Incremental Value of Ultrasonic Tissue Characterization (Backscatter) in the Evaluation of Left Ventricular Myocardial Structure and Mechanics in Essential Arterial Hypertension

Abstract

Background-Ultrasonic backscatter parameters were analyzed in hypertensive patients and divided into groups according to both severity of left ventricular hypertrophy (LVH) (

Downregulated myocardial connexin 43 and suppressed contractility in rabbits subjected to a cholesterol-enriched diet

“…In recent studies, CVI reduction has been considered as an early indicator of contractile dysfunction before recognizing the geometric remodeling or the drop in fractional shortening, being attributed to the increase or disarray in the myocardial collagen network. 14,35 However, the downregulation and redistribution of Cx43 has been also found in the hypertrophied myocardium, 30 suggesting a possible role for the remodeling of gap junctions in the attenuated CVI. In this study, we reported the sequential alterations in contractile function and the expression and distribution of Cx43 in hearts of rabbits fed on cholesterol-enriched diet, that have normal myocardial architecture and ridding of transmural fibrosis, and also the reversal of these findings on withdrawal of the diet.…”

“…The hypercholesterolemic rabbit hearts were also demonstrated to have systolic dysfunction in vivo, as measured using the CVI, mitral ring systolic velocity, and modified Tei index, all of which have been reported to be more sensitive than the fractional shortening. 14,22,29 These findings of hyperlipidemia-induced protein and contractile change raised an interesting question regarding the relationship between the alterations. Our findings suggest that in the hyperlipidemic rabbits, the remodeling of cardiomyocyte gap junctions may contribute to the impaired systolic function.…”

“…11 The myocardial CVI, proven to be heart rate and load independent, could be considered as an index of intrinsic myocardial contractility. 14,33 According to the elastic modules model 13 and the microscopic elastic wave theory, 16 the size and interdistance of scatters (myocytes), the acoustic impedance mismatching between the myocytes' intracellular contents and the extracellular collagen networks, as well as the ultrasonic insonification angle, 34 determine the acoustic contrast responsible for the scattering and generate the CVI. In recent studies, CVI reduction has been considered as an early indicator of contractile dysfunction before recognizing the geometric remodeling or the drop in fractional shortening, being attributed to the increase or disarray in the myocardial collagen network.…”

“…12 Ultrasonic tissue characterization (UTC) with cardiac cycle-dependent variation of integrated backscatters (CVI) has been shown to be representation of intrinsic myocardial contractility and a potential indicator of early systolic dysfunction. [13][14][15] Different structural components of the myocardium can influence its acoustic properties under different physiological and pathological conditions. Generated from the altered acoustic impedance mismatching between the myocytes' intracellular contents and the extracellular collagen networks during a cardiac cycle, 16 the magnitude of CVI depends not only on the microstructural arrangement of myocytes embedded in a collagen matrix, 17,18 but also on coordinated contraction of adjacent cardiomyocytes.…”

Myocardial Ultrasound Tissue Characterization in Patients with Chronic Renal Failure

“…Patients with previous cardiovascular disease were excluded. patients with EH with comparable LVMI were selected to avoid the confounding effect of the increase of LVM on IBS measures, because an increase in IBS absolute values and a reduction of IBS cyclic variation (CV) has been described in patients with EH with markedly increased LVM (19). BP was measured by the same physician with a mercury sphygmomanometer.…”