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Drug-coated balloons (DCB) have shown promising results for the treatment of in-stent restenosis (ISR) and small vessel disease (SVD). However, data comparing the treatment efficacy of different DCBs are limited.Methods and Results: AGENT Japan is a prospective randomized controlled trial that compares the Agent balloon coated with a low-dose formulation of paclitaxel (2 μg/mmData from this study demonstrate good clinical outcomes with the Agent DCB when used to treat patients with SVD or ISR.

Background: Fulminant myocarditis presentation (FMP) is a rare and severe presentation of myocarditis. The natural history of FMP and its clinical features associated with poor outcomes are incompletely understood because there is a lack of generalizable evidence. Methods: This multicenter retrospective cohort study included patients hospitalized with histologically proven myocarditis who underwent catecholamine or mechanical support from 235 cardiovascular training hospitals across Japan between April 2012 and March 2017. Clinical features and the prognostic predictors of death or heart transplantation within 90 days on the basis of clinical and pathologic findings were determined using the Kaplan-Meier method, log-rank test, and Cox regression analysis. Results: This study included 344 patients with histologically proven FMP (median age, 54 years; 40% female). The median follow-up was 600 days (interquartile range, 36 to 1599 days) and the cumulative risk of death or heart transplantation at 90 days was 29% (n=98). Results from multivariable Cox regression analysis showed that older age, nonsinus rhythm, low left ventricular wall motion ( Conclusions: The results from analyses of data from this multicenter registry demonstrated that patients with FMP are at a higher risk of death or heart transplantation in real-world settings. These observations inform which clinical and pathologic findings may be useful for prognostication in FMP. Registration: URL: https://www.umin.ac.jp/ctr ; Unique identifier: UMIN000039763.

The global coronavirus disease-2019 (COVID-19) pandemic is associated with reduced rate of percutaneous coronary intervention (PCI). However, there were a few data showing how emergency medical system (EMS) and management strategies for acute coronary syndrome (ACS) changed during the pandemic. We sought to clarify changes on characteristics, treatments, and in-hospital mortality of patients with ACS transported via EMS between pre- and post-pandemic. We examined consecutive 656 patients with ACS admitted to Sapporo City ACS Network Hospitals between June 2018 and November 2021. The patients were divided into pre- and post-pandemic groups. The number of ACS hospitalisations declined significantly during the pandemic (proportional reduction 66%, coefficient − 0.34, 95% CI -0.50 to -0.18, p

Japanese patients have shown improved outcomes after treatment with drug eluting stents compared with Western patients. Outcomes with the ridaforolimus-eluting EluNIR stent in Japanese patients are unknown. This was a multi-center trial in Japanese patients undergoing PCI with the ridaforolimus eluting EluNIR stent. A propensity-score matched analysis was performed with the EluNIR arm of the BIONICS trial. The matched cohort was compared with the Japanese patients for the primary endpoint of target lesion failure (TLF) in a non-inferiority study. 104 Japanese patients were compared with 410 matched patients from BIONICS. Baseline characteristics were similar except for more frequent multi-vessel disease in the BIONICS cohort. Post dilation was more likely in Japanese patients (90.4% vs. 64.6%, p

BACKGROUND Intravascular lithotripsy (IVL) delivers acoustic pressure waves to modify calcium, enhance vessel compliance and optimize stent deployment. The objective of this study was to assess the safety and effectiveness of IVL treatment of de novo stenoses involving severely calcified coronary vessels in a Japanese population.Methods and Results:Disrupt CAD IV (NCT04151628) was a prospective, multicenter study designed for Japanese regulatory approval of coronary IVL (SWM-1234). The primary safety endpoint was freedom from major adverse cardiac events (MACE) at 30 days. The primary effectiveness endpoint was procedural success (residual stenosis

Objectives: This study investigated the diagnostic performance of instantaneous wave-free ratio (iFR) in patients with aortic valve stenosis (AS).Background: The iFR was introduced as a new...

