , Kasai Hiroki , Aizawa Kazunori , Yoshioka Tohru , Tomita Takeshi , Kumazaki Setsuo , Tsutsui Hiroshi , Koyama Jun , Yazaki Yoshikazu , Ikeda Uichi
Published: August 2012

An 80‐year‐old man was implanted with a DDD pacemaker to treat his sick sinus syndrome in 1990. Eleven years later, he had a pocket infection and cutaneous inflammation. Blood cultures were negative, and 67Ga scintigraphy revealed uptake in the left subclavian region. However, intense abnormal fluorodeoxyglucose (FDG) uptake along the pacemaker leads was detected with positron emission tomography (PET). Thoracotomy was performed, vegetations were removed from the right atrial wall and the tricuspid leaflet, encapsulating fibrous tissue was incised, and the lead was removed from the right ventricle.
QT Interval Revisited —Not Just the Matter of “Interval,” but “Dynamics, Variability and Morphology” Matter!—
Authors: Saikawa Tetsunori , Nakagawa Mikiko , Takahashi Naohiko
Published: August 2012

Recently, the effects of QT interval prolongation have received more attention among clinicians, industry, and official regulatory agencies. Some have advocated the total elimination or discontinuing development of drugs which prolong the QT interval. In this review, we will give a brief overview of the pathophysiology and the dynamic variability and morphology of the QT interval. From the view point of arrhythmogenesis, QT interval prolongation with increased heterogeneity of ventricular repolarization is critical. The problem is how to detect such an abnormal repolarization. To detect heterogeneity, a new index should be developed and validated, and it must incorporate QT variability and morphology of the T wave. The heart rate correction of the QT interval is also an important issue, and disclosing conflict‐corrected QT intervals depend on the formulae used.

Not just QT interval prolongation is important; what also matters is the heterogeneity of ventricular repolarization.
Efficacy and Safety of Catheter Ablation for Persistent or Permanent Atrial Fibrillation
Authors: Muraoka Soichi , Mitsutake Chiharu , Takashima Hideo , Nakashima Hideko , Yasuda Tomoo , Matsumoto Naomichi , Kumagai Koichiro , Saku Keijiro
Published: August 2012

Introduction: Radiofrequency catheter ablation (RFCA) that targets pulmonary veins (PV) is an established treatment for paroxysmal atrial fibrillation (PAF). Recent studies have demonstrated that RFCA can eliminate PAF in over 90% of patients. However, the effectiveness for persistent or permanent AF has not been clarified.

Methods and Results: 27 patients (29%) had persistent or permanent AF. RFCA including PV antrum isolation (PVAI) was performed using a circular mapping catheter in the patients with persistent or permanent AF. Four patients (15%) underwent only PVAI. Thirteen patients (48%) underwent PVAI and left atrium roof and/or mitral isthmus linear ablation. Ten patients (37%) underwent PVAI and RFCA to an area with complex fractionated atrial electrograms. All patients were observed for over a year. After repeat ablation at mean followup of 16 ± 5 months, 23 patients (85%) had normal sinus rhythm and were free of symptomatic AF or atrial flutter. Three patients required antiarrhythmic drugs to maintain sinus rhythm during follow‐up period. One patient had a transient phrenic nerve injury. Two patients were documented with sustained atrial tachycardia (AT). Mapping in 2 patients showed a macro reentry AT due to gaps in the ablation lines and further ablation was needed. No other complications including PV stenosis occurred.

Conclusions: The present study demonstrated that RFCA is an effective and feasible treatment for persistent or permanent AF.
Manifestation of ST‐Segment Elevation in Right Precordial Leads during Ischemia at a Right Ventricular Outflow Tract Area in a Patient with Brugada Syndrome
Authors: Takahashi Naohiko , Shinohara Tetsuji , Tsuchiya Takeshi , Torigoe Yasuko , Nakagawa Mikiko , Hara Masahide , Saikawa Tetsunori , Yoshimatsu Hironobu
Published: August 2012

