Mechanisms of Early Filling in the Left Ventricle
Date
2021-01-08
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Abstract
The mechanism by which ventricular filling occurs has been debated for centuries. Originally, it was believed that ventricular filling was an entirely passive process. However, in the 20th-century, researchers proposed that LV played a role in its own filling sucking blood into itself. At the early phase of diastole, the LV enlarges faster than it is able to fill passively by the Left Atrium (LA); therefore, aspirating blood into itself. Diastolic suction (DS) is the term applied to the phenomenon whereby the left ventricle (our study will be limited to the LV), in part, fills itself. Two approaches to study DS are the volume of filling due to suction, VDS (Katz’ approach), and the energy of the Backward Decompression Wave, BDW (Wang’s approach). Our first aim was to determine if DS exists at LV volumes that exceed the unstressed volume. Our second aim was to compare Katz’ Criterion to the energy of the BDW generated by the LV (Wang’s approach). The study was performed using a porcine model. Hemodynamics and mitral blood flow velocity were measured over a range of filling pressures during baseline, inferior vena cava occlusion (IVCO), and volume loading. Our findings suggests that the LV generates suction when ESV is greater than ESV at baseline (ESVB), which opposes the view that the LV is not capable of generating suction at increasing ESV’s. We found non-zero values of VDS and IW-DS when ESV>ESVB which suggest a non-recoil mechanism responsible for suction. In addition, our data shows that both approaches to DS, measured by VDS and IW-DS, are indeed related as they responded in the same manner to changes in EDV, ESV, and EDP.
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Keywords
Diastolic Suction, Early Left Ventricular Filling
Citation
Urroz Lopez, M. G. (2021). Mechanisms of Early Filling in the Left Ventricle (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.