Document Detail

Preload dependency of left ventricular torsion: the impact of normal saline infusion.
MedLine Citation:
PMID:  20826594     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: left ventricular (LV) rotation results from contraction of obliquely oriented myocardial fibers. The net difference between systolic apical counterclockwise rotation and basal clockwise rotation is left ventricular torsion (LVT). Although LVT is altered in various cardiac diseases, determinants of LVT are incompletely understood.
METHODS AND RESULTS: LV end-diastolic volume, LV apical and basal rotation, peak systolic LVT, and peak early diastolic untwisting rate were measured by speckle-tracking echocardiography in healthy subjects (n=8) before and after infusion of a weight-based normal saline bolus (2.1±0.3 L). Saline infusion led to a significant increase in end-diastolic LV internal diameter (45.9±3.7 versus 47.6±4.2 mm; P=0.002) and LV end-diastolic volume (90.0±21.6 versus 98.3±19.6 mL; P=0.01). Stroke volume (51.3±10.9 versus 63.0±15.5 mL; P=0.003) and cardiac output (3.4±0.8 versus 4.4±1.5 L/min; P=0.007) increased, whereas there was no change in heart rate and blood pressure. There was a significant increase in the magnitude of peak systolic apical rotation (7.5±2.4° versus 10.5±2.8°; P<0.001) but no change in basal rotation (-4.1±2.3° versus -4.8±3.1°; P=0.44). Accordingly, peak systolic LVT increased by 33% after saline infusion (11.2±1.3° versus 14.9±1.7°; P<0.001). This saline-induced increase in LVT was associated with a marked increase in peak early diastolic untwisting rate (72.3±21.4 versus 136.8±30.0 degrees/s; P<0.001).
CONCLUSIONS: peak systolic LVT and peak early diastolic untwisting rate are preload-dependent. Changes in LV preload should be considered when interpreting results of future LVT studies.
Rory B Weiner; Arthur E Weyman; Abigail May Khan; Jason S Reingold; Annabel A Chen-Tournoux; Marielle Scherrer-Crosbie; Michael H Picard; Thomas J Wang; Aaron L Baggish
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2010-09-08
Journal Detail:
Title:  Circulation. Cardiovascular imaging     Volume:  3     ISSN:  1942-0080     ISO Abbreviation:  Circ Cardiovasc Imaging     Publication Date:  2010 Nov 
Date Detail:
Created Date:  2010-11-18     Completed Date:  2010-12-23     Revised Date:  2013-03-06    
Medline Journal Info:
Nlm Unique ID:  101479935     Medline TA:  Circ Cardiovasc Imaging     Country:  United States    
Other Details:
Languages:  eng     Pagination:  672-8     Citation Subset:  IM    
Division of Cardiology, Massachusetts General Hospital, Boston, Mass., USA.
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MeSH Terms
Analysis of Variance
Cardiac Volume / drug effects
Echocardiography, Doppler, Color / methods
Heart Ventricles / ultrasonography
Image Interpretation, Computer-Assisted / methods*
Infusions, Intravenous
Myocardial Contraction / drug effects*
Observer Variation
Reference Values
Sodium Chloride / pharmacology*
Torsion Abnormality / therapy*,  ultrasonography*
Ventricular Dysfunction, Left / physiopathology,  ultrasonography*
Ventricular Function, Left / drug effects*
Grant Support
Reg. No./Substance:
7647-14-5/Sodium Chloride

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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