A 35‐year‐old man experienced chest pain and a subsequent syncope attack at during the night. Ventricular fibrillation (VF) was documented, which was successfully defibrillated. The ST‐segment of his 12‐lead electrocardiogram (ECG) showed day‐by‐day variation, sometimes showing spontaneous coved‐type elevation in V1 and V2. He was diagnosed as having Brugada syndrome, and an implantable cardioverter defibrillator was implanted. A coronary angiography was performed. During the procedure, the catheter was selectively inserted to the right ventricular (RV) branch of the right coronary artery (RCA) whereupon the ST‐segment in V1 and V2 elevated rapidly, manifesting a coved‐type Brugada ECG. The main RCA angiogram revealed the conus branch running to the RV outflow tract area, indicating that the ST‐segment elevation was due to ischemia of the RV outflow tract area by transient occlusion of conus branch. The findings indicate that some patients with Brugada syndrome are specifically sensitive to ischemia in the RV outflow tract area, leading to manifestation of the ST‐segment elevation in precordial ECG leads.
The Effects of Nicorandil and Nifekalant, Which Were Injected into the Pericardial Space, for Transmural Dispersion of Repolarization in the Pig
Authors: Ito Hiroyuki , Asano Taku , Kobayashi Youichi , Onuki Tatsuya , Miyoshi Fumito , Matsuyama Taka‐aki , Minoura Yoshino , Watanabe Norikazu , Kawamura Mitsuharu , Tanno Kaoru , Katagiri Takashi
Published: August 2012

Introduction: Some studies have reported that transmural dispersion of repolarization (TDR) is involved in the onset of ventricular arrhythmia. We investigated the effects of nicorandil (NIC) and nifekalant (NIF) injected into the pericardial space, on TDR and T waves in the pig. Methods and Results: We injected NIC 4 or 8 mg and NIF 50 or 100 mg at intervals into the pericardial space for eleven pigs. The effects of these drugs were investigated on the effective refractory period (ERP) between the endocardial and epicardial myocardial cells, as well as on QT time, QT peak‐end (QTcpe) as an index of TDR, and T waveforms, respectively. QTcpe increased from 91 ± 21 to 116 ± 19 msec, 2.8 min after injection of NIC (p < 0.01), although corrected QT (QTc) interval did not changed. But 5.5 min after injection, QTc decreased while QTcpe recovered. T wave amplitude significantly increased, and epicardium ERP decreased. When NIF was injected, TDR decreased from 55 ± 10 msec to 44 ± 8 msec (p < 0.01) although QTc did not change. In a later phase, QTc increased (p < 0.01) and QTcpe recovered. T wave amplitude rapidly decreased and became negative. Conclusion: Injected into the pericardial space, NIC and NIF brought about certain changes in ERP, QT and T waveform. Furthermore, NIC increased TDR while NIF decreased TDR.
Atrioventricular Pacemaker Lead Reversal
Authors: Aktas Mehmet K , Shah Abrar H , Akiyama Toshio
Published: August 2012

During cardiac surgery temporary epicardial atrial and ventricular leads are placed in case cardiac pacing is required postoperatively. We present the first reported series of patients with reversal of atrioventricular electrodes in the temporary pacemaker without any consequent deleterious hemodynamic effect. We review the electrocardiographic findings and discuss the findings that lead to the discovery of atrioventricular lead reversal.
Catheter Ablation of Atrial Fibrillation
Authors: Ching Chi Keong , Patel Dimpi , Natale Andrea
Published: August 2012

Atrial fibrillation is the most common arrhythmia encountered in clinical practice and can result in significant morbidity and mortality. Catheter ablation has become a feasible therapeutic option for the management of this complex and challenging arrhythmia. In this article, we have discussed the mechanism of atrial fibrillation, different imaging modalities used for atrial fibrillation ablation, different ablation strategies targeting non‐pulmonary veins, complications associated with atrial fibrillation ablation and its management, alternative energy sources for ablation and new antiarrhythmic drugs.
Pharmacological Therapy for Fibrillations
Authors: Fujiki Akira
Published: August 2012

