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HotBalloon-based pulmonary vein isolation (HBPVI) has yielded encouraging clinical results in the treatment of atrial fibrillation (AF). Balloon ablation requires a larger sheath, which raises the concern for a persistent iatrogenic atrial septal defect (iASD). The present study aimed to investigate the incidence, clinical features, and the predictive factors of transthoracic echocardiography (TTE)-detectable iASD after HBPVI. All patients who underwent HBPVI of AF with pre- and post-ablation TTE were retrospectively analyzed. A 17-French steerable deflectable guiding sheath was inserted into the left atrium (LA) after a transseptal puncture, and an 8-French sheath was inserted via a single transseptal hole. In a total of 190 patients, 98 (52%) paroxysmal AF (PAF) and 92 (48%) non-PAF, the iASD was detected in 18 (9.4%) with a mean follow-up period of 12.7 ± 2.5 months after HBPVI. All patients had no clinical symptoms related to iASD. No embolic or heart failure events occurred. In the multivariate analysis, LA volume index and LA procedure time were identified as significant independent predictors of iASD. After HBPVI, TTE-detectable iASD was found in 9.4% of study patients. Larger LA size and longer LA procedure time were predictive factors for the persistence of iASD. All patients with iASD had no clinical symptoms 12 months after HBPVI; however, long-term follow-up may be necessary.

Radiofrequency hotballoon (RHB) is an ablation device used for atrial fibrillation (AF) treatment. The efficacy and safety of RHB-based pulmonary vein isolation (PVI) in real-world practice are unknown.Methods and Results: A multicenter, prospective registry study (UMIN000029567) enrolled AF patients who underwent RHB-PVI. The primary endpoint was the AF recurrence-free survival rate at 12 months after PVI. Of the 679 patients enrolled, 613 (90.3%; paroxysmal AF, n=370; persistent AF, n=136; long-standing AF, n=107) underwent initial RHB-PVI. Acute isolation using only the RHB was successful for 55.6% of patients and 83.5% of pulmonary veins (PVs). The acute isolation rate was higher for patients with paroxysmal AF and more experienced centers. Antiarrhythmic drugs were prescribed after 3 months for 47.5% of patients. The AF recurrence-free survival rate at 12 months was 83.7%. Procedure-related complications including atrio-esophageal fistula (n=1) and phrenic nerve injury (persistent; n=4, permanent; n=2) were observed in 19 (3.1%) patients. Five (1.7%) of the 302 patients who underwent pre-procedural and post-procedural multidetector computed tomography had severe PV stenosis.The size-adjustable RHB has been used for the treatment of various AF types. The arrhythmia recurrence-free rate at 12 months, with the use of antiarrhythmic drugs in approximately half of the patients, was acceptable, but the acute isolation rate using the RHB requires further improvement.

Background SATAKE HotBalloon®catheter (HBC) is a radiofrequency balloon catheter for the treatment of atrial fibrillation (AF), and was approved for use in Japan to treat drug-resistant paroxysmal AF in 2015. Post-marketing surveillance study was conducted by Toray Industries, Inc. to evaluate the efficacy and safety of HBC treatment in patients with paroxysmal AF in a real-world setting. This study is the first nation-wide survey of HBC treatment for paroxysmal AF in clinical practice in Japan.Methods and Results:This was a single-arm, multicenter observational study with an observation period of 48 weeks after ablation. Pulmonary vein isolation and AF non-recurrence rates were evaluated and adverse events (AEs) were observed at 46 sites in Japan. An AF event was defined as recurrence of AF or re-ablation from 12 to 48 weeks after ablation. The success rate of pulmonary vein isolation was 99.0% (486/491) for patients with AF. The cumulative AF non-recurrence rate was 94.1% at 24 weeks and 87.8% at 48 weeks. AEs were found to occur 21.5% (114/530), and ablation-related AEs were found to occur 2.6% (14/530) during the study period, with the most common being pericardial effusion (0.8%, 4/530). Conclusions This study demonstrates the efficacy and safety of HBC ablation in Japanese patients with recurrent symptomatic paroxysmal AF refractory to antiarrhythmic therapy.

