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The ventilatory efficiency for carbon dioxide output ([Formula: see text]CO

Aims The kinetics of recovery‐period oxygen uptake (VO2) are affected by the O2 deficit generated during exercise. However, studies using ramp tests (RTs) and constant work rate tests (CT) have differently characterized VO2 responses to increased exercise intensity differently. We used these two types of loading patterns to investigate the effects of low‐intensity, medium‐intensity, and high‐intensity exercises on the half time (T1/2) of recovery‐period VO2 and the mechanism. Methods and results Ten healthy men aged 21.2 ± 0.9 years underwent symptom‐limited cardiopulmonary exercise tests with the ramp protocol to determine their anaerobic threshold. All subjects subsequently underwent three submaximal RT and CT at low, moderate, and high intensities. In all RTs, subjects began exercise by warming up (20 W). In CT, T1/2 was significantly lengthened as exercise intensity increased (CT‐low: 34.0 ± 3.9 s, CT‐moderate: 39.5 ± 3.5 s, CT‐high:44.6 ± 4.2 s; P

BACKGROUND There is little evidence regarding the effect of outpatient cardiac rehabilitation (CR) on exercise capacity or the long-term prognosis in patients after coronary artery bypass graft surgery (CABG). This study aimed to determine whether participation in outpatient CR improves exercise capacity and long-term prognosis in post-CABG Japanese patients in a multicenter cohort.Methods and Results:We enrolled 346 post-CABG patients who underwent cardiopulmonary exercise testing during early (2-3 weeks) and late (3-6 months) time points after surgery. They formed the Active (n=240) and Non-Active (n=106) CR participation groups and were followed for 3.5 years. Primary endpoint was a major adverse cardiac event (MACE): all-cause death or rehospitalization for acute myocardial infarction/unstable angina/worsening heart failure. Peak oxygen uptake at 3-5 months from baseline was significantly more increased in Active than in Non-Active patients (+26±24% vs. +19±20%, respectively; P

Purpose This retrospective study aimed to identify predictive factors and imaging features of adrenohepatic adhesion found during laparoscopic right adrenalectomy. Materials and methods Altogether, 77 patients underwent laparoscopic right adrenalectomy between January 2005 and December 2018. Adrenohepatic adhesion was defined as strict adhesion that required either partial adrenalectomy with coagulation of residual tissue or partial hepatectomy to accomplish complete resection. We assessed their surgical video records to determine if adrenohepatic adhesion was present. Age, sex, body mass index, tumor size, tumor diagnosis and radiological findings (attachment between the liver and the adrenal gland, diameters of the right and left adrenal veins and its ratio) were evaluated as preoperative variables. Results Adrenohepatic adhesion was present in 11 of the 77 patients (14.3%). Age, sex, and body mass index were not statistically significant factors. Tumor size was significantly small in adhesion group (14.2 mm vs. 25.9 mm, p=0.02). Attachment to the liver and adrenal gland was frequently seen regardless of the adhesion. The mean right/left adrenal veins diameters ratio was significantly lower in the adhesion group (0.8 vs. 1.1, p=0.01). Multivariate logistic regression analysis demonstrated the right/left adrenal veins diameters ratio was the only significant predictor of adhesion. The sensitivity, specificity, negative predictive value and positive predictive value were 0.82, 0.76, 0.43, and 0.95 respectively when the optimal cutoff value for the ratio was 0.9 (area under the curve, 0.75; 95% confidence interval, 0.60-0.90). Conclusions The right/left adrenal veins diameters ratio was possible predictor of adrenohepatic adhesion.

Cardiac rehabilitation (CR) is a well-known intervention for the secondary prevention of cardiovascular diseases. However, in Japan, the outpatient CR participation rate is estimated to be very low. Cardiac telerehabilitation (CTR) can be defined as a remote CR program using digital health technology to support it. Evidence regarding the use of CTR has been accumulated, and the COVID-19 pandemic has accelerated the need for CTR. Japan has sufficient potential to benefit from CTR because, nationally, digital literacy is high and the infrastructure for telemedicine is developed. To overcome several barriers, evidence of CTR in Japan, well-educated multidisciplinary CTR teams, a good combination of center-based CR and CTR, and sophisticated systems including social insurance and adequate legislation need to be developed immediately. CTR has the potential to increase the low CR participation rate in Japan. CTR also has many different effects that not only cardiologists, but also paramedics who engage in CTR, have to be aware of. The authors thank all the staff members of the laboratories at Jessa Hospital and St. Marianna University School of Medicine Hospital for their efforts and understanding of the principle in this vision document.