Background The clinical usefulness of peripheral blood (PB) mononuclear cell (MNC) transplantation in patients with peripheral arterial disease (PAD), especially in those with mild-to-moderate severity, has not been fully clarified.Methods and Results:A randomized clinical trial was conducted to evaluate the efficacy and safety of granulocyte colony-stimulating factor (G-CSF)-mobilized PBMNC transplantation in patients with PAD (Fontaine stage II-IV and Rutherford category 1-5) caused by arteriosclerosis obliterans or Buerger's disease. The primary endpoint was progression-free survival (PFS). In total, 107 subjects were enrolled. At baseline, Fontaine stage was II/III in 82 patients and IV in 21, and 54 patients were on hemodialysis. A total of 50 patients had intramuscular transplantation of PBMNC combined with standard of care (SOC) (cell therapy group), and 53 received SOC only (control group). PFS tended to be improved in the cell therapy group than in the control group (P=0.07). PFS in Fontaine stage II/III subgroup was significantly better in the cell therapy group than in the control group. Cell therapy-related adverse events were transient and not serious. Conclusions In this first randomized, large-scale clinical trial of G-CSF-mobilized PBMNC transplantation, the cell therapy was tolerated by a variety of PAD patients. The PBMNC therapy was significantly effective for inhibiting disease progression in mild-to-moderate PAD.

Objectives The NIPPON (Nobori Dual Antiplatelet Therapy as Appropriate Duration) study was a multicenter randomized investigation of the noninferiority of short-term versus long-term dual antiplatelet therapy (DAPT) in patients with implantation of the Nobori drug-eluting stent (DES) (Terumo, Tokyo, Japan), which has a biodegradable abluminal coating. Background The optimum duration of DAPT for patients with a biodegradable polymer-coated DES is unclear. Methods The subjects were 3,773 patients with stable or acute coronary syndromes undergoing Nobori stent implantation. They were randomized 1:1 to receive DAPT for 6 or 18 months. The primary endpoint was net adverse clinical and cerebrovascular events (NACCE) (all-cause mortality, myocardial infarction, stroke, and major bleeding) from 6 to 18 months after stenting. Intention-to-treat analysis was performed in 3,307 patients who were followed for at least 6 months. Results NACCE occurred in 34 patients (2.1%) receiving short-term DAPT and 24 patients (1.5%) receiving long-term DAPT (difference 0.6%, 95% confidence interval [CI]: 1.5 to 0.3). Because the lower limit of the 95% CI was inside the specified margin of −2%, noninferiority of short-term DAPT was confirmed. Mortality was 1.0% with short-term DAPT versus 0.4% with long-term DAPT, whereas myocardial infarction was 0.2% versus 0.1%, and major bleeding was 0.7% versus 0.7%, respectively. The estimated probability of NACCE was lower in the long-term DAPT group (hazard ratio: 1.44, 95% CI: 0.86 to 2.43). Conclusions Six months of DAPT was not inferior to 18 months of DAPT following implantation of a DES with a biodegradable abluminal coating. However, this result needs to be interpreted with caution given the open-label design and wide noninferiority margin of the present study. (Nobori Dual Antiplatelet Therapy as Appropriate Duration [NIPPON]; NCT01514227)

When an automatic wheelchair or a self-carrying robot moves along with human agents, prediction for the next possible actions by the participating agents, play an important role in realization of successful cooperation among them. In this paper, we mounted a robot to a wheelchair body so that it provides embodied projective signals to the human agents, indicating the next possible action to be performed by the wheelchair. We have analyzed how human participants, particularly when they are in a multiparty interaction, would respond to such a system in experiments. We designed two settings for the robot's projective behavior. The first design allows the robot to face towards the human agents (Face-to-Face model), and the other allows it to face forward as the human agents do, then turn around to the human agents when it indicates where the wheelchair will move to (Body-Torque model). The analysis examined reactions by the human agents to the wheelchair, his/her accompanying human agent, and others who pass by them in the experiment's setting. The results show that the Body-Torque model seems more effective in enhancing cooperative behavior among the human participants than the Face-to-Face model when they are moving to a forward direction together.

As the advance of an aging society in Japan, along with the lack of caregivers, the elderly care has become a crucial social problem. To cope with this problem, we are focusing on shopping. Shopping is one of the important daily activities and expected to be effective for the elderly rehabilitation because it feels easier than walking rehabilitation and it can give the positive effect for the cognitive functions by memorizing and checking out items to buy. The current shopping rehabilitation is carried out with a caregiver accompanied by the elderly one by one for guiding inside the store, carrying shopping basket, monitoring, etc. Consequently, the caregivers’ load is very high. In this paper, we propose a robotic shopping trolley that can reduce the caregivers’ load in shopping rehabilitation. We evaluate its effectiveness through experiments at an actual supermarket.

