Prediction of hemodynamics under left ventricular assist device

Kakino, Takamori; Saku, Keita; Sakamoto, Takafumi; Sakamoto, Kazuo; Akashi, Takuya; Ikeda, Masataka; Ide, Tomomi; Kishi, Takuya; Tsutsui, Hiroyuki; Sunagawa, Kenji

doi:10.1152/ajpheart.00617.2016

Cited by 10 publications

(12 citation statements)

References 21 publications

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“…Once we established the model using haemodynamic parameters in a given condition, we could predict haemodynamics under various conditions such as myocardial infarction, blood volume gain and/or loss, extra-corporeal membrane oxygenation, and left ventricular assist device. [12][13][14] The results of this study also support the robustness of generalized circulatory equilibrium. Except for severe HF, Q S hardly decreases because the oxygen demand of the whole body determines Q S .…”

Section: Prediction Of Interatrial Shunting Haemodynamics By Generalisupporting

confidence: 76%

“…In this study, we set F R = 2.13, H R = 1.9, and RVEF e = 0.6 for normal RV function, and R-P = 0.1 mmHg/mL/min/kg for normal pulmonary circulation as reported previously. 12,14,15 We previously reported that in a distributed resistance-compliance vascular model, the following equations represent the stressed blood volume of the systemic circulation and pulmonary circulation 11 :…”

Section: Theoretical Considerationsmentioning

confidence: 99%

“…The generalized circulatory equilibrium enabled us to predict haemodynamics under extracorporeal membrane oxygenation and left ventricular assist device. [11][12][13][14] Using the concept of generalized circulatory equilibrium, we developed a simple framework to predict the impact of IAS on haemodynamics aiming to optimize IAS therapy in individual patients with HF. We validated the framework using a dog model of IAS with graded changes of the left to the right atrial shunt flow.…”

Section: Introductionmentioning

confidence: 99%

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Prediction of haemodynamics after interatrial shunt for heart failure using the generalized circulatory equilibrium

et al. 2020

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Aims Interatrial shunting (IAS) reduces left atrial pressure in patients with heart failure. Several clinical trials reported that IAS improved the New York Heart Association score and exercise capacity. However, its effects on haemodynamics vary depending on shunt size, cardiovascular properties, and stressed blood volume. To maximize the benefit of IAS, quantitative prediction of haemodynamics under IAS in individual patients is essential. The generalized circulatory equilibrium framework determines circulatory equilibrium as the intersection of the cardiac output curve and the venous return surface. By incorporating IAS into the framework, we predict the impact of IAS on haemodynamics. Methods and results In seven mongrel dogs, we ligated the left anterior descending artery and created impaired cardiac function with elevated left atrial pressure (baseline: 7.8 ± 1.0 vs. impaired: 11.9 ± 3.2 mmHg). We established extracorporeal left-to-right atrial shunting with a centrifugal pump. After recording pre-IAS haemodynamics, we changed IAS flow stepwise to various levels and measured haemodynamics under IAS. To predict the impact of IAS on haemodynamics, we modelled the fluid mechanics of IAS by Newton's second law and incorporated IAS into the generalized circulatory equilibrium framework. Using pre-IAS haemodynamic data obtained from the dogs, we predicted the impact of IAS flow on haemodynamics under IAS condition using a set of equations. We compared the predicted haemodynamic data with those measured. The predicted pulmonary flow [r 2 = 0.88, root mean squared error (RMSE) 11.4 mL/min/kg, P < 0.001), systemic flow (r 2 = 0.92, RMSE 11.2 mL/ min/kg, P < 0.001), right atrial pressure (r 2 = 0.92, RMSE 0.71 mmHg, P < 0.001), and left atrial pressure (r 2 = 0.83, RMSE 0.95 mmHg, P < 0.001) matched well with those measured under normal and impaired cardiac function. Using this framework, we further performed a simulation study to examine the haemodynamic benefit of IAS in heart failure with preserved ejection fraction. We simulated the IAS haemodynamics under volume loading and exercise conditions. Volume loading and exercise markedly increased left atrial pressure. IAS size-dependently attenuated the increase in left atrial pressure in both volume loading and exercise. These results indicate that IAS improves volume and exercise intolerance. Conclusions The framework developed in this study quantitatively predicts the haemodynamic impact of IAS. Simulation study elucidates how IAS improve haemodynamics under volume loading and exercise conditions. Quantitative prediction of IAS haemodynamics would contribute to maximizing the benefit of IAS in patients with heart failure.

