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Although the mechanism for the occurrence of acute myocardial infarction (MI) has been investigated by many pathological and clinical studies, it has not been adequately clarified yet. Although the disruption of vulnerable plaque is a well-known cause of acute MI, there are many silent plaque disruptions detected in the coronary artery by intravascular imaging studies. Therefore, many vulnerable plaques may disrupt and heal without causing acute MI. Some additional mechanisms other than the disruption of vulnerable plaque would be essential for the onset of acute MI. On the other hand, blood thrombogenicity would change dynamically due to circadian rhythms and many other factors. The combination of plaque and blood thrombogenicity would play an important and determinant role for the onset of acute MI.

Sudden cardiac arrest is a serious complication of acute myocardial infarction (MI). Although in-hospital mortality from MI has decreased, the mortality of MI patients complicated with out-of-hospital cardiac arrest (OHCA) remains high. However, the features of acute MI patients with OHCA have not been well known.We sought to characterize the clinical and angiographic features of acute MI patients with OHCA comparing with those without OHCA.We retrospectively analyzed 480 consecutive patients with acute MI undergoing percutaneous coronary intervention. Patients complicated with OHCA were compared with patients without OHCA.Of the patients, 141 (29%) were complicated with OHCA. Multivariate analysis revealed that age (odds ratio [OR]: 0.8; 95% confidence interval [CI]: 0.7 to 0.9 per 5 years; p 0.001), estimated glomerular filtration rate (OR: 0.8; 95% CI: 0.7 to 0.8 per 10 ml/min/1.73 mYounger age, no use of calcium-channel antagonists, worse renal function, larger infarct size, culprit lesion in the left main coronary artery, and having chronic total occlusion were associated with OHCA.

Aims Nutritional status as well as physical capacity is related to prognosis in patients with heart failure. The purpose of this study was to explore a simple prognostic indicator in patients with acute decompensated heart failure (ADHF) by including both nutritional status and physical capacity. Methods and results Patients hospitalized with ADHF (N = 203; mean age, 81 years) were enrolled. We evaluated the geriatric nutritional risk index (GNRI) on hospital admission and at discharge. A GNRI score

Background Although late gadolinium enhancement magnetic resonance imaging (LGE‐MRI) allows the identification of lesions and gaps after a cryothermal balloon (CB) ablation of paroxysmal atrial fibrillation (PAF), the accuracy has not yet been well established. Methods The subjects consisted of 10 consecutive patients who underwent a second ablation procedure among our cohort of 80 patients who underwent LGE‐MRI after the CB ablation of PAF. LGE‐MRI scar regions were compared with electroanatomical mapping during the second procedure. In the analysis, the unilateral pulmonary vein (PV) antrum was divided into 7 regions. Results The gap characterization analysis was performed in 140 regions around 40 PVs in total. There were 16 LGE‐MRI gaps around 11 PVs (mean 1.6 ± 1.4 gaps/patient) in 7 patients and 14 electrical gaps around 10 PVs in 8 patients (mean 1.4 ± 1.1 gaps/patient). The locations of 13 electrical gaps were well matched to that on the LGE‐MRI, whereas the remaining 1 electrical gap had not been predicted on the LGE‐MRI. Compared to the electrical gaps in the second procedure, the sensitivity and specificity of the LGE‐MRI gaps were 93% (13 LGE‐MRI gaps of 14 electrical gaps) and 98% (123 LGE‐MRI scars out of 126 electrical scars), respectively. Conclusion LGE‐MRI can accurately localize the lesion gaps after CB ablation of PAF.

A 60-year-old man with out-of-hospital cardiac arrest was transported to our hospital by an emergency medical service. Ventricular fibrillation was finally terminated after the initiation of circulation support by percutaneous cardiopulmonary support device. Although acute myocardial infarction was suspected, emergency coronary angiography could not identify the culprit lesion of myocardial infarction while there were multiple intermediate stenotic lesions. Since re-elevation of troponin I was recorded on the 4th day after admission, coronary angiography was performed again, and diffuse severe stenosis in the right coronary artery and total occlusion in the left circumflex coronary artery that disappeared by the injection of isosorbide dinitrate was detected. Therefore, we reached the diagnosis of acute myocardial infarction due to coronary vasospasm. It is very rare that emergency coronary angiogram reveals coronary vasospasm at the culprit lesion of myocardial infarction. The guideline recommends calcium channel antagonist and long-acting nitrates for vasospastic angina; however, it would be really difficult to make correct diagnosis of coronary vasospasm among the patients with acute myocardial infarction or out-of-hospital cardiac arrest. Repeated measurements of troponin and coronary angiography identified the cause of acute myocardial infarction as coronary vasospasm in the present case. Learning objectives: Coronary vasospasm may be one of important causes of acute MI and of OHCA, although it is difficult to be diagnosed correctly. We should always take into consideration the possibility of coronary vasospasm as the cause of acute MI or OHCA. Repeated measurements of troponin and coronary angiography were useful for the diagnosis of coronary vasospasm in the present case.

