Usefulness of Speckle Tracking Imaging to Assess Myocardial Contractility in Intra-Abdominal Hypertension: Study in a Mini-Pig Model

This study evaluated the usefulness of speckle tracking imaging (STI) in assessment of myocardial contractility in intra-abdominal hypertension experimentally induced in mini-pigs. To this effect, 12 mini-pigs were anesthetized with intravenous injection of 3 % sodium pentobarbital, hemorrhaged to reach the shock status, and resuscitated with excessive volume of lactated Ringer's solution. The animals were either sham-operated (study group 1) or underwent treatment with intra-abdominal volume increment (study group 2). Observations were made prior to induction of shock, 1 h after shock, 2 h after induction of intra-abdominal hypertension, and 8 and 12 h after treatment. The heart rate and mean artery pressure were conventionally measured. STI was used to assess radial and circumferential strains of segmental ventricular wall. The results obtained demonstrated that myocardial contractility, as manifested by radial and circumferential strains of different ventricular wall segments, was decreased after induction of intra-abdominal hypertension. Treatment with intra-abdominal volume increment was able to decrease heart rate and intra-bladder pressure (indicator of effectiveness of treatment) and significantly improved myocardial contractility of involved ventricular wall segments. In conclusion, STI is a useful method to assess myocardial regional functions.