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PURPOSE Cardiac implantable electronic devices (CIEDs) offer diagnostic information such as device-measured physical activity (PA). Peak oxygen consumption (VO2) measured by cardiopulmonary exercise testing (CPET) is the most objective variable showing exercise capacity. The purpose of this study was to investigate the relationship between these 2 variables. METHODS We retrospectively studied consecutive patients with CIEDs undergoing CPET between April 1, 2018, and January 31, 2021. These patients were divided into 2 groups: patients with peak VO2 ≤ 14 ml/kg/min (low peak VO2 group) and those showing peak VO2 > 14 ml/kg/min (high peak VO2 group). The peak device-measured PA was compared between the 2 groups. The relationship between the peak device-measured PA and peak VO2 was also investigated. RESULTS There were 50 and 51 patients in the low and high peak VO2 groups, respectively. The peak device-measured PA, which was expressed in units of hours/day, was significantly lower in the low peak VO2 group than in the high peak VO2 group (3.06, interquartile range [2.43-4.00] vs. 5.50, interquartile range [4.04-6.70] p 3.87 h/day could predict high peak VO2 (80.4%, sensitivity; 72.0%, specificity). In multivariate linear regression analysis, peak device-measured PA was an independent predictor of peak VO2 (regression coefficient, 0.61; 95% confidence interval, 0.33-0.89; p

Obstructive sleep apnea (OSA) is associated with the occurrence of various kinds of bradyarrhythmia and tachyarrhythmia. The activation of the autonomic nerve system is an important causative factor of the pathogenesis of the arrhythmia in OSA patients. Previous studies have shown that the R-R interval is an effective parameter for evaluating autonomic nerve activities. However, whether or not OSA can induce variations in the R-R interval and whether or not continuous positive airway pressure (CPAP) therapy can improve these variations in OSA patients are unclear. The present study explored whether or not CPAP therapy could improve the regularity of the R-R interval.

Cardiac implantable electronic devices (CIEDs) offer heart failure (HF) diagnostic information, including intrathoracic impedance (ITI) or physical activity (PA). However, few studies have evaluated the utility of these parameters measured by CIEDs with CorVue algorithm. The purpose of this study was to investigate the relationship between ITI alerts triggered by the CorVue algorithm and HF development. We also examined the association between device-measured PA and ITI alerts associated with HF development. We retrospectively studied consecutive patients with CIEDs equipped with CorVue algorithm, which were implanted between June 1, 2011 and August 31, 2019. These patients were divided into two groups: patients with decreased ITI followed by the ITI alerts (ITI alert group) and those without the alerts (non-ITI alert group). There were 35 and 14 patients in the ITI and non-ITI alert groups, respectively. A total of 96 ITI alerts were observed. ITI alerts associated with HF development were observed in 21% (20/96); whereas, ITI alerts not associated with HF development were observed in 79% (76/96). Accurate device-measured PA was confirmed in 76 ITI alerts, which consisted of 30 alerts with lower PA and 46 alerts without lower PA. ITI alerts associated with HF development were observed in 30% (9/30) of the alerts with lower PA, whereas observed only in 6.5% (3/46) of the alerts without lower PA. In conclusion, the CorVue ITI alerts indicated a high false-positive rate. However, device-measured PA may be useful to determine whether ITI alerts are associated with HF development or not, which was attributed to the high negative predictive value.

Resting end-tidal CO2 levels obtained from capnography are associated with the severity of heart failure (HF). It has not been fully investigated whether other respiratory parameters acquired from detailed capnography waveform analyses could evaluate the recovery process in HF patients. In this case, the analysis of nasal capnography waveforms (diurnal five minutes recording) was performed to monitor and analyze end-tidal CO2 (ETCO2) values, inspiratory/expiratory ratio and respiratory intervals. We observed that these three parameters increased concurrently with decreasing plasma BNP levels during the recovery stage of HF. The kurtosis of frequency distributions of capnography waveforms became larger as HF improved. Proper utilization of these analyses could evaluate HF severity during the recovery process in patients with HF.

