Document Detail

Pacing tachycardia exaggerates left ventricular diastolic dysfunction but not systolic function and regional asynergy or asynchrony in patients with hypertrophic cardiomyopathy.
MedLine Citation:
PMID:  20647230     Owner:  NLM     Status:  MEDLINE    
AIMS: Myocardial ischaemia and angina have been demonstrated in patients with hypertrophic cardiomyopathy (HCM). We hypothesized that left ventricular (LV) systolic or diastolic dysfunction would be provocated by pacing tachycardia in patients with HCM.
METHODS AND RESULTS: We investigated LV global and regional systolic and diastolic function in 17 patients with HCM without LV outflow obstruction and 7 normal subjects by analysing LV angiograms and simultaneously obtained high-fidelity LV pressures before and after rapid cardiac pacing (150 b.p.m.). Biplane LV silhouettes were digitized frame by frame (50 frames/s). To quantify regional dynamics, the ventricular area of the right anterior oblique projection was divided into six sections originating from the midpoint of the long axis at end-diastole. There were no significant changes in LV function after pacing in normal subjects. In HCM, the ejection fractions remained unchanged. However, LV end-diastolic pressures rose (+12 mmHg, P < 0.01), and the time constants of isovolumic pressure decay were significantly increased (T(1/2): +5.2 ms, P < 0.01; T(1/)(e): +6.8 ms, P < 0.01). The LV global diastolic pressure-volume relationships and regional diastolic pressure-area relationships of regional myocardium shifted upward (indicating decreased diastolic distensibility) in all patients. These diastolic abnormalities were not accompanied by regional asynchrony or asynergy.
CONCLUSION: Most patients with HCM have a reduced reactive capacity to chronotropic stress, which is haemodynamically characterized by evenly distributed diastolic dysfunction. In contrast with coronary artery disease, these diastolic abnormalities were not accompanied by systolic dysfunction, regional asynchrony, asynergy, or inhomogenous diastolic distensibility.
Toshiaki Tarumi; Shigeto Takebayashi; Masatoshi Fujita; Takeshi Nakano; Masaaki Ito; Tetsu Yamakado
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-07-20
Journal Detail:
Title:  Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology     Volume:  12     ISSN:  1532-2092     ISO Abbreviation:  Europace     Publication Date:  2010 Sep 
Date Detail:
Created Date:  2010-08-25     Completed Date:  2011-01-03     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100883649     Medline TA:  Europace     Country:  England    
Other Details:
Languages:  eng     Pagination:  1308-15     Citation Subset:  IM    
Department of Cardiology, Mie University of Medicine, Tsu, Mie, Japan.
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MeSH Terms
Cardiac Pacing, Artificial
Cardiomyopathy, Hypertrophic / physiopathology*
Diastole / physiology*
Heart Rate
Middle Aged
Systole / physiology*
Ventricular Dysfunction, Left*
Young Adult

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