Solid-State Reaction Heterogeneity During Calcination of Lithium-Ion Battery Cathode.

During solid-state calcination, with increasing temperature, materials undergo complex phase transitions with heterogeneous solid-state reactions and mass transport. Precise control of the calcination chemistry is therefore crucial for synthesizing state-of-the-art Ni-rich layered oxides (LiNi1-x-y Cox Mny O2 , NRNCM) as cathode materials for lithium-ion batteries. Although the battery performance depends on the chemical heterogeneity during NRNCM calcination, it has not yet been elucidated. Herein, through synchrotron-based X-ray, mass spectrometry microscopy, and structural analyses, it is revealed that the temperature-dependent reaction kinetics, the diffusivity of solid-state lithium sources, and the ambient oxygen control the local chemical compositions of the reaction intermediates within a calcined particle. Additionally, it is found that the variations in the reducing power of the transition metals (i.e., Ni, Co, and Mn) determine the local structures at the nanoscale. The investigation of the reaction mechanism via imaging analysis provides valuable information for tuning the calcination chemistry and developing high-energy/power density lithium-ion batteries.

Quantum dot-integrated GaN light-emitting diodes with resolution beyond the retinal limit.

Near-eye display technology is a rapidly growing field owing to the recent emergence of augmented and mixed reality. Ultrafast response time, high resolution, high luminance, and a dynamic range for outdoor use are all important for non-pixelated, pupil-forming optics. The current mainstream technologies using liquid crystals and organic materials cannot satisfy all these conditions. Thus, finely patterned light-emissive solid-state devices with integrated circuits are often proposed to meet these requirements. In this study, we integrated several advanced technologies to design a prototype microscale light-emitting diode (LED) arrays using quantum dot (QD)-based color conversion. Wafer-scale epilayer transfer and the bond-before-pattern technique were used to directly integrate 5-µm-scale GaN LED arrays on a foreign silicon substrate. Notably, the lithography-level alignment with the bottom wafer opens up the possibility for ultrafast operation with circuit integration. Spectrally pure color conversion and solvent-free QD patterning were also achieved using an elastomeric topographical mask. Self-assembled monolayers were applied to selectively alter the surface wettability for a completely dry process. The final emissive-type LED array integrating QD, GaN, and silicon technology resulted in a 1270 PPI resolution that is far beyond the retinal limit.

Contact Engineering of Vertically Grown ReS2 with Schottky Barrier Modulation.

Forming metal contact with low contact resistance is essential for the development of electronics based on layered van der Waals materials. ReS2 is a semiconducting transition metal dichalcogenide (TMD) with an MX2 structure similar to that of MoS2. While most TMDs grow parallel to the substrate when synthesized using chemical vapor deposition (CVD), ReS2 tends to orient itself vertically during growth. Such a feature drastically increases the surface area and exposes chemically active edges, making ReS2 an attractive layered material for energy and sensor applications. However, the contact resistances of vertically grown materials are known to be relatively high, compared to those of common 2H-phase TMDs, such as MoS2. Most reported methods for lowering the contact resistance have been focused on exfoliated 2H-phase materials with only a few devices tested, and few works on distorted T-phase materials exist. Moreover, nearly all reported studies have been conducted on only a few devices with mechanically exfoliated fl Most reported methods for lowering the contact resistance have been 2 contacts was modulated by conformally coating a thin tunneling interlayer between the metal and the dendritic ReS2 film. Over a hundred devices were tested, and contact resistances were extracted for large-scale statistical analysis. Importantly, we compared various known materials and techniques for lowering contact resistance and found an optimized method. Finally, the reductions in barrier height were directly correlated with exponential reductions in contact resistance and increases in drive-current by almost 2 orders of magnitude.

Novel Model to Predict HCC Recurrence after Liver Transplantation Obtained Using Deep Learning: A Multicenter Study.

