Vector U Loop in Patients with Left Ventricular Overloading

Abstract

The U loops of vectorcardiograms were recorded in 30 normal subjects, 34 patients with left ventricular pressure overloading (VLPO group) whose underlying diseases were hypertensive heart disease or aortic stenosis, 42 with left ventricular volume overloading (LWO group) whose underlying diseases were aortic regurgitation or mitral regurgitation. These U loops were examined qualitatively and quantitatively, and were correlated with échocardiographie findings. In normal subjects the U loop was directed to the left, anteriorly and inferiorly, and in all cases it was inscribed counterclockwise in the horizontal plane. In both the LVPO and the LWO groups, the U loop tended to be displaced anteriorly and to the right, and was significantly greater in magnitude than that of normal subjects in the horizontal and left sagittal planes. In the mitral regurgitation group the maximum U vector was significantly greater in magnitude than that of the normal group, but no significant anterior displacement was observed. The clockwise rotation of the U loop in the horizontal plane was more frequently observed in patients with left ventricular overloading, and it was associated with the severity of the disease. There were correlations between the magnitude of the maximum U vector and left ventricular posterior wall thickness in the LVPO groups, and between the degree of anterior displacement of the U loop and left ventricular dimension in the LWO group. These findings suggest that the vector U loop is useful as clinical parameters of the hemodynamic state in the left ventricular overloading.

U Wave of High-Speed and Magnified Electrocardiogram in Left Ventricular Overloading

“…In the present study also, we found that the magnified ECG was more sensitive than the standard ECG for detecting a negative U wave, suggesting that this method could be dial lead. Previously we reported [9] that the U vector was displaced anteriorly and to the right in the LYO group, suggesting that the displacement of the U vector produced negative U waves in left precordial leads.…”

“…There have been few quantitative studies on the spatial characteristics of the U wave, because of its small size compared with the QRS or T waves [9,16].…”

Polymeric scaffolds for cardiac tissue engineering: requirements and fabrication technologies

“…Synthetic polymers, indeed, are biocompatible and biodegradable, and show high workability and good mechanical and physical properties that can be foreseen and conveniently tuned . Among synthetic polymers, polyesters and polyurethanes have been considered for the development of cardiac TE substrates . Among polyesters, poly(glycerol sebacate) and poly[(1,8‐octanediol)‐ co ‐(citric acid)] show elastomeric properties that make them appropriate raw materials for scaffold fabrication .…”

“…Among polyesters, poly(glycerol sebacate) and poly[(1,8‐octanediol)‐ co ‐(citric acid)] show elastomeric properties that make them appropriate raw materials for scaffold fabrication . The same promising properties can be found in conveniently synthesized polyurethanes . Moreover, biomimetic synthetic polymers can be produced to elicit specific cellular functions and direct tissue formation mediated by biomolecular recognition.…”

“…An increase in the concentration of the starting solution can be exploited to induce an increase in pore wall thickness and a decrease in pore size . The same effect can be produced by increasing the temperature gradient during the cooling phase . Other things being equal, scaffolds fabricated starting from a DMSO–polymer solution show larger and more interconnected pores than those fabricated from 1,4‐dioxane .…”