Atrial fibrillation (AF) is common in heart failure with preserved ejection fraction (HFpEF).This study aimed to investigate the prognostic value of echocardiographic markers of congestion that can be applied to both AF and patients without AF with HFpEF.We conducted a multicenter study of 505 patients with HFpEF admitted to hospitals for acute decompensated heart failure. The ratio of early diastolic transmitral flow velocity to mitral annulus velocity (E/e'), the tricuspid regurgitation peak velocity, and the collapsibility of the inferior vena cava were obtained at discharge. Congestion was determined by echocardiography if any one of E/e' ≥14 (E/e' ≥11 for AF), tricuspid regurgitation peak velocity ≥2.8 m/s, or inferior vena cava collapsibility 50% was positive. We classified patients into grade A, grade B, and grade C according to the number of positive congestion indices. The primary endpoint was the composite of cardiovascular death and heart failure hospitalization.During the follow-up period (median: 373 days), 162 (32%) patients experienced the primary endpoint. Grade C patients had a higher risk for the primary endpoint than grade A (HR: 2.98; 95% CI: 1.97-4.52) and grade B patients (HR: 1.92; 95% CI: 1.29-2.86) (log-rankEchocardiographic congestion grade has prognostic value in patients with HFpEF with and without AF.

Background: Pulmonary vein isolation (PVI) is a cornerstone of catheter ablation in patients with paroxysmal atrial fibrillation, and balloon-based ablation has been recently performed worldwide. The second-generation cryoballoon (CB2) ablation has proven to be highly effective in achieving freedom from paroxysmal atrial fibrillation. However, there are some debatable questions, including the ideal number of freeze cycles. Methods: The AD-Balloon study (Multicenter Study of the Validity of Additional Freeze Cycles for Cryoballoon Ablation) was designed as a prospective, multicenter, and randomized clinical trial for investigation of the optimal strategy of freeze cycles for the CB2 ablation. One hundred and ten consecutive patients (aged 64±11 years) were randomly assigned to 2 groups after achieving a PVI by the CB2 ablation: 3-minute freeze cycles were added to each pulmonary vein (AD group: n=55) or not (non-AD group: n=55). Delayed-enhancement magnetic resonance imaging was also performed 1 to 2 months after the PVI to assess the ablation lesions. Results: The patient characteristics did not differ between the 2 groups. A complete PVI was achieved in all patients. The total number of freeze cycles and durations for all pulmonary veins were significantly shorter in the non-AD group than in the AD group (5.7±1.6 versus 9.1±1.6 cycles, P P P =0.78). There was no significant difference in the frequency of gaps on the PVI lines in the delayed-enhancement magnetic resonance imaging (46% in the AD group versus 36% in the non-AD group; P =0.38). Conclusions: No benefit was found in the patients receiving additional 3-minute freeze cycles after the complete PVI with the CB2 ablation, suggesting that an insurance freeze after achieving a PVI with the CB2 may be unnecessary and time consuming.

Although the presence of chronic total occlusion (CTO) has been associated with long-term mortality in the patients with ST-segment elevation myocardial infarction, the influence of having CTO on in-hospital mortality in sudden cardiac arrest (SCA)-acute coronary syndrome (ACS) patients has not been reported. Therefore, we examined the association between the presence of CTO and in-hospital mortality in those patients. Consecutive 106 SCA-ACS patients who received coronary angiography were retrospectively included. The factors associated with in-hospital mortality were analyzed. Among 106 patients, 40 (38%) patients died during hospitalization. Multivariate analysis revealed presence of CTO dependent on infarct-related artery (IRA-dependent-CTO) (hazard ratio [HR] = 2.88, p = 0.004), diabetes mellitus (HR = 2.04, p = 0.044), percutaneous cardiopulmonary support use (HR = 2.22, p = 0.045), successful recanalization (HR = 0.31, p = 0.004), and peak creatine kinase muscle-brain fraction (HR = 1.11, p0.001) were significantly associated with mortality. In conclusion, presence of IRA-dependent-CTO was significantly associated with in-hospital mortality in SCA-ACS patients.