Several models have been developed using conventional regression approaches to extend the criteria for liver transplantation (LT) in hepatocellular carcinoma (HCC) beyond the Milan criteria. We aimed to develop a novel model to predict tumor recurrence after LT by adopting artificial intelligence (MoRAL-AI). This study included 563 patients who underwent LT for HCC at three large LT centers in Korea. Derivation (n = 349) and validation (n = 214) cohorts were independently established. The primary outcome was time-to-recurrence after LT. A MoRAL-AI was derived from the derivation cohort with a residual block-based deep neural network. The median follow-up duration was 74.7 months (interquartile-range, 18.5-107.4); 204 patients (36.2%) had HCC beyond the Milan criteria. The optimal model consisted of seven layers including two residual blocks. In the validation cohort, the MoRAL-AI showed significantly better discrimination function (c-index = 0.75) than the Milan (c-index = 0.64), MoRAL (c-index = 0.69), University of California San Francisco (c-index = 0.62), up-to-seven (c-index = 0.50), and Kyoto (c-index = 0.50) criteria (all p < 0.001). The largest weighted parameter in the MoRAL-AI was tumor diameter, followed by alpha-fetoprotein, age, and protein induced by vitamin K absence-II. The MoRAL-AI had better predictability of tumor recurrence after LT than conventional models. The MoRAL-AI can also evolve with further data.

Deep learning model for prediction of hepatocellular carcinoma in patients with HBV-related cirrhosis on antiviral therapy.

BACKGROUND & AIMS: Personalised risk prediction of the development of hepatocellular carcinoma (HCC) among patients with liver cirrhosis on potent antiviral therapy is important for targeted screening and individualised intervention. This study aimed to develop and validate a new model for risk prediction of HCC development based on deep learning, and to compare it with previously reported risk models. METHODS: A novel deep-learning-based model was developed from a cohort of 424 patients with HBV-related cirrhosis on entecavir therapy with 2 residual blocks, including 7 layers of a neural network, and it was validated using an independent external cohort (n = 316). The deep-learning-based model was compared to 6 previously reported models (platelet, age, and gender-hepatitis B score [PAGE-B], Chinese University HCC score [CU-HCC], HCC-Risk Estimating Score in CHB patients Under Entecavir [HCC-RESCUE], age, diabetes, race, etiology of cirrhosis, sex, and severity HCC score [ADRESS-HCC], modified PAGE-B score [mPAGE], and Toronto HCC risk index [THRI]) using Harrell's concordance (c)-index. RESULTS: During a median 5.2 yr of follow-up (inter-quartile range 2.8-6.9 yr), 86 patients (20.3%) developed HCC. The deep-learning-based model had a Harrell's c-index of 0.719 in the derivation cohort and 0.782 in the validation cohort. Goodness of fit was confirmed by the Hosmer-Lemeshow test (p >0.05). Moreover, this model in the validation cohort had the highest c-index among the 6 previously reported models: PAGE-B (0.570), CU-HCC (0.548), HCC-RESCUE (0.577), ADRESS-HCC (0.551), mPAGE (0.598), and THRI (0.587) (all p <0.001). The misclassification rate of this model was 23.7% (model accuracy: 76.3%) in the validation group. CONCLUSIONS: The deep-learning-based model had better performance than the previous models for predicting the HCC risk in patients with HBV-related cirrhosis on potent antivirals. LAY SUMMARY: For early detection of hepatocellular carcinoma, it is important to maintain regular surveillance. However, there is currently no standard prediction model for risk stratification that can be used to establish a personalised surveillance strategy. We develop and validate a deep-learning-based model that showed better performance than previous models.

Elevation of heart-femoral pulse wave velocity by short-term low sodium diet followed by high sodium diet in hypertensive patients with sodium sensitivity.