Background This study investigated the prevalence of sarcopenia or sarcopenic obesity and their association with frailty and protein-energy wasting (PEW) in hemodialysis patients. Methods The present study enrolled 117 adult hemodialysis patients (35% female, 64 ± 12 years old) from single units of a hemodialysis center. The patients were divided into four groups: normal, obese, sarcopenia, and sarcopenic obesity. Sarcopenia was diagnosed by Asian Working Group for Sarcopenia (AWGS) criteria, and obesity was defined as an extensive percent body fat mass greater than 40% in females and 30% in males. Skeletal muscle mass and percent fat mass were evaluated by multifrequency whole-body bioimpedance electrical analysis after a midweek dialysis session. Handgrip strength and a short physical performance battery (SPPB) were assessed before a dialysis session as indicators of muscle strength and physical performance. Moreover, participants completed the Kihon Checklist and the criteria proposed by the International Society of Renal Nutrition and Metabolism expert panel to classify frailty and PEW. We performed multivariate logistic regression analysis to identify the clinical risk of frailty and PEW in patients with sarcopenia or sarcopenic obesity. Results Forty-six (39.3%) patients were classified as normal; 18 (15.4%), as obese; 35 (29.9%), as having sarcopenia; and 18 (15.4%), as having sarcopenic obesity. The sarcopenia or sarcopenic obesity group had significantly lower handgrip strength than the normal or obesity group (all p < 0.05). In addition, the sarcopenia and sarcopenic obesity groups had significantly lower SPPB scores than the normal group (p < 0.05, respectively). In the multivariate analysis, the sarcopenic obesity group had a significantly higher risk of frailty than the normal group in the multivariate analysis after adjusting for age and gender (OR 4.518, 95%CI 1.218–16.752, p = 0.024). However, sarcopenic obesity was not associated with a higher likelihood of PEW, and sarcopenia imposed a significantly higher risk of PEW (OR 4.272, 95%CI 1.157–15.778, p = 0.029) than that in the normal group after adjusting for confounding factors. Conclusion Sarcopenic obesity was closely associated with frailty compared with the normal condition in HD patients. However, sarcopenic obesity was not associated with a higher likelihood of PEW.

Because electronic medical record systems may affect productivity of clinical practice, we examined the effects of different types of medical record systems on consultation time and total fee claims for outpatient consultation for cardiovascular cases. We investigated consultation time (i.e., the sum of practice time and work-up time) and total fee claims by 13 cardiovascular physicians for 862 outpatients. The means of consultation time and total fee claims were calculated for 3 types of medical records: electronic, paper-based, and hybrid. No difference in mean consultation time was seen between the electronic and paper-based medical record groups (paper based, 11.4±0.3 min/case; electronic, 12.7±0.8 min/case; hybrid, 13.5±0.5 min/case). In contrast, the electronic group had the highest mean practice time (10.9±0.6 min/case) and the lowest mean work-up time (1.7±0.4 min/case). There was no difference in total fee claims between the 3 medical record groups. The total fee claims per practice time was lower for the electronic group than the paper-based (67.5±52.8 vs. 108.8±108.1 points/min, P

Background To evaluate the relationship between phase angle (PA) measured by bioimpedance electrical analysis and protein-energy wasting (PEW) or frailty, and its impact on 2-year mortality in patients with hemodialysis (HD). Methods This retrospective observational study included 116 adult HD patients (35% female, 64 ± 12 years of age) in a single dialysis center. Patients were classified according to the PA quartiles into four groups (quartile 1, lowest; quartile 4, highest). International Society of Renal Nutrition and Metabolism (ISRNM) criteria and Japanese version of Cardiovascular Health Study (J-CHS) criteria were used to identify PEW and frailty. Results The lower PA group was associated with a greater risk of PEW (35% vs. 24% vs. 21% vs. 3%; p = 0.032), frailty (59% vs. 40% vs. 21% vs. 3%; p

Background Phase angle (PA), measured by bioelectrical impedance analysis (BIA) has been studied as indicator of nutritional status or muscle function in hemodialysis (HD) patients. It remains unclear if the phase angle is associated protein-energy wasting (PEW) or frailty, which are common complication in hemodialysis patients. The aim of this study is to determine whether BIA-derived PA is a marker of PEW or frailty in HD patients. Methods This retrospective observational study included 116 adult HD patients (35% female, 64 ± 12 years of age) in a single dialysis center. Patients were classified according to the PA quartiles into four groups; 1) first quartile: PA Results The lower PA group was associated with a greater risk of PEW (35% vs. 24% vs. 21% vs. 3%; p = 0.032), frailty (59% vs. 40% vs. 21% vs. 3%; p Conclusions Lower PA was associated with a greater risk of PEW and frailty in HD patients.

Background The current understanding of ventilator efficiency variables during ramp exercise testing in the normal Japanese population is insufficient, and the responses of tidal volume (VT) and minute ventilation (VE) to the ramp exercise test in the normal Japanese population are not known. Methods A total of 529 healthy Japanese subjects aged 20–78 years underwent cardiopulmonary exercise testing using a cycle ergometer with ramp protocols. VT and VE at rest, at anaerobic threshold, and at peak exercise were determined. The slope of VE versus carbon dioxide (VCO2) (VE vs. VCO2 slope), minimum VE/VCO2, and oxygen uptake efficiency slope (OUES) were determined. Results For males and females in their 20 s, peak VT (VTpeak) was 2192 ± 376 and 1509 ± 260 mL (p Conclusions We have established the normal range of VT and VE responses, the VE vs. VCO2 slope, the minimum VE/VCO2, and the OUES for a healthy Japanese population. Some of these parameters were influenced by weight, height, sex, and age. These results provide useful reference values for interpreting the results of cardiopulmonary exercise testing in cardiac patients.

