scholarly journals Analysis of Operating Modes for Left Ventricle Assist Devices via Integrated Models of Blood Circulation

Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1331 ◽  
Author(s):  
Sergey Simakov ◽  
Alexander Timofeev ◽  
Timur Gamilov ◽  
Philip Kopylov ◽  
Dmitry Telyshev ◽  
...  
Keyword(s):  
Left Ventricular ◽  
Operating Conditions ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Left Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Lumped Model ◽  
Assist Devices ◽  
Operating Modes ◽  
Mock Circulation

Left ventricular assist devices provide circulatory support to patients with end-stage heart failure. The standard operating conditions of the pump imply limitations on the rotation speed of the rotor. In this work we validate a model for three pumps (Sputnik 1, Sputnik 2, Sputnik D) using a mock circulation facility and known data for the pump HeartMate II. We combine this model with a 1D model of haemodynamics in the aorta and a lumped model of the left heart with valves dynamics. The model without pump is validated with known data in normal conditions. Simulations of left ventricular dilated cardiomyopathy show that none of the pumps are capable of reproducing the normal stroke volume in their operating ranges while complying with all criteria of physiologically feasible operation. We also observe that the paediatric pump Sputnik D can operate in the conditions of adult circulation with the same efficiency as the adult LVADs.

scholarly journals Advances in Hemodynamic Analysis in Cardiovascular Diseases Investigation of Energetic Characteristics of Adult and Pediatric Sputnik Left Ventricular Assist Devices during Mock Circulation Support

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Alexander A. Pugovkin ◽  
Aleksandr G. Markov ◽  
Sergey V. Selishchev ◽  
Leonie Korn ◽  
Marian Walter ◽  
...  
Keyword(s):  
Heart Failure ◽  
Aortic Valve ◽  
Left Ventricular ◽  
Operating Conditions ◽  
Ventricular Assist Devices ◽  
Left Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Mock Circulation ◽  
Left Ventricular Assist

The need to simulate the operating conditions of the human body is a key factor in every study and engineering process of a bioengineering device developed for implantation. In the present paper, we describe in detail the interaction between the left ventricle (LV) and our Sputnik left ventricular assist devices (LVADs). This research aims to evaluate the influence of different rotary blood pumps (RBPs) on the LV depending on the degree of heart failure (HF), in order to investigate energetic characteristics of the LV-LVAD interaction and to estimate main parameters of left ventricular unloading. We investigate energetic characteristics of adult Sputnik 1 and Sputnik 2 LVADs connected to a hybrid adult mock circulation (HAMC) and also for the Sputnik pediatric rotary blood pump (PRBP) connected to a pediatric mock circulation (PMC). A major improvement of the LV unloading is observed during all simulations for each particular heart failure state when connected to the LVAD, with sequential pump speed increased within 5000–10000 rpm for adult LVADs and 6000–13000 rpm for PRBP with 200 rpm step. Additionally, it was found that depending on the degree of heart failure, LVADs influence the LV in different ways and a significant support level cannot be achieved without the aortic valve closure. Furthermore, this study expands the information on LV-LVAD interaction, which leads to the optimization of the RBP speed rate control in clinics for adult and pediatric patients suffering from heart failure. Finally, we show that the implementation of control algorithms using the modulation of the RBP speed in order to open the aortic valve and unload the LV more efficiently is necessary and will be content of further research.

scholarly journals Endocrine Challenges in Patients with Continuous-Flow Left Ventricular Assist Devices

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 861
Author(s):  
Gennaro Martucci ◽  
Federico Pappalardo ◽  
Harikesh Subramanian ◽  
Giulia Ingoglia ◽  
Elena Conoscenti ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Left Ventricular ◽  
Endocrine Function ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Endocrine Dysfunction ◽  
Left Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Left Ventricular Assist