BACKGROUND/OBJECTIVES: We compared changes in heart-femoral pulse wave velocity (hfPWV) in response to low sodium and high sodium diet between individuals with sodium sensitivity (SS) and resistance (SR) to evaluate the influence of sodium intake on arterial stiffness. SUBJECTS/METHODS: Thirty-one hypertensive and 70 normotensive individuals were given 7 days of low sodium dietary approach to stop hypertension (DASH) diet (LSD, 100 mmol NaCl/day) followed by 7 days of high sodium DASH diet (HSD, 300 mmol NaCl/day) during 2 weeks of hospitalization. The hfPWV was measured and compared after the LSD and HSD. RESULTS: The hfPWV was significantly elevated from LSD to HSD in individuals with SS (P = 0.001) independently of changes in mean arterial pressure (P = 0.037). Conversely, there was no significant elevation of hfPWV from LSD to HSD in individuals with SR. The percent change in hfPWV from the LSD to the HSD in individuals with SS was higher than that in individuals with SR. Subgroup analysis revealed that individuals with both SS and hypertension showed significant elevation of hfPWV from LSD to HSD upon adjusted analysis using changes of the means arterial pressure (P = 0.040). However, there was no significant elevation of hfPWV in individuals with SS and normotension. CONCLUSION: High sodium intake elevated hfPWV in hypertensive individuals with SS, suggesting that high sodium intake increases aortic stiffness, and may contribute to enhanced cardiovascular risk in hypertensive individuals with SS.

Glucose-insulin-potassium solution protects ventricular myocytes of neonatal rat in an in vitro coverslip ischemia/reperfusion model.

BACKGROUND AND OBJECTIVES: The benefit of high glucose-insulin-potassium (GIK) solution in clinical applications is controversial. We established a neonatal rat ventricular myocyte (NRVM) in vitro coverslip ischemia/reperfusion (I/R) model and investigated the effects of GIK solution on suppressing reactive oxygen species (ROS) and upregulating O-GlcNacylation, which protects cells from ischemic injury. MATERIALS AND METHODS: NRVMs were isolated from postnatal day 3-4 Sprague-Dawley rat pups and grown in Dulbecco's modified Eagle's medium containing high glucose (4.5 g/L), fetal bovine serum, and penicillin/streptomycin. The effects of the GIK solution on ROS production, apoptosis, and expression of O-GlcNAc and O-GlcNAc transferase (OGT) were investigated in the coverslip I/R model. RESULTS: Covering the 24-well culture plates for 3 hr with 12 mm diameter coverslips resulted in the appropriate ischemic shock. Glucose and insulin synergistically reduced ROS production, protected NRVM dose-dependently from apoptosis, and altered O-GlcNAc and OGT expression. CONCLUSION: The high GIK solution protected NRVM from I/R injury in vitro by reducing ROS and altering O-GlcNacylation.

A case of popliteal artery entrapment syndrome presenting with acute limb ischaemia.

Popliteal artery entrapment syndrome (PAES) is caused by an anomalous anatomic relationship between the popliteal artery and the musculotendinous structures in the popliteal fossa. In the early stage of PAES, patients most commonly present with intermittent claudication. If we don't perform appropriate investigation, the diagnosis of PAES is easily missed and may lead to irreversible arterial damage. Thrombus formation in the damaged popliteal artery can cause complete obstruction of the popliteal artery leading to acute limb-threatening ischaemia.

High sodium intake in women with metabolic syndrome.

BACKGROUND AND OBJECTIVES: Metabolic syndrome and high sodium intake are associated with frequent cardiovascular events. Few studies have estimated sodium intake in subjects with metabolic syndrome by 24-hour urine sodium excretion. We evaluated sodium intake in individuals with metabolic syndrome. SUBJECTS AND METHODS: Participants were recruited by random selection and through advertisement. Twenty four-hour urine collection, ambulatory blood pressure measurements, and blood test were performed. Sodium intake was estimated by 24-hour urine sodium excretion. Participants receiving antihypertensive medications were excluded from analysis. RESULTS: Among the 463 participants recruited, subjects with metabolic syndrome had higher levels of 24-hour urine sodium excretion than subjects without metabolic syndrome (p=0.0001). There was a significant relationship between the number of metabolic syndrome factors and 24-hour urine sodium excretion (p=0.001). The proportion of subjects with metabolic syndrome was increased across the tertile groups of 24-hour urine sodium excretion (p<0.0001). The association of high sodium intake and metabolic syndrome was significant only among women. Among the factors related to metabolic syndrome, body mass index had an independent association with 24-hour urine sodium excretion (p<0.0001). CONCLUSION: Women with metabolic syndrome exhibited significantly higher sodium intake, suggesting that dietary education to reduce sodium consumption should be emphasized for women with metabolic syndrome.