INTRODUCTION HotBalloon material is compliant and the balloon size can be enlarged by increasing the intraballoon injection volume. HotBalloon-based pulmonary vein isolation (PVI) has demonstrated encouraging clinical results in the treatment of paroxysmal atrial fibrillation (PAF), however, the acute efficacy and clinical outcomes of the HotBalloon-based PVI have never been fully investigated in patients with a left common pulmonary vein (LCPV). METHODS AND RESULTS One hundred fifty-three PAF patients underwent HotBalloon-based PVI. Three-dimensional computed tomography was performed in all patients before the ablation. An LCPV was observed in 40 (26%) patients. For HotBalloon ablation of an LCPV, in patients with an LCPV of superoinferior diameter

Increased variety and use of chemicals and the number of chemical disasters have changed chemical management. Europe and the United States have adopted self-regulation in chemical management; furthermore, countries worldwide must comply with the relevant United Nations recommendations and international standards for chemical management. Japan has experienced numerous pollution incidents and occupational disasters, resulting in the development of laws and regulations on chemical management; however, these policies are inconsistent with international trends. In particular, the shift from a compliance approach to self-regulation and measures for small businesses remain as challenges. This paper discusses the current situation and issues in chemical management in Japan, focusing on international trends.

SATAKE HotBalloonThis study demonstrates the efficacy and safety of HBC ablation in Japanese patients with recurrent symptomatic paroxysmal AF refractory to antiarrhythmic therapy.

HotBalloon-based pulmonary vein isolation (HBPVI) has yielded encouraging clinical results in the treatment of paroxysmal atrial fibrillation (PAF). However, pulmonary vein (PV) stenosis remains a concern. The influence of longer application duration on PV stenosis has not yet been systematically evaluated. All patients who underwent first HBPVI of PAF with pre- and post-ablation computed tomography (CT) were included. We used single-shot technique with application duration of 180 s in the RSPV, 180–240 s in the LSPV, and 120 s in the lower PV procedures. PV stenosis was analyzed using CT and categorized as moderate (50–70%), and severe (> 70%) reduction in PV diameter. We analyzed imaging of the PV anatomy before ablation and during follow-up in 84 patients. Among them, 7 (8.3%) showed moderate stenosis, and 3 (3.6%) had severe stenosis including one total occlusion patient. All severe stenosis and total occlusion occurred in RSPV and LSPV procedures with longer application duration. No severe stenosis nor total PV occlusion occurred in inferior PV procedures with shorter application duration. The incidence of PV stenosis ≥ 50% or total PV occlusion was significantly lower in inferior PV than RSPV and LSPV procedures (0.6%, 6.0%, 8.0%, p = 0.01, respectively). All cases of PV stenosis including total PV occlusion patients were asymptomatic. No intervention for PV stenosis was performed. The risk of PV stenosis in HBPVI was rare in lower PV procedure with shorter application duration. An application duration setting of 120 s in lower PV procedure might be effective to prevent PV stenosis.

Background Point-by-point catheter ablation is an established treatment for drug-refractory paroxysmal atrial fibrillation (PAF). However, it is time consuming, requires excellent technique to achieve complete pulmonary vein (PV) isolation, and is associated with severe complications. Objectives The purpose of this study was to evaluate the safety and effectiveness of a HotBalloon ablation (HBA) compared with antiarrhythmic drug therapy (ADT) for the treatment of PAF. Methods A prospective multicenter randomized controlled study was conducted in Japan. Patients with symptomatic PAF refractory to antiarrhythmic drugs (Class I to IV) were randomized to HBA or ADT at a 2:1 ratio and assessed for effectiveness in a comparable 9-month follow-up period. Results A total of 100 patients in the HBA group and 43 patients in the ADT group received treatment at 17 sites. HBA procedure produced acute complete PV isolation in 98.0% (392 of 400) of the PVs and in 93.0% (93 of 100) of patients in the HBA group. The chronic success rates after the 9-month effective evaluation period were 59.0% in the HBA group (n = 100) and 4.7% in the ADT group (n = 43; p 70%) and transient phrenic nerve injury were 5.2% and 3.7%, respectively. The mean fluoroscopy time was 49.4 ± 26.6 min (n = 134), and the mean procedure duration was 113.9 ± 31.9 min (n = 133). Conclusions This study demonstrates the superiority of HBA compared with ADT for treatment of patients with PAF, and a favorable safety profile.