Background. Medical costs associated with cardiovascular disease are increasing considerably worldwide; therefore, an efficacious, cost-effective therapy which allows the effective use of medical resources is vital. There have been few economic evaluations of cardiac rehabilitation (CR), especially meta-analyses of medical cost versus patient outcome.Methods. The target population in this meta-analysis included convalescent and comprehensive CR patients with coronary artery disease (CAD), the status most commonly observed postmyocardial infarction (MI). Here, we evaluated medical costs, quality-adjusted life year (QALY), cost-effectiveness, mortality, and life year (LY). Regarding cost-effectiveness analysis, we analyzed medical costs per QALY, medical costs per LY, and the incremental cost-utility ratio (ICUR). We then examined the differences in effects for the 2 treatment arms (CR vs. usual care (UC)) using the risk ratio (RR) and standardized mean difference (SMD).Results. We reviewed 59 studies and identified 5 studies that matched our selection criteria. In total, 122,485 patients were included in the analysis. Meta-analysis results revealed that the CR arm significantly improved QALY (SMD: −1.78; 95% confidence interval (CI): −2.69, −0.87) compared with UC. Although medical costs tended to be higher in the CR arm compared to the UC arm (SMD: 0.02; 95% CI: −0.08, 0.13), cost/QALY was significantly improved in the CR arm compared with the UC arm (SMD: −0.31; 95% CI: −0.53, −0.09). The ICURs for the studies (4 RCTs and 1 model analysis) were as follows: −48,327.6 USD/QALY; −5,193.8 USD/QALY (dominant, CR is cheaper and more effective than UC); and 4,048.0 USD/QALY, 17,209.4 USD/QALY, and 26,888.7 USD/QALY (Conclusions. While there are some limitations, primarily regarding data sources, our results suggest that CR is potentially cost-effective.

A 66-year-old man had undergone multiple treatments for metastatic renal cell carcinoma, including 11 cycles of nivolumab, which was discontinued because of disease progression. About three weeks after discontinuing nivolumab, he reported suffering from worsening of dyspnea. Pulse oximetry showed no desaturation. His cardiovascular and pulmonary functions were normal. His dyspnea slowly worsened with no underlying diagnosis. Two months after symptoms developed, he was diagnosed with isolated adrenocorticotropic hormone deficiency. His dyspnea disappeared soon after receiving hydrocortisone. Nivolumab-induced isolated adrenocorticotropic hormone deficiency may not present with typical symptoms, and can occur even after discontinuing nivolumab. Cortisol levels should be routinely monitored in patients who receive nivolumab.

Patients under hemodialysis present protein-energy wasting (PEW), which is related with higher mortality rates. The study aimed to determine whether intradialytic resistance exercise training could improve physical performance, physical activity, and PEW in hemodialysis patients. In single center study, 75 hemodialysis patients were enrolled in an intradialytic resistance exercise training consisting of 20 min of adapted leg press, with a gymnastic ball, 3 days/week, during 9 months on the same day of hemodialysis therapy. Physical performance by short physical performance battery (SPPB), physical activity by life space assessment (LSA), and PEW score based on the nomenclature proposed by the International Society of Renal Nutrition and Metabolism in 2008 were assessed at baseline and after 9 months. Intradialytic resistance exercise training significantly improved SPPB score, LSA score, and PEW score (all, P

This study reveals a novel role of d-amino acid oxidase in promoting cellular senescence induced by genotoxic stresses via enzymatic generation of reactive oxygen species., d-amino acid oxidase (DAO) is a flavin adenine dinucleotide (FAD)–dependent oxidase metabolizing neutral and polar d-amino acids. Unlike l-amino acids, the amounts of d-amino acids in mammalian tissues are extremely low, and therefore, little has been investigated regarding the physiological role of DAO. We have recently identified DAO to be up-regulated in cellular senescence, a permanent cell cycle arrest induced by various stresses, such as persistent DNA damage and oxidative stress. Because DAO produces reactive oxygen species (ROS) as byproducts of substrate oxidation and the accumulation of ROS mediates the senescence induction, we explored the relationship between DAO and senescence. We found that inhibition of DAO impaired senescence induced by DNA damage, and ectopic expression of wild-type DAO, but not enzymatically inactive mutant, enhanced it in an ROS-dependent manner. Furthermore, addition of d-amino acids and riboflavin, a metabolic precursor of FAD, to the medium potentiated the senescence-promoting effect of DAO. These results indicate that DAO promotes senescence through the enzymatic ROS generation, and its activity is regulated by the availability of its substrate and coenzyme.