Human beings suffer from two different kinds of fibrillations: one is atrial fibrillation (AF) and the other is ventricular fibrillation (VF). AF is the most common sustained arrhythmia and VF is the most serious. Pharmacological cardioversion with conventional class I antiarrhythmic drugs is usually little help in terminating long‐lasting AF. However, bepridil, a multi‐channel blocker, alone or in combination with aprindine restored the sinus rhythm in about 70% of patients. The average time to conversion was one month, and cardioversion was associated with a significant increase in fibrillation cycle length. After cardioversion, atrial contraction recovered within one week, and sinus rhythm was maintained better than after conventional electrical cardioversion. Pharmacological cardioversion of long‐lasting AF with bepridil could become a new therapeutic option targeting remodeled atria. Patients with idiopathic VF have a characteristic J wave and ST elevation along with a lower QT‐RR slope and short QT interval at slower heart rates. Although an implantable cardioverter defibrillator (ICD) is the most reliable therapy for idiopathic VF, both bepridil and disopyramide normalized repolarization dynamics (slope of the QT‐RR relationship) and reduced the frequency of spontaneous VF episodes and ICD shocks. Pharmacological therapy for cardioversion of persistent AF and prevention of idiopathic VF may play a key role in improving not only quantity but also quality of life.
Transient T wave Changes Concerning Arrhythmia
Authors: Tasaki Hirofumi , Matsuo Kiyotaka , Komiya Norihiro , Seto Shinji , Yano Katsusuke
Published: August 2012

T‐wave changes are thought to be associated with the repolarization phase of myocardial action potential. Although it has been known that persistent T‐wave change is associated with the heart disease or the prognosis, the sensitivity and the specificity are not necessarily satisfactory for clinical therapeutic strategy. Recent basic studies have shown that, in some kinds of pathological states, transient repolarization changes of myocardial action potential were associated with life‐threatening arrhythmia. Also clinical studies are being conducted to elucidate the clinical implication of transient T‐wave changes on electrocardiography (ECG) in such an arrhythmia. Transient repolarization or T‐wave change is thought to occur because of environmental or neurohumoral factors, circadian variation, stretching of myocardium or other triggers in daily life, resulting in fatal arrhythmia. Such fatal arrhythmias are thought to occur under restricted conditions even in the patients with serious heart disease. It is important to clarify and utilize the transient T‐wave change directly associated with the fatal arrhythmia on a clinical basis. In this article, we first assess the mechanisms of transient repolarization or T‐wave changes on ECG concerning fatal arrhythmia, and afterwards refer to possible attempts at clinical evaluation and application.
Efficacy and Safety of Intravenous Amiodarone Infusion in Japanese Patients with Hemodynamically Compromised Ventricular Tachycardia or Ventricular Fibrillation
Authors: Katoh Takao , Ogawa Satoshi , Yamaguchi Iwao , Kasanuki Hiroshi , Hayakawa Hirokazu
Published: August 2012

Introduction: Amiodarone infusion has been recommended for life‐threatening ventricular arrhythmias. However its effectiveness in Japanese patients has not yet been determined.

Methods: This was an uncontrolled, open‐label trial involving patients with hemodynamically unstable ventricular tachycardia (VT) or ventricular fibrillation (VF). Intravenous amiodarone was delivered as a 125 mg bolus followed by infusion of 50 mg/h for 6 hours, then 25 mg/h for 42 hours. The primary endpoint for efficacy was the proportion of patients free from hemodynamically unstable VT/VF at 48‐hour. Secondary endpoints included: event frequency; proportion of patients event‐free, treatment outcome, and safety.

Results: Forty‐seven patients were enrolled. Forty‐one patients were evaluated for efficacy and safety parameters were assessed for all 47 patients. The proportion of patients free from hemodynamically unstable VT/VF was 53.9%; the proportion of patients free from hemodynamically unstable VT/VF relapse or whose treatment was discontinued was 48.8%. Eight patients died; all deaths were judged, by the investigator, as being unrelated to amiodarone. No cases of torsades de pointes were reported. Mild abnormal thyroid function was noted in one patient. No cases of interstitial lung disease or pulmonary fibrosis were observed.