Background The purpose of this study is to investigate if a laryngeal mask could improve respiratory condition during radiofrequency catheter ablation (RFCA). Methods Twenty-four consecutive patients who underwent RFCA for atrial fibrillation were divided into two groups (Facemask group; n = 10, Laryngeal mask group; n = 14). All patients were completely sedated under intravenous anesthesia and fitted with artificial respirators during the RFCA. The capnography waveforms and their differential coefficients were analyzed to evaluate the changes of end-tidal CO2 (ETCO2) values, respiratory intervals, expiratory durations, and inspiratory durations. Results During the RFCA, ETCO2 values of the laryngeal mask group were higher than those of the facemask group (36.0 vs. 29.2 mmHg, p = 0.005). The respiratory interval was significantly longer in the laryngeal mask group than those in the facemask group (4.28 s vs.5.25 s, p 2 was significantly higher when using a laryngeal mask than when using a facemask. The inspiratory-expiratory ratio of the laryngeal mask group was significantly larger than that of the facemask group (1.59 vs. 1.27, p 2 value is the most influential parameter on the fluoroscopic duration during the RFCA procedure (β = − 0.477, p = 0.029). Conclusions The use of a laryngeal mask could stabilize respiration during intravenous anesthesia, which could improve the efficiency of RFCA.

Sleep-disordered breathing (SDB) is one of the most common complications among heart failure (HF) patients. Changes of respiratory patterns during the various stages in patients with HF have not been fully investigated. In this case, the algorism using thoracic impedance sensor and minute ventilation (sleep apnea monitoring [SAM] algorithm) with implanted pacemaker (REPLY 200 SR or DR, Sorin CRM SAS, Clamart, France) was used to monitor respiration. Impedance data from the implanted pacemaker can be converted into respiratory data, which can be used to calculate the respiratory disturbance index (RDI) per unit of time. Using this algorithm, we observed a sudden appearance of abnormal breathing at the onset of HF, followed by gradual improvement of respiratory patterns during the recovery stage. The results from respiratory monitoring using the SAM algorithm were strongly correlated with those from the positive airway pressure device. This case report could imply that proper utilization of this sensor could facilitate the early detection and therapeutic control of HF. Keywords: Heart failure, Pacemaker, Respiratory monitoring

This study aimed to elucidate the influential parameter, acquired from the analyses of nasal capnography waveforms, for the elevated plasma brain natriuretic peptide (BNP) levels in patients (n = 34) with heart failure (HF). The capnography waveforms were analyzed to evaluate changes in end-tidal CO2 (ETCO2) values and expiratory and inspiratory durations. The relationship between these parameters, estimated from capnography analyses and plasma BNP, was then evaluated. Mean ETCO2 values and BNP levels showed a strong negative correlation (R2 = 0.6355, p < 0.0001) in HF patients with chronic kidney disease (CKD) (R2 = 0.6355, p < 0.0001). The ETCO2 value was the most influential parameter that indicated elevated BNP levels in HF patients with CKD (β = − 0.577; p = 0.031). The mean ETCO2 level could be a potentially influential parameter reflecting elevated BNP levels in HF patients, especially in HF patients with CKD. Respiratory parameters, acquired from detailed nasal capnography analyses, might be reasonable for evaluating the severity of HF.

Previous studies suggested that sleep-disordered breathing was associated with cardiovascular diseases such as heart failure (HF). Recently, algorithms of cardiac implantable electronic devices (CIEDs) have been developed to detect advanced sleep apnea (SA); the Apnea Scan (AP Scan) being an example. The purpose of this study was to investigate the association between respiratory disturbance index (RDI) measured using the AP Scan algorithm and HF development. We retrospectively studied consecutive patients with CIEDs equipped with the AP Scan algorithm which were implanted between December 1, 2011 and March 31, 2019. These patients were divided into 2 groups according to the trends of RDI: patients with a continually high RDI > 30 (severe SA group) and those without a continually high RDI (non-severe SA group). There were 16 and 46 patients in the severe and non-severe SA groups, respectively. Increased left ventricular end-diastolic and end-systolic dimensions were observed in the severe SA group. Regarding cardiovascular events, HF was observed in 8 patients (50.0%) in the severe SA group and 1 patient (2.2%) in the non-severe SA group; thus, there was a significantly higher proportion of patients with HF in the severe SA group. In conclusion, continually high RDI was associated with HF development in patients with CIEDs equipped with the AP Scan algorithm. Therefore, an elevated RDI may be a risk factor for the development of HF in patients with CIEDs.

