Comparison of resident performance in interpreting mammography results using a probabilistic or a natural frequency presentation: a multi-institutional randomized experimental study.

BACKGROUND: Residents are being increasingly challenged on how best to integrate diagnostic information in making decisions about patient care. The aim of this study is to assess the ability of residents to accurately integrate statistical data from a screening mammography test in order to estimate breast cancer probability and to investigate whether a simple alteration of the representation mode of probabilities into natural frequencies facilitates these computations. METHODS: A multi-institutional randomized controlled study of residents was performed in eight major hospitals in the city of Athens. Residents were asked to estimate the positive predictive value of the screening mammography test given its sensitivity and 1-specificity as well as the prevalence of breast cancer in the relevant population. One version of the scenario was presented in the single-event probability format that is commonly used in the medical literature, while the other used the natural frequency representation. The two questionnaire versions were randomly assigned to the participants. RESULTS: Out of 200 residents, 153 completed and returned the questionnaire (response rate 76.5%). Although more than one-third of the residents reported excellent or close to excellent familiarity with sensitivity and positive predictive value, the majority of responses (79.1%) were incorrect. However, a significantly higher proportion of residents in the natural frequency group (n = 88) selected the correct response compared with residents (n = 65) in the single-event probability group (28.4% vs 10.8%; 95% confidence intervals of the difference between the two proportions = 5.6-29.7%; P < 0.01). DISCUSSION: Residents more often correctly understand test performance accuracy when test characteristics are presented to them as natural frequency representations than the more common approach of presenting single event probabilities. Educators and journal editors should be aware of this facilitative effect.

Cardiopulmonary rehabilitation enhances heart rate recovery in patients with COPD.

BACKGROUND: Autonomic dysfunction is present early in the course of COPD, and is associated with adverse outcomes. We utilized heart rate recovery, a simple and validated index of autonomic balance, to investigate the effects of exercise training on autonomic dysfunction in patients with COPD. METHODS: We evaluated 45 stable subjects with COPD who participated in a 36-session exercise-based cardiopulmonary rehabilitation program. Subjects underwent maximal cardiopulmonary exercise testing at baseline and after completion of the rehabilitation program. We recorded exercise testing parameters and heart rate during rest, exercise, and recovery. Heart rate recovery was calculated as heart rate at peak exercise minus heart rate at the first minute of recovery. RESULTS: Thirty-nine subjects (age 66.3 ± 7.8 y, 90% male, body mass index 27.1 ± 4.1 kg/m(2), FEV(1) 45.7 ± 18.7%) completed the program. In these subjects, heart rate recovery increased from 16.2 ± 8.0 beats/min to 18.4 ± 8.4 beats/min (P = .01), resting heart rate decreased from 88.0 ± 10.7 beats/min to 83.3 ± 10.5 beats/min (P = .004), and heart rate at anaerobic threshold decreased from 109.0 ± 12.5 beats/min to 105.5 ± 11.7 beats/min (P = .040). In addition, oxygen consumption (V(O(2))) increased from 14.3 ± 3.7 mL/kg/min to 15.2 ± 3.8 mL/kg/min at peak exercise, and from 9.7 ± 2.4 mL/kg/min to 10.4 ± 2.6 mL/kg/min at anaerobic threshold (both P = .02), while the V(O(2))/t slope increased from -0.32 ± 0.16 mL/kg/min(2) to -0.38 ± 0.19 mL/kg/min(2) (P = .003). Parameters of ventilatory performance improved also. CONCLUSIONS: In subjects with COPD, exercise-based rehabilitation improves heart rate recovery, modestly though, which indicates a degree of attenuated autonomic dysfunction. Exercise and muscular oxidative capacity, as expressed by V(O(2))/t slope, is also improved.

Effects of interval cycle training with or without strength training on vascular reactivity in heart failure patients.

