CARDIAC APEX ROTATION ASSESSED BY AN IMPLANTABLE GYRO SENSOR: CORRELATION WITH A LV PRESSURE-DERIVED MYOCARDIAL PERFORMANCE INDEX IN EXPERIMENTALLY INDUCED ISCHEMIA

Despite many investigators have focused attention on cardiac apex rotation (CAR) as a sensitive marker of left ventricle (LV) function, no studies have been specifically aimed to evaluate the correlation of CAR with myocardial performance index (MPI), a well-known index of both systolic and diastolic performance. In four sheep, we measured CAR using a miniature gyro sensor epicardically positioned at LV apex and we evaluated the beat-to-beat correlation between CAR and a myocardial performance index calculated from LV-pressure (LVP) measurements (MPILVP). We also compared CAR with hemodynamic parameters (LVdP/dtMAX, LVdP/dtMIN). A strong negative correlation was observed between CAR and MPILVP during the experimental cardiac conditions (baseline, acute ischemia induced by coronary ligation and release of ligation). At 30 s after ligation a marked decrease of CAR was observed, while LVdP/dtMAX showed minor changes. CAR has good potential to reflect changes of global myocardial performance and to predict hemodynamic changes in acute impairment of cardiac function.