Speckle Tracking Analysis of Left Ventricular Systolic Function Following Traumatic Brain Injury: A Pilot Prospective Observational Cohort Study. - Krishnamoorthy V; Chaikittisilpa N; Lee J; Mackensen GB; Gibbons EF; Laskowitz D; Hernandez A; Velazquez E; Lele AV; Vavilala MS (Journal of neurosurgical anesthesiology, 2020)