BACKGROUND: Exercise training confers beneficial effects on vascular reactivity in patients with chronic heart failure (CHF). This randomized study compares the effects of interval cycle training combined with strength training versus interval training alone on vascular reactivity in CHF patients. METHODS: Twenty-eight consecutive stable CHF patients (23 males, 53 ± 10 years, 28.4 ± 4.1 kg/m(2), left ventricular ejection fraction of 37 ± 12%) were randomly assigned to 3 times' weekly training sessions for 3 months, consisting of a) 40 minutes of interval cycle training (n = 14), versus b) 20 minutes of similar interval training plus 20 minutes of strength training of the quadriceps, hamstrings, muscles of the shoulder and biceps brachialis (n = 14). The work/recovery ratio of each session was 30/60 seconds. The intensity of interval training was set at 50% of the peak workload achieved at the steep ramp test (consisted of a 25-Watt increase on a cycle ergometer every 10 seconds until exhaustion). All patients underwent maximal, symptom-limited cardiopulmonary exercise testing and ultrasound evaluation of vascular reactivity by flow-mediated vasodilation (FMD) before and after the program. RESULTS: A significant improvement in FMD was observed in the combined training group (P = 0.002), in contrast to the interval training alone group (P = NS); the improvement was significantly greater in the combined training than in the interval training alone group (P < .05). Peak oxygen uptake increased significantly and similarly in both groups, in the interval training group (P = .03), and in the combined training group (P = .006). No significant correlation was found between FMD improvement and cardiopulmonary exercise parameters. CONCLUSIONS: A combined high-intensity, interval cycle exercise with strength training induces a greater beneficial effect on vascular reactivity rather than interval exercise training alone in CHF patients.

Chronotropic incompetence and abnormal heart rate recovery early after left ventricular assist device implantation.

BACKGROUND: Chronotropic response to exercise and heart rate recovery immediately after exercise (HRR(1) ) are valid prognostic markers in patients with chronic heart failure (CHF). The aim of this study was to evaluate heart rate profile during and after exercise in CHF patients early after left ventricular assist device (LVAD) implantation. METHODS: We enrolled seven stable consecutive CHF patients (five males, mean age: 45 ± 16 years) after 1 month of LVAD (HeartMate II; Thoratec Corp, Pleasanton, CA, USA) implantation, seven healthy subjects, and 14 patients with advanced HF (HF control group) who performed an incremental symptom-limited cardiopulmonary exercise testing (CPET). CHF patients performed CPET at 1 and 3 months after LVAD. HRR(1) was defined as the HR difference from peak to 1 minute after exercise and chronotropic response to exercise as the chronotropic reserve ([CR, %]=[peak HR-resting HR/220-age-resting HR]× 100). RESULTS: LVAD patients 3 months after implantation had a significantly different HR profile during exercise compared to healthy controls, with significantly lower CR (57 ± 31 vs 90 ± 14, %, P < 0.001) and HRR(1) (14 ± 6 vs 28 ± 8, bpm, P < 0.01). HR profile during exercise did not significantly change 1 and 3 months after LVAD implantation. There was no statistical difference compared to HF control group and LVAD group regarding cardiopulmonary parameters. CONCLUSIONS: LVAD patients present an impaired CR and an abnormal HRR(1) after implantation, indicating significant cardiac autonomic abnormalities. These alterations seem to remain unaltered 3 months after LVAD implantation.

End-of-life decisions in Greek intensive care units: a multicenter cohort study.

