BackgroundLeft ventricular ejection fraction (LVEF) results from the combined action of longitudinal and circumferential contraction, radial thickening, and basal and apical rotation. The study of these parameters together may lead to an accurate assessment of the cardiac function.MethodsNinety healthy volunteers, categorized by gender and age (≤ 55 and > 55 years), were evaluated using two-dimensional speckle tracking echocardiography. Transversal views of the left ventricle (LV) were obtained to calculate circumferential strain and left ventricular twist, while three apical views were obtained to determine longitudinal strain (LS) and mitral annular plane systolic excursion (MAPSE). We established the integral myocardial function of the LV according to: 1. The Combined Deformation Parameter (CDP), which includes Deformation Product (DP) - Twist x LS (° x %) - and Deformation Index (DefI) -Twist / LS (° / %)-; and 2. the Torsion Index (TorI): Twist / MAPSE (° / cm).ResultsThe mean age of our patients was 50.3 ± 11.1 years. CDP did not vary with gender or age. The average DP was − 432 ± 172 ° x %, and the average DefI was − 0.96 ± 0.36 ° / %. DP provides information about myocardial function (normal, pseudonormal, depressed), and the DefI quotient indicates which component (s) is/are affected in cases of abnormality. TorI was higher in volunteers over 55 years (16.5 ± 15.2 vs 13.1 ± 5.0 °/cm, p = 0.003), but did not vary with gender.ConclusionsThe proposed parameters integrate values of twisting and longitudinal shortening. They allow a complete physiological assessment of cardiac systolic function, and could be used for the early detection and characterization of its alteration.
La función del corazón es de una dimensión mecánica que debe indagarse en los términos de su estructura. En la apreciación de su anatomía se halla el principio de la reflexión que llevó a investigaciones que explicasen su integridad organicofuncional. Si se hace una parada en las descripciones clásicas, se verá que la atención anatómica se prestó a sus superficies externa e interna, con muy poca importancia a la conformación muscular íntima. Se determinó de carácter homogéneo y sólido, con una contracción global uniforme y se soslayó que su capacidad mecánica exigía una reinterpretación de su anatomía espacial y de sus movimientos.
Background: The purpose of this work was to determine the influence of myocardial wringing on ventricular function in patients with cardiac amyloidosis (CA).Methods: Fifteen healthy volunteers (group 1) and 34 patients with CA (17 with left ventricular ejection fractions [LVEFs] $ 53% [group 2] and 17 with LVEFs < 53% [group 3]) were evaluated using two-dimensional speckletracking echocardiography. A control group of mass-matched patients (n = 20) with left ventricular (LV) hypertrophy and LVEFs $ 53% was also included. Longitudinal strain (LS), circumferential strain, and LV twist and torsion were calculated. Deformation index (DefI), a new parameter of wringing, calculated as twist/LS, that takes into account actions that occur simultaneously during LV systole (i.e., longitudinal shortening and twist), was evaluated. Torsional and wringing parameters were calculated according to LVEF.
Background. The aim of this study was to investigate: a) the starts and ends of the myocardial band; b) the slippage between the band segments, when performing both torsion and ventricular detorsion, implies that there should be an antifriction mechanism that avoids dissipating the energy; c) the electrical activation of the endocardial and epicardial bands and secondarily understand ventricular twist and the mechanism of active suction during the diastolic isovolumic phase. Methods. They were used: a) Ten young-bovine hearts (800-1000 g) and seven human hearts (one embrión, 4 g; one 10 years, 250 g and five adult, 300 g/average); b) five patients with no structural cardiac abnormalities and normal QRS complexes underwent three-dimensional endoepicardial electroanatomic mapping. Results. We have found in all the bovine and human hearts studied a nucleus (fulcrum) underlying the right trigone, whose osseus, chondroid or tendinous histological structure depends on the specimen analyzed. All the hearts studied presented myocardial attachment to the rigid structure of the fulcrum. Hyaluronic acid was found in the cleavage planes between the myocardial bundles.Endo-epicardial mapping demonstrates an electrical activation sequence in the area of the apex loop in agreement with the synchronic contraction of the descending and ascending band segments, consistent with the mechanism of ventricular twist. The late activation of the ascending band segment is consistent with its persistent contraction during the initial period of the isovolumic diastolic phase (the basis of the suction mechanism). Conclusions. The finding of the fulcrum gives support to the spiral myocardial band being the point of fixation that allows the helicoidal torsion. The hyaluronic acid would act as a lubricant and provide great resistance to mechanical pressures. This study explains the ventricular twist and the active suction mechanism during the isovolumic diastolic and early ventricular filling phases.Trial. This work does not correspond to a trial
In NSTEACS patients treated with invasive strategie CKD is associated independently with an increased risk of adverse cardiovascular outcomes at 3years.
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