Introduction There are some cases with frequent luminal esophageal temperature (LET) rises despite titrating the radiofrequency energy while creating a linear lesion for the Box isolation of atrial fibrillation (AF). Little is known about the feasibility of redesigning the ablation lines for a modified Box isolation strategy to prevent fatal esophageal injury in those cases. Methods and results Two hundred and seventeen patients who underwent a Box isolation of non-paroxysmal AF were evaluated. We divided them into 2 groups, patients in whom a box lesion set of the entire posterior left atrium had been achieved (complete Box isolation [CBI]; n = 157) and those in whom 2 additional peri-esophageal vertical lines were created at both the right and left ends of the esophagus, and those areas were left with an incomplete isolation when frequent rapid LET rises above 39.0 °C were observed while creating the floor line (partial Box isolation [PBI]; n = 60). During 20.1 ± 13.9 months of follow-up, the arrhythmia-free rates were 54.1% in the CBI group versus 48.3% in the PBI group (P = 0.62). In the second session, a complete Box isolation was highly achieved even in the PBI group (94.3% vs. 83.3%, respectively; P = 0.17) and after 2 procedures, the arrhythmia-free rates increased to 75.2% vs. 68.3%, respectively (P = 0.34). There was no symptomatic esophageal injury in the PBI group. Conclusion In the case of frequent LET rises while creating the linear lesions for the Box isolation strategy for non-paroxysmal AF, shifting to the PBI strategy was feasible.

Long-Term Outcomes Following Hot Balloon AblationIntroduction Isolation of pulmonary veins (PVs) and the posterior left atrium (LA) can be safely performed by radiofrequency hot balloon (RHB)-based box isolation. However, data on long-term effects for the treatment of atrial fibrillation (AF) by the use of this method remain limited. Methods and Results We treated 238 patients with paroxysmal AF (194 male; age. 62.6 ± 9.4 years) by RHB ablation. During 6.2-year (75 months) follow-up, 154 (64.7%) patients were free from atrial tachyarrhythmias (ATAs) without antiarrhythmic-drugs (AADs). We performed re-ablation in 69 of 84 patients with ATA recurrence (average 1.3 ± 0.6; median 1, total 91 procedures) using a 3D-mapping system and a conventional catheter. The sites of reconnection were observed at the PV in 61 of 69 (88.4%) patients and at the posterior LA in 58 of 69 (84.1%) patients. Finally, during mean follow-up of 4.6 ± 1.6 years, no-ATA episodes were detected in 201 (84.5%) patients without AADs. Independent predictors of ATA recurrence following a single procedure were heart failure with preserved ejection fraction (HR: 2.67, 95%CI: 1.40–5.10, P = 0.003) and low estimated glomerular filtration rate (HR: 1.81, 95%CI: 1.11–2.93, P = 0.03; cut-off of 62.0 mL/min/1.73 m2). During the follow-up period, there were 4 (1.7%) patients with PV stenosis (>70% reduction in PV diameter); however, none of these cases required intervention. Phrenic nerve palsy was detected in 8 patients (3.4%), but resolved during 3 months in all cases. Conclusion RHB ablation can be effective during a long-term follow-up for patients with paroxysmal AF. Safety outcomes were within an acceptable range.

Focal point-by-point radiofrequency (RF) ablation has shown considerable success in treating paroxysmal AF [1, 2]. However, the procedure is complex, time consuming, and dependent on operator’s skill to create durable lesion and is sometimes associated with severe complications. Balloon-based ablation has a potential advantage of simpler and faster procedure to achieve Pulmonary vein (PV) isolation (PVI) beyond the operator’s dexterity.

Esophageal Cooling During Hot Balloon AblationBackground Little is known about luminal esophageal temperature (LET) monitoring during catheter ablation for atrial fibrillation (AF) using the radiofrequency hot balloon (RHB) technology. Objective The aim of this study is to investigate the impact of the use of a unique esophageal cooling method during RHB ablation. Methods and Results In this observational study, 318 consecutive patients (231 men; mean age, 63 ± 9 years) with symptomatic, drug-refractory, paroxysmal (n = 183) or persistent (n = 135) AF underwent RHB ablation with LET monitoring followed by a postprocedural, nonsymptom-driven esophageal endoscopy within 3 days of the ablation procedure. The patients have been divided into 3 groups. The first 22 patients treated are in Group A (n = 22) and had only LET monitoring without cooling of the esophagus. In Groups B (n = 128) and C (n = 168), patients had LET monitoring with cooling of the esophagus when the LET exceeded 43 °C and 39 °C, by infusion of cooled saline mixed with Gastrographin or Iopamidol, respectively. Group A had a higher risk of esophageal ulceration among the 3 groups (P < 0.0001). Saline infusion cooling initiated when the LET exceeded 43 °C (Group B) was not as safe as saline infusion cooling initiated when the LET exceeded 39 °C (Group C), demonstrated by the Group C minimum ulceration score and LET measurements while ablating the left superior pulmonary vein (LSPV) and left inferior pulmonary vein (LIPV) (P < 0.0001). Conclusion Cooling the esophagus by a mix of Iopamidol and saline infusion when the LET exceeds 39 °C during RHB ablation may decrease the incidence and severity of esophageal thermal injury.