Conclusion: Amiodarone infusion provides a useful tool in preventing acute relapse of lifethreatening ventricular arrhythmias in Japanese patients.
Effect of Lateral Body Position on Heart Rate Variability in Patients with Sleep Apnea Syndrome
Authors: Urabe Takako , Takase Bonpei , Tomiyama Yumi , Maeda Yumiko , Ishikawa Yoshiko , Hattori Hidemi , Uehata Akimi , Ishihara Masayuki
Published: August 2012

Sleep apnea syndrome (SAS) can exacerbate cardiovascular disease by augmenting activity of the sympathetic nervous system. One method of treating SAS is via modulation of body posture. Therefore, the goal of the present study was to investigate whether assuming the lateral position during sleep can influence autonomic nervous system activity, as assessed by measurement of heart rate variability (HRV). Six patients with coronary artery disease (CAD) complicated by SAS underwent serial measurements of HRV and arterial blood oxygen saturation (SPO2) during sleep. Online analyses for HRV was performed using five consecutive RR intervals from electrocardiography using the modified Maximum Entropy Method. Low frequency spectra (LF, 0.04–0.15 Hz), high frequency spectra (HF, 0.15–0.40 Hz) and the ratio of low and high frequency spectra (LF/HF ratio) were continuously calculated. HRV and SPO2 measurements were performed after 30 min of sleep in different sleeping positions (supine vs. lateral) with or without supplementary oxygen administration by nasal cannula. The LF and LF/HF ratio were significantly smaller in the lateral position with and without oxygen when compared with the supine position with or without oxygen (LF: Supine to Lateral position, from 673 ± 643 ms2/Hz to 201 ± 221 ms2/Hz, P < 0.05; Supine to Lateral position with supplementary oxygen, from 617 ± 511 ms2/Hz to 288 ± 389 ms2/Hz, P < 0.05; LF/HF ratio: Supine to Lateral position, from 9.4 ± 643 to 2.9 ± 1.9, P < 0.05; Supine to Lateral position with supplementary oxygen, from 6.1 ± 3.5 to 2.3 ± 1.5, P < 0.05). Further, arterial blood oxygen saturation was higher in the lateral position than in the supine position and was higher with supplementary oxygen than without supplementary oxygen (Supine, 86.7 ± 4.3%; Lateral, 94.5 ± 0.8%; Supine + O2, 93.2 ± 4.5%; Lateral + O2, 98.2 ± 1.5%). In conclusion, the lateral position during sleep attenuated sympathetic nervous system activity and improved oxygenation in patients with concomitant CAD and SAS.
Spontaneous Localized Persistent Atrial Fibrillation with an Exit Block Mimicking Atrial Tachycardia at the Left Posterior Wall
Authors: Kubota Shoichi , Nogami Akihiko , Kowase Shinya , Oginosawa Yasushi , Sugiyasu Aiko , Nakajima Naohisa , Aoki Hajime , Yumoto Kazuhiko , Tamaki Toshiyuki , Kato Kenichi
Published: August 2012

We describe a 37‐year‐old man with spontaneous localized atrial fibrillation (AF) with an exit block at the posterior wall of the left atrium (LA). The 12‐lead ECG exhibited an atrial tachycardia‐like pattern, with distinctive P waves and an isoelectric baseline between the P waves. The cycle length of the P waves ranged from 320 to 500 msec. While the fractionated and rapid deflections were recorded from the posterior wall of the LA, the rest of the atria and the coronary sinus exhibited discrete atrial potentials with irregular intervals. Radiofrequency energy applications to the surrounding tissue created complete isolation of the localized AF area, and the AF was terminated. Fibrillatory activation in the posterior wall of the LA can act as a driver as well as an initiator of atrial fibrillation.
Critical Slow Conduction Zone Located between the Tricuspid Annulus and a Myocardial Infarct Scar in a Patient with Multiple Ventricular Tachycardia Late after Myocardial Infarction
Authors: Nakano Emi , Harada Tomoo , Nakazawa Kiyoshi , Osada Keizou , Takagi Akihiko , Sasaki Toshio , Yoneyama Kihei , Wakimoto Hirofumi , Tanaka Osamu , Mizuno Kouichi , Azuma Nobuyuki , Kishi Ryouji , Miyake Fumihiko
Published: August 2012

A patient underwent an electrophysiological study (EPS) and catheter ablation (CA) for ventricular tachycardia (VT) that developed 11 years after myocardial infarction.

