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Figure 9 LV Wall Stress–Volume Diagrams in Aortic Stenosis

The straight dashed lines show an example of the end-systolic left ventricular (LV) wall stress–volume relation in compensated aortic stenosis, with a relatively normal wall stress–volume loop (dashed loop). With LV dysfunction, the end-systolic wall stress–volume relation is shifted to the right (solid line), and the LV loop shows increased LV end-diastolic volume with marked loss of pre-load reserve, and increased systolic wall stress (the ejection fraction [EFx] is 60%, center loop solid line). With progression of aortic stenosis, afterload becomes markedly increased, pre-load reserve is lost, and the stroke volume and EFx are greatly reduced (EFx 33%). After aortic valve replacement, the post-operative loop shows reduced afterload and end-diastolic volume, and the EFx improves to 52%. Reprinted with permission from Ross (19).