Chlorofluorocarbon (CFC) and sulfur hexafluoride (SF
) were used to investigate the timescale of Antarctic Bottom Water (AABW) that spreads off Cape Darnley (CD) in East Antarctica. The age of the ...AABW was estimated based on the observed SF
/CFC-12 ratio while taking into account tracer dilution by Lower Circumpolar Deep Water. Along the western canyons off CD and the ~ 3000 to 3500 m isobaths, the bottom water age was < 5 years, reflecting the spread of newly formed CD Bottom Water. Higher ages of ~ 8 years obtained for areas east of CD and > 20 years in the northwestern offshore region indicate inflows of AABW through the Princess Elizabeth Trough and Weddell Sea Deep Water, respectively. This study determined the age distribution in the region off CD, where three different types of AABW spread.
Contact force (CF) monitoring could be useful in accomplishing circumferential pulmonary vein (PV) isolation (CPVI) for atrial fibrillation (AF).
The purpose of this study was to compare procedure ...parameters and outcomes between CF-guided and non-guided CPVI.
Thirty-eight consecutive AF patients (mean age 60 ± 11 years, 28 paroxysmal AF) undergoing CPVI were randomized to non-CF-guided (n = 19) and CF-guided (n = 19) groups. CPVI was performed with the ThermoCool SmartTouch catheter in both groups. The end-point was bidirectional block between the left atrium (LA) and PV. In the CF group, CF was kept between 10 and 20 g during CPVI, whereas in the non-CF group, all CF information was blanked. Radiofrequency energy at 30 W in the anterior and 25 W in the posterior LA wall was applied for 20-25 seconds at each point.
CPVI was successfully accomplished without any major complications in both groups. Mean CF in the non-CF and CF groups were 5.9 ± 4.5 g and 11.1 ± 4.3 g, respectively, for left-side CPVI, and 9.8 ± 6.6 g and 12.1 ± 4.8 g, respectively, for right-side CPVI (both P <.001). The procedure and fluoroscopy times for CPVI in the non-CF and CF groups were 96 ± 39 minutes and 59 ± 16 minutes, respectively (P <.001), and 22 ± 63 seconds and 9 ± 20 seconds (P = NS), respectively. Total number of residual conduction gaps was 6.3 ± 3.0 in the non-CF group and 2.8 ± 1.9 in the CF group (P <.001). During 6-month follow-up, 84.2% of patients in the non-CF group and 94.7% in the CF group were free from any atrial tachyarrhythmias (P = .34).
CF-guided CPVI is effective in reducing procedure time and additional touch-up ablation and may improve long-term outcome.
In this study, we propose a robust debris estimation model applied to satellite imagery that is suitable for practical applications. In our previous study, we proposed a coastal marine debris ...estimation model using semantic segmentation applied to very high-resolution satellite images. We identified limitations when applying the model to various lower spatial and spectral resolution satellite images or to areas with fewer satellite images cases. To overcome these limitations, we now employed unsupervised domain adaptation (UDA) techniques to transfer the earlier model to these lower resolution or fewer satellite images. These domain adaptation techniques consider differences in spatial feature distributions and/or satellite sensor characteristics. We confirmed the ability of UDA to classify Planet Skysat and Airbus Pleiades images using MAXAR WorldView images to generate an accurate segmentation map. The UDA, then, allows us to analyze the lower satellite images without the need to independently generate new segmentation labels. We conducted statistical analyses and demonstrated the high correlation between the local debris cleanup data and entropy metrics computed using our UDA approach. Our method enhances the sampling frequency of satellite images by analyzing lower resolution imagery, allowing monthly to weekly, or even daily intervals, and facilitates rapid estimation utilizing fewer images, thereby providing an invaluable tool for coastal debris characterization and assessment.