Background— Atrial fibrillation originates mostly from the pulmonary vein (PV) foci or non-PV foci in the posterior left atrium (LA). The present study was designed to evaluate the feasibility and safety of a novel radiofrequency hot balloon catheter for the treatment of patients with atrial fibrillation by electrically isolating the posterior LA, including all PVs. Methods and Results— One hundred consecutive patients with drug-resistant atrial fibrillation (63 paroxysmal, 37 persistent) were enrolled. The isolation of the PVs was performed by wedging the balloon at each PV antrum to create circumferential lesions in each case. Contiguous linear lesions were also created at the roof between the superior PVs and at the bottom of the posterior LA between the inferior PVs by dragging the balloon along the endocardium. Complete elimination of the posterior LA and PV potentials was achieved in all 100 cases, confirmed by either conventional or electro-anatomic mapping system. The total procedure time was 129�26 minutes, inclusive of 29.9�7.3 minutes of fluoroscopy time. Follow-up during 11.0�4.8 months confirmed that 92 patients (60 paroxysmal, 32 persistent) were free from atrial fibrillation without antiarrhythmic drugs, and in the remaining patients except for 2 with LA tachycardia, sinus rhythm was maintained with antiarrhythmic drugs. With precautions of esophageal cooling by irrigation dictated by temperature monitoring and monitoring phrenic nerve pacing, no LA-esophageal fistula or permanent phrenic nerve injury occurred. Conclusion— This feasibility study supports the safety and efficacy of radiofrequency hot balloon catheter for complete isolation of the posterior LA and PVs.

Point-by-point catheter ablation is an established treatment for drug-refractory paroxysmal atrial fibrillation (PAF). However, it is time consuming, requires excellent technique to achieve complete pulmonary vein (PV) isolation, and is associated with severe complications.The purpose of this study was to evaluate the safety and effectiveness of a HotBalloon ablation (HBA) compared with antiarrhythmic drug therapy (ADT) for the treatment of PAF.A prospective multicenter randomized controlled study was conducted in Japan. Patients with symptomatic PAF refractory to antiarrhythmic drugs (Class I to IV) were randomized to HBA or ADT at a 2:1 ratio and assessed for effectiveness in a comparable 9-month follow-up period.A total of 100 patients in the HBA group and 43 patients in the ADT group received treatment at 17 sites. HBA procedure produced acute complete PV isolation in 98.0% (392 of 400) of the PVs and in 93.0% (93 of 100) of patients in the HBA group. The chronic success rates after the 9-month effective evaluation period were 59.0% in the HBA group (n = 100) and 4.7% in the ADT group (n = 43; p 0.001). The incidence of major complications was 11.2% (15 of 134 patients). The incidences of PV stenosis (70%) and transient phrenic nerve injury were 5.2% and 3.7%, respectively. The mean fluoroscopy time was 49.4 ± 26.6 min (n = 134), and the mean procedure duration was 113.9 ± 31.9 min (n = 133).This study demonstrates the superiority of HBA compared with ADT for treatment of patients with PAF, and a favorable safety profile.

There are some cases with frequent luminal esophageal temperature (LET) rises despite titrating the radiofrequency energy while creating a linear lesion for the Box isolation of atrial fibrillation (AF). Little is known about the feasibility of redesigning the ablation lines for a modified Box isolation strategy to prevent fatal esophageal injury in those cases.Two hundred and seventeen patients who underwent a Box isolation of non-paroxysmal AF were evaluated. We divided them into 2 groups, patients in whom a box lesion set of the entire posterior left atrium had been achieved (complete Box isolation [CBI]; n = 157) and those in whom 2 additional peri-esophageal vertical lines were created at both the right and left ends of the esophagus, and those areas were left with an incomplete isolation when frequent rapid LET rises above 39.0 °C were observed while creating the floor line (partial Box isolation [PBI]; n = 60). During 20.1 ± 13.9 months of follow-up, the arrhythmia-free rates were 54.1% in the CBI group versus 48.3% in the PBI group (P = 0.62). In the second session, a complete Box isolation was highly achieved even in the PBI group (94.3% vs. 83.3%, respectively; P = 0.17) and after 2 procedures, the arrhythmia-free rates increased to 75.2% vs. 68.3%, respectively (P = 0.34). There was no symptomatic esophageal injury in the PBI group.In the case of frequent LET rises while creating the linear lesions for the Box isolation strategy for non-paroxysmal AF, shifting to the PBI strategy was feasible.