INTRODUCTION: Intensive care may prolong the dying process in patients who have been unresponsive to the treatment already provided. Limitation of life-sustaining therapy, by either withholding or withdrawing support, is an ethically acceptable and common worldwide practice. The purpose of the present study was to examine the frequency, types, and rationale of limiting life support in Greek intensive care units (ICUs), the clinical and demographic parameters associated with it, and the participation of relatives in decision making. METHODS: This was a prospective observational study conducted in eight Greek multidisciplinary ICUs. We studied all consecutive ICU patients who died, excluding those who stayed in the ICU less than 48 hours or were brain dead. RESULTS: Three hundred six patients composed the study population, with a mean age of 64 years and a mean APACHE II score on admission of 21. Of study patients, 41% received full support, including unsuccessful cardiopulmonary resuscitation (CPR); 48% died after withholding of CPR; 8%, after withholding of other treatment modalities besides CPR; and 3%, after withdrawal of treatment. Patients in whom therapy was limited had a longer ICU (P < 0.01) and hospital (P = 0.01) length of stay, a lower Glasgow Coma Scale score (GCS) on admission (P < 0.01), a higher APACHE II score 24 hours before death (P < 0.01), and were more likely to be admitted with a neurologic diagnosis (P < 0.01). Patients who received full support were more likely to be admitted with either a cardiovascular (P = 0.02) or trauma diagnosis (P = 0.05) and to be surgical rather than medical (P = 0.05). The main factors that influenced the physician's decision were, when providing full support, reversibility of illness and prognostic uncertainty, whereas, when limiting therapy, unresponsiveness to treatment already offered, prognosis of underlying chronic disease, and prognosis of acute disorder. Relatives' participation in decision making occurred in 20% of cases and was more frequent when a decision to provide full support was made (P < 0.01). Advance directives were rare (1%). CONCLUSIONS: Limitation of life-sustaining treatment is a common phenomenon in the Greek ICUs studied. However, in a large majority of cases, it is equivalent to the withholding of CPR alone. Withholding of other therapies besides CPR and withdrawal of support are infrequent. Medical paternalism predominates in decision making.

Burnout and training satisfaction of medical residents in Greece: will the European Work Time Directive make a difference?

BACKGROUND: The aim of this study is to determine the prevalence of burnout in Greek medical residents, investigate its relationship with training satisfaction during residency and survey Greek medical residents' opinion towards the European Work Time Directive (EWTD). METHODS: A Multi-centre, cross-sectional survey of Greek residents was performed. The Maslach Burnout Inventory (MBI) was used to measure burnout, which was defined as high emotional exhaustion, combined with high depersonalization or low personal accomplishment. In addition, seven questions were designed for this study to evaluate self-reported resident training satisfaction and three questions queried residents' opinion on the EWTD and its effects on their personal and social life as well as their medical training. Univariate, bivariate and multivariate statistical models were used for the evaluation of data. RESULTS: Out of 311 respondents (77.8% response rate), 154 (49.5%) met burnout criteria and 99 (31.8%) indicated burnout on all three subscale scores. The number of residents that were dissatisfied with the overall quality of their residency training were 113 individuals (36.3%). Only 32 residents (10.3%) believed that the EWTD implementation will not have any beneficial effects for them. CONCLUSIONS: Both burnout and training dissatisfaction were common among Greek residents. Systemic interventions are thus required within the Greek health system, aimed at reducing resident impairment due to burnout and at improving their educational and professional perspectives. Although residents' opinion on the EWTD was not associated with burnout levels, the EWTD was found to be predominantly supported and anticipated by Greek residents and should be implemented to alleviate their workload and stress.

Exercise training improves characteristics of exercise oscillatory ventilation in chronic heart failure.

Background Exercise oscillatory ventilation in chronic heart failure has been suggested as a factor related to adverse cardiac events, aggravated prognosis and higher mortality. Exercise training is well known to affect exercise capacity and mechanisms of pathophysiology beneficially in chronic heart failure. Little is known, however, about the exercise training effects on characteristics of exercise oscillatory ventilation in chronic heart failure patients. Design and methods Twenty (out of 38) stable chronic heart failure patients exhibited exercise oscillatory ventilation (age 54 ± 11 years, peak oxygen uptake 15.0 ± 5.0 ml/kg per minute). Patients attended 36 sessions of high intensity interval exercise. All patients underwent cardiopulmonary exercise testing before and after the programme. Assessment of exercise oscillatory ventilation was based on the amplitude of cyclic fluctuations in breathing during rest and exercise. All values are mean ± SD. Results Exercise training reduced ( P < 0.05) the percentage of exercise oscillatory ventilation duration (79.0 ± 13.0 to 50.0 ± 25.0%), while average amplitude (5.2 ± 2.0 to 4.9 ± 1.6 L/minute) and length (44.0 ± 10.9 to 41.0 ± 6.7 seconds) did not change ( P > 0.05). Exercise oscillatory ventilation patients also increased exercise capacity ( P < 0.05). Conclusions A rehabilitation programme based on high intensity interval training improved exercise oscillatory ventilation observed in chronic heart failure patients, as well as cardiopulmonary efficiency and functional capacity.

