Abstract 3047: Role of Pericardium in Maintaining the Left Ventricular Twist
Background: The role of pericardium in left ventricular (LV) twist has not been directly investigated. We sought to determine a role of pericardium in maintaining LV twist function in animal experiment, before and after pericardial opening.
Methods: Thirteen mongrel dogs were initially operated, but 2 dogs were excluded for final analyses due to poor speckle tracking. Intraoperative echocardiography for conventional and speckle tracking measurements was performed at baseline with intact pericardium, and after pericardial opening. With speckle tracking technique, LV twist and strains were obtained before and after pericardial opening in 11 animals and additionally after pericardial repair in 5 animals.
Results: LV twist was significantly decreased after pericardial opening (11.9±5.6° to 7.0±3.6°, P=0.001). LV twist rate and untwist rate were also decreased. (138.0±77.4°/sec to 74.6±29.2°/sec for twist rate, −131.1±55.8°/sec to −72.3±41.77°/sec for untwist rate, P=0.015 and 0.009, respectively) LV stoke volume and ejection fraction were similar irrespective of pericardial presence, but radial strain measured at the mid ventricular level was significantly increased (31.0±13.3% to 38.3±14.1%, P=0.02) without changes in circumferential and longitudinal strains. LV twist degree was restored after pericardial repair.
Conclusion: Pericardium is an important structure in maintaining LV twist. Given no significant impact of the presence or absence of pericardium on LV systolic function, an increase in LV radial strain serves as a compensatory mechanism to preserve LV systolic function despite a decrease in LV twist in the absence of pericardium.