Background: During transradial (TR) access, it remains unclear whether differences in baseline patients characteristics and hemostasis care impact the rate of radial artery occlusion (RAO). We sought to compare the rate of RAO after TR access with the 6 French(Fr) Glidesheath Slender (GSS6Fr, Terumo, Japan) or a standard 5 Fr sheath in Japanese and non-Japanese patients. Methods and Results: The Radial Artery Patency and Bleeding, Efficacy, Adverse evenT (RAP and BEAT) trial randomized 1,836 patients undergoing TR coronary angiography and/or interventions to receive the GSS6Fr or the standard 5 Fr Glidesheath (GS5Fr, Terumo, Japan). Out of this study population, 1,087 were Japanese patients and 751 non-Japanese patients. The overall incidence of RAO was significantly higher in Japanese patients (3.6% vs. 1.2%, P = 0.002). Use of GSS6Fr was associated with higher rates of RAO than GS5Fr in Japanese patients (5% vs. 2.2%, P = 0.02) and with similar RAO rates in non-Japanese patients (1.3 vs. 1.1%, P = 1). The mean hemostasis time was significantly longer in Japanese patients (378 ± 253 vs. 159 ± 136 min, P < 0.001) and more Japanese patients had a hemostasis time of more than 6 hr (16.2% vs. 4.9%, P < 0.0001). Longer hemostasis time was an independent predictor of RAO (OR per additional hour 1.070, 95% CI 1.008–1.136, P = 0.03). Conclusions: Use of GSS6Fr was associated with a higher rate of RAO than a standard 5 Fr sheath in Japanese patients but not in non-Japanese patients. Whether improvement in post-procedural care and reduced hemostasis time could impact the incidence of RAO in Japanese patients should be further assessed.

Item does not contain fulltext AIMS: The 6 Fr Glidesheath Slender (GSS6Fr) is a recently developed thin-walled radial sheath with an outer diameter (OD) that is smaller than the OD of standard 6 Fr sheaths. The purpose of this trial was to clarify whether the use of this new slender sheath would result in similar rates of RAO to a standard 5 Fr sheath in unselected patients undergoing transradial (TR) coronary angiography and/or intervention, and to assess the relative importance of sheath size and haemostasis protocol on the rate of RAO. METHODS AND RESULTS: We conducted a randomised, multicentre, non-inferiority trial comparing the GSS6Fr against the standard GS5Fr in patients undergoing TR coronary angiography and/or intervention. Patients in each group were subsequently randomised to undergo patent haemostasis or the institutional haemostasis protocol. The primary endpoint was the occurrence of RAO at discharge. A total of 1,926 patients were randomised in 12 centres. The incidence of RAO was 3.47% with GSS6Fr compared with 1.74% with GS5Fr (risk difference 1.73%, 95% CI: 0.51-2.95%; pnon-inferiority=0.150). Patients randomised to patent haemostasis had a similar rate of RAO compared with institutional haemostasis (2.61% vs. 2.61%, p=1). There was no difference with regard to all secondary endpoints, including vascular access-site complications, local bleeding and spasm. CONCLUSIONS: In this large multicentre randomised trial, the GSS6Fr was associated with a low event rate for the primary endpoint (RAO), although non-inferiority to the GS5Fr was not met, due to a lower than expected rate of RAO in the GS5Fr group. As compared to institutional haemostasis, the use of patent haemostasis was not associated with a reduced rate of RAO.

The frequency of radial artery occlusion was compared between patients receiving 4Fr versus 6Fr transradial coronary interventions (TRIs) in an open-label randomized trial (ClinicalTrials.gov identifier: NCT00815997). The primary outcome measure was radial artery occlusion on the day after TRI. The secondary outcome measures were the procedural success, major advanced cardiac events, access site-related complications, procedural times, fluoroscopy times, and contrast dye usage. A total of 160 patients were included. The procedure was successful in 79 of 80 patients (99%) in both groups. Whereas the 4Fr group showed no access site-related complications, the 6Fr developed 5 (6%), including 3 radial artery occlusions and 2 bleedings (1 radial artery perforation and 1 massive hematoma; p = 0.02). Although the radial artery occlusion rate was lower in the 4Fr versus the 6Fr groups, the difference was not significant (0% vs 4%, p = 0.08). The mean hemostasis time was significantly shorter in the 4Fr than in the 6Fr groups (237 ± 105 vs 320 ± 238 minutes, p = 0.007). In conclusion, these findings suggest that 4Fr TRI may become a less invasive alternative to 6Fr TRI in treating coronary artery diseases.

