Homeometric autoregulation in severe aortic stenosis: insights from transcatheter aortic valve replacement

Figures

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  Figure 1. Left ventricular ejection fraction before and after TAVR. LVEF increased only marginally despite significant afterload reduction. The arrow indicates average change.

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  Figure 2. The stress-shortening relationship before and after TAVR. Each patient is represented by a line, with red dots indicating preoperative values and blue dots postoperative values. The dots falling within the 95% CI represent normal contractility. This graph demonstrates that contractility was impaired in many patients at baseline and, on average, declined further following TAVR, as evidenced by horizontal movement crossing the lower bound 95% confidence interval of normal. The arrow indicates average change. CI indicates confidence intervals.

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  Figure 3. Theoretic pressure–volume diagrams depicting proposed changes in LVEF following TAVR. Two hypothetical patients with normal and abnormal LV systolic function, respectively, are illustrated. In the presence of impaired LV contractility (signified by decreased ESPVR slope), stroke volume is more sensitive to changes in afterload. Accordingly, patients with reduced LVEF experience a significant increase in LVEF following TAVR, driven by a reduction in valvuloarterial impedance, despite a 10% contractility decline. Conversely, patients with preserved baseline LVEF experience minimal or no increase despite substantial afterload reduction. Red and blue lines indicate before and after TAVR, respectively. The solid and dashed lines indicate preserved and reduced baseline LVEF, respectively.