This paper describes on-orbit operations of a power system for Japan’s Venus explorer Akatsuki. It was launched on May 20, 2010, and approached Venus on December 7, 2010, but orbit insertion failed because of a propulsion system malfunction. After the failure, the spacecraft stayed on an orbit nearer to the sun than Venus for 5 years before successfully entering an orbit around Venus in 2015. Telemetry data that show radiation degradation of the solar arrays, and here analytical results by the relative damage coefficients method are presented. The capacity loss of the batteries was successfully suppressed by lowering the state of charge and temperature. We plan to extend the mission period from 4.5 years to longer than 9 years to obtain more fruitful scientific results.

The purpose of this study was to determine the relationship between obstructive sleep apnea (OSA) and cardiovascular disorders in a large Japanese population, and to assess the efficacy of continuous positive airway pressure (CPAP) in the treatment of OSA-associated arrhythmias. The study population comprised 1394 Japanese subjects (1086 men and 308 women) who were divided into four groups on the basis of polysomnography (PSG) analysis as follows: the no sleep apnea (N-SA) group (n = 44, apnea-hypopnea index [AHI]5), the mild OSA (Mi-OSA) group (n = 197, 5AHI15), the moderate OSA (Mo) group (n = 368, 15AHI30), and severe OSA (SOSA) group (n = 785, AHI30). The following baseline characteristics were significantly associated with OSA: age (P0.001), gender (P0.001), body mass index (P0.001), hypertension (P0.001), diabetes (P = 0.009), and hyperlipidemia (P = 0.013). In the OSA group, PSG revealed the predominance of paroxysmal atrial fibrillation (PAF) (P = 0.051), premature atrial complex short run (P0.005), premature ventricular complex (PVC, P = 0.004), sinus bradycardia (P = 0.036), and sinus pause (arrest2 s, P0.001) during the PSG recording. A total of 316 patients from the group underwent CPAP titration and were then re-evaluated. Continuous positive airway pressure therapy significantly reduced the occurrences of PAF (P0.001), PVC (P = 0.016), sinus bradycardia (P = 0.001), and sinus pause (P = 0.004). The results of this study demonstrate a significant relationship between OSA and several cardiac disorders, and also demonstrate the efficacy of CPAP in preventing OSA-associated arrhythmias in a large population of Japanese patients.

Background: Recent studies suggest that treatment of heart failure (HF) could improve cardiac function and sleep apnea syndrome (SAS), but it is unknown how cardiac surgery may affect SAS in HF patients. Relationships between HF with valvular heart diseases and 2 types of SAS (obstructive sleep apnea (OSA) and central sleep apnea (CSA)) were examined. The effects of valve repair surgery on OSA and CSA was also investigated. Methods and Results: Polysomnography, echocardiography and right cardiac catheterization were used to study 150 severe HF patients with mitral valvular and/or aortic valvular diseases. Significant associations between SAS and age, gender, body mass index, or hypertension were observed. The value of the CSA-apnea index (AI) was significantly correlated with pulmonary capillary wedge pressure (PCWP) and mean pulmonary artery pressure (PAP). These associations were not identified for OSA-AI. Valve repair surgery was used to treat 74 patients with severe SAS. The treatment led to a significant improvement in PCWP and mean PAP, and CSA-AI, but not in OSA-AI. Conclusions: These findings suggest close associations between CSA and cardiac function in HF patients with valvular heart diseases. Furthermore, improvement of cardiac function with valvular surgery reduces the severity of CSA in HF patients with valvular heart diseases. (Circ J 2009; 73: 2148-2153)

