Preload Dependency of Left Ventricular Torsion

• DOI: 10.1161/circimaging.109.932921
• Publication Date: 2010-09-09T01:50:21Z
• Authors: Rory B. Weiner; Arthur E. Weyman; Abigail May Khan; Jason S. Reingold; Annabel A. Chen-T...; Marielle Scherrer...; Michael H. Picard; Thomas J. Wang; Aaron L. Baggish
• Keywords: Preload

left ventricular (LV) rotation results from contraction of obliquely oriented myocardial fibers. The net difference between systolic apical counterclockwise and basal clockwise is torsion (LVT). Although LVT altered in various cardiac diseases, determinants are incompletely understood.LV end-diastolic volume, LV rotation, peak LVT, early diastolic untwisting rate were measured by speckle-tracking echocardiography healthy subjects (n=8) before after infusion a weight-based normal saline bolus (2.1±0.3 L). Saline led to significant increase internal diameter (45.9±3.7 versus 47.6±4.2 mm; P=0.002) volume (90.0±21.6 98.3±19.6 mL; P=0.01). Stroke (51.3±10.9 63.0±15.5 P=0.003) output (3.4±0.8 4.4±1.5 L/min; P=0.007) increased, whereas there was no change heart blood pressure. There the magnitude (7.5±2.4° 10.5±2.8°; P<0.001) but (-4.1±2.3° -4.8±3.1°; P=0.44). Accordingly, increased 33% (11.2±1.3° 14.9±1.7°; P<0.001). This saline-induced associated with marked (72.3±21.4 136.8±30.0 degrees/s; P<0.001).peak preload-dependent. Changes preload should be considered when interpreting future studies.