Modeling study of the failing heart and its interaction with an implantable rotary blood pump

Ramachandran, Deepa; Luo, Chi‐Cheng; Tony, S.; Clark, John W.

doi:10.1109/iembs.2011.6090670

Cited by 9 publications

(3 citation statements)

References 10 publications

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“…24–26 A higher rotational speed has short-term advantages in hemodynamics, but sometimes causes aortic insufficiency and right ventricular failure over the longer term. 27–29 Thus, we hope the future study which demonstrates that amelioration of CI without increasing rotational speed is effective in improving exercise intolerance; modifying the CI with medications such as diuretics and pulmonary hypertension drugs. And, physical therapy is more actively recommended for patients with reduced CI.…”

Section: Discussionmentioning

confidence: 99%

Associations between hemodynamic parameters at rest and exercise capacity in patients with implantable left ventricular assist devices

et al. 2020

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Background: Hemodynamic parameters at rest are known to correlate poorly with peak oxygen uptake (VO2) in heart failure. However, we hypothesized that hemodynamic parameters at rest could predict exercise capacity in patients with left ventricular assist device (LVAD), because LVAD pump rotational speed does not respond during exercise. Therefore, we investigated the relationships between hemodynamic parameters at rest (measured with right heart catheterization) and exercise capacity (measured with cardiopulmonary exercise testing) in patients with implantable LVAD. Methods: We performed a retrospective medical record review of patients who received implantable LVAD at our institution from November 2013 to December 2017. Results: A total of 20 patients were enrolled in this study (15 males; mean age, 45.8 years; median duration of LVAD support, 356 days). The mean peak VO2 and cardiac index (CI) were 13.5 mL/kg/min and 2.6 L/min/m2, respectively. CI and hemoglobin level were significantly associated with peak VO2 (CI: r = 0.632, p = 0.003; hemoglobin: r = 0.520, p = 0.019). In addition, pulmonary capillary wedge pressure, right atrial pressure, and right ventricular stroke work index were also significantly associated with peak VO2. In multiple linear regression analysis, CI and hemoglobin level remained independent predictors of peak VO2 (CI: β = 0.559, p = 0.006; hemoglobin: β = 0.414, p = 0.049). Conclusions: CI at rest and hemoglobin level are associated with poor exercise capacity in patients with LVAD.

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Section: Discussionmentioning

confidence: 99%

Associations between hemodynamic parameters at rest and exercise capacity in patients with implantable left ventricular assist devices

et al. 2020

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“…A cardiovascular-respiratory modeling study using an implantable rotary blood pump demonstrated that reduced septal contribution with increasing pump speeds resulted in elevated RV work and mechanical dyssynchrony. 15 …”

Section: Definition and Incidence Of Right Ventricular Failure After mentioning

confidence: 99%

Predictors and Management of Right Heart Failure after Left Ventricular Assist Device Implantation

Fida¹,

Loebe²,

Estep³

et al. 2015

Methodist DeBakey Cardiovascular Journal

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Early recognition and improved outcomes of ischemic heart disease has resulted in an aging population and a global increase in the prevalence of heart failure (HF).1 Consequently, the burden of stage D heart failure (HF), which is unresponsive to conventional medical therapy, has surpassed the availability of the finite donor organ pool. 2 Significant advances in the field of mechanical circulatory support has made destination therapy (DT) with left ventricular assist devices (LVADs) a promising alternative to heart transplantation, with 1-year postimplant actuarial survival at about 80% with a continuous flow LVAD (CF-LVAD). 3However, despite newer technology and greater familiarity with patient management, physicians continue to be confronted by early and/or late right ventricular failure (RVF) that significantly impacts survival post-LVAD implantation. As none of the current mechanical circulatory support (MCS) devices are approved for DT for solitary right heart support or biventricular support, it is critical to identify preoperative predictors of right heart failure post-LVAD implant. Definition and Incidence of Right Ventricular Failure after LVAD PlacementIn the absence of a universally agreed-upon definition of RVF after LVAD placement, its reported incidence varies with the institutional practice, the United Network for Organ Sharing (UNOS) indication for MCS, the device type, and the criteria used to define failure. Additionally, it is now recognized that RVF is a progressive condition that can occur beyond the immediate postoperative period. However, this emerging concept of "late RVF" remains ill-defined and difficult to predict. The Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) defines RVF as persistent signs and symptoms of RV dysfunction evident by central venous pressure (CVP) > 18 mm Hg with a cardiac index (CI) < 2.0 L/min/m 2 in the absence of increased left atrial filling pressure/pulmonary capillary wedge pressure (PCWP) > 18 mm Hg, cardiac tamponade, ventricular arrhythmias, and/or pneumothorax requiring either right ventricular assist device (RVAD) implantation or inhaled nitric oxide or inotropic therapy for ≥ 14 days after LVAD implantation. 4 According to INTERMACS, RVF severity is described as follows:• Severe, when there is a need for RVAD; • Moderate, when inotropes or intravenous or inhaled pulmonary vasodilators are used; and • Mild, when a combination of ≥ 2 signs and symptoms are present but without the need for RVAD or inotropic and/ or vasodilator support. Signs and symptoms include CVP > 18 mm Hg, CI < 2.3 L/min/m 2 , ascites, moderate to severe peripheral edema, or evidence of high CVP on physical exam or transthoracic echocardiogram.The incidence of severe RVF necessitating RVAD placement after LVAD or preemptive BiVAD support is reported to be anywhere from 9.4% to 37.0%. [5][6][7][8][9] Most studies have reported the incidence encompassing the need for inotropic support with or without RVAD (≥ 14 days) after LVAD implant, with a range of b...

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“…46 In an in silico cardiovascular-respiratory system model, increased LVAD pump speeds appear to reduce septal contribution to RV and LV ejection and increase RV work. 47 Finally, patients with more severe RV dysfunction may be more prone to LV suction with higher LVAD pump speeds. 48 …”

Section: Pathophysiology Of Post-lvad Right Ventricular Failurementioning

confidence: 99%

Assessment of Right Ventricular Function in Left Ventricular Assist Device Candidates

Hayek

Sims

Markham

et al. 2014

Circ: Cardiovascular Imaging

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Modeling study of the failing heart and its interaction with an implantable rotary blood pump

Cited by 9 publications

References 10 publications

Associations between hemodynamic parameters at rest and exercise capacity in patients with implantable left ventricular assist devices

Associations between hemodynamic parameters at rest and exercise capacity in patients with implantable left ventricular assist devices

Predictors and Management of Right Heart Failure after Left Ventricular Assist Device Implantation

Assessment of Right Ventricular Function in Left Ventricular Assist Device Candidates

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