Background— Atherosclerotic plaques progress in a highly individual manner. The purposes of the Prediction of Progression of Coronary Artery Disease and Clinical Outcome Using Vascular Profiling of Shear Stress and Wall Morphology (PREDICTION) Study were to determine the role of local hemodynamic and vascular characteristics in coronary plaque progression and to relate plaque changes to clinical events. Methods and Results— Vascular profiling, using coronary angiography and intravascular ultrasound, was used to reconstruct each artery and calculate endothelial shear stress and plaque/remodeling characteristics in vivo. Three-vessel vascular profiling (2.7 arteries per patient) was performed at baseline in 506 patients with an acute coronary syndrome treated with a percutaneous coronary intervention and in a subset of 374 (74%) consecutive patients 6 to 10 months later to assess plaque natural history. Each reconstructed artery was divided into sequential 3-mm segments for serial analysis. One-year clinical follow-up was completed in 99.2%. Symptomatic clinical events were infrequent: only 1 (0.2%) cardiac death; 4 (0.8%) patients with new acute coronary syndrome in nonstented segments; and 15 (3.0%) patients hospitalized for stable angina. Increase in plaque area (primary end point) was predicted by baseline large plaque burden; decrease in lumen area (secondary end point) was independently predicted by baseline large plaque burden and low endothelial shear stress. Large plaque size and low endothelial shear stress independently predicted the exploratory end points of increased plaque burden and worsening of clinically relevant luminal obstructions treated with a percutaneous coronary intervention at follow-up. The combination of independent baseline predictors had a 41% positive and 92% negative predictive value to predict progression of an obstruction treated with a percutaneous coronary intervention. Conclusions— Large plaque burden and low local endothelial shear stress provide independent and additive prediction to identify plaques that develop progressive enlargement and lumen narrowing. Clinical Trial Registration— URL: http:www.//clinicaltrials.gov . Unique Identifier: NCT01316159.

Provisional stenting is the most common strategy in the treatment of bifurcated lesions. However, such a situation as the failure in additional stent deployment to the side branch through the stent strut is occasionally encountered. In this paper, we report on two cases, in which we managed to successfully cross an additional stent to the angulated side branch through the stent strut using the four-in-six system after failed attempts using conventional techniques. This system will allow us to perform provisional stenting more easily.

Selective production of isobutylene from acetone was examined over BEA zeolites. Isobutylene production from acetone proceeds over solid-acid catalysts via a series of consecutive reactions, which include propylene and ethylene formation by cracking and coke formation. Because the isobutylene is an intermediate chemical in this process, low diffusion resistance of the isobutylene within the pore of the catalyst is needed to prevent its further conversion. To achieve this goal, we selected a BEA-type zeolite with 12-membered rings and a 3-dimensional pore structure. To obtain high yields of isobutylene, it is also important to inhibit undesired reactions of isobutylene and other intermediates that produce aromatics and coke. In this study, the acidity of the BEA zeolites was controlled using an ion-exchange method with alkali metals. The order of catalytic activity of the ion-exchanged BEA zeolites is as follows: H-BEA, Na-BEA, K-BEA, Rb-BEA, Cs-BEA, and is the same as the order of acidity of the zeolites. Though H-BEA zeolite showed a high acetone conversion at an initial reaction time, the activity of the catalyst drastically decreased due to coke formation. In contrast, the alkali metal ion-exchanged BEA zeolites exhibited high isobutylene selectivity at high acetone conversion conditions. Moreover, the amount of coke deposited on the catalyst decreased as compared to H-BEA zeolite. In K-BEA zeolite, the isobutylene yield reached 55%.

A new outside mirror which enhances rearward visibility on a rainy day has been developed using a TiO2–SiO2 coating on the glass base. Prepared by the sol–gel process, the coating spreads out rain droplets on the mirror surface into a thin film of water by a photocatalytic hydrophilic effect in the TiO2–SiO2. This mirror maintains its good hydrophilicity for a long time, and when hydrophobic contaminations collect on the glass surface, the sun's radiation induces a photocatalytic effect that serves to decompose the contaminations. Furthermore, the new mirror has sufficiently high durability for use in the severe automotive environment.

