Mechanisms of exercise limitation in hypertrophic cardiomyopathy

Chikamori, Taishiro, Counihan, Peter J., Doi, Yoshinori L., Takata, Jun, Stewart, James T., Frenneaux, Michael P. and McKenna, William J. (1992) Mechanisms of exercise limitation in hypertrophic cardiomyopathy. Journal of the American College of Cardiology, 19 (3). pp. 507-512. ISSN 0735-1097

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Abstract

To assess the relation of exercise capacity to indexes of systolic and diastolic function in hypertrophic cardiomyopathy, 81 patients underwent two-dimensional echocardiography, technetium-99m equilibrium radionuclide angiography acquired in list mode and maximal, symptom-limited, treadmill exercise testing with measurement of maximal oxygen consumption (VO2 max). VO2 max for the group was 13.9 to 49.3 (mean 25.4) ml/min per kg. Thirty-six patients (44%) achieved less than or equal to 70% of age-predicted VO2 max. Patients with such a degree of limitation were more likely to be in New York Heart Association functional class II or III (23 of 36 vs. 14 of 45; p = 0.005); there was no such relation between VO2 and the incidence and magnitude of rest left ventricular outflow tract pressure gradient greater than 30 mm Hg (11 of 36 vs. 11 of 45; p = NS and 58 +/- 24 vs. 65 +/- 19 mm Hg; p = NS). In the 22 patients with a left ventricular outflow tract gradient, the ratios of peak ejection to peak filling rate and of atrial contribution to left atrial dimension were related to percent of the age-predicted VO2 max (r = 0.49, p = 0.02 and r = 0.54, p less than 0.02). These ratios reflect impaired left ventricular systolic performance and atrial systolic failure, respectively. Stepwise discriminant analysis revealed these two ratios to be the two strongest predictors (p = 0.0001) of patients with a left ventricular outflow tract gradient whose VO2 max was less than or equal to 70% of the age-predicted value (sensitivity 90%, specificity 100%).(ABSTRACT TRUNCATED AT 250 WORDS)

Item Type: Article
Uncontrolled Keywords: adult,cardiomyopathy, hypertrophic,discriminant analysis,echocardiography,exercise,exercise test,female,hemodynamics,humans,male,middle aged,oxygen consumption,radionuclide angiography,sensitivity and specificity,ventricular function, left,ventricular outflow obstruction
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
Depositing User: Pure Connector
Date Deposited: 27 Feb 2015 13:18
Last Modified: 21 Apr 2020 23:53
URI: https://ueaeprints.uea.ac.uk/id/eprint/52368
DOI: 10.1016/S0735-1097(10)80262-1

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