Entrainment mapping (EM) of the left ventricle did not identify the origin of the VT during induction. Electro‐anatomical mapping revealed a low voltage area from the anterior to the inferior left ventricular wall. Another EPS was performed for right ventricular mapping.

A basket catheter was placed in the right ventricle to evaluate impulse propagation and we attempted to identify the VT circuit with EM during the same VT (complete left bundle branch block configuration, inferior axis) as the previous EPS.

Eight different VT appeared, three of which were sustained during CA. The reentry circuit exit was identified on the tricuspid annulus (TA) at the 9:00 site and radiofrequency (RF) ablation was performed, but the axis transformed from the inferior to the superior and another VT appeared. Despite RF ablation to the VT circuit exit at the 5:00 site, another sustained VT appeared. Finally, it was terminated by ablation to a critical slow conduction zone (SCZ) located near the 7:00 site one year later. Electro‐anatomical voltage mapping detected a critical isthmus between TA and right ventricle infarct scar.

Here, we describe a rare SCZ proximal to the TA in a patient with VT late after myocardial infarction.
A Case Study on Cardiac Imaging in Patients with Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy —A Comparison between 64‐Slice Computed Tomography, Magnetic Resonance Imaging and Electroanatomical Mapping—
Authors: Nishiyama Kei , Doi Takahiro , Shizuta Satoshi , Yamamoto Takayuki , Hanazawa Kouji , Kita Toru , Kimura Takeshi
Published: August 2012

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an uncommon type of cardiomyopathy with fibrofatty tissue replacement. Magnetic resonance imaging (MRI) is a sophisticated method for the diagnosis of ARVD/C. Electroanatomical mapping has been reported to rapidly provide accurate data that facilitates catheter ablation of VT in ARVD/C. In addition, multislice CT (MSCT) is fast, easy to perform, and has a more reliable image quality. MSCT is considered a clinically valuable, noninvasive tool for assessment of myocardial pathology. However, the relationship between MSCT, cardiac MRI and electroanatomical mapping imaging in patients with ARVD/C is unknown. We report two cases diagnosed as ARVD/C by endomyocardial biopsy. In one case MRI imaging revealed marked wall thinning and a decrease in wall motion in the inferior wall and basal interventricular septum of the left ventricle. In another case an electroanatomical map of the RV was created. Endocardial voltage mapping in sinus rhythm revealed a large low voltage area and a focal pattern of activation was documented in activation mapping during VT. In both cases MSCT demonstrated low density areas indicative of focal fatty infiltration and morphological and functional abnormalities which were simultaneously assessed with MRI or electroanatomical mapping.
Association of Syncope and Atrioventricular Nodal Reentrant Tachycardia in a Patient with Brugada‐type Electrocardiogram —Importance of Electrophysiologic Study in Differential Diagnosis of Wide QRS Tachycardia—
Authors: Hayashi Hidemori , Sumiyoshi Masataka , Suwa Satoru , Sakurai Hidehiko
Published: August 2012

A 65‐year‐old man developed syncope following palpitation during an outdoor activity in the daytime. The 12‐lead electrocardiogram (ECG) showed Brugada‐type ST segment elevation. Holter ECG monitoring documented an episode of regular wide QRS tachycardia. During an electrophysiologic study (EPS), ventricular tachyarrhythmia was not induced. However, a common (slow‐fast) type atrioventricular nodal reentrant tachycardia with aberrant ventricular conduction, which was the same configuration as the wide QRS tachycardia recorded by the Holter ECG monitoring, was induced. The patient has been asymptomatic for the 12‐month follow‐up after the successful slow pathway ablation. This patient reminds us of the importance of EPS in the differential diagnosis of a wide QRS tachycardia.