Objective: The purpose of this study was to provide detailed information as to the modification of electrophysiological properties of pulmonary veins (PVs) and adjacent left atrial (LA) tissue caused by circumferential ablation (ABL) of superior and inferior pulmonary vein ostia using a novel radio-frequency balloon catheter (RBC), and to correlate such changes with recurrence or non-recurrence of atrial fibrillation (AF). Background: Although isolation of the triggering foci in PVs using conventional ABL techniques is useful in the treatment of AF, ABL of PVs per se is time consuming and tends to be associated with high AF recurrence rate. Methods and Results: Forty-nine patients with AF refractory to antiarrhythmic medication underwent circumferential ablation of PV-LA junction by RBC. Post ablation changes in electrophysiological properties around the PV ostia were studied with a basket catheter and were correlated with AF recurrence in 34 (1st study) early cases (ablating 68 superior PVs) and 15 (2nd study) later cases (53 superior and inferior PVs). Total elimination of PV potentials or PV-LA dissociation was achieved in 93% (63/68 PVs) and 93% (49/53 PVs), respectively. During mean follow-up periods of 24.1 ± 4.1 and 13.3 ± 1.7 months, AF recurred in 38% (13/34 cases) and 13% (2/15) in early and later groups, respectively, but no case developed severe PV stenosis. Although the amplitude of PV and periostial LA potentials were decreased (p < 0.0001) in all patients, the remaining PV potentials in 34 non-recurrence cases were definitely smaller than those in 15 recurrence cases (p

We treated a case of ventricular septal perforation (VSP) who survived for 14 years after myocardial infarction. Nine years after the onset of myocardial infarction, an apparent cardiac murmur was discovered by chance, and following further examination, the patient was diagnosed as having VSP. The patient is still in the NYHA functional class I, and requiring no surgical treatment. In general, the prognosis of myocardial infarction complicated with VSP is so poor that there have only been 14 reported cases of long survival without surgical treatment. Among these patients, only 2 survived for more than 10 years. The present case is extremely rare, and evidently is the longest living survivor with this condition yet reported.

His-bundle pacing gives a more physiological ventricular contraction in comparison to right ventricular apical pacing. However the problems of lead fixation and stability of long-term His-bundle pacing are yet unsolved. We used six adult beagles, in which a screw-in lead was anchored in the His-bundle region for observation of the pacing conditions and histopathologic changes of the conduction system over the course of 2 months. In the results, a satisfactory fixation was obtained using a conventional screw-in lead and no histological influence on the conduction system was observed. The pacing threshold at the time of implantation was 1.15 +/- 0.69 V (3.23 +/- 3.08 mA) in the pulse width of 0.5 ms. R wave amplitude, the impedance and slew rate were 7.28 +/- 2.04 mV, 409 +/- 102 Ohm, and 0.65 +/- 0.41 V/s, respectively. Two months later, these parameters changed to 2.83 +/- 1.06 V (10.4 +/- 5.71 mA), 5.63 +/- 1.62 mV, 310 +/- 71.3 Ohm, and 0.49 +/- 0.22 V/s, respectively. These results suggest the feasibility of clinical application of permanent His-bundle pacing.

A 63-year-old man and a 49-year-old man who underwent PTMC eight years before were admitted in our hospital because of regurgitation and restenosis of the mitral valve. Both of them had ulcer like lesion on the anterior leaflet near the commissure of the mitral valve. These changes were made by PTMC and likely caused thrombosis. Long-term follow up data of PTMC is essential to chose the correct operative method for treating mitral stenosis.

We evaluated a 68-year-old male patient with isolated levocardia without intracardiac anomaly. The patient's condition was complicated by the absence of the inferior vena cava, a lobulated spleen and sick sinus syndrome. Isolated levocardia without intracardiac anomaly is very rare and only 25 cases of this disease have been reported, to our knowledge. In general, it is accepted that cardiac rhythm disorder is frequently observed in cases of isolated levocardia and/or absence of inferior vena cava. However, there are few cases of isolated levocardia without intracardiac anomaly complicated by the absence of the inferior vena cava, a lobulated spleen and apparent sick sinus syndrome.

