Document Detail

Delayed untwisting: the mechanistic link between dynamic obstruction and exercise tolerance in patients with hypertrophic obstructive cardiomyopathy.
MedLine Citation:
PMID:  19778676     Owner:  NLM     Status:  MEDLINE    
OBJECTIVES: We sought to determine the mechanisms linking dynamic obstruction and exercise tolerance in patients with hypertrophic obstructive cardiomyopathy (HOCM). BACKGROUND: Patients with HOCM have reduced exercise tolerance. However, the association between dynamic obstruction and peak oxygen consumption (VO2max) is weak. METHODS: We enrolled 25 patients with HOCM, 20 with hypertrophic cardiomyopathy (HCM), and 20 normal control patients. Two-dimensional, Doppler, strain, and left ventricular (LV) twist mechanics by speckle tracking echocardiography were obtained. The 25 HOCM patients had left heart catheterization, and 16 were re-examined after septal reduction. RESULTS: Deformation measurements were the lowest in HOCM patients and increased (p<0.05) after septal reduction. Twist and untwisting rate were not different between patients with HCM and control patients, but untwisting was significantly delayed in HCM patients and longest in HOCM patients. The delay related well with LV end-diastolic pressure (r=0.76) and volume (r=-0.73), and VO2max (r=-0.75, all p<0.01). After septal reduction, untwisting occurred earlier and accounted for the increase in end-diastolic volume (r=0.65), and VO2max (r=0.74, both p<0.05). CONCLUSIONS: Dynamic obstruction leads to delayed untwisting in HOCM, which accounts well for the increased LV filling pressures, the reduced LV volumes, and VO2max. After septal reduction, untwisting occurs earlier and leads to an improvement in LV filling and exercise tolerance.
Jianwen Wang; John M Buergler; Kumuthavally Veerasamy; Yelena P Ashton; Sherif F Nagueh
Related Documents :
17604696 - Determinants of an abnormal response to exercise in patients with asymptomatic valvular...
3595246 - Role of exercise doppler echocardiography in isolated mitral stenosis.
16810446 - Doppler tissue imaging evaluation of right ventricular function at rest and during dobu...
3592296 - Prognostic implications of left ventricular function during exercise in asymptomatic pa...
19185636 - Daily walking performance as an independent predictor of advanced heart failure: predic...
10799376 - Energy expenditure and free-living physical activity in black and white women: comparis...
Publication Detail:
Type:  Controlled Clinical Trial; Journal Article    
Journal Detail:
Title:  Journal of the American College of Cardiology     Volume:  54     ISSN:  1558-3597     ISO Abbreviation:  J. Am. Coll. Cardiol.     Publication Date:  2009 Sep 
Date Detail:
Created Date:  2009-09-25     Completed Date:  2009-11-10     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8301365     Medline TA:  J Am Coll Cardiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1326-34     Citation Subset:  AIM; IM    
Department of Cardiology, Methodist DeBakey Heart and Vascular Center, The Methodist Hospital, Houston, Texas 77030, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Cardiac Volume / physiology
Cardiomyopathy, Hypertrophic / physiopathology*,  therapy*
Diastole / physiology
Ethanol / administration & dosage
Exercise Tolerance / physiology*
Heart Catheterization
Heart Septum
Middle Aged
Oxygen Consumption / physiology
Torsion Abnormality / physiopathology,  ultrasonography*
Reg. No./Substance:

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

Previous Document:  Effects of cardiac resynchronization therapy on left ventricular twist.
Next Document:  Glutamatergic neurotransmission in the nucleus tractus solitarii: structural and functional characte...