Background: High shock impedance is associated with conversion failure among patients with subcutaneous implantable cardioverter defibrillators (S-ICD). Currently, there is no preoperative assessment ...method for predicting high shock impedance. This study examined the efficacy of chest computed tomography (CT) as a preoperative evaluation tool to assess the shock impedance of S-ICDs.Methods and Results: The amount of adipose tissue adjacent to the device and anteroposterior diameter at the basal heart region were measured preoperatively using chest CT. We examined the correlation between these measurements and shock impedance at the conversion test. We enrolled 43 patients with S-ICDs (mean ±SD age 54±15 years; body mass index 23±4 kg/m2; PRAETORIAN score 30–270 points; amount of adipose tissue 1,250±716 cm3), who underwent intraoperative conversion tests by inducing ventricular fibrillation, which was terminated with a 65-J shock. A sufficient concordance correlation coefficient was observed between the shock impedance and the amount of adipose tissue (r=0.616, P<0.01) and anteroposterior diameter (r=0.645, P<0.01). In multiple regression analysis, the amount of adipose tissue (β=0.439, P=0.009) and anteroposterior diameter (β=0.344, P=0.038) were identified as independent predictive factors of shock impedance.Conclusions: The preoperative CT-measured amount of adipose tissue and basal heart anteroposterior diameter are independent predictors of shock impedance. These parameters may be more accurate in identifying higher shock impedance in patients with S-ICDs.
Background:The optimum cut-off value of premature atrial contraction (PAC) burden (CV-PACb) in 24-h Holter electrocardiography (24-h ECG) for predicting atrial fibrillation (AF) is debatable, with ...few validation data.Methods and Results:We retrospectively analyzed 61 patients already diagnosed with AF (AD-AF) and 147 patients never diagnosed with AF (ND-AF), aged ≥50 years, free of heart disease, and who had undergone 24-h ECG and transthoracic echocardiography (TTE). Receiver operating characteristic analysis demonstrated that 0.4% was the optimal CV-PACb differentiating AD-AF from ND-AF, with 69% sensitivity and 72% specificity (area under the curve AUC 0.72; 95% confidence interval CI 0.65–0.79); however, the left atrial volume index was not significant (AUC 0.60; 95% CI 0.51–0.68). To verify the CV-PACb, new propensity-matched cohorts (i.e., subjects with a PAC burden ≥0.4% and <0.4%; n=69 in each group) were compared based on new detection of AF at a median follow-up of 50 months (interquartile range 12–60 months) Multivariable Cox regression analysis revealed that among 24-h ECG and TTE findings, only PAC burden ≥0.4% was independently associated with incident AF (hazard ratio 5.28; 95% CI 1.28–26.11; P=0.023).Conclusions:A high PAC burden (≥0.4%) in 24-h ECG was a reliable indicator to identify undiagnosed AF, whereas TTE parameters did not show any predictive value.
Background:Implanting a ventricular demand leadless pacemaker (VVI-LPM) for patients with non-atrial fibrillation (AF) bradyarrhythmias such as sick sinus syndrome (SSS) or high-grade (i.e., second- ...or third-degree) atrioventricular (AV) block is not recommended unless they have limited vascular access or a high infection risk; nevertheless, an unexpectedly high number of VVI-LPM implantations have been performed. This study investigated the clinical outcomes of these unusual uses.Methods and Results:This study retrospectively analyzed 193 patients who were newly implanted with a VVI-LPM or an atrioventricular synchronous transvenous pacemaker (DDD-TPM) for non-AF bradyarrhythmias at a high-volume center in Japan from September 2017 to September 2020. Propensity score-matching produced 2 comparable cohorts treated with a VVI-LPM or DDD-TPM (n=58 each). Each group had 20 (34%) patients with SSS and 38 (66%) patients with high-grade AV block. During a median follow up of 733 (interquartile range 395−997) days, there were no significant differences between the VVI-LPM and DDD-TPM groups regarding late device-related adverse events (0% vs. 4%, log-rank P=0.155), but the VVI-LPM group had a significantly increased readmission rate for heart failure (HF) (29% vs. 2%, log-rank P=0.001) and a tendency to have higher all-cause mortality (28% vs. 4%, log-rank P=0.059).Conclusions:The implantation of a VVI-LPM for non-AF bradyarrhythmias increased the incidence of HF-related rehospitalization at the mid-term follow up compared to the use of a DDD-TPM.
Purpose
The low anterior resection syndrome (LARS) score (LS) has been widely validated and has become an international tool for evaluating postoperative bowel dysfunction. However, many physicians ...still use the conventional incontinence scores in LARS treatment. Moreover, interpretation of LS and its relationship with conventional incontinence scores are not yet well understood. Here we compared the LS with the Cleveland Clinic Incontinence Score (CCIS) to clarify the clinical utility and characteristics of the LARS score.
Methods
We performed a multicentre observational study, recruiting 246 rectal cancer patients following sphincter-preserving surgery. Patients completed the LS, CCIS, and SF36 questionnaires.
