Document Detail

Left ventricular torsion parameters are affected by acute changes in load.
MedLine Citation:
PMID:  20070357     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Quantification of left ventricular torsion may provide new indices of systolic and diastolic function. We sought to characterize the effect of acute manipulation of load on cardiac torsion, plecotropy in human subjects. METHODS: Simultaneous Millar LV pressure, micromanometry, and echocardiograms were performed on 18 patients (10 male, mean age 66 years) with normal systolic function. Loading was altered sequentially by the administration of glyceryl trinitrate (GTN) and saline fluid loading. Echocardiographic speckle tracking imaging was used to quantify LV torsion and event timing was recorded relative to mitral valve opening (MVO). RESULTS: GTN administration decreased preload (LV end diastolic pressure: 15.7 vs 8.4 mmHg, P < 0.001), and afterload (wall stress: 140 vs 84 x10(3)dyn/cm(2), P < 0.02). Administration of fluid increased preload (LVEDP 11.3 vs 18.1 mmHg, P < 0.001) and increased wall stress, but to a lesser extent (102 vs 117 x10(3)dyn/cm(2), P < 0.003). GTN administration augmented peak torsion (8.4 vs 11.0 deg, P < 0.05), increased systolic torsion velocity (46.6 vs 65.3deg/sec, P < 0.01) and resulted in earlier onset of untwisting (-105 vs -127ms, P < 0.05). Fluid loading decreased the proportion of untwisting prior to MVO (39.0 vs 31.0%, P < 0.05), untwisting acceleration (-750 vs -592deg/sec/sec, P < 0.05) and delayed the timing of peak untwisting (-37.0 vs 9.1ms, P < 0.01), but did not affect systolic torsion parameters. CONCLUSIONS: Left ventricular torsion parameters are sensitive to acute changes in load and therefore need to be interpreted in the context of current loading conditions.
Andrew T Burns; Andre La Gerche; David L Prior; Andrew I Macisaac
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-01-13
Journal Detail:
Title:  Echocardiography (Mount Kisco, N.Y.)     Volume:  27     ISSN:  1540-8175     ISO Abbreviation:  Echocardiography     Publication Date:  2010 Apr 
Date Detail:
Created Date:  2010-06-09     Completed Date:  2010-10-08     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8511187     Medline TA:  Echocardiography     Country:  United States    
Other Details:
Languages:  eng     Pagination:  407-14     Citation Subset:  IM    
Cardiac Investigation Unit, St. Vincent's Hospital Melbourne, Victoria, Australia 3065.
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MeSH Terms
Heart Ventricles / ultrasonography*
Image Processing, Computer-Assisted / methods
Middle Aged
Torsion Abnormality / ultrasonography*
Ventricular Dysfunction, Left / ultrasonography*

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