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Section: Prediction Of Interatrial Shunting Haemodynamics By Generalisupporting

confidence: 76%

Section: Theoretical Considerationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Prediction of haemodynamics after interatrial shunt for heart failure using the generalized circulatory equilibrium

et al. 2020

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“…Nevertheless, acute pulmonary edema upon initiation of VA-ECMO has been described ( 35 ). In such patients, it may be beneficial to consider left atrial decompression (balloon atrial septostomy or placement of a new left atrial cannula) or transitioning to ventricular assist device [VAD] rather than ECMO ( 36 ).…”

Section: Overview Of Ecmo and Important Physiological And Hemodynamicmentioning

confidence: 99%

The Role of Echocardiography in Neonates and Pediatric Patients on Extracorporeal Membrane Oxygenation

2018

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Indications for extracorporeal membrane oxygenation (ECMO) and extracorporeal cardiopulmonary resuscitation (ECPR) are expanding, and echocardiography is a tool of utmost importance to assess safety, effectiveness and readiness for circuit initiation and separation. Echocardiography is key to anticipating complications and improving outcomes. Understanding the patient's as well as the ECMO circuit's anatomy and physiology is crucial prior to any ECMO echocardiographic evaluation. It is also vital to acknowledge that the utility of echocardiography in ECMO patients is not limited to the evaluation of cardiac function, and that clinical decisions should not be made exclusively upon echocardiographic findings. Though echocardiography has specific indications and applications, it also has limitations, characterized as: prior to and during cannulation, throughout the ECMO run, upon separation and after separation from the circuit. The use of specific and consistent echocardiographic protocols for patients on ECMO is recommended.

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“…These contrasting views have not been reconciled in a subsequent theoretical debate (2,9,28). The control of VR is highly relevant in clinical treatment of circulatory failure, especially in the widespread use of modern circulatory assist devices (24).…”

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confidence: 99%

Right atrial pressure and venous return during cardiopulmonary bypass

Moller

Winkler

Hurni

et al. 2017

American Journal of Physiology-Heart and Circulatory Physiology

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The relevance of right atrial pressure (RAP) as the backpressure for venous return (Q) and mean systemic filling pressure as upstream pressure is controversial during dynamic changes of circulation. To examine the immediate response of Q (sum of caval vein flows) to changes in RAP and pump function, we used a closed-chest, central cannulation, heart bypass porcine preparation ( = 10) with venoarterial extracorporeal membrane oxygenation. Mean systemic filling pressure was determined by clamping extracorporeal membrane oxygenation tubing with open or closed arteriovenous shunt at euvolemia, volume expansion (9.75 ml/kg hydroxyethyl starch), and hypovolemia (bleeding 19.5 ml/kg after volume expansion). The responses of RAP and Q were studied using variable pump speed at constant airway pressure (P) and constant pump speed at variable P Within each volume state, the immediate changes in Q and RAP could be described with a single linear regression, regardless of whether RAP was altered by pump speed or P ( = 0.586-0.984). RAP was inversely proportional to pump speed from zero to maximum flow ( = 0.859-0.999). Changing P caused immediate, transient, directionally opposite changes in RAP and Q (RAP: ≤ 0.002 and Q: ≤ 0.001), where the initial response was proportional to the change in Q driving pressure. Changes in P generated volume shifts into and out of the right atrium, but their effect on upstream pressure was negligible. Our findings support the concept that RAP acts as backpressure to Q and that Guyton's model of circulatory equilibrium qualitatively predicts the dynamic response from changing RAP. Venous return responds immediately to changes in right atrial pressure. Concomitant volume shifts within the systemic circulation due to an imbalance between cardiac output and venous return have negligible effects on mean systemic filling pressure. Guyton's model of circulatory equilibrium can qualitatively predict the resulting changes in dynamic conditions with right atrial pressure as backpressure to venous return.

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Prediction of hemodynamics under left ventricular assist device

Cited by 10 publications

References 21 publications

Prediction of haemodynamics after interatrial shunt for heart failure using the generalized circulatory equilibrium

Prediction of haemodynamics after interatrial shunt for heart failure using the generalized circulatory equilibrium

The Role of Echocardiography in Neonates and Pediatric Patients on Extracorporeal Membrane Oxygenation

Right atrial pressure and venous return during cardiopulmonary bypass

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