Brachial-ankle pulse wave velocity for the prediction of the presence and severity of coronary artery disease.

The predictability of brachial-ankle pulse wave velocity (baPWV) for the presence and severity of coronary artery disease (CAD) was investigated by measuring baPWV in 501 subjects scheduled for coronary angiography. Severity of CAD was measured using modified Gensini stenosis score (GSS) and classified as a vessel disease score (VDS) of 0-3. The presence of CAD was defined as diameter stenosis>50%. Subjects were grouped in tertile by level of baPWV (<14, 14-17, >17 m/s). Subjects with CAD showed higher mean age, prevalence of men and diabetes, and systolic blood pressure. The prevalence of hypertension, use of antihypertensive medications and use of statin was not different. Subjects with CAD had higher baPWV than subjects without CAD (16.70 ± 3.46 versus 15.21 ± 3.19 m/s, p<0.001). Multiple linear regression analysis showed significant correlation of baPWV and modified GSS (p=0.0337). ANCOVA adjusted with age, gender, body mass index, presence of hypertension or diabetes, status of smoking, use of antihypertensive medications and risk of hypercholesterolemia showed a statistically significant association of baPWV with VDS (p<0.0001). Highest tertile of baPWV had a statistically significant effect on the severity of CAD from an ANCOVA model. The predictive power of highest tertile of baPWV for the presence of CAD was 3.600 [95% confidence interval (CI) 1.884-6.881, p<0.0001]. It is concluded that increased baPWV is a reliable predictor of the presence and severity of CAD, suggesting that baPWV>17 m/s may be a threshold value for the presence and severity of CAD.

Severe hyperkalemia can be detected immediately by quantitative electrocardiography and clinical history in patients with symptomatic or extreme bradycardia: a retrospective cross-sectional study.

PURPOSE: Detecting severe hyperkalemia is challenging. We explored its prevalence in symptomatic or extreme bradycardia and devised a diagnostic rule. MATERIALS AND METHODS: This retrospective cross-sectional study included patients with symptomatic (heart rate [HR] ≤ 50/min with dyspnea, chest pain, altered mentality, dizziness/syncope/presyncope, general weakness, oliguria, or shock) or extreme (HR ≤ 40/min) bradycardia at an emergency department for 46 months. Risk factors for severe hyperkalemia were chosen by multiple logistic regression analysis from history (sex, age, comorbidities, and medications), vital signs, and electrocardiography (ECG; maximum precordial T-wave amplitude, PR, and QRS intervals). The derived diagnostic index was validated using bootstrapping method. RESULTS: Among the 169 participants enrolled, 87 (51.5%) were female. The mean (SD) age was 71.2 (12.5) years. Thirty-six (21.3%) had severe hyperkalemia. The diagnostic summed "maximum precordial T ≥ 8.5 mV (2)," "atrial fibrillation/junctional bradycardia (1)," "HR ≤ 42/min (1)," "diltiazem medication (2)," and "diabetes mellitus (1)." The C-statistics were 0.86 (0.80-0.93) and were validated. For scores of 4 or higher, sensitivity was 0.50, specificity was 0.92, and positive likelihood ratio was 6.02. The "ECG-only index," which sums the 3 ECG findings, had a sensitivity of 0.50, specificity of 0.90, and likelihood ratio (+) of 5.10 for scores of 3 or higher. CONCLUSIONS: Severe hyperkalemia is prevalent in symptomatic or extreme bradycardia and detectable by quantitative electrocardiographic parameters and history.

