Background: stroke volume was influenced on various factor, especially contractility and arterial compliance, ventricular-arterial interaction, diastolic function and so on. We hypothesize that diastolic reserve function, defined as difference of Mitral tissue velocity after leg elevation test, will be effect on augmentation of stroke volume by leg elevation
Method and Result
From August 2009 to July 2010, 237 patients were referred to our Echo lab. for evaluation of HTN. Almost patients were performed Comprehensive echocardiographic evaluation of systolic and diastolic function was performed at rest and leg elevation status during 3minites and Laboratory test, ECG, ABI and PWV test, 24 hours ambulatory BP monitoring, 237 patients were classified into 2 groups: Group 1(n=45) had decreased or no change of SV after leg elevation test. Group 2(n=192) had increased SV after leg elevation test. There were no significant differences of Age, Sex, BSA, Ejection fraction, LVEDD, LVESD, LAVI, mitral E, A, DT, SBP/DBP, Heart rate at rest and after leg elevation, Mitral tissue velocity at septal, lateral, average, E/E’, and PWV in between 2 groups. Delta E’ ave.(E’ave. is defined as average of septal and lateral E’ velocity) was significantly lower(0.59±1.03 vs 0.98±1.11, p=0.032) in Group 1. There was no difference of delta E’septal, delta E’lateral in between 2 groups. Baseline Ea(effective arterial elastance), CA(total arterial compliance), SV and CO is significantly higher in Group1(1.50±0.36 vs 1.75±0.45, p=0.001; 1.56±0.42 vs 1.42±0.41, p=0.031; 81.29±17.32 vs 71.29±15.49, p<0.001; 5.25±1.35 vs 4.85±1.20, p=0.046, respectively), baseline Ed(index of diastolic stiffness=diastolic elastance) is significantly lower in Group 1. (0.15±0.07 vs 0.18±0.08, p=0.041)
Conclusion: among the patients with hypertension, SV augmentation by leg elevation was more prominent in patients with good diastolic functional reserve (delta E’ave.). Our Study suggested that diastolic functional reserve effect on stroke volume and cardiac output at volume loading condition.
CO; cardiac output, SV; stroke volume, delta E’; difference of E’ at rest and after leg elevation
E’ave; average E’ at septal and lateral, PWV; pulse wave velocity, DT; deceleration time, LVEDD; LV end diastolic dimension, LVESD; LV end systolic dimension, SBP/DBP; systolic/diastolic blood pressure, BSA; body surface area, LAVI; LA volume index.
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