Document Detail


Left ventricular strain and untwist in hypertrophic cardiomyopathy: relation to exercise capacity.
MedLine Citation:
PMID:  20435192     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Nonobstructive hypertrophic cardiomyopathy (nHCM) is often associated with reduced exercise capacity despite hyperdynamic systolic function as measured by left ventricular ejection fraction. We sought to examine the importance of left ventricular strain, twist, and untwist as predictors of exercise capacity in nHCM patients.
METHODS: Fifty-six nHCM patients (31 male and mean age of 52 years) and 43 age- and gender-matched controls were enrolled. We measured peak oxygen consumption (peak Vo(2)) and acquired standard echocardiographic images in all participants. Two-dimensional speckle tracking was applied to measure rotation, twist, untwist rate, strain, and strain rate.
RESULTS: The nHCM patients exhibited marked exercise limitation compared with controls (peak Vo(2) 23.28 +/- 6.31 vs 37.70 +/- 7.99 mL/[kg min], P < .0001). Left ventricular ejection fraction in nHCM patients and controls was similar (62.76% +/- 9.05% vs 62.48% +/- 5.82%, P = .86). Longitudinal, radial, and circumferential strain and strain rate were all significantly reduced in nHCM patients compared with controls. There was a significant delay in 25% of untwist in nHCM compared with controls. Both systolic and diastolic apical rotation rates were lower in nHCM patients. Longitudinal systolic and diastolic strain rate correlated significantly with peak Vo(2) (r = -0.34, P = .01 and r = 0.36, P = .006, respectively). Twenty-five percent untwist correlated significantly with peak Vo(2) (r = 0.36, P = .006).
CONCLUSIONS: In nHCM patients, there are widespread abnormalities of both systolic and diastolic function. Reduced strain and delayed untwist contribute significantly to exercise limitation in nHCM patients.
Authors:
Khalid Abozguia; Ganesh Nallur-Shivu; Thanh T Phan; Ibrar Ahmed; Rajat Kalra; Rebekah A Weaver; William J McKenna; John E Sanderson; Perry Elliott; Michael P Frenneaux
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  American heart journal     Volume:  159     ISSN:  1097-6744     ISO Abbreviation:  Am. Heart J.     Publication Date:  2010 May 
Date Detail:
Created Date:  2010-05-03     Completed Date:  2010-05-24     Revised Date:  2013-05-29    
Medline Journal Info:
Nlm Unique ID:  0370465     Medline TA:  Am Heart J     Country:  United States    
Other Details:
Languages:  eng     Pagination:  825-32     Citation Subset:  AIM; IM    
Copyright Information:
2010 Mosby, Inc. All rights reserved.
Affiliation:
Department of Cardiovascular Medicine, University of Birmingham, Edgbaston, United Kingdom. abozguia@gmail.com
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MeSH Terms
Descriptor/Qualifier:
Aged
Cardiomyopathy, Hypertrophic / physiopathology*,  ultrasonography*
Echocardiography, Doppler / methods*
Electrocardiography
Exercise Tolerance / physiology*
Female
Heart Rate / physiology
Humans
Male
Middle Aged
Oxygen Consumption / physiology
Rotation
Torsion Abnormality / physiopathology
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