Subclinical renal insufficiency range of estimated glomerular filtration rate and microalbuminuria are independently associated with increased arterial stiffness in never treated hypertensives.

BACKGROUND AND OBJECTIVES: Microalbuminuria (MAU) and decreased estimated glomerular filtration rate (eGFR) are risk factors for cardiovascular disease (CVD) in patients with hypertension. However, in hypertensive patients with normal or minimally reduced eGFR (≥60 mL/min/1.73 m(2)) and with normo- or MAU, the value of combined estimation of eGFR and urine microalbumin for the risk assessment has not been widely reported. We evaluated the association between arterial stiffness and the combined estimation of eGFR and urine microalbumin. SUBJECTS AND METHODS: Subjects with never treated hypertension and normal or minimally reduced eGFR were evaluated (n=491, 50.1±10.4 years). eGFR was calculated by the simplified Modification of Diet in Renal Disease formula. Urinary albumin-to-creatinine ratio (UACR) was assessed with spot urine. Arterial stiffness was assessed with heart-femoral pulse wave velocity (hfPWV). All subjects were divided into four groups; group 1, eGFR ≥90 mL/min/1.73 m(2) (normal eGFR) and normo-albuminuria (NAU); group 2, eGFR 89.9-60 mL/min/1.73 m(2) (minimally reduced eGFR) and NAU; group 3, normal eGFR and MAU; group 4, minimally reduced eGFR and MAU. RESULTS: Group 1 had the lowest hfPWV (964.6±145.4; group 2, 1013.5±168.9; group 3, 1058.2±238.0; group 4, 1065.8±162.9 cm/sec). Analysis adjusting age, sex, body mass index, heart rate and mean arterial pressure showed significantly lower hfPWV of group 1 compared to group 2 (p=0.032) and 3 (p=0.007). Multiple regression analysis showed a significant association of hfPWV with logUACR {beta=0.096, 95% confidence interval (CI) 8.974-60.610, p=0.008} and eGFR (beta=-0.069, 95% CI -1.194 - -0.005, p=0.048). CONCLUSION: Minimally reduced eGFR or MAU is independently associated with increased arterial stiffness, indicating greater CVD risk.

Frequency and related factors of masked hypertension at a worksite in Korea.

OBJECTIVES: Masked hypertension is associated with metabolic risks and increased risk of cardiovascular disease. The purpose of this study was to identify the frequency of and risk factors of masked hypertension in Korean workers. METHODS: The study was conducted among 121 employees at a hotel in Gyeongju, Korea, from December 2008 to February 2009. We measured blood pressure (BP) both in the clinic and using 24-hour ambulatory BP monitors for all subjects. Hypertension was defined independently by both methods, and subjects were classified into four groups: true normotension, masked hypertension, white coat hypertension, and sustained hypertension. RESULTS: The frequency of masked hypertension in our study group was 25.6%. Compared with true normotension, the factors related to masked hypertension were male gender (odds ratio [OR], 10.7; 95% confidence interval [CI], 1.41 to 81.09), aging one year (OR, 0.88; 95% CI, 0.78 to 0.99), clinic BP 120-129/80-84 mmHg (OR, 8.42; 95% CI, 1.51 to 46.82), clinic BP 130-139 / 85-89 mmHg (OR, 12.14; 95% CI, 1.80 to 81.85), smoking (OR, 5.51; 95% CI, 1.15 to 26.54), and increase of total cholesterol 1 mg / dL (OR, 1.05; 95% CI, 1.02 to 1.08). In males only, these factors were clinic BP 120-129 / 80-84 mmHg (OR, 15.07; 95% CI, 1.55 to 146.19), clinic BP 130-139 / 85-89 mmHg (OR, 17.16; 95% CI, 1.56 to 189.45), smoking (OR, 11.61; 95% CI, 1.52 to 88.62), and increase of total cholesterol 1 mg/dL (OR, 1.05; 95% CI, 1.01 to 1.09). CONCLUSIONS: The frequency of masked hypertension was high in our study sample. Detection and management of masked hypertension, a known strong predictor of cardiovascular risk, could improve prognosis for at-risk populations.