Background The responses of heart rate (HR) and blood pressure to the ramp exercise test are not known and the current understanding of peak oxygen uptake and anaerobic threshold (AT) values in the normal Japanese population is insufficient. Methods and results A total of 749 healthy Japanese subjects aged 20–78 years underwent a cardiopulmonary exercise test using a cycle ergometer or treadmill ergometer with ramp protocols. HR, systolic blood pressure (SBP), and oxygen uptake ( V ˙ O 2 ) at rest, at AT, and at peak exercise were determined. HR and SBP at peak exercise in a cycle ergometer and treadmill ergometer test decreased with age. Work rate at peak exercise in a cycle ergometer increased with body weight and decreased with age. V ˙ O 2 / weight at AT and at peak exercise were higher in treadmill ergometer testing than in cycle ergometer testing, and were not affected by exercise protocol. Both of these decreased with age. Conclusions The normal responses of HR and SBP to ramp exercise testing are reported for the first time. AT, peak V ˙ O 2 , and V ˙ O 2 at each stage are shown for a healthy population. Some of these parameters were influenced by weight, gender, and age, as well as mode of exercise and the protocol used. These results provide useful reference values for interpreting the results of cardiopulmonary exercise testing.

Patients under hemodialysis present protein-energy wasting (PEW), which is related with higher mortality rates. The study aimed to determine whether intradialytic resistance exercise training could improve physical performance, physical activity, and PEW in hemodialysis patients. In single center study, 75 hemodialysis patients were enrolled in an intradialytic resistance exercise training consisting of 20 min of adapted leg press, with a gymnastic ball, 3 days/week, during 9 months on the same day of hemodialysis therapy. Physical performance by short physical performance battery (SPPB), physical activity by life space assessment (LSA), and PEW score based on the nomenclature proposed by the International Society of Renal Nutrition and Metabolism in 2008 were assessed at baseline and after 9 months. Intradialytic resistance exercise training significantly improved SPPB score, LSA score, and PEW score (all, P 0.05). In addition, intradialytic resistance exercise training improved SPPB score in patients with moderate and severe PEW subgroups (P 0.05), associated with reduced prevalence of the patients with moderate to severe PEW (53% vs. 36%, P 0.05). Intradialytic resistance exercise training was safe and effective to improve physical performance, physical activity, and PEW in hemodialysis patients.

Background: We evaluated the production efficiency of physicians in outpatient consultation using Data Envelopment Analysis (DEA) to verify the applicability of this method in health care field. Methods: Clinical accomplishment by outpatient consultation (number of complex cases) and economic contribution to health service income (fee claims) were defined as the contributions of physicians in medical institutions. We investigated consultations and fee claims of 963 outpatients (all aged: 72.9 ± 11.8 years, males aged: 72.0 ± 11.7 years / females aged: 74.0 ± 12.0 years, hypertension: 17.5% / angina: 13.1%) consulted by 15 physicians in a week at a medical institution specialized in cardiovascular disease. The physician’s fee claim per practice time was used as an index in production efficiency of each cardiovascular case. We determined production efficiency of physicians using both of total fee claim and number of complex cases per consultation time using DEA. Results: There was no statistically significant difference between main disease of outpatients in consultation time (p=0.28). We showed a significant increment of physicians fee claim (point per min) according to the patient condition aggravated from mild to moderate cases in severity (71.4 ± 2.4: p=0.004). The production efficiency also significantly increased from the first consultation to follow-up (71.6 ± 2.4: p=0.048). There was a large variation among the 15 physicians in the consultations, and 4 physicians (26% of all subjects) formed a group with the most favorable production efficiency according to DEA. Conclusion: We demonstrated evaluation of production efficiency of physicians using clinical and economic accomplishments. The production efficiency is significantly influenced by disease severity and consultation step. Our finding suggests that DEA may be applicable for evaluation of health care services.

The response to cardiopulmonary exercise (CPX) in patients with heart failure (HF) with normal left ventricular (LV) ejection fractions (EFs) is not well characterized. To determine if CPX testing could distinguish between patients with HF with normal EFs (>50%; i.e., diastolic HF) and those with decreased EFs (> or =50%; i.e., systolic HF), CPX responses were compared between 185 patients with systolic HF (79% men, mean age 62.6 +/- 10.9 years) and 43 with diastolic HF (54% men, mean age 67.4 +/- 9.8 years) enrolled in a phase II multicenter clinical trial. All patients were evaluated with echocardiography and a standardized CPX test as part of the trial. CPX variables, including oxygen uptake at peak exercise (peak VO(2)) and the slope of the ventilation/carbon dioxide production ratio (VE/VCO(2)), were determined and analyzed by core laboratory personnel. Echocardiographic measurements included the LV EF, the E/A ratio, filling time, cavity volumes, right ventricular function, and mitral regurgitation. Patients in the diastolic HF group tended to be older (p