Silica coating films with various surface morphologies, such as flat, porous (with deep pores), concave-convex (with hills and valleys), and convex (with hills on flat plane) structure were prepared from a mixture of two kinds of sols derived from polymerized tetraethoxy-silane (TEOS) and methyltriethoxysilane (MTES). Different surface morphologies were obtained by varying the molar ratio r = MTES/TEOS of the coating solution. The surface was flat for r less than 2.5, porous for 2.5 ≤ r < 5, concave-convex for 5 ≤ r < 7.5, convex for 7.5 ≤ r < 13, and again flat for r larger than 13. For 2.5 ≤ r < 5, the apparent refractive index of the silica film with porous morphology was decreased to 1.23 by selecting the solvent and by controlling the relative humidity of the coating atmosphere and the heat treatment temperature. Coating of glass with silica films of low refractive index of 1.23 led to the low reflective glasses with visible light reflectance Rvis of less than 0.2%.

女性の生理的に起こりうる全身的変化として閉経がある。この生理的なホルモン分泌の減少期が歯周疾患の進行に与える影響を調査する目的で, 閉経前と閉経後の女性歯周疾患罹患患者を被験者として, 臨床パラメーターと歯槽骨吸収量とを比較した。被験者総数は233名 (閉経前群125名, 閉経後群108名) であり, 全身疾患および歯周治療の既往がなく, 咬合性外傷, 若年性歯周炎と診断されたものは除外した。女性歯周病患者各群は閉経前群と閉経後群に, 閉経後群は閉経1～5年群, 閉経6～10年群および閉経11年以上群に分類した。さらに男性歯周病患者106名を対象群とした。被験者は10年ごとの年齢層, 閉経後年数, 歯周疾患進行度により分類した。臨床パラメーターとして現在歯数, プラークコントロールレコード, プロービングによるポケット深さ, Gingival Index, 動揺度, Gingival Bleeding Indexを測定し, さらに歯槽骨吸収量をデンタルX線写真を用いて測定した。歯槽骨吸収量および臨床パラメーターは女性患者の閉経前後群および男性患者群とを比較した。その結果, 閉経前群と比較して閉経後群が歯槽骨吸収量は大きく, 前歯部に閉経後歯槽骨吸収量が大きかった。閉経後群の女性を同年齢層の男性患者群と比較すると, 閉経後問もない50歳代で歯槽骨吸収量が有意に大きくなったことから, 女性の歯周疾患患者における歯槽骨吸収量の増加には閉経というホルモン分泌の激減する全身的変化の影響が考えられた。

Silica films with various surface morphologies, such as flatness, mesoporosity, uneveness, convexity, were prepared by hydrolysis and polymerization of tetraethoxysilane, Si(OC2H5)4(TEOS) and methyltrietoxysilane, CH3Si(OC2H5)3(MTES) under acid-catalyzed conditions. The morphology of coatings could be changed by changing the molar ratio (denoted as f, f=KITES/TEOS) in TEOS-MTES mixture, as well as the conditions of drying process and heat treatment temperature. Especially, in the case of 5

We agree entirely with Dr Kaneda that both the local endothelial shear stress (ESS) stimulus and the local atherosclerotic plaque change may occur in a highly focal manner within each 3-mm segment, and one must look at both ESS and the arterial wall in portions of the wall circumference to assess plaque behavior accurately. In our original article,1 we were limited by space to describe the effect of focal ESS on focal plaque progression around the circumference of the 3-mm segment, but we presented those results from a database study at the American Heart Association Scientific Sessions in 2012.2 Focal eccentric plaque growth in a portion of the circumference of the arterial wall is indeed strongly related …

