Investigating the variability in pressure–volume relationships during hemorrhage and aortic occlusion

Frontiers in Cardiovascular Medicine

Cardiovascular Medicine

Timothy K. Williams¹  James E. Jordan²  Lucas P. Neff³  M. Austin Johnson⁴  Enrique Carrasco Perez⁵  Fahim Usshihab Mobin⁶  Elaheh Rahbar⁶  Antonio C. Renaldo⁶ 

[1]Advanced Computational Cardiovascular Lab for Trauma, Hemorrhagic Shock & Critical Care, Wake Forest University School of Medicine, Winston Salem, NC, United States

[2]Certus Critical Care™ Inc., Salt Lake City, UT, United States

[3]Department of Vascular and Endovascular Surgery, Wake Forest University School of Medicine, Winston Salem, NC, United States

[4]Advanced Computational Cardiovascular Lab for Trauma, Hemorrhagic Shock & Critical Care, Wake Forest University School of Medicine, Winston Salem, NC, United States

[5]Department of Cardiothoracic Surgery, Wake Forest University School of Medicine, Winston Salem, NC, United States

[6]Advanced Computational Cardiovascular Lab for Trauma, Hemorrhagic Shock & Critical Care, Wake Forest University School of Medicine, Winston Salem, NC, United States

[7]Department of General Surgery, Section of Pediatric Surgery, Wake Forest University School of Medicine, Winston Salem, NC, United States

[8]Certus Critical Care™ Inc., Salt Lake City, UT, United States

[9]Certus Critical Care™ Inc., Salt Lake City, UT, United States

[10]Department of Surgery, Division of Emergency Medicine, The University of Utah, Salt Lake City, UT, United States

[11]Department of Biomedical Engineering, Wake Forest University School of Medicine, Winston Salem, NC, United States

[12]Department of Biomedical Engineering, Wake Forest University School of Medicine, Winston Salem, NC, United States

[13]Virginia Tech, Wake Forest University School of Biomedical Engineering and Sciences, Blacksburg, VA, United States

[14]Advanced Computational Cardiovascular Lab for Trauma, Hemorrhagic Shock & Critical Care, Wake Forest University School of Medicine, Winston Salem, NC, United States

关键词: pressure–volume;    cardiac function;    longitudinal;    hemorrhage;    variability;    REBOA;    EVAC;   

DOI  :  10.3389/fcvm.2023.1171904

 received in 2023-02-22, accepted in 2023-08-01,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionThe pressure–volume (P-V) relationships of the left ventricle are the classical benchmark for studying cardiac mechanics and pumping function. Perturbations in the P-V relationship (or P-V loop) can be informative and guide the management of heart failure, hypovolemia, and aortic occlusion. Traditionally, P-V loop analyses have been limited to a single-beat P-V loop or an average of consecutive P-V loops (e.g., 10 cardiac cycles). While there are several algorithms to obtain single-beat estimations of the end-systolic and end-diastolic pressure–volume relations (i.e., ESPVR and EDPVR, respectively), there remains a need to better evaluate the variations in P-V relationships longitudinally over time. This is particularly important when studying acute and transient hemodynamic and cardiac events, such as active hemorrhage or aortic occlusion. In this study, we aim to investigate the variability in P-V relationships during hemorrhagic shock and aortic occlusion, by leveraging on a previously published porcine hemorrhage model.MethodsBriefly, swine were instrumented with a P-V catheter in the left ventricle of the heart and underwent a 25% total blood volume hemorrhage over 30 min, followed by either Zone 1 complete aortic occlusion (i.e., REBOA), Zone 1 endovascular variable aortic control (EVAC), or no occlusion as a control, for 45 min. Preload-independent metrics of cardiac performance were obtained at predetermined time points by performing inferior vena cava occlusion during a ventilatory pause. Continuous P-V loop data and other hemodynamic flow and pressure measurements were collected in real-time using a multi-channel data acquisition system.ResultsWe developed a custom algorithm to quantify the time-dependent variance in both load-dependent and independent cardiac parameters from each P-V loop. As expected, all pigs displayed a significant decrease in the end-systolic pressures and volumes (i.e., ESP, ESV) after hemorrhage. The variability in response to hemorrhage was consistent across all three groups. However, upon introduction of REBOA, we observed significantly high levels of variability in both load-dependent and independent cardiac metrics such as ESP, ESV, and the slope of ESPVR (Ees). For instance, pigs receiving REBOA experienced a 342% increase in ESP from hemorrhage, while pigs receiving EVAC experienced only a 188% increase. The level of variability within the EVAC group was consistently less than that of the REBOA group, which suggests that the EVAC group may be more supportive of maintaining healthier cardiac performance than complete occlusion with REBOA.DiscussionIn conclusion, we successfully developed a novel algorithm to reliably quantify the single-beat and longitudinal P-V relations during hemorrhage and aortic occlusion. As expected, hemorrhage resulted in smaller P-V loops, reflective of decreased preload and afterload conditions; however, the cardiac output and heart rate were preserved. The use of REBOA and EVAC for 44 min resulted in the restoration of baseline afterload and preload conditions, but often REBOA exceeded baseline pressure conditions to an alarming level. The level of variability in response to REBOA was significant and could be potentially associated to cardiac injury. By quantifying each P-V loop, we were able to capture the variability in all P-V loops, including those that were irregular in shape and believe that this can help us identify critical time points associated with declining cardiac performance during hemorrhage and REBOA use.

【 授权许可】

Unknown   
© 2023 Mobin, Renaldo, Carrasco Perez, Jordan, Neff, Williams, Johnson and Rahbar.