Fractional excretion of sodium (FENa) before discharge has been reported to predict the prognosis in patients with acute decompensated heart failure (ADHF). Fractional excretion of urea nitrogen (FEUN) and urine osmolality (U-OSM) in the spot urine, which also reflect the activity of renal tubules

Tricuspid annular plane systolic excursion (TAPSE) is a simple and widely used method for assessing right ventricular systolic function. TAPSE has been related to the prognosis in patients with heart failure with preserved ejection fraction (HFpEF) by many earlier researches. Nonetheless, these

Aims Although patients with paroxysmal atrial fibrillation (AF) and prolonged sinus pauses [tachycardia–bradycardia syndrome (TBS)] are generally treated by permanent pacemaker, catheter ablation has been reported to be a curative therapy for TBS without pacemaker implantation. The purpose of this study was to define the potential role of successful ablation in patients with TBS. Methods and results Of 280 paroxysmal AF patients undergoing ablation, 37 TBS patients with both AF and symptomatic sinus pauses (age: 62 ± 8 years; mean maximum pauses: 6 ± 2 s) were analysed. During the 5.8 ± 1.2 years (range: 5–8.7 years) follow-up, both tachyarrhythmia and bradycardia were eliminated by a single procedure in 19 of 37 (51%) patients. Repeat procedures were performed in 14 of 18 patients with tachyarrhythmia recurrence (second: 12 and third: 2 patients). During the repeat procedure, 79% (45 of 57) of previously isolated pulmonary veins (PVs) were reconnected to the left atrium. Pulmonary vein tachycardia initiating the AF was found in 46% (17 of 37) and 43% (6 of 14) of patients during the initial and second procedure, respectively. Finally, 32 (86%) patients remained free from AF after the last procedure. Three patients (8%) required pacemaker implantation, one for the gradual progression of sinus dysfunction during a period of 6.5 years and the others for recurrence of TBS 3.5 and 5.5 years after ablation, respectively. Conclusion Catheter ablation can eliminate both AF and prolonged sinus pauses in the majority of TBS patients. Nevertheless, such patients should be continuously followed-up, because gradual progression of sinus node dysfunction can occur after a long period of time.

A 66-year-old man underwent a second ablation for atrial fibrillation (AF). Intravenous isoproterenol administration caused the atrial premature beat (APB), triggering AF. The APB originated in the right atrium and invariably initiated AF. Therefore, contact activation mapping could not be performed without frequent electrocardioversion. To prevent the initiation of AF without inhibiting the APB firing, we administered nifekalant intravenously, which facilitated precise activation mapping and ablation of the AF-triggering APB. The administration of nifekalant may improve clinical outcomes of catheter ablation for AF triggered by non-pulmonary vein APB, which invariably initiates AF.

We report on a 73-year-old man who had been diagnosed with dilated cardiomyopathy by myocardial biopsy 6 years before. He has been also suffered from renal failure on HD for 3 years. In spite of appropriated medications, previous echocardiography showed very poor left ventricular contraction (EF

MOX fuel which stands for Mixed Oxide fuel is one of the most realistic options for utilizing plutonium as an energy resource in the future with nuclear fuel cycle system including breede reactors.Development of MOX fuel is undertaken in Tokai Laboratory of PNC (Power Reactor and Nuclear Fuel Development Corporation) faced with the PNC's breeder reactor program.In the text, features of nuclear fuel, completely different from fossil fuel, and state of the art of MOX fuel development is discribed plain.

The plutonium inventory control (PINC) system is a real-time material accountability control system that is expected to be applied to a new large-scale plutonium fuel production facility for both fast breeder reactor and heavy water reactor at the Power Reactor and Nuclear Development Corporation. The PINC is basically a system for material control but is expected to develop into a whole facility control system, including criticality control, process control, quality control, facility protection, and so forth. Under PINC, every process and storage area is divided into a unit area, which is the smallest unit for both accountability and process control. Item and material weight automatically are accounted for at every unit area, and data are simultaneously treated by a computer network system. Sensors necessary for the system are being developed. 9 figures.