Age dependency of myocardial structure: a quantitative two-dimensional echocardiographic study in a normal population

Echocardiographic evaluation of left atrial strain for predicting iron overload in pediatric patients with β-thalassemia with preserved ejection fraction

Pediatric patients with β-thalassemia (β-TM) with preserved ejection fraction may experience early myocardial damage. This prospective study aimed to investigate left atrial (LA) function restructure in pediatric patients with β-TM by two-dimensional speckle tracking echocardiography (2D-STE) and evaluate the value of LA strain for predicting myocardial iron overload (MIO). We recruited 50 β-TM pediatric patients and 30 healthy children aged 3-14 years. The patients were assigned to a normal left ventricular (LV) lesion group (n = 20) and an enlarged LV lesion group (n = 30). Subjects all underwent echocardiography to measure conventional cardiac function parameters and LA strain parameters. The results displayed that LA reservoir strain (LASr), conduit strain (LAScd), contractile strain (LASct) and strain rate were significantly reduced in pediatric patients with β-TM with preserved ejection fraction. LASr, LAScd, and LASct were negatively correlated with the E/e' ratio, of which LASr had the most significant correlation (r = - 0.69, P < 0.001). LASr and LASct correlated positively with T2* (r = 0.70 and 0.62, respectively, all P < 0.001). In the multiple regression, LASr and LASct were independent predictors for T2*. The areas under the curve for LASr and LASct were 0.87 (P < 0.001) and 0.78 (P = 0.004), respectively. Our results demonstrated that LA strains were dramatically impaired in pediatric patients with β-TM, and LASr is an efficient indicator for detecting LV early diastolic dysfunction in β-TM pediatric patients and reflects early myocardial damage. LASr and LASct were independently predictive of MIO, but LASr was a more sensitive predictor.

Cardiac tissue remodeling in healthy aging: the road to pathology

This review aims to highlight the normal physiological remodeling that occurs in healthy aging hearts, including changes that occur in contractility, conduction, valve function, large and small coronary vessels, and the extracellular matrix. These "normal" age-related changes serve as the foundation that supports decreased plasticity and limited ability for tissue remodeling during pathophysiological states such as myocardial ischemia and heart failure. This review will identify populations at greater risk for poor tissue remodeling in advanced age along with present and future therapeutic strategies that may ameliorate dysfunctional tissue remodeling in aging hearts.

Age-related changes in endothelin-1 receptor subtypes in rat heart

Density, affinity, and subtype distribution of endothelin-1 (ET-1) binding sites were determined in rat cardiac tissue as a function of age in order to evaluate the association of alterations in the endothelin receptor system and aging in the heart. A significant decrease in the receptor subtype ET-A, which represents 70% to 80% of the total receptor population in cardiac tissue of 3- and 12-month-old rats, was observed in 24-month-old rats with respect to the younger groups. These findings indicate an alteration in ET-1 cardiac receptors associated with aging, mainly due to a variation in the receptor subtype distribution.

Electrocardiographic criteria of left ventricular hypertrophy in general population

The question on whether the electrocardiographic criteria are reliable for detection of left ventricular hypertrophy (LVH) and play a role in predicting outcome is open. Answer can only proceed from population-based studies over unselected people followed up for years. In this study, 1,699 subjects from general population underwent echocardiogram and standard electrocardiogram (ECG) codified for LVH with Minnesota code and with other five methods. Other items were also recorded and used as covariables. Left ventricular mass index (LVMI) was 127.6 +/- 44.9 g m(-2) in men and 120.8 +/- 41.2 g m(-2 )in women, and correlated directly with age in both genders. Prevalence of echocardiographic LVH was 36.6% in men and 53.4% in women. LVMI correlated directly with the Sokolow-Lyon score in both genders at any age, with the Romhilt-Estes, Cornell and R(aVL) scores in all subjects but elderly men, and with the Lewis score in men and women aged < or =69 years. Sensitivity and the predictive value of electrocardiographic tests, as well as the prevalence of LVH diagnosed with electrocardiographic criteria, were always low. Specificity was high for all the tests, and in particular for the Cornell index. Only when diagnosed with echocardiogram or with the Sokolow-Lyon criterion, LVH was an independent predictor of mortality. We conclude that electrocardiographic tests cannot be used as a surrogate of echocardiogram in detecting LVH in the general population because their positive predictive value (PPV) is unacceptably low. On the contrary, they could replace echocardiography in the follow up and for prediction of outcome, when LVH has previously been correctly diagnosed with other methods.

Texture Analysis of Post Breast Cancer Lymphedema Ultrasound Images Obtained Using a Portable Device—A Pilot Study

BACKGROUND

Lymphedema is a common complaint of post-breast cancer treatment. Some prior ultrasound imaging studies of lymphedema-affected upper extremities focused upon estimating the thickness of the dermis and subcutis areas. In contrast, however, the reliability and validity of texture features derived from ultrasound images obtained using a low-cost portable ultrasound device have not been reported. This study examined the reliability and validity of the first and second order quantitative image texture measures, average pixel intensity and entropy, and compared their site-specific correlations.

METHODS AND RESULTS

A total of 10 ultrasound images of an ipsilateral affected elbow and the corresponding unaffected contralateral elbow were obtained using a portable ultrasound device. A Graphical User Interface software package for image analysis was developed and tested. Entropy and average pixel intensity at six adjacent regions of interest corresponding to the dermis and subcutis areas were calculated. Entropy had smaller coefficients of variation for each image compared to average pixel intensity with the intracluster correlation reliability coefficient for entropy being twice that of average pixel intensity. Both measures discriminated between the affected and unaffected sites (p < 0.001). However, the correlation between the two measures differed for affected (r = -0.060, p = 0.667) and unaffected (r = +0.595, p < 0.001) sites.

CONCLUSIONS

The second order measure entropy is preferable to that of the first order average pixel intensity as a measure of image texture to characterize ultrasound images of extremity lymphedema.

Biophysics of aging and therapeutic interventions by entropy-variation systems

The cell is thermodynamically an open system and aging is characterized by an increasingly higher structural disorder (increase of entropy) and functional loss. If a variation of negative entropy is introduced by an external source, an anti-clockwise effect leading to regenerative processes and/or increase of the functional reserve supporting regenerative tissue changes is theoretically expected. The achievement of a negative variation of entropy is the main principle of a new technology which implies an exogenous delivery of energy with higher performance than the physiological production. Promising clinical experiences in liver cirrhosis and in long-standing scarring lesions seem to confirm the clinical applicability of the theoretical model.