Three months after implantation of endocardial pacing leads in 10 mongrel dogs, the tensile forces needed to remove 5 tined type and 5 screw-in type leads were compared experimentally. Mean maximum tensile force was 291 +/- 174 g with the screw-in type and 1174 +/- 369 g with the tined type (p < 0.01). Histopathologically, no changes suggesting any myocardial damage due to lead extraction were recognized in cases where screw-in type leads were used. These results support the clinical feasibility of safe and easy manual retraction of infected pacing leads of the screw-in type.

A case of infective endocarditis (IE) caused by a rare pathogen, Gemella morbillorum, is presented. Because of persistent low-grade fever after dental treatment, the patient was given oral antibiotics. Whereas he was diagnosed as having aortic regurgitation by a cardiologist, and IE was not suggested unfortunately. After long-term chemotherapy over five months, he was aware of nocturnal dyspnea and Gemella morbillorum was detected by blood culture. Then, he was treated with intravenous administration of Penicillin-G, and underwent surgical operation for valve replacement. No cases of IE due to this organism have been reported in Japan.

Atrial fibrillation (AF) is originated from mostly from pulmonary vein (PV) foci or non-PV foci in the posterior left atrium (PLA). The present study was designed to evaluate the usefulness of a radiofrequency HOT balloon catheter (RBC) for isolation of the PLA including all PVs en masse in the patients with AF. In a total of 96 patients (75 men and 21 women; mean age 64±8 years old) with drug-resistant paroxysmal (n=63) and persistent AF(n=33), PLA including all PVs were ablated and isolated using RBC. Dragging the balloon, contiguous lesions at the roof between the superior PVs were first created, then each antrum of all PVs were ablated, and finally, contiguous lesions at the PLA between the both inferior PVs were made, while we performed monitoring esophagus temperature and phrenic nerve pacing. Electro-anatomical bipolar voltage amplitude mapping (CARTO) of the LA-PVs was performed to determine the extent of this electrical isolation after all procedure. Successful isolation of the PLA including all PVs was achieved in all of 96 cases with elimination of all the PLA and PV potentials. The mean total procedure time 133 ± 31 minutes including 32±9 minutes fluoroscopy time. Recurrences of AF were diagnosed by Holter monitoring, mobile electrocardiogram. After first session, eighty- seven (59 paroxysmal, 28 persistent) of 96 patients were free from AF without anti-arrhythmic drugs and the remaining patients could maintain sinus rhythm with anti-arrhythmic drugs except two cases with LA flutter during 11.0±4.1 months follow-up. No major complications such as cerebral embolism, PV stenosis, or phrenic nerve palsy, and LA-esophageal fistula were observed. Complete isolation of the PLA including all PVs using a RBC, is useful for the treatment of both paroxysmal and persistent AF without severe complication.

Introduction: A rapidly firing or triggered ectopic focus located within a pulmonary vein (PV) or close to the PV ostium could induce atrial fibrillation (AF). The aim of this study was to evaluate the efficacy and safety of a radiofrequency thermal balloon catheter for isolation of the PV from the left atrium (LA). Methods and Results: Twenty patients with drug-resistant paroxysmal AF were treated by isolating the superior PVs using an RF thermal balloon catheter. Using a transseptal approach, the balloon, which had an inflated diameter 5 to 10 mm larger than that of the PV ostium, was wedged at the LA-PV junction. It was heated by a very-high-frequency current (13.56 MHZ) applied to the coil electrode inside the balloon for 2 to 3 minutes, and the procedure was repeated up to four times. The balloon center temperature was maintained at 60° to 75°C by regulating generator output. Successful PV isolation was achieved in 19 of the 20 left superior PVs and in all 20 of the right superior PVs and was associated with a decrease in amplitude of the ostial potentials. Total procedure time was1.8 ± 0.5hours, which included22 ± 7minutes of fluoroscopy time. After a follow-up period of8.1 ± 0.8months, 17 patients were free from AF, with 10 not taking any antiarrhythmic drugs and 7 taking the same antiarrhythmic agent as before ablation. Electron beam computed tomography revealed no complications, such as PV stenosis at ablation sites. Conclusion: The PV and its ostial region can be safely and quickly isolated from the LA by circumferential ablation around the PV ostia using a radiofrequency thermal balloon catheter for treatment of AF. (J Cardiovasc Electrophysiol, Vol. 14, pp. 609-615, June 2003)

