Strain rate imaging for the assessment of preload-dependent changes in regional left ventricular diastolic longitudinal function.
BACKGROUND
Strain rate imaging is a new and intriguing way of displaying myocardial deformation properties by means of echocardiography. With high frame rate strain rate imaging we observed a spatial inhomogeneity in diastolic longitudinal strain rates in healthy persons. A base-to-apex time delay in diastolic lengthening could be seen both in early diastole and at atrial contraction.


RESULTS
We investigated this consistent finding and its dependence on loading conditions in 20 healthy volunteers. Propagation velocities of lengthening of 91 +/- 31 cm/s (E-wave) and 203 +/- 11 cm/s (A-wave) at rest (equal to time delays of 104 +/- 29 ms and 56 +/- 24 ms, respectively) increased significantly to 101 +/- 27 cm/s (E) and 283 +/- 17 cm/s (A) with lifting the volunteers' legs. Applying nitroglycerin sublingually and sitting upright significantly decreased propagation velocities (E-wave 76 +/- 20 cm/s, A-wave 172 +/- 93 cm/s and E-wave 66 +/- 17 cm/s, A-wave 150 +/- 64 cm/s, respectively). Free lateral walls showed a lower propagation velocity than septal walls.


CONCLUSIONS
We conclude that the propagation velocities of left ventricular lengthening waves are dependent on preload changes and increase with increasing preload.
Voigt
Jens-Uwe
JU
Medical Clinic II, University Erlangen-Nuernberg, Erlangen, Germany. jens.uwe.voigt@gmx.net
Lindenmeier
Gerd
G
Werner
Dierk
D
Flachskampf
Frank A
FA
Nixdorff
Uwe
U
Hatle
Liv
L
Sutherland
George R
GR
Daniel
Werner G
WG
D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D003971:Diastole / Q000502:physiology*; D004452:Echocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000502:physiology; D012016:Reference Values; D018615:Ultrasonography, Doppler, Color; D016276:Ventricular Function; D016277:Ventricular Function, Left / Q000502:physiology*