Objective To investigate the effects of simulated toss on the myocardial mechanics following early burn injury in rabbits.  Methods Eighty-four rabbits were subjected to 40% total body surface area thirddegree burn

and randomly divided into simple burn group (S group) and toss after burn group (DS group). There was no burn injury in another 48 rabbits

and they were randomly divided into simple toss group (DN group

n=42) and normal control group (n=6). The my

ocardial mechanic parameters (AOSP

AODP

MAP

LVSP

LVEDP and LV±dp/dt

max

) of groups DN

S and DS were investigated at 2

6

8

12

24

36 and 48 h after burn.  Results The levels of AOSP

AODP

MAP

LV+dp/dt

max

in DS group were significantly lower than those of S group from 12 h after burn. The levels of LVSP and LV-dp/dt

max

in DS group were obviously lower than those of the S group from 6 h after burn. The levels of LVEDP in DS group was also predominantly lower than those of S group from 2 h after burn. The myocardial mechanic parameters in DS group were the lowest in the three experimental groups at 2

6

8

12

24

36 and 48 h after burn.  Conclusion The simulated toss significantly aggravates the degression of the myocardial mechanic parameters and impairs heart function in burned rabbits.