Background It has been recently reported that cerebral oxyhemoglobin (O2Hb) decreases during exercise in nearly 50% of patients with dilated cardiomyopathy. The present study evaluated whether the inhalation of supplemental O2 diminishes the decrease in cerebral O2Hb during exercise. Methods and Results Ten patients with a left ventricular ejection fraction

Background It is well-known that both B-type natriuretic peptide (BNP) and peak oxygen uptake (VO2) are independent predictors of mortality in patients with heart failure. This study investigates the predictive power of BNP and peak VO2 for survival in cardiac patients. Methods and Results A total of 609 patients with cardiac disease participated in the study. They underwent cardiopulmonary exercise testing to determine peak VO2, with BNP being measured before exercise testing During 502.5 median follow-up days, 29 patients died of cardiovascular disease. In the univariate Cox proportional hazards analysis, peak VO2 and BNP were both found to be significant prognostic indices for survival. The time-dependent ROC curve analysis (Heagerty 2006) was applied to 3 predictors: peak VO2, BNP, and then both, with gender and age as adjusted variables. The area under the curve (AUC) compared with the follow-up period curves of peak VO2 and the 2 combined variables (ie, BNP and peak VO2) were consistently over that of BNP. The integrated AUC indices were 0.80 (peak VO2), 0.81 (peak VO2 and BNP) and 0.70 (BNP), respectively. Conclusions These results indicate that peak VO2 is more potent than BNP for predicting the mortality in patients with mixed cardiac disease. (Circ J 2008; 72: 575 - 581)

Background: While the improvement of anemia with erythropoietin (EPO) treatment increases peak VO 2 in anemic patients, the effects of EPO on minute ventilation (VE), VO 2 , and VCO 2 kinetics are not well described. Objectives: The aim of this study was to evaluate the improvement in hemodynamic, metabolic, and ventilatory response during exercise along with the improvement of anemia with EPO treatment in anemic hemodialysis patients. Methods: Thirty-seven hemodialysis patients with anemia (48.8 ± 13.6 years) received EPO (1500 or 3000 unit, 3 times a week). Parameters measured prospectively before and after EPO treatment included hemoglobin, cardiac output by dye dilution method, echocardiography, and cardiopulmonary exercise parameters. Results: With EPO treatment, hemoglobin increased from 6.4 ± 0.9 to 10.3 ± 0.9g/dl (p

Evaluating blood pressure response during exercise rather than during rest might better detect a subtle impairment in relaxation of the resistance vessel in hypercholesterolemia. We examined the relation between serum cholesterol and blood pressure response during exercise in patients with coronary artery disease. One hundred and forty-eight consecutive patients with coronary artery disease were monitored during symptom-limited incremental exercise testing with a cycle ergometer. Cuff blood pressure was measured every minute during exercise testing with an automatic indirect manometer. Although there were no significant differences in systolic or diastolic blood pressure at rest between the patients with hypercholesterolemia (total cholesterol > or = 220 mg/dL, n = 39) and those without it (n = 109), the former reached a higher diastolic blood pressure at peak exercise (94.8+/-16.0 versus 87.8+/-12.9 mmHg, P = 0.007). The increase in diastolic blood pressure at peak exercise versus the resting value in the patients with hypercholesterolemia was 20.6+/-11.3 mmHg, and this was significantly higher than the increase in patients without hypercholesterolemia (14.8+/-11.8 mmHg, P = 0.009). However, there were no differences in the peak exercise systolic blood pressure and the magnitude of the increase in systolic blood pressure between the two groups. Among the patients with coronary artery disease in our study, we found that those with hypercholesterolemia had significantly higher diastolic blood pressure during exercise than those without hypercholesterolemia, strongly suggesting that patients with hyperlipidemia are at a higher risk of developing hypertensive complications.

We compared cerebral oxygenation during exercise and during exercise recovery between 22 healthy subjects and 35 patients with idiopathic dilated cardiomyopathy (IDC). Although cerebral oxyhemoglobin increased during exercise in most of the healthy subjects, oxyhemoglobin decreased during exercise in 15 of 35 patients with IDC. Cerebral oxygenation during exercise and exercise recovery was related to left ventricular function in the patients with IDC.

A double product break point (DPBP) occurs simultaneously with both ventilatory threshold (VT) and lactate threshold (LT) in normal subjects. We sought to determine whether a DPBP also occurs in cardiac patients and to investigate correlations between DPBP, VT and LT (study 1). We also evaluated a non-invasive DPBP measurement system that determined blood pressure automatically by the cuff method (study 2). Study 1 comprised 15 patients [8 men and 7 women, mean (SD) age 47.7 (11.1) years] who performed cardiopulmonary exercise tests on a cycle ergometer. The double product was defined as the product of heart rate and direct systolic blood pressure. Arterial blood samples were obtained for measurement of lactate, pyruvate, pH, and norepinephrine levels. VT was determined by gas analysis, and LT was determined as the lactate/pyruvate ratio. DPBPs were detected in all 15 patients. Double product slopes above the DPBP were significantly greater than those below the DPBP (286.2 vs 98.5/W, P

