Extracorporeal Life Support Enhances the Forward Pressure Wave to Cause a Mismatch between Cardiac Oxygen Demand and Supply

Sung-Liang Yu,Liang-Chuan Lai,En- Ting Wu,Ming-Shiou Wu,Yih-Sharng Chen,Chih-Hsien Wang,Hsi-Yu Yu,Ru-Wen Chang,Yi-Jing Hsiao

doi:10.1038/s41598-019-50428-1

Sung-Liang Yu, Liang-Chuan Lai + Show 7 more

Open Access

https://doi.org/10.1038/s41598-019-50428-1

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Abstract

Extracorporeal life support (ECLS) is a world-famous life-saving method. Until now, changes in arterial wave properties due to ECLS have remained unexamined. In this study, we determined the effects of ECLS on arterial wave properties and ventricular/arterial coupling in male Wistar rats with the measured aortic pressure alone. Ascending aortic pressure signals were measured before ECLS and at 30, 60, and 90 min after weaned off. The aortic pressure signal then calculated by fourth-order derivative to obtain an assumed triangular flow wave. The ratio of mean systolic pressure to mean diastolic pressure (Pms/Pmd), a parameter for evaluating the matching condition between myocardial oxygen demand and supply, was significantly higher after ECLS. The magnitude of forward pressure (|Pf|) augmented by ECLS prevailed over the backward pressure (|Pb|), leading to a decline in wave reflection factor. Pms/Pmd was positively linearly correlated with |Pf| (Pms/Pmd = 0.9177 + 0.0078 × |Pf|, r = 0.8677; P < 0.0001). These findings suggest that |Pf| was a predominant factor responsible for the mismatch between the myocardial oxygen demand and supply in rats after ECLS phase of experiment.

Highlights

By Westerhof et al is that the constructed Qtri, approximately to its paired flow signal, is based on the measured aortic pressure wave, and the calibration is not required in the analysis[13]
We demonstrated the mechanical defects of the vasculature in rats receiving Extracorporeal life support (ECLS) based on the measured ascending aortic pressure and an assumed triangular flow
reflection index (RI) was diminished by ECLS, there existed a negative linear correlation between Pms/Pmd and RI

Summary

Introduction

By Westerhof et al is that the constructed Qtri, approximately to its paired flow signal, is based on the measured aortic pressure wave, and the calibration is not required in the analysis[13]. As pressure in the ventricle during systole is approximated by aortic pressure during systole, for practical purpose, O’Rourke[10] and O’Rourke et al.[16] suggested that ventricular function as pumping action could be described using mean pressure generated in the ascending aorta during systole. We used the measured aortic pressure and an assumed Qtri to determine the effects of ECLS on arterial wave properties and ventricular/arterial coupling in male Wistar rats. The arterial τw, and magnitudes of the forward (|Pf|) and backward (|Pb|) pressure waves were derived from the only measured aortic pressure to delineate the changes caused by ECLS in the pulsatile nature of the LV afterload

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