A technical and data analytic approach to pressure-volume loops over numerous cardiac cycles

Stonko, David P.; Edwards, Joseph; Abdou, Hossam; Elansary, Noha; Lang, E; Savidge, Samuel G.; Morrison, Jonathan J.

doi:10.1016/j.jvssci.2021.12.003

Cited by 17 publications

(22 citation statements)

References 20 publications

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“…Pressure-volume loops (PV loops) are the gold standard for real-time load-dependent and load-independent measures of the left ventricular systolic and diastolic function. A practical guide on PV loop measurements in pigs has recently been published (27). However, PV loop measurements are easily disturbed through further interventions, such as aortic valve leaflet piercing.…”

Section: Discussionmentioning

confidence: 99%

“…Stonko et al (27) previously described the optimal access point for the PV Loop catheter advancement in pigs to be through the right brachial artery, or either of the carotid arteries, with each of these access routes, the catheter can be naturally steered into the ascending aortic arch. However, as the carotid artery was used in our setting to introduce the steerable sheath for aortic leaflet piercing, we used the left femoral artery to insert the PV loop catheter.…”

Section: Catheter Placement and In-situ Calibrationmentioning

confidence: 99%

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Dos and don'ts in large animal models of aortic insufficiency

et al. 2022

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Aortic insufficiency caused by paravalvular leakage (PVL) is one of the most feared complications following transcatheter aortic valve replacement (TAVI) in patients. Domestic pigs (Sus scrofa domestica) are a popular large animal model to study such conditions and develop novel diagnostic and therapeutic techniques. However, the models based on prosthetic valve implantation are time intensive, costly, and often hamper further hemodynamic measurements such as PV loop and 4D MRI flow by causing implantation-related wall motion abnormalities and degradation of MR image quality. This study describes in detail, the establishment of a minimally invasive porcine model suitable to study the effects of mild-to-moderate “paravalvular“ aortic regurgitation on left ventricular (LV) performance and blood flow patterns, particularly under the influence of altered afterload, preload, inotropic state, and heart rate. Six domestic pigs (Swiss large white, female, 60–70 kg of body weight) were used to establish this model. The defects on the hinge point of aortic leaflets and annulus were created percutaneously by the pierce-and-dilate technique either in the right coronary cusp (RCC) or in the non-coronary cusp (NCC). The hemodynamic changes as well as LV performance were recorded by PV loop measurements, while blood flow patterns were assessed by 4D MRI. LV performance was additionally challenged by pharmaceutically altering cardiac inotropy, chronotropy, and afterload. The presented work aims to elaborate the dos and don'ts in porcine models of aortic insufficiency and intends to steepen the learning curve for researchers planning to use this or similar models by giving valuable insights ranging from animal selection to vascular access choices, placement of PV Loop catheter, improvement of PV loop data acquisition and post-processing and finally the induction of paravalvular regurgitation of the aortic valve by a standardized and reproducible balloon induced defect in a precisely targeted region of the aortic valve.

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Section: Discussionmentioning

confidence: 99%

Section: Catheter Placement and In-situ Calibrationmentioning

confidence: 99%

Dos and don'ts in large animal models of aortic insufficiency

et al. 2022

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“…The sample size, subspecies choice and sex composition were pre-determined using a power calculation (using G*Power v3.1) ( Faul et al, 2009 ) following a comprehensive literature review performed with the IACUC at our institution using a qualified Librarian. The power analysis was constructed to assess for an effect size of 20% in mean coronary flow and mean ESP, with baseline parameters abstracted from our laboratory experience with swine of this age, weight, and sex ( Patel et al, 2021 ; Stonko et al, 2021 ; Abdou et al, 2021 ; Edwards et al, 2021 ; Stonko et al, 2022 ). Here, the power analysis suggested the use of at least 4 swine to capture the expected effect in ESP and at least 5 animals for mean coronary flow, so we selected a sample size of 5 to accommodate both outcomes.…”

Section: Methodsmentioning

confidence: 99%

The Underlying Cardiovascular Mechanisms of Resuscitation and Injury of REBOA and Partial REBOA

et al. 2022

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Introduction: Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is used for aortic control in hemorrhagic shock despite little quantification of its mechanism of resuscitation or cardiac injury. The goal of this study was to use pressure-volume (PV) loop analysis and direct coronary blood flow measurements to describe the physiologic changes associated with the clinical use of REBOA.Methods: Swine underwent surgical and vascular access to measure left ventricular PV loops and left coronary flow in hemorrhagic shock and subsequent placement of occlusive REBOA, partial REBOA, and no REBOA. PV loop characteristics and coronary flow are compared graphically with PV loops and coronary waveforms, and quantitatively with measures of the end systolic and end pressure volume relationship, and coronary flow parameters, with accounting for multiple comparisons.Results: Hemorrhagic shock was induced in five male swine (mean 53.6 ± 3.6 kg) as demonstrated by reduction of stroke work (baseline: 3.1 vs. shock: 1.2 L*mmHg, p < 0.01) and end systolic pressure (ESP; 109.8 vs. 59.6 mmHg, p < 0.01). ESP increased with full REBOA (178.4 mmHg; p < 0.01), but only moderately with partial REBOA (103.0 mmHg, p < 0.01 compared to shock). End systolic elastance was augmented from baseline to shock (1.01 vs. 0.39 ml/mmHg, p < 0.01) as well as shock compared to REBOA (4.50 ml/mmHg, p < 0.01) and partial REBOA (3.22 ml/mmHg, p = 0.01). Percent time in antegrade coronary flow decreased in shock (94%–71.8%, p < 0.01) but was rescued with REBOA. Peak flow increased with REBOA (271 vs. shock: 93 ml/min, p < 0.01) as did total flow (peak: 2136, baseline: 424 ml/min, p < 0.01). REBOA did not augment the end diastolic pressure volume relationship.Conclusion: REBOA increases afterload to facilitate resuscitation, but the penalty is supraphysiologic coronary flows and imposed increase in LV contractility to maintain cardiac output. Partial REBOA balances the increased afterload with improved aortic system compliance to prevent injury.

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“…Catheter and pressure monitor placement were confirmed via C-arm fluoroscopy (OEC 9800; General Electric, Boston, MA), as previously described. 9 , 13 , 14 , 15 Open cystostomy was performed for urinary drainage, and electrocardiography, temperature probes, and pulse oximetry were used for monitoring.…”

Section: Methodsmentioning

confidence: 99%