Background Percutaneous coronary interventions involving small coronary vessels represent a true challenge because of the increased risk of restenosis and adverse outcomes. We evaluated the 2-year clinical outcomes between single everolimus-eluting stents (EES) and paclitaxel-eluting stents (PES) in small coronary artery disease. Methods From the data of SACRA (SmAll CoronaRy Artery treated by TAXUS Liberte) and PLUM (PROMUS/Xience V Everolimus-ELUting Coronary Stent for sMall coronary artery disease) registries, 245 patients with 258 lesions and 264 patients with 279 lesions, respectively, were enrolled in this study. Results The 2-year clinical driven target lesion revascularization (4.5% vs. 10.6%, p = 0.01) and target vessel revascularization (8.0% vs. 13.9%, p = 0.03) rates were significantly lower in the EES group compared with the PES group. Major adverse cardiac events in the EES group tended to be lower than those in the PES group (8.7% vs. 14.3%, p = 0.05). On the other hand, all new lesions for remote target vessel revascularization were observed at the proximal site of target lesions in both groups and those rates were not different between the two groups (3.4% vs. 3.3%, p > 0.99). Conclusion EES showed better clinical results at 2-year follow-up compared with PES in small coronary artery diseases, however, new lesions at the proximal remote site of the target lesion remain problematic.

Primary linitis plastica type of the colon ic cancer is uncommon. Only one hundred-odd cases have been reported in Japan since Watanabe and Yamamoto first reported in 1976. This type of cancer represents under one per cent of total colorectal cancers. This paper describes a recent case of primary diffuse infiltrative carcinoma of the rectum with a review of the literature. A 68-year-old woman was admitted to the hospital because of 2-month lasting melena and anal pain. On admission, the patient showed elevated levels of tumor markers. From barium enema and MRI findings, a diagnosis of the disease infiltrating into the uterus and vagina was made. Posterior pelvic excentration was carried out, resulteing in non-curative resection (S3, Ai Si, N4, Pl, and Stage IV). Postoperative course was uneventful and symptoms such as anal pain disappeared, however, since 2 months after the operation, lumbago, abdominal pain, and ascites occurred. Serum tumor markers also elevated remarkably. The patient died of cancer with peritonitis carcinomatosa and cahexia 6 months after the operation.

Objective The prevalence of complex sleep apnea syndrome (CompSAS) among Asian patients with obstructive sleep apnea syndrome (OSAS) has not yet been reported. Distinguishing CompSAS from pure OSAS is difficult using only diagnostic polysomnography (PSG). We examined the prevalence of CompSAS in Japanese patients with OSAS and the possibility to distinguish CompSAS from pure OSAS by analyzing the severity of respiratory events based on either sleep body position or sleep stage using a diagnostic PSG. Patients and Methods A retrospective chart review of 297 consecutive Japanese patients who were 15 years of age or older with a primary diagnosis of OSAS who were referred for CPAP titration (AHI. 20 events/hr). Results Seventeen patients (5.7%) out of the 297 patients who had an obstructive apnea hypopnea index (AHI) of 20 or higher showed adverse increases in central apnea index (CAI) by the treatment with CPAP whereas obstructive apnea index (OAI) and mixed apnea index (MAI) were significantly decreased. In the results, the AHI on the PSG for CPAP titration reached only approximately half of the values on the diagnostic PSG. In these CompSAS patients, both the total CAI and the CAI in the supine position during NREM sleep on the diagnostic PSG were significantly higher than those in the OSAS group. The sleep body position did not so strongly affect the AHI, OAI and MAI in the CompSAS group. Multiple, stepwise, and logistic regression analyses revealed that the CAI in the supine position during NREM (p=0.026) was a significant variable to distinguish CompSAS from OSAS statistically although the variables were within the normal range. Conclusion The prevalence of CompSAS in Japanese OSAS patients may be lower when compared with Caucasian patients. The increase of CAI in the supine position during NREM sleep on diagnostic PSG may be a characteristic feature in CompSAS., Article, INTERNAL MEDICINE. 48(6):427-432 (2009)

Background: The purpose of this study was to determine the relationship between sleep apnea syndrome (SAS) and cardiovascular disorders, and to assess the efficacy of continuous positive airway pressure (CPAP) in SAS-associated arrhythmias. SAS is associated with cardiovascular disorders, such as hypertension, ischemic heart disease, and arrhythmias. CPAP is one of the effective treatments for SAS; however, this relationship and efficacy remain undefined. Methods and Results: The study population comprised 1413 Japanese subjects (mean age: 56.6 years old, 1123 men and 290 women) who were divided into two groups: SAS group (n=1064, apnea-hypopnea index (AHI)≥20) and control group (n=349, AHI

The relation between the transition temperature of typical nematic liquid crystal mixtures and the dynamic properties of twisted nematic (TN) cells are presented. The extrapolated response time at ...