Journal of the American College of Cardiology
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J. Am. Coll. Cardiol. · Nov 1992
Comparative StudyPhysiologic changes with maximal exercise in asymptomatic valvular aortic stenosis assessed by Doppler echocardiography.
We hypothesized that the physiologic response to exercise in valvular aortic stenosis could be measured by Doppler echocardiography. ⋯ Doppler echocardiography allows assessment of physiologic changes with exercise in adults with asymptomatic aortic stenosis. A majority of subjects show a rest-exercise response that closely parallels the predicted relation between Vmax and Qmax for a given orifice area. The potential utility of this approach for elucidating the relation between hemodynamic severity and clinical symptoms deserves further study.
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J. Am. Coll. Cardiol. · Nov 1992
Comparative StudyLeft ventricular relaxation in dilated cardiomyopathy: relation to loading conditions and regional nonuniformity.
The purpose of the present study was to investigate how loading conditions and regional nonuniformity affect left ventricular relaxation in dilated cardiomyopathy. ⋯ These results suggest that myocardial relaxation is sensitive to loading conditions and regional nonuniformity in dilated cardiomyopathy and that load reduction can improve both relaxation and systolic performance of the left ventricle.
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J. Am. Coll. Cardiol. · Nov 1992
Comparative StudyBenefits of intraoperative echocardiography in the surgical management of hypertrophic cardiomyopathy.
The purpose of this study was to determine the role of intraoperative echocardiography in planning the site and extent of myectomy and in ensuring adequate control of the left ventricular outflow tract gradient. ⋯ Intraoperative echocardiography proved a useful tool to guide the site and extent of septal myectomy, leading to more adequate surgical resection and to persistence of satisfactory control of the outflow tract obstruction into the early follow-up period.
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J. Am. Coll. Cardiol. · Oct 1992
Comparative StudyNoninvasive determination of aortic input impedance and external left ventricular power output: a validation and repeatability study of a new technique.
The study was designed to test whether aortic input impedance and left ventricular power output can be accurately assessed noninvasively. ⋯ Measurement of noninvasive impedance by this technique provides an accurate and repeatable assessment of mean and pulsatile cardiac load.