Background End-tidal CO2 partial pressure (PETCO2) has been suggested as a noninvasive index reflecting cardiac output under constant ventilation. The aim of this study was to examine whether PETCO2 does reflect cardiac output, even during exercise, in patients with acute myocardial infarction (AMI) undergoing exercise training early after onset. Method and Results Patients aged 47-73 years were randomly assigned to either a training group (n=18) or a control group (n=18) 1 week after the onset of AMI. Those in the training group performed exercise training under supervision at the anaerobic threshold level for 2 weeks, while patients in the control group followed a conventional walking regimen. In the training group, but not in the control group, PETCO2 at the respiratory compensation point increased significantly from 39.1±3.5 to 41.1±3.7 mmHg (p

Although nocturnal Cheyne-Stokes respiration alternating between hyperpnea and hypopnea has been considered a sign of severe heart failure, the clinical status of cardiac patients who exhibit oscillatory ventilation during wakefulness has not been clarified. This study was carried out to determine the relation between oscillatory ventilation during wakefulness and exercise capacity in patients with chronic heart disease. We also evaluated retrospectively whether the presence of oscillatory ventilation influences the long-term prognosis in these patients.A total of 164 patients with left ventricular dysfunction performed a symptom-limited incremental exercise test. Respiratory gas exchange was measured on a breath-by-breath basis throughout the test. Oscillatory ventilation was defined when clear ventilatory oscillation of at least two consecutive cycles was identified at rest before exercise testing and the difference between the peak and nadir of oscillating ventilation was30% of the mean value of ventilation.Oscillatory ventilation was noted in 45 of 164 cardiac patients (27%), and the magnitude (mean +/- SD) of oscillation in these patients was 45.5 +/- 16.9%. Patients with oscillatory ventilation had significantly lower left ventricular ejection fraction than those without it (40.7 +/- 12.7% vs 44.9 +/- 11.6%, p0.05). However, parameters of exercise capacity such as the peak oxygen uptake (O(2)), the slope of the increase in O(2) relative to the increase in work rate (DeltaO(2)/DeltaWR), and the ratio of the increase in ventilation to the increase in carbon dioxide output (DeltaE/DeltaCO(2)) were not significantly different between the two groups. The mortality rate during 1,797 +/- 599 days of follow-up did not differ between the groups (p = 0.65).Oscillatory ventilation present at rest before cardiopulmonary exercise testing is not significantly related to the peak O(2), DeltaO(2)/DeltaWR, DeltaE/DeltaCO(2), or prognosis in patients with left ventricular dysfunction.

The present study was undertaken to investigate the relationship between the extent of impaired chronotropic response and cardiac output during exercise, and exercise tolerance in patients with chronic heart failure. The subjects consisted of 24 patients (mean 60.1 +/- 14.0 years) who had mild chronotropic incompetence. Cardiopulmonary exercise testing was performed in all patients, and heart rate (HR), anaerobic threshold (AT), maximum oxygen uptake (peak VO2), slope of the regression line relating the ventilatory equivalent to carbon dioxide output (VE/VCO2 slope), and exercise time were measured. Cardiac output (CO) was measured by a thoracic bioimpedance method and cardiac index (CI) was calculated. Plasma norepinephrine (NE) was measured at rest and immediately after the exercise test. The changes in HR, NE, and CI from the resting state to immediately after exercise were calculated as deltaHR, deltaNE, and deltaCI, respectively. The deltaNE was converted to a logarithmic scale and deltaHR/log deltaNE was used as a parameter of HR response to sympathetic nerve stimulation. The results were as follows: HR and NE in the resting state had no correlation with AT and with peak VO2. DeltaHR/log deltaNE correlated positively with both AT and peak VO2, and negatively with the VE/CO2 slope. DeltaHR/log deltaNE correlated positively with peak CI, %deltaCI, and deltaCI/exercise time. The data suggest that one of the mechanisms of low exercise tolerance in chronic heart failure patients was due to an inadequate increase in CO response against exercise caused by an impaired HR response to increased NE.

The purpose of this study was to determine the rate of participation of patients after acute myocardial infarction (AMI) in phase II cardiac rehabilitation with exercise training (ie, exercise cardiac rehabilitation, ECR) in Japan. Forty-six hospitals treating patients with AMI were surveyed for their implementation of phase II ECR after AMI in 1996-98. Of the 46 hospitals, 19 were approved and 27 were not approved for health insurance payment for ECR. A total of 13685 patients with AMI were admitted to the 46 hospitals. There were no differences between approved and non-approved hospitals in the annual number of patients with AMI (Approved, 117+61 vs Non-approved, 86+71 patients per hospital, NS), the rate of performance of emergency coronary angioplasty (63+16 vs 65+20%, NS), or the rate of emergency coronary stenting (31+16 vs 34+22%, NS). However, ECR was performed routinely in 84.2% (16/19 hospitals) of the approved hospitals, but in only 22.2% (6/27 hospitals) of the non-approved hospitals (p