Respiratory drive and breathing pattern abnormalities are related to exercise intolerance in chronic heart failure patients.

BACKGROUND: Patients with chronic heart failure (CHF) are characterized by exercise intolerance and ventilatory abnormalities that are related to poor prognosis. We hypothesized that CHF patients have increased respiratory drive and abnormal breathing pattern during exercise in relation to disease severity. MATERIALS AND METHODS: The study population consisted of 219 stable CHF patients and 30 healthy control subjects. All subjects underwent a symptom-limited cardiopulmonary exercise testing (CPET), pulmonary function tests, measurement of the maximal inspiratory pressure (PImax) and respiratory drive (P0.1). Measurements included peak oxygen uptake ( [Formula: see text] peak, ml/kg/min). Respiratory drive was measured by mouth occlusion pressure P0.1 and P0.1/PImax ratio at rest, and by mean inspiratory flow (VT/TI) at rest and during exercise. CHF patients were divided into 3 groups according to [Formula: see text] peak (Group A: >20, Group B: 20-16 and Group C: <16ml/kg/min). RESULTS: CHF patients presented higher P0.1/PImax (4.1±3.6 vs 3.0±1.5, p=0.007) and VT/TI at rest (0.48±0.14 vs 0.41±0.10, L/s respectively, p=0.004) and lower VT/TI at peak exercise (2.17±0.66 vs 2.56±0.73, L/s, p=0.009) compared to controls. P0.1/PImax was higher in CHF Group C vs B vs A (4.9±2.9 vs 3.6±1.8 vs 3.1±1.8, respectively, p<0.001), while VT/TI at peak exercise was lower (1.71±0.43 vs 2.15±0.52 vs 2.65±0.64, L/s, respectively, p<0.001). CONCLUSIONS: CHF patients present increased respiratory drive at rest and abnormal breathing pattern during exercise in relation to CHF severity.

Value of apical circumferential strain in the early post-myocardial infarction period for prediction of left ventricular remodeling.

BACKGROUND: Left ventricular (LV) remodeling after acute myocardial infarction (AMI) is related to increased morbidity and mortality. The aim of the present study was to examine whether LV deformational and torsional parameters can predict LV remodeling in patients with AMI. METHODS: Forty-two patients (age 57 ± 14 years) presenting with an anterior ST-elevation AMI and treated with primary percutaneous transluminal coronary angioplasty (PTCA) were included in the study. Four days post MI, LV ejection fraction (EF), LV torsion, longitudinal (4-, 3- & 2-chamber) and circumferential strain of the LV apex were evaluated by conventional and speckle-tracking echocardiography. The echocardiographic study was repeated at 3 months post-AMI and patients with LV remodeling, i.e. an increase >15% in LV end-systolic volume (LVESV), were identified. RESULTS: The 13 patients with LV remodeling had significantly more impaired apical circumferential strain (-7.3 ± 2.2% vs. -18.9 ± 5.2%, p=0.001), EF (42 ± 7% vs. 48.9 ± 6%, p=0.005), LV apical rotation (6.8 ± 4.8° vs. 11.1 ± 4.0°, p=0.027), and LV global longitudinal strain (-9.7 ± 1.9% vs. -12.9 ± 2.9%, p=0.03) on the 4th day post-AMI, in comparison to those without LV remodeling. Apical circumferential strain on the 4th day post-AMI showed the strongest correlation with the LVESV 3 months post-AMI (r=0.76, p=0.001), compared to EF (r=-0.60, p=0.001), global longitudinal strain (r=0.56, p=0.001), and LV apical rotation (r=-0.53, p=0.001). Furthermore, apical circumferential strain demonstrated the highest diagnostic accuracy: area under the receiver operating characteristic (ROC) curve 0.98, with sensitivity 100% and specificity 96% for prediction of LV remodeling, using a cutoff value <-11.0%. CONCLUSION: In patients with anterior AMI, LV apical circumferential strain in the early post-MI period constitutes a significant prognostic factor for LV remodeling at 3 months. Assessment of this parameter may identify patients at high risk for heart failure development.

