The effect of open-chest cardiac resuscitation on mitral regurgitant flow: an on-line transesophageal echocardiographic study in XXXX .

@entity235 @entity339 @entity2224 @entity1167
INTRODUCTION: We sought to determine the effect of cardiac massage on a pre-existing regurgitant mitral valve during open-chest cardiopulmonary resuscitation (OCCPR) in an animal experiment. METHODS: Our study included 29 @entity235 that were used as experimental models. We anesthetized them and inserted a transesophageal echocardiographic (TEE) probe. Then we performed a transverse thoracotomy, attempting to produce @entity339 ( @entity339 ). In models that showed @entity1167 we initiated OCCPR to restore cardiac function. The regurgitant area of mitral jet and left ventricular (LV) diameters and volumes were calculated before and during OCCPR using TEE. RESULTS: @entity2224 and/or electromechanical dissociation occurred in 13 animals (45%). In 4 models without preexisting @entity339 , no additional regurgitation was detected during OCCPR, while in another 5 with preexisting @entity339 we noticed a slight increase in the regurgitant flow. The regurgitant flow area changed from 0.62 +/- 1 cm2 before to 1.1 +/- 0.36 cm2 during OCCPR (p<0.008). In the 4 animals that had severe damage to the mitral apparatus after the attempts, the regurgitant flow increased from 4.01 +/- 0.93 cm2 to 7.7 +/- 2.6 cm2 (p<0.002). The LV transverse diameter decreased from 4.39 +/- 0.62 cm to 1.54 +/- 0.5 cm and its volume from 60.5 +/- 7.14 cm3 to 17.02 +/- 4.14 cm3 (both p<0.001), thus showing the effectiveness of OCCPR. CONCLUSIONS: Given the presence of preexisting @entity339 , direct cardiac massage during OCCPR would probably be less effective than expected, because of an increase in the amount of the regurgitant.