The purpose of this study was to determine the incidence of subacute stent thrombosis related to exercise testing (ETT) or exercise training in cardiac rehabilitation (exercise cardiac rehabilitation (ECR)) and to clarify the appropriate timing of ETT and ECR in patients with acute myocardial infarction (AMI) treated with coronary stenting, because the safety and appropriate timing of ETT and ECR after coronary stenting for AMI have not been established. Forty-six institutes performing emergency percutaneous coronary intervention (PCI) for AMI were surveyed for the incidence of exercise-related subacute stent thrombosis and the timing of the start of ETT and ECR in patients with AMI in 1996-1998. Among the total 13,685 patients with AMI, 4,360 (31.9%) underwent coronary stenting. Of the 132 (3.0%) subacute stent thromboses that developed within 1 month after stenting, only one event was related to maximal ETT and occurred in a patient not receiving ticlopidine. No stent thrombosis occurred in association with submaximal ETT or ECR. In 7 institutes, maximal ETT was routinely performed at 14 days after stenting for AMI without any adverse events, and in 6 institutes, ECR was routinely started within 7 days without any adverse events. This survey found that only 21.0% of all AMI patients participated in ECR. In conclusion, subacute stent thrombosis related to ETT or ECR is extremely rare (0-0.02%) in patients with AMI, especially when they are receiving ticlopidine, and therefore ETT and ECR for stented patients with AMI need not be delayed (ie, approximately 7 days after stenting for submaximal ETT and ECR, and 14 days after stenting for maximal ETT). The rate of participation of post-AMI patients in ECR is low in Japan, even in major hospitals that are actively working in the field.

The issue of whether exercise training improves exercise hyperpnea in patients after coronary arterial bypass graft (CABG) surgery has not been fully explored. Effects of short-term physical training on ventilatory response and cardiac output during exercise in patients following coronary arterial bypass grafting surgery is studied. Thirty-four patients underwent exercise training for 2 weeks after the second postoperative week (Ex group); 23 stayed sedentary (Sed group). Ventilatory and cardiac output response during the cardiopulmonary exercise test was measured before and after the training period. The minute ventilation-carbon dioxide output (VE-VCO2) slope decreased from 38.9+/-8.1 to 35.1+/-6.7 (p

Electrostatic Powder coating which is a surface finishing technique has widely been used in paint industry since its invention in the 1960s. However, so far, insufficient attention has been paid to the powder fires and/or explosion hazards caused by electrostatic spark during coating process. This paper is a report of the electrostatic spark ignitability of aluminous coating powders (dry blend-type) used in practical electrostatic powder coating. The Hartman vertical-tube apparatus was used for the minimum ignition energy (MIE) test. Various aluminous coating powders, different with respect to the amount of aluminum pigment, were used in this study. Experimental results obtained in this study are as follows: (1) The aluminous coating powder was so sensitive that even an electrostatic spark with an energy as low as 10 mJ could ignite it. (2) The particle size of aluminous coating powder has a considerable effect on the ignitability when the aluminum pigment concentration is within 6 wt% of the practical coating powder manufacturing standards. Thus, the conventional expression for estimating the MIE can be useful when assessing the electrostatic hazards associated with aluminum coating powders.

OBJECTIVESWe measured end-tidal CO2 pressure (PETCO2) during exercise and investigated the relationship between PETCO2 and exercise capacity, ventilatory parameters and cardiac output to de...

The present study investigated the serial changes in serum magnesium (Mg) and erythrocyte concentration of Mg in patients with acute myocardial infarction (AMI) and the relationship between these changes and left ventricular ejection fraction (LVEF) at 1 month after the onset of infarction. The study group comprised 26 patients with AMI (mean age, 57.9+/-8.9 years). Serum Mg and erythrocyte Mg were measured on hospital days 1, 2, 4, 7 and 21. The change in erythrocyte Mg during the acute phase was calculated as a ratio: [(erythrocyte Mg at day 2)-(erythrocyte Mg at day 1)]/(erythrocyte Mg at day 1). The change in serum Mg was calculated similarly. The following results were obtained. (1) Serum Mg tended to increase from the onset of myocardial infarction (day 1: 1.86+/-0.19, day 2: 1.93+/-0.22, day 4: 2.17+/-0.23; day 7: 2.25+/-0.20; day 21: 2.12+/-0.15 mg/dl). (2) Erythrocyte Mg on day 2 and day 4 showed a significant decrease compared with day 1 (day 1: 2.45+/-0.40, day 2: 2.09+/-0.41, day 4: 2.07+/-0.37, day 7: 2.22+/-0.33, day 7: 2.34+/-0.28 mg/dl per 400x10(4)/mm3 cells). (3) A significant positive correlation was observed between the change in serum Mg and LVEF (r=0.55, p