Effect of Korean red ginseng on arterial stiffness in subjects with hypertension.

OBJECTIVES: Korean red ginseng (KRG) improves endothelial function and lower blood pressure (BP), which may affect arterial stiffness. The present study evaluated whether KRG treatment could improve arterial stiffness in subjects with hypertension. SUBJECTS AND METHODS: Eighty (80) participants with hypertension who were treated with antihypertensive agents were randomly assigned to an active (KRG 3 g/day) or a placebo treatment group in a double-blind manner. Participants were not allowed to change their antihypertensive medications. Systolic BP (SBP) and diastolic BP (DBP) were measured at baseline, and at 1, 2, and 3 months. Arterial stiffness was assessed by the measurement of brachial-ankle pulse wave velocity (baPWV) at baseline, and at 1 and 3 months. RESULTS: Thirty (30) subjects in the active group (AG) and 34 subjects in the placebo group (PG) completed 3 months of treatment and then a per-protocol analysis was done. SBP and DBP at baseline, and at 1, 2, and 3 months were not different between the AG and PG (p>0.05). After 3 months of treatment, SBP of AG was not changed from SBP at baseline. However, DBP of AG, and SBP and DBP of PG after 3 months of treatment were significantly reduced (p<0.05). baPWV of both groups was significantly reduced at 1 and 3 months (p<0.05), but was not different between the groups at each time point. Analysis after adjustment for age, time-dependent mean arterial BP, heart rate, and levels of fasting blood glucose and triglycerides showed no significant difference between AG and PG in changes of baPWV from baseline to 1 and 3 months (p>0.05). CONCLUSIONS: Three (3) months' treatment with KRG did not improve arterial stiffness in subjects with hypertension.

Titanium dioxide inclusion in backing reduce the photoallergenicity of ketoprofen transdermal patch.

Ketoprofen (KP) is a widely used transdermal non-steroidal anti-inflammatory drug. However, increasing number of adverse effect case reports suggests that KP transdermal formulation can cause photoallergic reaction. The photoallergic potential of KP is attributable to the instability of KP under UV/visible light and subsequent formation of reactive degradation products. In this study, we investigated whether the inclusion of titanium dioxide (TiO(2)), a well-known mineral sunscreen agent, in the KP transdermal patch can prevent the photodegradation of KP and ultimately, can reduce photoallergic reaction. TiO(2) inclusion in fabric backing effectively decreased the UV transmission through fabric patch throughout all UVA region from 320 to 380 nm and consistently, KP patch with TiO(2) exhibited significantly increased photostability of KP. This enhanced photostability of KP resulted in reduced generation of photodegradation product as determined by HPLC-UV analysis. In a good accordance with these in vitro results, photosensitization test in guinea pig in vivo demonstrated low photoallergic reactions of KP patch with TiO(2) compared to KP patch without TiO(2), indeed. This study demonstrated that KP transdermal patch with TiO(2)-included backing can provide with improved photostability and photosafety over conventional fabric KP patch.

The variant type of preauricular sinus: postauricular sinus.