Beneficial effects of combined exercise training on early recovery cardiopulmonary exercise testing indices in patients with chronic heart failure.

PURPOSE: Exercise training induces several beneficial effects in patients with chronic heart failure (CHF). This study investigated the effects of high-intensity aerobic interval training (AIT) compared with combined AIT and strength training (COM) on early ventilatory and metabolic recovery pattern after symptom-limited cardiopulmonary exercise testing (CPET) in CHF patients. METHODS: Stable CHF patients (N = 42; 54 ± 10 years [mean ± SD], 35 males) participated in an exercise training program for 12 weeks, 3 times per week. Participants were randomly assigned to either AIT (n = 20) or COM group (n = 22). Cardiopulmonary exercise testing was performed before and after completion of the program. Primary measurements included absolute and percentage difference of oxygen uptake, carbon dioxide output, minute ventilation ((Equation is included in full-text article.)E), tidal volume (VT), respiratory rate, and the first-degree slope of oxygen uptake ((Equation is included in full-text article.)O2/t slope) and carbon dioxide output ((Equation is included in full-text article.)CO2/t slope) during the first minute of recovery after maximal exercise. RESULTS: The COM group had a greater improvement in the absolute and the percentage difference of (Equation is included in full-text article.)E (P = .03 and P = .04, respectively) and respiratory rate (P = .02 and P = .01, respectively) during the first minute of recovery period after exercise compared with the AIT group alone. No significant changes were noted for VT measurements. A significant increase in (Equation is included in full-text article.)CO2/t slope was observed in COM compared with the AIT group (P = .01). There was a trend for a greater increase in (Equation is included in full-text article.)O2/t slope in the COM group (P = .07). CONCLUSIONS: The addition of strength training to AIT induces significant beneficial effects in terms of ventilatory and metabolic recovery kinetics than AIT alone in CHF patients, possibly indicating greater ventilatory efficiency and metabolic improvement.

Assessment of cognitive biases and biostatistics knowledge of medical residents: a multicenter, cross-sectional questionnaire study.

PURPOSE: The aim of this study is to determine the perceived familiarity of medical residents with statistical concepts, assess their ability to integrate these concepts in clinical scenarios, and investigate their susceptibility to the gambler's fallacy and the conjunction fallacy. METHODS: A multi-institutional, cross-sectional survey of Greek medical residents was performed. Participants were asked to indicate their familiarity with basic statistical concepts and answer clinically oriented questions designed to assess their biostatistics knowledge and cognitive biases. Univariate, bivariate, and multivariate statistical models were used for the evaluation of data. RESULTS: Out of 153 respondents (76.5% response rate), only two participants (1.3%) were able to answer all seven biostatistics knowledge questions correctly while 29 residents (19%) gave incorrect answers to all questions. The proportion of correct answers to each biostatistics knowledge question ranged from 15 to 51.6%. Residents with greater self-reported familiarity were more likely to perform better on the respective knowledge question (all p<0.01). Multivariate analysis of the effect of individual resident characteristics on questionnaire performance showed that previous education outside Greece, primarily during medical school, was associated with lower biostatistics knowledge scores (p<0.001). A little more than half of the respondents (54.2%) answered the gambler's fallacy quiz correctly. Residents with higher performance on the biostatistics knowledge questions were less prone to the gambler's fallacy (odds ratio 1.38, 95% confidence intervals 1.12-1.70, p=0.003). Only 48 residents (31.4%) did not violate the conjunction rule. CONCLUSIONS: A large number of medical residents are unable to correctly interpret crucial statistical concepts that are commonly found in the medical literature. They are also especially prone to the gambler's fallacy bias, which may undermine clinical judgment and medical decision making. Formalized systematic teaching of biostatistics during residency will be required to de-bias residents and ensure that they are proficient in understanding and communicating statistical information.

