Copyright © 1980 by the European Society of Cardiology.
© 1980 The European Society of Cardiology
Computerized simultaneous pressure-volume analysis in aortic valve disease*
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Department of Internal Medicine Rheinisch - Westfälische Technische Hochschule, Aachen, Federal Republic of Germany
Department of Electronic Data Processing Systems Rheinisch - Westfälische Technische Hochschule, Aachen, Federal Republic of Germany
Received 1 August 1979; revised 4 January 1980; .
Requests for reprints to: Jürgen Meyer, M.D., Department of Internal Medicine 1, RWTH Aachen, Goethestr, 27, D-5100 Aachen, Federal Republic of Germany
Simultaneous and continuous evaluation of LV pressure, and volume assessed by videometry, combined with computer analysis of these data allows a comprehensive analysis of left ventricular performance. The muscle mass of the left ventricle, the systolic wall stress, the rate ofventricular volume changes, the systolic work of the left ventricle and the systolic maximal and mean power of the left ventricle as well as the conventional pressure and volume parameters were measured in 14 patients with pure aortic valve stenosis as a model of pressure hypertrophy, in nine patients with pure aortic valve regurgitation as a model of volume hypertrophy, in 14 patients with combined aortic valve disease and in six normal controls.
LV muscle mass per body surface area over 270 g/m2 and end-diastolic volume over 160 ml/m2 were regularly combined with clinical deterioration in all groups, volume overload being a stronger stimulus to ventricular hypertrophy than pressure load. In patients with ventricular decompensation, the maximum rate of volume change drops and the time required to reach this point is delayed into the second half of the systole. As long as myocardial function remained adequate, left ventricular systolic work in aortic stenosis greatly exceeded that in pure aortic regurgitation, while maximal and mean power were increased in all three groups. With myocardial failure, the ratio of work and power to the individual end-diastolic volume and to left ventricular muscle mass declined, since the former fell and the latter rose. These parameters were closely correlated to the severity of the disease in the individual patient.
The computer aided pressure-volume analysis provides a precise and detailed analysis of LV function in the individual patient in estimating operative risk and comparing pre- and postoperative findings. Although, because of the expense involved, this type of detailed study may not be suitable for routine clinical use, it does allow better quantification, definition, and understanding of the pathophysiological changes in left ventricular hypertrophy.
Key Words: Computer analysis • hemodynamic measurements • pressure-volume analysis • aortic valve diseases • videometry • cath-lab automation