Related Experiment Videos
Can left ventricular diastolic stiffness be measured noninvasively?
Paolo Marino1, William C Little, Andrea Rossi
1Cardiology Service, Policlinico G.B. Rossi, Division of Cardiology, Ospedale Maggiore, University of Verona, P.le L.A. Scuro 10, 37134 Verona, Italy. paolo.marino@univr.it
Summary
Noninvasive estimation of left ventricular (LV) diastolic chamber stiffness (K(LV)) is achievable using Doppler mitral flow deceleration time (DT). This method accurately predicts K(LV) in patients with diverse cardiac conditions.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Diagnostics
Background:
- Accurate noninvasive assessment of left ventricular (LV) diastolic chamber stiffness (K(LV)) remains a clinical challenge.
- Previous research suggests a potential relationship between K(LV) and Doppler mitral flow deceleration time (DT).
- This study aimed to validate a noninvasive formula for K(LV) estimation using DT.
Purpose of the Study:
- To assess the accuracy of a noninvasive method for estimating left ventricular (LV) diastolic chamber stiffness (K(LV)) using Doppler mitral flow deceleration time (DT).
- To compare noninvasive K(LV) estimates with invasive measurements across a spectrum of LV sizes and functions.
- To evaluate the formula's performance under various hemodynamic loading conditions.
Main Methods:
- Twenty-five patients with ischemic heart disease or LV dysfunction underwent simultaneous invasive LV pressure measurement and 2D echocardiography-guided Doppler mitral flow velocity assessment.
- LV volume was calculated using mitral flow velocity integral and annular area, calibrated to 2D echocardiography stroke volume.
- Invasive K(LV) was determined from pressure and volume changes, with measurements repeated after LV unloading in most patients. Noninvasive K(LV) was calculated using the formula: K(lv) = (70/[DT-20])(2) mm Hg/mL.
Main Results:
- A significant inverse relationship was observed between DT and K(LV) (P <.001) in patients with normal mitral annular area.
- The noninvasive K(LV) estimation demonstrated a close correlation with directly measured K(LV) (r = 0.67, P <.001) across all conditions.
- The relationship approached the line of identity (y = 0.93x + 0.05), despite a notable standard error of the estimate (0.26 mm Hg/mL).
Conclusions:
- Left ventricular (LV) diastolic chamber stiffness (K(LV)) can be reliably calculated from noninvasively measured Doppler mitral flow deceleration time (DT).
- The proposed formula provides a clinically applicable method for estimating K(LV) with an accuracy of +/- 0.5 mm Hg/mL.
- This noninvasive approach offers a valuable tool for assessing diastolic function in patients.