Results
The response rate was 76.4%, and a total of 180 patients were analysed. The LS was strongly correlated with the CCIS (
P
< 0.001, rs = 0.727). However, among 116 patients determined to not have incontinence (CCIS 0–5), 51 (44%) were diagnosed with LARS (29 with minor LARS and 22 with major LARS). Among 68 patients without LARS, only 3 were diagnosed as having incontinence (CCIS > 6). In comparison with background factors, aging and elapsed time were associated with only LS. High LS and CCIS both showed significant quality-of-life impairment as assessed by the SF-36.
Conclusion
This is the first study to determine the difference in the numeric values between the CCIS and LS. The LS can be a convenient tool for LARS screening, identifying a wide range of patients with LARS, including those with incontinence evaluated by CCIS. Assessment using the CCIS may often underestimate LARS.
Background:Although left bundle-branch block (LBBB) is a known conduction disorder that occurs after transcatheter aortic valve implantation (TAVI), its clinical impact in the Japanese population ...remains unclear.Methods and Results:Of the 298 consecutive patients who underwent TAVI from January 2016 to December 2018 in a high-volume center in Japan, 68 with prior or periprocedural permanent pacemaker implantation (PPI), pre-existing LBBB, death during hospitalization, aborted procedure, or incomplete data were excluded. Among the final cohort of 230 patients, new-onset LBBB occurred in 90 (39%) after TAVI and persisted at 1-month follow up in 29 patients (13%; persistent new-onset LBBB, PN-LBBB). On multivariable analysis, self-expandable valve (SEV) use was found to be the only predictor of PN-LBBB (odds ratio: 4.39, 95% confidence interval: 1.69–11.41, P=0.002). There were no differences between patients with and without PN-LBBB in terms of overall mortality (18.8% vs. 26.0%, log-rank P=0.90) or need for late PPI (4.0% vs. 3.5%, log-rank P=0.74), yet there was an increased re-admission rate for heart failure (HF) in the PN-LBBB group (15.6% vs. 8.0%, log-rank P=0.046) at a median follow up of 431 (interquartile range, 271–733) days.Conclusions:PN-LBBB following TAVI was not associated with mortality or late PPI, but with a higher incidence of HF-related re-hospitalization at the mid-term follow up.
Background: In the short- to mid-term, cardiomyocytes generated from human-induced pluripotent stem cells (hiPSC-CMs) have been reported to be less mature than those of adult hearts. However, the ...maturation process in a long-term culture remains unknown. Methods and Results: A hiPSC clone generated from a healthy control was differentiated into CMs through embryoid body (EB) formation. The ultrastructural characteristics and gene expressions of spontaneously contracting EBs were analyzed through 1-year of culture after cardiac differentiation was initiated. The 14-day-old EBs contained a low number of myofibrils, which lacked alignment, and immature high-density Z-bands lacking A-, H-, I-, and M-bands. Through the long-term culture up to 180 days, the myofibrils became more tightly packed and formed parallel arrays accompanied by the appearance of mature Z-, A-, H-, and I-bands, but not M-bands. Notably, M-bands were finally detected in 360-day-old EBs. The expression levels of the M-band-specific genes in hiPSC-CMs remained lower in comparison with those in the adult heart. Immunocytochemistry indicated increasing number of MLC2v-positive/MLC2a-negative cells with decreasing number of MLC2v/MLC2a double-positive cells, indicating maturing of ventricular-type CMs. Conclusions: The structural maturation process of hiPSC-CMs through 1-year of culture revealed ultrastructural sarcomeric changes accompanied by delayed formation of M-bands. Our study provides new insight into the maturation process of hiPSC-CMs. (Circ J 2013; 77: 1307–1314)
Marine debris is a serious problem for marine ecosystems and related coastal activities. We carry out a study using in-situ debris clean-up data (collected by a local Japanese company) together with ...high spatial resolution satellite images to determine how well the satellite images can be used to estimate the amount and type of debris deposited on the beaches of the island in southern Japan. We use machine learning techniques to analyze the satellite images and find that Shannon's entropy computed from World-View 2 and 3 imagery from Maxar Corporation yields a useful detection and mapping of the coastal debris when compared with the in-situ clean-up data. We also assign a debris concentration to each satellite image pixel to visualize the distribution of the debris. The algorithm linking the satellite images to the ground truth clean-up data can now be used in areas, where no ground truth data are available.
PDF