The significance of the time from anaerobic threshold to respiratory compensation point (RCP-AT time) in patients with chronic heart failure was investigated. Thirty-seven patients with chronic heart failure (New York Heart Association class II or III) were enrolled into the study. Cardiopulmonary exercise testing was performed using breath-by-breath gas sampling. A bicycle ergometer was used, and incremental exercise testing was carried out. Anaerobic threshold, respiratory compensation point (RCP), and the slope of oxygen uptake (VO2) as a function of work rate (deltaVO2/deltaWR) were measured. A positive correlation (r=0.53) between RCP-AT time and deltaVO2/deltaWR was found. RCP-AT time was corrected for the whole exercise period (ramp exercise-RCP point), and the correlation between corrected RCP-AT time and deltaVO2/deltaWR was still present (r=0.46). There was no correlation between RCP-AT time and anaerobic threshold. These findings suggest that RCP-AT time is a new parameter that reflects the rate of the aerobic and anaerobic metabolism after AT.

The purpose of this study was to evaluate cardiopulmonary responses during submaximal cycle exercise at various angles of backrest inclination. Ten healthy Japanese men of mean age 25.9 yrs, height 170.6 cm, and body mass 66.1 kg, performed cycle exercises at a constant workload which reached the anaerobic threshold, at 20 degrees, 40 degrees, and 60 degrees of backrest inclination from the vertical plane, but the angle between the seat and back rest was kept at 110 degrees. The results were as follows: 1) Both cardiac output and stroke volume showed a higher value at the resting control state and during exercise as the backrest angle increased. 2) Oxygen consumption, carbon dioxide output, heart rate, gas exchange ratio, and oxygen pulse were not affected by the angle of backrest inclination. 3) Tidal volume at 20 degrees of backrest inclination was higher than at 60 degrees. 4) No significant differences were found in minute ventilation between each backrest angle. These findings suggest that changes in the backrest angle significantly alter cardiopulmonary parameters at rest and during exercise; in particular, an angle difference of 40 degrees may be enough to alter tidal volume, cardiac output and stroke volume, but not the minute ventilation.

Recent observations have shown that plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) correlate with cardiac function or prognosis in heart failure patients. However, relatively little is known about changes in their plasma concentration during commonly occurring physiological states such as fatigue. Therefore, this study was designed to examine the physiological changes of plasma ANP and BNP concentrations using a chronic sleep-deprivation model. Bicycle ergometer cardiopulmonary exercise tests were performed in 10 healthy volunteers (mean age: 22.7 years). Blood samples for measuring ANP and BNP were drawn during the resting state and immediately after each exercise test. Cardiac output (CO) was measured during the exercise test by the impedance method. The study conditions were designed as follows: (A) a day following a period of normal sleep (control state) and (B) a day preceded by 1 month during which sleep lasted

Brain natriuretic peptide (BNP) secretion increases after myocardial infarction (MI); its plasma level may reflect the degree of left ventricular dysfunction. This study examines how aerobic exercise therapy for MI influences BNP secretion. Subjects included 70 patients (mean age, 62.0±11.3 years) who were divided into four groups: (1) 20 patients with an anterior MI and exercise training; (2) 20 patients with an anterior MI and no exercise training; (3) 15 patients with an inferior MI and exercise training; and (4) 15 patients with an inferior MI and no exercise training. The training groups performed aerobic exercise 3 times a week for 2 months. Exercise intensity was defined as a heart rate of anaerobic threshold (AT), derived from the treadmill cardiopulmonary exercise testing at 1 month after the onset of MI. The subjects underwent cardiopulmonary exercise testing again at 3 months after the onset of MI. To measure BNP, blood samples were obtained in the resting state and immediately after the peak exercise. AT and peak oxygen uptake increased in the training group with anterior MI and in both the training and nontraining groups with inferior MI. Significant serial change in plasma BNP level was not observed in the inferior MI groups. Plasma BNP level decreased longitudinally only in the nontraining anterior MI group. It was concluded that exercise training in patients with an anterior MI could delay the recovery of left ventricular function, but will increase exercise tolerance. (Jpn Circ J 1998; 62: 658 - 664)

We have previously reported that chronic sleep deprivation causes a deficiency of intracellular magnesium (Mg) and decreased exercise tolerance. The aim of this study was to clarify whether oral administration of Mg could be effective in restoring the exercise tolerance that is decreased by chronic sleep deprivation. A bicycle ergometer cardiopulmonary exercise test was performed by 16 healthy volunteers (mean age 21.9 years). They were divided into 2 groups: 8 received doses of 100 mg of Mg orally per day for 1 month (Mg group) and the remaining 8 received no Mg and served as the control group. The study conditions were designed as follows: (1) the usual state (good sleep); and (2) the sleep-deprived state (sleeping time up to 60% less than the usual state for 1 month). The ratio of intracellular Mg content of the sleep-deprived state to the usual sleep state was significantly higher in the Mg group (p