Neuroticism personality trait is associated with Quality of Life in patients with Chronic Heart Failure.

AIM: To evaluate Quality of life (QoL) in chronic heart failure (CHF) in relation to Neuroticism personality trait and CHF severity. METHODS: Thirty six consecutive, outpatients with Chronic Heart Failure (6 females and 30 males, mean age: 54 ± 12 years), with a left ventricular ejection fraction ≤ 45% at optimal medical treatment at the time of inclusion, were asked to answer the Kansas City Cardiomyopathy Questionnaire (KCCQ) for Quality of Life assessment and the NEO Five-Factor Personality Inventory for personality assessment. All patients underwent a symptom limited cardiopulmonary exercise testing on a cycle-ergometer, in order to access CHF severity. A multivariate linear regression analysis using simultaneous entry of predictors was performed to examine which of the CHF variables and of the personality variables were correlated independently to QoL scores in the two summary scales of the KCCQ, namely the Overall Summary Scale and the Clinical Summary Scale. RESULTS: The Neuroticism personality trait score had a significant inverse correlation with the Clinical Summary Score and Overall Summary Score of the KCCQ (r = -0.621, P < 0.05 and r = -0.543, P < 0.001, respectively). KCCQ summary scales did not show significant correlations with the personality traits of Extraversion, Openness, Conscientiousness and Agreeableness. Multivariate linear regression analysis using simultaneous entry of predictors was also conducted to determine the best linear combination of statistically significant univariate predictors such as Neuroticism, VE/VCO2 slope and VO2 peak, for predicting KCCQ Clinical Summary Score. The results show Neuroticism (ß = -0.37, P < 0.05), VE/VCO2 slope (ß = -0.31, P < 0.05) and VO2 peak (ß = 0.37, P < 0.05) to be independent predictors of QoL. In multivariate regression analysis Neuroticism (b = -0.37, P < 0.05), the slope of ventilatory equivalent for carbon dioxide output during exercise, (VE/VCO2 slope) (b = -0.31, P < 0.05) and peak oxygen uptake (VO2 peak), (b = 0.37, P < 0.05) were independent predictors of QoL (adjusted R2 = 0.64; F = 18.89, P < 0.001). CONCLUSION: Neuroticism is independently associated with QoL in CHF. QoL in CHF is not only determined by disease severity but also by the Neuroticism personality trait.

Peripheral muscle microcirculatory alterations in patients with pulmonary arterial hypertension: a pilot study.

BACKGROUND: Pulmonary microcirculation abnormalities are the main determinants of pulmonary arterial hypertension (PAH) pathophysiology. We hypothesized that PAH patients have peripheral tissue microcirculation alterations that might benefit from hyperoxic breathing. We evaluated peripheral muscle microcirculation with near-infrared spectroscopy, before and after hyperoxic breathing. METHODS: Eight PAH subjects, 8 healthy subjects (controls) matched for age, sex, and body mass index, and 16 subjects with chronic heart failure and matched for functional capacity with the PAH subjects underwent near-infrared spectroscopy. Tissue O(2) saturation, defined as the hemoglobin saturation (%) in the microvasculature compartments, was measured on the thenar muscle. Then the 3-min brachial artery occlusion technique was applied before, during, and after 15 min of breathing 100% O(2). We calculated the oxygen consumption rate (%/min), the reactive hyperemia time, and the time needed for tissue O(2) saturation to reach its baseline value after the release of the occlusion. RESULTS: Compared to the controls, the PAH subjects had a significantly lower resting tissue O(2) saturation (65.8 ± 14.9% vs 82.1 ± 4.0%, P = .005), a trend toward a lower oxygen consumption rate (35.3 ± 9.1%/min vs 43.4 ± 19.7%/min, P = .60), and a significantly higher reactive hyperemia time (3.0 ± 0.6 min vs 2.0 ± 0.3 min, P < .001). The PAH subjects also had lower tissue O(2) saturation (P = .08), lower peripheral arterial oxygen saturation (P = .01), and higher reactive hyperemia time (P = .02) than the chronic heart failure subjects. After hyperoxic breathing, the PAH subjects had increased tissue O(2) saturation (65.8 ± 14.9% to 71.4 ± 14.5%, P = .01), decreased oxygen consumption rate (35.3 ± 9.1%/min to 25.1 ± 6.6%/min, P = .01), and further increased reactive hyperemia time (3.0 ± 0.6 min to 4.2 ± 0.7 min, P = .007). CONCLUSIONS: The PAH subjects had substantial impairments of peripheral muscle microcirculation, decreased tissue O(2) saturation (possibly due to hypoxemia), slower reactive hyperemia time, (possibly due to endothelium dysfunction), and peripheral systemic vasoconstriction. Acute hyperoxic breathing improved resting tissue O(2) saturation (an expression of higher oxygen delivery) and decreased the oxygen consumption rate and reactive hyperemia time during reperfusion, possibly due to increased oxidative stress and evoked vasoconstriction.