We studied the effects of inactivators of the central histaminergic neuron system, (R)-alpha-methylhistamine, a histamine H3 receptor agonist, and (S)-alpha-fluoromethylhistidine, a histamine synthesis inhibitor, on locomotor activity and brain histamine content of mast cell-deficient W/Wv mice using a recently developed high-performance liquid chromatography system coupled with a fluorometric detector. IP injection of (R)-alpha-methylhistamine (6-50 mg/kg) increased brain histamine content after 1 h but caused no significant change in locomotor activity. IP injection of (S)-alpha-fluoromethylhistidine decreased brain histamine content at doses of 6-50 mg/kg and locomotor activity at doses of 12.5-50 mg/kg. However, locomotor activity was decreased significantly (in Student's t-test) by sequential administrations of (S)-alpha-fluoromethylhistidine (6 mg/kg) and (R)-alpha-methylhistamine (12.5 or 25 mg/kg), but not by (S)-alpha-fluoromethylhistidine (6 mg/kg) and other doses of (R)-alpha-methylhistamine (6 or 50 mg/kg). These results support the hypothesis that the central histaminergic neuron system is involved in the control of spontaneous locomotion or alertness.

The purpose of this study was to validate a new quantitative index of salvaged myocardial mass calculated from Tc-99m tetrofosmin SPECT for evaluating the therapeutic effect of emergent reperfusion therapy in acute myocardial infarction (AMI).Tc-99m tetrofosmin SPECT was performed before and after emergent percutaneous transluminal coronary angioplasty (PTCA) in eight patients with AMI. In the pre-PTCA study, Tc-99m tetrofosmin was injected before emergent PTCA. Two weeks after the PTCA, post-PTCA study was performed. As a quantitative index of salvaged myocardial mass, salvaged myocardial volume (SMV) was defined as the difference of myocardial functional volume between the SPECT studies before and after the PTCA. To investigate the clinical significance of SMV, SMV was compared with the grade of therapeutic efficacy determined visually from pre- and post-PTCA SPECT images and clinical parameters, namely peak creatine phosphokinase level (pCK) and the time from the onset of the AMI to reperfusion (RPT).SMV showed a significant correlation with the visual grade of therapeutic efficacy (r = 0.737, p0.037) and a trend toward significant correlation with pCK (r = -0.622, p0.1). SMVs in early- and late-reperfusion groups (RPTor = 6 hr and RPT6 hr) were 30.0 +/- 14.0 and -6.2 +/- 25.5 ml, showing a greater mean SMV value in the early-reperfusion group (p0.07).SMV could be used as a quantitative index of salvaged myocardial mass for evaluating the therapeutic effect of emergent reperfusion therapy.

Authors: Saeko Takahashi, Michail Papafaklis, Shigeru Saito, Yasuhiro Makita, Shigeru Nakamura, Tomohiro Kawasaki, Akihiko Takahashi, Takaaki Katsuki, Sunao Nakamura, Atsuo Namiki, Atsushi Hirohata, Toshiyuki Matsumura, Seiji Yamazaki, Hiroyoshi Yokoi, Shinji Tanaka, Satoru Otsuji, Fuminobu Yoshimachi, Junko Honye, Masaya Tsuda, Antonios Antoniadis, Ahmet Coskun, Charles Feldman, Peter Stone, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA, Shonan Kamakura General Hospital, Kamakura, Japan

A new emulsification method using a liquid crystalline phase of an ionic surfactant, l -arginine β-branched monoalkyl phosphate (R6R10MP-1Arg), which is hardly affected by temperature, has been developed. In this method, a dispersed phase (oil) is added to the liquid crystalline phase to form a gel-like oil-in-liquid crystal (O/LC) emulsion, followed by dilution with water to form a fine three-phase emulsion in which individual oil droplets are surrounded by liquid crystalline phase. From the spin labeling method of electron paramagnetic resonance, it was revealed that the presence of an appropriate amount of glycerol enhanced the rigidity of bilayers forming a lamellar liquid crystal thus promoting the formation of O/LC emulsions. The phase diagram of the R6R10MP-1Arg/oil/glycerol/water system indicates that the O/LC emulsions can be formed over quite a wide range of oil/surfactant ratios and that the droplet sizes of the resulting emulsions chiefly depended upon the oil/surfactant ratio. Submicro- and fine macroemulsions of nonpolar oils and polar oils were prepared regardless of their required hydrophil-lipophil balance by using this method.

This paper is a contribution to work on the problems of synthetic testing under short line fault conditions. The various factors which must be taken into account when assessing validity are discussed, and the experimental evidences to support the validity of the parallel current injection method are described. The paper also deals with the severest current range in short line fault conditions for different types of circuit breakers.