P612Averaged, diastolic mitral inflow velocity mapping versus peak velocity for the assessment of left ventricular haemodynamics

The aim of this study was to determine the feasibility and accuracy of wall motion score index (WMSI) and myocardial performance index (MPI) for measuring regional and global left ventricular (LV) function with use of high-resolution echocardiography after myocardial infarction (MI) in mice. In 48 mice, myocardial infarction was induced by ligation in the middle of the left anterior descending coronary artery. Echocardiography was performed under anesthesia at baseline and 1 mo after MI. WMSI was analyzed by a 16-segment model on short-axis views, and wall motion was scored as 1 for normal, 2 for hypokinetic, 3 for akinetic, 4 for dyskinetic, and 5 for aneurysmal. WMSI was calculated as the sum of scores divided by the total number of segments. MPI was calculated on the basis of isovolumetric contraction time (IVCT), isovolumetric relaxation time (IVRT), and ejection time (ET): MPI = (IVCT + IVRT)/ET. We measured LV ejection fraction (LVEF), end-systolic and end-diastolic volumes (ESV and EDV), fractional shortening (FS), and infarct size (IS). LVEF at 4 wk after MI was reduced at 32.8 ± 9.0%. Linear correlation analyses showed that WMSI (1.6 ± 0.3) correlated with LVEF ( r = −0.84, P < 0.0005), FS ( r = −0.43, P = 0.003), and IS (34.3 ± 15.3%, r = 0.86, P < 0.0005). MPI (0.67 ± 0.09) correlated with LVEF ( r = −0.67, P < 0.0005) and IS ( r = 0.72, P < 0.0005). MPI also correlated with mitral inflow velocity ( r = −0.68, P < 0.0005) and deceleration time ( r = −0.42, P = 0.003). Stepwise regression analysis revealed that WMSI was independently associated with IS. IS, FS, mitral inflow velocity, and deceleration time were independent determinants of MPI. In conclusion, echocardiographic assessments of WMSI and MPI in mice are feasible and correlate strongly with two-dimensional measurement of LV function and IS. These novel parameters provide additional noninvasive assessment of regional and global LV function in mice after MI.

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Left ventricular diastolic filling and systolic function of young and older trained and untrained men

Journal of Applied Physiology ◽

10.1152/japplphysiol.00441.2003 ◽

2003 ◽

Vol 95 (6) ◽

pp. 2570-2575 ◽

Cited By ~ 39

Author(s):

James C. Baldi ◽

Kendra McFarlane ◽

Helen C. Oxenham ◽

Gillian A. Whalley ◽

Helen J. Walsh ◽

...

Keyword(s):

Endurance Training ◽

Young Men ◽

Older Men ◽

Left Ventricular ◽

Doppler Imaging ◽

Diastolic Filling ◽

Inflow Velocity ◽

Mitral Inflow ◽

Mitral Annular Velocity ◽

Mitral Inflow Velocity

Aging is associated with impaired early diastolic filling; however, the effect of endurance training on resting diastolic function in older subjects is unclear. Heart rate and ventricular loading conditions affect mitral inflow velocities measured by Doppler echocardiography; therefore, tissue Doppler imaging of mitral annular velocity, which is relatively preload independent, was combined with mitral inflow velocity and maximal oxygen consumption (V̇o2 max) in young (20-35 yr) and older (60-80 yr) trained and untrained men to determine whether endurance training is associated with an attenuation of age-associated changes in diastolic filling. As expected, V̇o2 max was higher in trained men ( P < 0.01) and lower in older men ( P < 0.01). Peak early mitral inflow velocity (E) and early-to-late mitral inflow velocity ratios were lower in older vs. young men ( P < 0.01); however, there was no training effect ( P > 0.05). Peak early mitral annular velocity (E′) was higher and peak late mitral annular velocity (A′) was lower in young vs. older men ( P < 0.01). A significant interaction effect was found for A′, E′/A′, and peak systolic mitral annular velocity (S′). Training was associated with lower A′ in young and higher A′ in older men. S′ was greater in trained vs. untrained older men ( P < 0.05), but it was similar in trained and untrained young men. These findings suggest that early diastolic filling is not affected by training in older men, and the effect of training on A′ and S′ is different in young and older men.

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25 Mitral inflow velocity encoded imaging by CMR for the assessment of left ventricular haemodynamics

10.1136/heartjnl-2019-bscmr.25 ◽

2019 ◽

Author(s):

Nithin Balasubramanian ◽

Natasha Barker ◽

Benjamin Fidock ◽

Alistair W Macdonald ◽

David Capener ◽

...

Keyword(s):

Left Ventricular ◽

Inflow Velocity ◽

Mitral Inflow ◽

Mitral Inflow Velocity

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Echocardiographic changes after myocardial infarction in a model of left ventricular diastolic dysfunction

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1997.273.4.h2018 ◽

1997 ◽

Vol 273 (4) ◽

pp. H2018-H2029 ◽

Cited By ~ 8

Author(s):

Gregory D. Pennock ◽

Douglas D. Yun ◽

Poonam G. Agarwal ◽

Peter H. Spooner ◽

Steven Goldman

Keyword(s):

Myocardial Infarction ◽

Diastolic Dysfunction ◽

Systolic Function ◽

Left Ventricular ◽

Coronary Artery Ligation ◽

Sham Operation ◽

Circumflex Artery ◽

Inflow Velocity ◽

Mitral Inflow ◽

Mitral Inflow Velocity

To determine the early and late effects of myocardial infarction on left ventricular (LV) diastolic function in the rabbit postinfarction model, male New Zealand White rabbits were randomly assigned to ligation of the circumflex artery or sham operation. Serial echocardiographic and Doppler studies were performed on both groups of animals at baseline and 1 h and 3 wk after surgery ( n = 10 for each group) after verification of the reproducibility and repeatability of the measurements. At 1 h postinfarction, decreases in early mitral inflow velocity (E wave) and mitral inflow velocity with atrial contraction (A wave) and increases in the mean pulmonary venous systolic-to-diastolic ratio and A wave reversal velocities were observed, without changes in LV geometry. By 3 wk postinfarction, increases in the mitral E-to-A ratio (1.1 ± 0.3 vs. 2.9 ± 0.9, P < 0.001) and left atrial area (131 ± 23 vs. 510 ± 72 mm2, P < 0.001) and decreases in the pulmonary venous systolic-to-diastolic ratio (0.56 ± 0.20 vs. 0.79 ± 0.14, P = 0.008) were consistent with severe diastolic abnormalities (restricted physiology). The findings of this study demonstrate that coronary artery ligation in the rabbit provides a reproducible echocardiographic and Doppler model of LV diastolic dysfunction that is consistent with abnormalities found in humans with previous myocardial infarction, symptoms of heart failure, and preserved LV systolic function.

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