OBJECTIVE: Preauricular sinuses (PAS) are common congenital malformations that usually occur at the anterior margin of the ascending limb of the helix, but the positions of PAS and directions on the fistular tracts are rarely posterior to the external auditory canal (EAC), which presents as a postauricular swelling. We named these cases as the variant type of PAS ('postauricular sinuses'), and compared their clinical manifestations with those of the classical type. STUDY DESIGN: A retrospective study. METHODS: We retrospectively reviewed the charts of patients who had undergone preauricular fistulectomy from 2002 to 2006. These patients were then categorized into two groups according to the position of the preauricular sinus sac. The classical group was defined as the group of patients with sacs located on the (superior) anterior to the EAC, and the variant group as those whose sacs are located on the posterior site of the EAC. We analyzed the incidence, previous histories, clinical manifestations, recurrence rates, and surgical techniques of the variant type of preauricular sinuses and compared them with those of the classical type. RESULTS: Eleven (10.9%) of 101 patients were diagnosed with preauricular sinuses of the variant type. The male to female ratios of the classical and the variant groups were 44:46 and 7:4, respectively. The average age of the patients was approximately 11 to 13 years in both groups. All variant types of preauricular sinuses showed preauricular pits located posterior to the imaginary line that connects the tragus with the posterior margin of the ascending limb of the helix, unlike the classical type. Most (72.8%) of the fistular tracts of the variant type were directed in the posterior-middle direction from the pits. The variant types were operated with a dual approach using preauricular and retroauricular incisions, unlike the classical type, and the recurrence rate was 0% (compared with 2.2% in the classical type). CONCLUSION: Frequent postauricular infected swellings may indicate the presence of the variant type of preauricular sinuses. The variant type of preauricular sinuses presenting in the postauricular area were found to have an unusual location of the fistula pit that was positioned posterior to the imaginary tragal extended line. A comprehensive physical examination of the preauricular pits should be performed to avoid incomplete excision of the variant types.

Prediction of paroxysmal atrial fibrillation using nonlinear analysis of the R-R interval dynamics before the spontaneous onset of atrial fibrillation.

BACKGROUND: New methods based on nonlinear theory have been developed to give more insight into complex heart rate (HR) dynamics. This study was designed to test the hypothesis that altered HR dynamics, as analyzed with complexity and fractal measures, may precede the spontaneous onset of paroxysmal atrial fibrillation (PAF). Secondly, the difference in the temporal change of these measurements between the different types of atrial fibrillation (AF) was assessed. METHODS AND RESULTS: From 105 Holter tapes in which PAF was recorded, 44 PAF (>or=5 min) episodes in 33 patients (22 men, 58 +/- 12 years), preceded by sinus rhythm for more than 1 h, were selected and submitted to time-and frequency-domain HR variability analyses, along with detrended fluctuation analysis, approximate entropy (ApEn) and sample entropy (SampEn). The 60 min before the onset of AF were divided into 6 10-min periods and studied using repeated measures ANOVA. PAF episodes were divided into 3 subgroups: an increased HF component and decreased L/H ratio (vagal type, n=20); increased L/H ratio and decreased HF component (sympathetic type, n=14); and non-related type (n=10). None of the time- or frequency-domain parameters showed any significant change before AF in any type of AF. The alpha(1) showed a tendency to decrease before the onset of AF and the change in alpha(1) was divergent according to the AF type. The ApEn decreased before the onset of AF (1.005+/-0.046, 60-50 min before AF to 0.894+/-0.052, 10-0 min before AF; p=0.032). The SampEn also decreased progressively before the start of AF (1.165 +/- 0.085, 60-50 min before AF to 0.887 +/- 0.077, 10-0 min before AF, p=0.003). The decrease in both the ApEn and SampEn was irrespective of the AF type. CONCLUSIONS: A reduction in the ApEn and SampEn, which reflects the nonlinear complexity of HR variability, is a hallmark of altered HR dynamics preceding the spontaneous onset of AF.

Apical hypertrophic cardiomyopathy with apical necrosis and aneurysm formation.

Apical hypertrophic cardiomyopathy, characterized by giant T-waves and spade-shaped left ventricular cavity is prevalent in Oriental people, particularly the Japanese. We report an asymptomatic case of apical hypertrophic cardiomyopathy progressing to myocardial necrosis and aneurysm formation because of the chronic myocardial ischemia at the apex.