A 43-year-old woman had undergone patch closure operation for atrial septal defect 27 years ago. She was referred to our hospital for evaluation of frequent palpitations since 1 year ago. Electrophysiological study was performed with recording of the coronary sinus, His bundle, and low lateral right free wall electrography utilizing a steerable duo-decapolar electrode catheter(Livewire, Daig). Supraventricular tachycardia with cycle length alternation of 300 and 320 msec similar to atrial flutter was reproducibly provoked by burst pacing from the coronary sinus. During the supraventricular tachycardia, abnormal atrial potentials occurred in the low lateral right free wall region with very low amplitude and splitting potentials. The cycle length alternation of the supraventricular tachycardia depended on the occurrence of the splitting potentials, that is, the splitting potentials were present during the supraventricular tachycardia with a long cycle and the splitting potentials were absent during the supraventricular tachycardia with a short cycle. This phenomenon suggested that the splitting potentials resulted from 2:1 functional intra-atrial local conduction block. In addition, during sinus rhythm the abnormal electrograms revealed fractionated activity. Thus, these findings strongly imply that the supraventricular tachycardia is due to a macro-reentrant right atrial tachycardia utilizing an anatomical obstacle caused by the atrial septal defect operation as a central area, namely incisional reentrant atrial tachycardia. Three-dimensional electroanatomical mapping using the CARTO system(Biosense-Webster) was conducted to investigate whether the low lateral right free wall area possessed the critical isthmus essential to the reentry circuit. Electroanatomical mapping revealed that the very low amplitude potentials and the splitting potentials corresponded to the scars and the functional conduction block area detected by mapping using the multipolar catheter, respectively. According to the propagation mapping, the incisional reentrant atrial tachycardia slowly conducted the channel created by multiple neighboring scars clockwise and the alternation of the tachycardia cycle length was dependent on the development of the functional local intra-atrial conduction block within the channel. An approximately 1.5 cm successful linear lesion was created by radiofrequency catheter ablation to transect the isthmus based on the electroanatomical mapping findings. Afterwards, the incisional reentrant atrial tachycardia could not be induced by burst stimuli from the coronary sinus even under administration of isoproterenol. The use of three dimensional electroanatomical mapping(CARTO system) to evaluate the reentry circuit after the detection of abnormal potentials by using multipolar catheter in advance is a very useful method to determine optimal target site of ablation for a patient with incisional reentrant atrial tachycardia.

To examine acute effects of olprinone hydrochloride (CAS 106730-54-0, Coretec) on pulmonary hypertension, hypoxic pulmonary hypertension was produced in 6 adult Beagle dogs. Using this pulmonary hypertension model, single intravenous bolus injections of olprinone at doses of 10, 30 and 100 micrograms/kg were administered at 5-min intervals and hemodynamic parameters were evaluated. Heart rate increased at doses of 30 and 100 micrograms/kg, but did not change at a dose of 10 micrograms/kg. Mean aortic pressure, mean pulmonary arterial pressure, pulmonary vascular resistance and systemic vascular resistance and right ventricular stroke work index did not change at doses of 10 and 30 micrograms/kg, but they decreased significantly at a dose of 100 micrograms/kg. On the other hand, cardiac index and the first derivative value of the left ventricular pressure did not show significant change at all doses. These results indicate the vasodilating effects on peripheral and pulmonary vessels in hypoxic model at high doses of olprinone. Its application in right heart failure accompanied by pulmonary hypertension therefore is expected to yield promising results.

We report an interesting case of aortic regurgitation. Phonocardiographically, the shape of the diastolic musical murmur in this case changed in each cardiac cycle despite being in sinus rhythm, in the same posture and in the same breathing phase. Experimentally, we were able to obtain a similar noise pattern using an artificial respirator and a hemispherical silicone membrane. We concluded that the irregular and chaotic change in the shape of the diastolic musical murmur in the present case occurred due to irregular swaying of the non-coronary cusp under the influence of the Venturi effect owing to a regurgitant jet stream. (Jpn Circ J 1996; 60: 993 - 997)

We report a case of sudden death due to variant angina during Holter electrocardiogram (ECG) monitoring. The patient, a 60-year-old man, had been aware of chest discomfort lasting less than one minute at midnight 2 days earlier. Because variant angina or arrhythmia was suspected, Holter ECG monitoring was performed. The patient spent a whole day without a recurrence of chest pain before going to bed, but at midnight he developed sudden chest pain, and died immediately after taking a sublingual tablet of isosorbide-dinitrite. Analysis of the Holter ECG revealed ventricular fibrillation after several ventricular premature beats following ST-segment elevation in both the CM5 and NASA leads. This case shows that sudden death from variant angina may occur within a few days after the first onset, and also highlights whether priority should be given to making a definite diagnosis or giving treatment when variant angina is strongly suspected.

