Amplitude and velocity of mitral annulus motion in rabbits.
OBJECTIVE
During recent years, the amplitude and the maximal systolic velocity of the mitral annulus motion (MAM) have been established as indices of the left ventricular systolic function and the maximal diastolic velocity of the annulus motion has been suggested as an index of diastolic function. The main aims of the present study were to investigate the feasibility of these techniques in rabbits and to investigate age-related changes concerning these variables.


METHODS
Twenty-one New Zealand white rabbits were investigated by echocardiographic M-mode and pulsed tissue Doppler. One subgroup (I) included 11 still-growing, 3.0 +/- 0.2 month-old, animals and another group (II) included 10 young grown up rabbits, 12.1 +/- 1.5 months old.


RESULTS
The amplitude (4.8 +/- 0.6 and 3.5 +/- 0.3 mm, respectively) and maximal systolic (98 +/- 14 and 66 +/- 7 mm/s, respectively) and diastolic (111 +/- 21 and 80 +/- 12 mm/s, respectively) velocities of the MAM were significantly (P < 0.001) higher in group I than in group II, despite a bigger heart in the animals in the latter group. A coefficient of variation of <5% was found for both inter- and intraobserver variability for both amplitude and velocities.


CONCLUSIONS
The amplitude and velocities of MAM are easily recorded in rabbits with excellent reproducibility and the changes with age seem to be very similar to those in humans. These noninvasive M-mode and tissue Doppler methods are therefore suitable for the investigation of left ventricular function in experimental studies in rabbits.
Gan
Li-Ming
LM
Department of Clinical Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden.
Wikström
Johannes
J
Brandt-Eliasson
Ulla
U
Wandt
Birger
B
D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D004452:Echocardiography; D005260:Female; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000502:physiology*; D023421:Models, Animal; D008955:Models, Cardiovascular; D015588:Observer Variation; D011817:Rabbits; D015203:Reproducibility of Results; D013599:Systole / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology