Diabetic cardiomyopathy (DCM), although a distinct clinical entity, is also a part of the diabetic atherosclerosis process. It may be independent of the coexistence of ischemic heart disease, hypertension, or other macrovascular complications. Its pathological substrate is characterized by the presence of myocardial damage, reactive hypertrophy, and intermediary fibrosis, structural and functional changes of the small coronary vessels, disturbance of the management of the metabolic cardiovascular load, and cardiac autonomic neuropathy. These alterations make the diabetic heart susceptible to ischemia and less able to recover from an ischemic attack. Arterial hypertension frequently coexists with and exacerbates cardiac functioning, leading to the premature appearance of heart failure. Classical and newer echocardiographic methods are available for early diagnosis. Currently, there is no specific treatment for DCM; targeting its pathophysiological substrate by effective risk management protects the myocardium from further damage and has a recognized primary role in its prevention. Its pathophysiological substrate is also the objective for the new therapies and alternative remedies.

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The aim of this study was to investigate to what extent the existence of objective signs of diabetic autonomic neuropathy affects the corrected QT interval (QTc) in diabetic subjects. A total of 105 diabetic subjects (type 1, n = 53; type 2, n = 52) as well as 40 matched (by age and sex) control subjects were studied. All subjects underwent the battery of five Ewing tests. Autonomic neuropathy was diagnosed if two of the five tests were abnormal. In addition, the result of each test was considered as normal (grade = 0), borderline (grade = 1) or abnormal (grade = 2), and on the basis of the sum of the scores we calculated a total score for autonomic neuropathy. The QTc interval was measured at rest, and a value > 440 ms was considered abnormal. The QTc interval was significantly more prolonged in diabetic persons with autonomic neuropathy than in those without neutopathy and in control subjects: 408.4 +/- 24.2 ms vs. 394.6 +/- 27.9 ms and 393.6 +/- 25.5 ms respectively (P = 0.001). Furthermore, multivariate analysis controlling for age, sex, systolic and diastolic blood pressure, body mass index (BMI), waist-hip ratio (WHR), smoking, type and duration of diabetes, type of treatment, HBA1c and total score of autonomic neuropathy eliminated the role of all these factors as potential confounders except for the total score of autonomic neuropathy, which was found to affect QTc interval independently and significantly (P = 0.012). In summary, the present study confirmed the well-known relation between autonomic neuropathy and QTc interval; in addition, it showed that QTc prolongation is associated with major degrees of autonomic neuropathy.

The spatial QRS-T angle obtained by vectorcardiography is a combined measurement of the electrical activity of the heart and predicts cardiovascular morbidity and mortality. Disturbances in repolarization and depolarization are common in diabetes. No data, however, exist on the effect of diabetes on QRS-T angle. In this study we examined differences in QRS-T angle between type 2 diabetic and non-diabetic subjects; in addition, the potential relationship between QRS-T angle and left ventricular performance as well as glycaemic control were also examined. A total of 74 subjects with type 2 diabetes and 74 non-diabetic individuals, matched for age and sex with the diabetic subjects were examined. All subjects were free of clinically apparent macrovascular complications. Spatial vectorcardiogaphic descriptors of ventricular depolarization and repolarization were reconstructed from the 12-electrocardiographic leads using a computer-based electrocardiogram. Left ventricular mass and performance were measured using M-mode and Doppler echocardiography. QRS-T angle values were higher (by almost 2-fold) in the diabetic in comparison with the non-diabetic subjects (P < 0.001). After multivariate adjustment, QRS-T angle was independently associated with age (P = 0.01), HbA(1c) (P = 0.003), and low-density lipoprotein cholesterol levels (P = 0.04) in the non-diabetic, and with HbA(1c) (P = 0.03) as well as Tei index (P = 0.003) in the diabetic subjects. The spatial QRS-T angle is high in subjects with type 2 diabetes and is associated with glycaemic control and left ventricular performance. The prognostic importance of the higher spQRS-T angle values in subjects with diabetes remains to be evaluated in prospective studies.

Masked hypertension is defined as low clinic and elevated out-of-clinic pressure (blood pressure, BP) assessed either by patients at home or by ambulatory monitoring. This study compared the cardiovascular status and psychometric characteristics of masked, white coat and sustained hypertensives. Three groups of consecutive subjects with masked (n ¼ 100, age 59 ± 11 years), white coat (n ¼ 100, 60 ± 10 years) and sustained hypertension (n ¼ 100, 60 ± 11 years) diagnosed by ambulatory BP monitoring were compared. Masked hypertensives had higher educational level, exercised more frequently, received fewer drugs and sensed more responsibilities at work than at home. Their left ventricular hypertrophy indexes fall inbetween those with white coat and sustained, the latter having the highest values. The estimated total cardiovascular risk was intermediate between white coat and sustained, whereas their cardiovascular morbidity and renal disease was higher than that of white coat and similar to sustained. Psychological profile analysis showed lower score for type-A personality and their mood behaviour in the hypomania-euthymia range compared with white coat and sustained hypertensives. The cardiovascular risk of masked hypertensives is higher than that of white coat and similar to sustained. Masked hypertensives have higher educational level, better physical training and different personality/mood pattern than white coat and sustained.