We examined histologically whether the severity of arterial stretch injury is related to the degree of subsequent intimal hyperplasia. In six male New Zealand White rabbits, the common carotid artery was hyperextended with a 3F Fogarty balloon catheter. Two weeks later, no proliferative change was evident in the intima in the most hyperextended portion. Paradoxically, however, intimal hyperplasia due to smooth muscle cell proliferation was observed in the moderately extended portions. The intimal hyperplasia appeared to be exacerbated where the arterial stretching was more severe. It is concluded that the severity of arterial stretch injury is closely related to the intimal proliferation of smooth muscle cells.

We observed a case of acute myocardial infarction induced by second diagonal branch occlusion. Electrocardiogram (ECG) on admission showed ST elevation in leads I, aVL and V2-6. Since emergency coronary angiography disclosed complete occlusion of the second diagonal branch, intra-coronary thrombolysis (ICT) was performed, superselectively. Transient coronary reperfusion was obtained, however, reocclusion occurred after several minutes. Rescue percutaneous transluminal coronary angioplasty (PTCA) was then performed immediately and blood flow was improved to TIMI grade 2. During these processes, the ST-segment on the ECG changed in leads I, aVL and V2-6 always corresponding to the blood flow of the second diagonal branch. We have not seen a report hitherto in which occlusion of only the second diagonal branch could be a cause of extensive anterior infarction-like ECG changes. Although the mechanism of ECG changes in this patient cannot be clearly explained by conventional concepts, we report this case because it is considered to be very rare.

Background: Non-uniform heating of the tissue due to direct resistive heating by radiofrequency current under regional cooling was changed blood flow or irrigation, resulting in thrombus formation. To avoid non-uniform heating, we have developed a radiofrequency hot balloon catheter system (RFHBS). Methods and Results: We treated 446 patients with atrial fibrillation (AF) (paroxysmal AF (PAF), n=269; persistent AF (Per-AF), n=78; long persistent AF (Long-AF), n=99) by pulmonary vein (PV) antral isolation or box isolation using RFHBS and performed MRI of brains after procedure. There were no complications such as cardiac tamponade, cerebral embolism, atrio-esophageal fistula, symptomatic PV stenosis or phrenic palsy, associated with the ablation procedure. During 12 months follow up, no AF episodes were detected without anti-arrhythmic drugs in 346 patients (PAF, n=230 (86%); Per-AF, n=53 (68%); Long-AF, n=55 (56%)). During 3.6±1.2 years follow-up period, no AF episodes were detected without anti-arrhythmic drugs in 279 patients (PAF, n=188 (70%); Per-AF, n=43 (55%); Long-AF, n=48 (48%)). Conclusion: PV antral isolation or box isolation using a RFHBS could be performed without serious complication and long-term effective for the patients with AF.

Background: We evaluate the safety and efficacy of a radiofrequency hot balloon catheter (Toray-Satake Balloon; TSB) for the treatment of the patients with AF. Methods and Results: A total of thirty patients (26 men, 60±9 years) with drug-resistant AF (paroxysmal n=26, persistent n=4) were enrolled in this study. Under general anesthesia (n=12) or deep sedation (n=18), we performed isolation of all PVs including PV antrum, only by use of TSB. The center temperature of the balloon (60–70C) and the delivery time of RF energy (90–240 seconds) were determined by the wall thickness of each PV, measured by intra-cardiac echo. Complete PV isolation was observed in 110 of 121 PVs (91%), and decreased PV potentials were left in 4/31 (13%) at right superior PV, 4/30 (13%) at left superior PV, and 3/30 (10%) at left inferior PV. Total procedure times were (102±27 min). Total fluoroscopic times and total application times were (31±14 min) and (12±2 times), respectively. After a single procedure, twenty-seven of 30 patients (87%) were free from AF without anti-arrhythmic drugs during 6 months follow-up period. There were no complications such as stroke, esophageal fistula, symptomatic PV stenosis, phrenic nerve palsy, pyloric spasm. Conclusion: Ablation by TSB might be time-saving, safety and quite promising therapy for the patients with AF.