Microcirculation and macrocirculation in cardiac surgical patients.

Background. The aim of our study was to investigate the relationship between microcirculatory alterations after open cardiac surgery, macrohemodynamics, and global indices of organ perfusion. Methods. Patients' microcirculation was assessed with near-infrared spectroscopy (NIRS) and the vascular occlusion technique (VOT). Results. 23 patients undergoing open cardiac surgery (11 male/12 female, median age 68 (range 28-82) years, EuroSCORE 6 (1-12)) were enrolled in the study. For pooled data, CI correlated with the tissue oxygen consumption rate as well as the reperfusion rate (r = 0.56, P < 0.001 and r = 0.58, P < 0.001, resp.). In addition, both total oxygen delivery (DO(2), mL/min per m(2)) and total oxygen consumption (VO(2), mL/min per m(2)) also correlated with the tissue oxygen consumption rate and the reperfusion rate. The tissue oxygen saturation of the thenar postoperatively correlated with the peak lactate levels during the six hour monitoring period (r = 0.50, P < 0.05). The tissue oxygen consumption rate (%/min) and the reperfusion rate (%/min), as derived from the VOT, were higher in survivors compared to nonsurvivors for pooled data [23 (4-54) versus 20 (8-38) P < 0.05] and [424 (27-1215) versus 197 (57-632) P < 0.01], respectively. Conclusion. Microcirculatory alterations after open cardiac surgery are related to macrohemodynamics and global indices of organ perfusion.

The effort-reward imbalance questionnaire in Greek: translation, validation and psychometric properties in health professionals.

OBJECTIVES: The aim of the present study was to translate, adapt and validate the Effort-reward imbalance (ERI) questionnaire in a sample of Greek healthcare professionals. METHODS: An internationally recommended methodology was followed to perform translation of the ERI instrument into the Greek language. The questionnaire was then randomly administered to 600 Greek physicians, nurses, physiotherapists and laboratory staff, and 456 questionnaires with no missing data on the ERI items were returned (76% response rate). Tool validation included assessment of internal consistency, factorial structure, discriminant validity and presence of floor or ceiling effects. Criterion validity was demonstrated by investigating the association of theoretically relevant ERI summary measurements with respondents' self-rated health. RESULTS: The Greek version of the ERI questionnaire showed good psychometric properties. Cronbach's alpha values were 0.79, 0.72 and 0.75 for the three ERI scales of effort, reward and overcommitment respectively. Exploratory factor analysis yielded a 5-factor solution that closely reflected the original theoretical ERI model. Significant associations were found between respondents' age, gender and specific occupation with ERI scores. ERI ratio and "overcommitment" scores in the highest tertiles were associated with elevated odds ratios (OR) of below-average self-rated health (OR=5.38, 95% confidence intervals 1.77 to 16.38, p=0.003, and OR=3.41, 95% confidence intervals 1.39 to 8.38, p=0.007, respectively). CONCLUSIONS: The translated and adapted Greek version is comparable with the original ERI instrument in terms of validity and factorial structure and is suitable for assessment of the psychosocial work environment of Greek healthcare professionals.

