Volume depletion provided by blood donation alters twist mechanics of the heart: Preload dependency of left ventricular torsion.

OBJECTIVES: The crucial role of twisting motion on both left ventricular (LV) contraction and relaxation has been clearly identified. However, the reports studying the association between LV torsion and loading conditions have revealed conflicting outcomes. Previously normal saline infusion was shown to increase LV rotation. Our aim was to test this phenomenon after volume depletion in healthy volunteer blood donors. DESIGN: A total of 26 healthy male volunteers were included in the study. LV end-diastolic and end-systolic diameter, LV ejection fraction, LV diastolic parameters, LV apical and basal rotation and peak systolic LV torsion were measured by speckle-tracking echocardiography before and after 450 mL blood donation. RESULTS: Blood donation led to a significant decrease in end-diastolic LV internal diameter (48.7 ± 0.4 versus 46.4 ± 0.4 mm; p < 0.001) and cardiac output (6.2 ± 1.0 versus 5.1 ± 0.7 L/min; p < 0.001). There was a significant decrease in the magnitude of peak systolic apical rotation (4.4 ± 1.9° versus 2.9 ± 1.5°; p < 0.001) but no change in basal rotation (2.6 ± 1.4° versus 2.7 ± 1.6°; p = 0.81). Peak systolic LV Torsion decreased after blood donation (6.9 ± 1.9° versus 5.7 ± 2.1°; p = 0.028). CONCLUSIONS: LV apical rotation and peak systolic LV torsion seem to be preload dependent. Preload reduction provided by 450-mL blood donation decreased LV torsion in healthy male volunteers. Volume dynamics should be taken into account in the evaluation of LV torsion.

High-density lipoprotein subfractions and influence of endothelial lipase in a healthy Turkish population: a study in a land of low high-density lipoprotein cholesterol.

PURPOSE: Low concentration of high-density lipoprotein (HDL) is prevalent in Turkey. Endothelial lipase (EL) regulates lipoprotein metabolism. Small, lipid-poor HDL particles represent more-efficient cholesterol acceptors than their large, lipid-rich counterparts. The aim of this study was to investigate HDL subfractions and the effect of EL on HDL concentrations in healthy Turkish population. METHODS: 102 healthy subjects were included in the study (mean age 33.6 ± 10.3 years, 42 female). HDL subfractions were assayed by single precipitation method and EL concentrations were measured by competitive enzyme immunoassay. RESULTS: Mean HDL concentrations were 1.45 ± 0.37 mmol/L in women, 1.10 ± 0.30 mmol/L in men. Small HDL subfraction levels did not differ statistically between < 1 mmol/L and ≥ 1.6 mmol/L total HDL groups. Small HDL was not correlated with EL, low density lipoprotein cholesterol (LDL), triglyceride (TG) and age but positively correlated with total cholesterol and HDL (r = 0.2, p = 0.017; r = 0.2, p = 0.028, respectively). Large HDL was not correlated with age, EL and total cholesterol, and negatively correlated with HDL, LDL, TG (r = - 0.7, p < 0.001; r = - 0.2, p = 0.045; r = - 0.3, p < 0.001, respectively). If subjects were divided into two groups as HDL< 1 mmol/L and HDL > 1.6 mmol/L, mean EL concentrations were 475.83 ± 521.77 nmol/L and 529.71 ± 276.92 nmol/L, respectively (p = 0.086). CONCLUSION: There were no differences between small HDL concentrations in the HDL low and high groups. Our data did not support EL to be the reason for low HDL in a healthy Turkish population. Our results in a healthy population may serve as a reference for clinical studies on HDL subfractions.