Document Detail


Failure of myocardial inactivation: a clinical assessment in the hypertrophied heart.
MedLine Citation:
PMID:  1284368     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Abnormal intracellular calcium handling is observed in hypertrophied cardiac muscle and in end-stage heart failure muscle. This abnormal calcium handling results in prolongation of the calcium transient and in a biphasic calcium transient with prominent late component. In the present studies, the mechanical correlates of abnormal calcium handling were investigated in the hypertrophied human left ventricle by analysis of: 1) isovolumic left-ventricular relaxation kinetics after drastic left-ventricular unloading in patients with severe aortic stenosis after sequential balloon aortic valvuloplasty-arterial vasodilation; and 2) morphology of the diastolic left-ventricular pressure signal in patients with aortic stenosis and hypertrophic cardiomyopathy. METHODS AND RESULTS: Drastic left-ventricular unloading in patients with severe aortic stenosis by sequential aortic valvuloplasty-arterial vasodilation resulted in a slow and dyssynchronous left-ventricular relaxation pattern, as evident from a prolongation of the time constant of left-ventricular pressure decay from 46.6 +/- 12.5 to 73.2 +/- 23.3 ms (p < 0.01), and from the development of a convex downward negative dP/dt upstroke pattern. Abnormal diastolic left-ventricular pressure wave forms consisting of continuous left-ventricular pressure decay throughout diastole and/or a secondary pressure rise in mid-diastole were observed in patients with aortic stenosis and with hypertrophic cardiomyopathy. Postextrasystolic potentiation caused further slowing of this abnormal diastolic left-ventricular pressure decay, as evident from the decrease in phase of the first harmonic of a Fourier transform applied to the diastolic left-ventricular pressure wave. When an abnormal diastolic left-ventricular pressure wave form was observed at rest or after postextrasystolic potentiation, a simultaneously recorded left-ventricular monophasic action potential signal revealed the occurrence of delayed afterdepolarizations. CONCLUSIONS: The mechanical correlates of abnormal calcium handling or of inactivation failure in the hypertrophied human left ventricle consist of slow and dyssynchronous left-ventricular isovolumic relaxation after left-ventricular unloading and of diastolic left-ventricular aftercontractions, which hinder left-ventricular filling and which are accompanied by delayed afterdepolarizations.
Authors:
W J Paulus; M A Goethals; S U Sys
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Basic research in cardiology     Volume:  87 Suppl 2     ISSN:  0300-8428     ISO Abbreviation:  Basic Res. Cardiol.     Publication Date:  1992  
Date Detail:
Created Date:  1993-05-11     Completed Date:  1993-05-11     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  0360342     Medline TA:  Basic Res Cardiol     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  145-61     Citation Subset:  IM    
Affiliation:
Cardiovascular Center, O.L.V. Ziekenhuis, Aalst, Belgium.
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MeSH Terms
Descriptor/Qualifier:
Action Potentials
Aged
Aortic Valve Stenosis / physiopathology
Calcium / metabolism
Cardiac Complexes, Premature / physiopathology
Cardiomegaly / metabolism,  physiopathology*
Diastole
Heart / physiopathology*
Heart Ventricles
Humans
Kinetics
Middle Aged
Myocardial Contraction
Myocardium / metabolism
Pressure
Ventricular Function, Left
Chemical
Reg. No./Substance:
7440-70-2/Calcium

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


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