The addition of strength training to aerobic interval training: effects on muscle strength and body composition in CHF patients.

PURPOSE: The loss of lean muscle mass and muscle strength is a common problem in chronic heart failure (CHF) patients. Endurance training is efficient in improving patient exercise capacity. This study sought to evaluate the additional effects of strength training on muscle strength and body composition in chf patients participating in an interval training program. METHODS: Twenty consecutive, stable CHF patients participated in a rehabilitation program. Subjects were randomly assigned to aerobic (n = 10) or combined aerobic plus strength training group (n = 10). Aerobic group performed interval training on cycle ergometers. Strength training incorporated exercises for various muscle groups, including quadriceps, hamstrings, biceps brachii, and the deltoids. Both regimes were of the same duration. Body composition was evaluated by whole-body dual energy x-ray absorptiometry and quadriceps strength by the sum of the 2-repetition maximum (2-RM) test for each leg. Peak oxygen uptake (.VO(2peak)) and peak work load (W(peak)) as well as oxygen uptake (.VO(2AT)) and workload at anaerobic threshold (W(AT)) were evaluated by a symptom limited cardiopulmonary exercise testing. RESULTS: Concerning leg lean mass, no significant within-subjects or between-groups changes were observed (P > .05). Both groups improved in 2-RM test (P < .05), while a significant difference was observed between groups (P < .05). .VO(2peak) and .VO(2AT) and W(peak) and W(AT) were equally improved between training groups (P < .05). CONCLUSIONS: Combined aerobic interval and strength training induces a greater benefit than interval training alone on muscle strength in CHF patients. Adaptations other than hypertrophy, such as muscle fiber type alterations and/or neuromuscular adjustments, may account for these results.

Skeletal muscle microcirculatory abnormalities are associated with exercise intolerance, ventilatory inefficiency, and impaired autonomic control in heart failure.

BACKGROUND: Several skeletal muscle abnormalities have been identified in patients with chronic heart failure (CHF), including endothelial dysfunction. We hypothesized that skeletal muscle microcirculation, assessed by near-infrared spectroscopy (NIRS), is impaired in CHF patients and is associated with disease severity. METHODS: Eighty-three stable patients with mild-moderate CHF (72 males, mean age 54 ± 14 years, body mass index 26.7 ± 3.4 kg/m(2)) and 8 healthy subjects, matched for age, gender and body mass index, underwent NIRS with the vascular occlusion technique and cardiopulmonary exercise testing (CPET) evaluation on the same day. Tissue oxygen saturation (StO(2), %), defined as the percentage of hemoglobin saturation in the microvasculature compartments, was measured in the thenar muscle by NIRS before, during and after 3-minute occlusion of the brachial artery. Measurements included StO(2), oxygen consumption rate (OCR, %/min) and reperfusion rate (RR, %/min). All subjects underwent a symptom-limited CPET on a cycle ergometer. Measurements included VO(2) at peak exercise (VO(2)peak, ml/kg/min) and anaerobic threshold (VO(2)AT, ml/kg/min), VE/VCO(2) slope, chronotropic reserve (CR, %) and heart rate recovery (HRR(1), bpm). RESULTS: CHF patients had significantly lower StO(2) (75 ± 8.2 vs 80.3 ± 6, p < 0.05), lower OCR (32.3 ± 10.4 vs 37.7 ± 5.5, p < 0.05) and lower RR (10 ± 2.8 vs 15.7 ± 6.3, p < 0.05) compared with healthy controls. CHF patients with RR ≥9.5 had a significantly greater VO(2)peak (p < 0.001), VO(2)AT (p < 0.01), CR (p = 0.01) and HRR(1) (p = 0.01), and lower VE/VCO(2) slope (p = 0.001), compared to those with RR <9.5. In a multivariate analysis, RR was identified as an independent predictor of VO(2)peak, VE/VCO(2) slope and HRR(1). CONCLUSIONS: Peripheral muscle microcirculation, as assessed by NIRS, is significantly impaired in CHF patients and is associated with disease severity.