Bachman, Timothy
(2021)
Pre- and Perioperative Assessment of Right Ventricular Afterload to Determine Chronic Right Ventricular Failure Post-implant of Durable Left Ventricular Assist Device: Feasibility and Clinical System Development.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Patients suffering from end-stage heart failure refractory to optimal medical treatment may require a durable left ventricular assist device (LVAD) as a bridge to transplant or as destination therapy. Unfortunately, as many as 40% of LVAD recipients experience right ventricular failure (RVF) post-implant. RVF post- implant results in a decrease in survival to transplant or continued support, and an increase in hospital stay. In the most severe RVF cases, mechanical circulatory support (MCS) for the right ventricle (RV) is needed. Short-term RV MCS is available; however, no durable RVAD currently exists. To date, research has focused mainly on predicting cases of RVF which occur immediately following LVAD implant or within the first 30 post-operative days. However, chronic RVF may also occur in subjects beyond one month.
In the clinical setting, echocardiography (echo) and right heart catheterization (RHC) are standard methods used to provide imaging and hemodynamic data for physicians. RHC reports resistance faced by the RV using only mean pressure and mean flow. However, it does not account for the oscillatory component of pulsatile blood flow generated during the cardiac cycle. Pulmonary vascular impedance (PVZ) completely characterizes the RV afterload by measuring both steady and oscillatory components in the frequency domain. Unfortunately, PVZ has not been used in the clinical setting due to technical limitations and cost-prohibitive equipment.
In this study, we attempted to calculate PVZ using signals obtained via standard of care echo and RHC, available before and during LVAD implantation. PVZ spectra were then used to
determine if there is a difference in RV afterload based on RVF outcome within one year of implant. Results ultimately showed that there was no difference in afterload between groups.
Though no difference in PVZ was found, the study showed that PVZ calculation is possible and may be of benefit to other patients. Following completion of the initial study, a graphically driven, software-based system was developed to calculate PVZ using only standard of care data from electronic health records. The software facilitates rapid assessment of PVZ in a manner that is intuitive to those who work in the clinical setting.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
13 June 2021 |
| Date Type: |
Publication |
| Defense Date: |
17 December 2020 |
| Approval Date: |
13 June 2021 |
| Submission Date: |
6 January 2021 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
90 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Bioengineering |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Left ventricular assist device; right ventricle; heart failure; hemodynamics; pulmonary vascular impedance |
| Date Deposited: |
13 Jun 2021 17:02 |
| Last Modified: |
13 Jun 2021 17:02 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/40137 |
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