Currently, there is no recommendation regarding the minimum number of pulse wave velocity (PWV) measurements to optimize individual's cardiovascular risk (CVR) stratification. The aim of this study was to examine differences between three single consecutive and averaged PWV measurements in terms of the extrapolated CVR and the classification of aortic stiffness as normal. In 60 subjects who referred for CVR assessment, three repeated measurements of blood pressure (BP), heart rate and PWV were performed. The reproducibility was evaluated by the intraclass correlation coefficient (ICC) and mean±s.d. of differences. The absolute differences between single and averaged PWV measurements were classified as: p0.25, 0.26-0.49, 0.50-0.99 and X1 m s À1 . A difference X0.5 m s À1 (corresponding to 7.5% change in CVR, metaanalysis data from 412 000 subjects) was considered as clinically meaningful; PWV values (single or averaged) were classified as normal according to respective age-corrected normal values (European Network data). Kappa statistic was used to evaluate the agreement between classifications. PWV for the first, second and third measurement was 7.0±1.9, 6.9±1.9, 6.9±2.0 m s À1 , respectively (P ¼ 0.319); BP and heart rate did not vary significantly. A good reproducibility between single measurements was observed (ICC40.94, s.d. ranged between 0.43 and 0.64 m s À1 ). A high percent with difference X0.5 m s À1 was observed between: any pair of the three single PWV measurements (26.6-38.3%); the first or second single measurement and the average of the first and second (18.3%); any single measurement and the average of three measurements (10-20%). In only up to 5% a difference X0.5 m s À1 was observed between the average of three and the average of any two PWV measurements. There was no significant agreement regarding PWV classification as normal between: the first or second measurement and the averaged PWV values. There was significant agreement in classification made by the average of the first two and the average of three PWV measurements (j ¼ 0.85, Po0.001). Even when high reproducibility in PWV measurement is succeeded single measurements provide quite variable results in terms of the extrapolated CVR and the classification of aortic stiffness as normal. The average of two PWV measurements provides similar results with the average of three.

International audienceIndirect combustion noise, generated by the acceleration and distortion of entropy waves through the turbine stages, has been shown to be the dominant noise source of gas turbines at low-frequencies and to impact the thermoacoustic behavior of the combustor. In the present work, indirect combustion noise generation is evaluated in the realistic, fully 3D transonic high-pressure turbine stage MT1 using large eddy simulations (LESs). An analysis of the basic flow and the different turbine noise generation mechanisms is performed for two configurations: one with a steady inflow and a second with a pulsed inlet, where a plane entropy wave train at a given frequency is injected before propagating across the stage generating indirect noise. The noise is evaluated through the dynamic mode decomposition (DMD) of the flow field. It is compared with the previous 2D simulations of a similar stator/rotor configuration, as well as with the compact theory of Cumpsty and Marble. Results show that the upstream propagating entropy noise is reduced due to the choked turbine nozzle guide vane. Downstream acoustic waves are found to be of similar strength to the 2D case, highlighting the potential impact of indirect combustion noise on the overall noise signature of the engine

Aortic stiffness (pulse wave velocity, PWV) and pressure wave reflections (augmentation index, AI) are two interrelated markers of mortality. Their potential synergistic effect on mortality has never been studied. We sought to investigate the association as well as the combined effect of PWV and AI on mortality in a cohort (PROTEGER Study) of very old (470 years, mean age ( ± s.d.): 85.4±7.4 years). Aortic PWV and pressure wave AI were assessed by pulse wave analysis; carotid structure and cardiac function were analyzed by ultrasound. The analysis was performed in 259 patients who had all the data available. Neither PWV nor AI was, in separate, predictors of mortality (log-rank test: P¼0.278 and P¼0.433, respectively, Kaplan-Meier analysis). No linear association was found between PWV and AI (P¼0.278). To investigate the possible synergistic effect of PWV and AI on mortality, the population was analyzed according to the tertiles of PWV and AI. Subjects with combined high PWV (third tertile) and moderate-to-high AI (second and third tertiles) had lower survival compared with the rest of the population (Kaplan-Meier survival curve, log-rank test: P¼0.030). Cox regression analysis showed that this effect was independent from age, gender, blood pressure, cardiac/carotid parameters and other confounders, except creatinine and insulin resistance. The present study provides further insight on the pathophysiological association between large artery stiffness and pressure wave reflections, suggesting that when both are elevated they may increase the mortality in the elderly.