Introduction The gold standard for the evaluation of ventricular function is currently the echocardiographic measured ejection fraction (EF). However, the use of this parameter has limitations, which are more important in populations with afterload mismatch and especially when this mismatch is severe. On the other hand, the assessment of a pump function in fluid dynamics is done using the head pressure, which is product of pressure when the flow is zero. During the cardiac cycle, this situation occurs during the isovolumetric contraction. Purpose The aim of this study is to assess the clinical and pathophysiological importance of the isovolumentric contraction in the evaluation of the ventricular performance. Method 110 patients with severe aortic stenosis and pulmonary arterial hypertension were investigated. The area under the curve (AUC) of the isovolumetric contraction was measured using the pressure curves of the right ventricle-pulmonary artery and left ventricle-aorta ascendens. This AUC was then correlated with the echocardiographic measured ejection fraction (EF), the stroke volume (SV) and the total ventricular work, defined as the product of pressure and flow. Results The AUC of the isovolumetric contraction correlates statistically significant with the ejection fraction of the corresponding ventricle (p 0.0001). Both AUC of the isovolumetric contraction and the ejection fraction showed a statistic significance with the total work of the ventricle (AUC with R2 0.49, p 0.0001, EF R2 0.51, p 0.0001). Stroke volume was significant only in the correlation with the ejection fraction. A statistic significant one sample t test could be found for the EF (decreased, p 0.001) and for the AUC of the isovolumetric contraction (increased, p 0.001) but not for the total work of the ventricle. Conclusion The AUC of the isovolumetric contraction correlates statistically significant with the ejection fraction and the total ventricular work but not the stroke volume in patients with afterload mismatch. Especially in these populations it demonstrates a significant increase when compared with normal values. Funding Acknowledgement Type of funding sources: None.

Introduction: The evaluation of myocardial contractility is essential in cardiology practice. The gold standard for this evaluation is the end-systolic elastance, but it the method involved is complex. Echocardiographic measurement of the ejection fraction (EF) is the most commonly used parameter in clinical practice, but it has significant limitations, especially in patients with afterload mismatch. In this study, the area under the curve (AUC) of the isovolumetric contraction was measured to evaluate the myocardial contractility in patients with pulmonary arterial hypertension and severe aortic stenosis. Methods: 110 patients with severe aortic stenosis and pulmonary arterial hypertension were included in this study. The AUC of the isovolumetric contraction was measured using pressure curves of the right ventricle–pulmonary artery and left ventricle–aorta ascendens. This AUC was then correlated with the echocardiographically measured EF, stroke volume (SV), and total ventricular work. Results: The AUC of the isovolumetric contraction showed a statistically significant correlation with the EF of the corresponding ventricle (p < 0.0001). Both the AUC of the isovolumetric contraction and the EF showed a statistically significant correlation with the total work of the ventricle (AUC: R2 0.49, p < 0.001; EF: R2 0.51, p < 0.001). However, the SV only showed a statistically significant correlation with the EF. A statistically significant one-sample t-test could be found for the EF (decreased, p < 0.001) and for the AUC of the isovolumetric contraction (increased, p < 0.001), but not for the total work of the ventricle. Conclusion: The AUC space of the isovolumetric contraction is a useful marker of ventricular performance in patients with afterload mismatch, showing a statistically significant correlation with the EF and the total ventricular work. This method may have potential for use in clinical practice, especially in challenging cardiological cases. However, further studies are needed to evaluate its usefulness in healthy individuals and in other clinical scenarios.