Heart failure (HF) remains a leading cause of morbidity, hospitalization, and mortality worldwide. Advancement of mechanical circulatory support technology has led to the use of continuous-flow left ventricular assist devices (LVADs), reducing hospitalizations, and improving quality of life and outcomes in advanced HF. Recent studies have highlighted how metabolic and endocrine dysfunction may be a consequence of, or associated with, HF, and may represent a novel (still neglected) therapeutic target in the treatment of HF. On the other hand, it is not clear whether LVAD support, may impact the outcome by also improving organ perfusion as well as improving the neuro-hormonal state of the patients, reducing the endocrine dysfunction. Moreover, endocrine function is likely a major determinant of human homeostasis, and is a key issue in the recovery from critical illness. Care of the endocrine function may contribute to improving cardiac contractility, immune function, as well as infection control, and rehabilitation during and after a LVAD placement. In this review, data on endocrine challenges in patients carrying an LVAD are gathered to highlight pathophysiological states relevant to this setting of patients, and to summarize the current therapeutic suggestions in the treatment of thyroid dysfunction, and vitamin D, erythropoietin and testosterone administration.

Development of Mechanical Circulatory Support Devices: 55 Years and Counting

2021 ◽  
Vol 32 (4) ◽  
pp. 424-433
Author(s):  
Emalie Petersen
Keyword(s):  
Mechanical Circulatory Support ◽  
Left Ventricular ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Left Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Left Ventricular Assist ◽  
Mechanical Circulatory Support Devices ◽  
Support Devices

Heart failure is a leading cause of morbidity and mortality in the United States. Treatment of this condition increasingly involves mechanical circulatory support devices. Even with optimal medical therapy and use of simple cardiac devices, heart failure often leads to reduced quality of life and a shortened life span, prompting exploration of more advanced treatment approaches. Left ventricular assist devices constitute an effective alternative to cardiac transplantation. These devices are not without complications, however, and their use requires careful cooperative management by the patient’s cardiology team and primary care provider. Left ventricular assist devices have undergone many technological advancements since they were first introduced, and they will continue to evolve. This article reviews the history of different types of left ventricular assist devices, appropriate patient selection, and common complications in order to increase health professionals’ familiarity with these treatment options.

Cerebrovascular Events in Patients with Centrifugal-Flow Left Ventricular Assist Devices: A Propensity Score Matched Analysis from the Intermacs Registry

Circulation ◽  
2021 ◽  
Author(s):  
Sung-Min Cho ◽  
J. Hunter Mehaffey ◽  
Susan L. Myers ◽  
Ryan S. Cantor ◽  
Randall C. Starling ◽  
...  
Keyword(s):  
Risk Factors ◽  
Propensity Score ◽  
Secondary Analysis ◽  
Left Ventricular ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Left Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Left Ventricular Assist

Background: Ischemic and hemorrhagic cerebrovascular accidents (ICVA and HCVA, respectively) remain common among patients with centrifugal-flow left ventricular assist devices (CF-LVADs), despite improvements in survival and device longevity. Therefore, the incidence of neurological adverse events (NAEs) associated with two contemporary CF-LVADs, the Abbott HeartMate3 ® (HM3) and the Medtronic HeartWare ™ HVAD ® (HVAD), were compared. Methods: Using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs), we collected data on adult patients who received a CF-LVAD as a primary isolated implant between 1/1/2017 and 9/30/2019. Major NAEs were defined as transient ischemic attack (TIA), ICVA, and HCVA. The association of HVAD with risk of NAE in the first year post implant was evaluated using propensity score matching to balance for pre-implant risk factors. After matching, freedom from first major NAE in the HM3 and HVAD cohorts was compared with Kaplan-Meier curves. A secondary analysis using multivariable multiphase hazard models was used to identify predictors of NAE, which uses a data driven parametric fit of the early declining and constant phase hazards and the associations of risk factor with either phase. Results: Of 6,205 included patients, 3,076 (49.6%) received the HM3 and 3,129 (50.4%) received the HVAD. Median follow-up was 9 and 12 months (HM3 and HVAD). HVAD patients had more major NAEs (16.4% vs. 6.4%, p <0.001), as well as each subtype (TIA: 3.3% vs. 1.0%, p <0.001; ICVA: 7.7% vs. 3.4%, p <0.001; and HCVA: 7.2% vs. 2.0%, p <0.001), than did HM3 patients. A propensity-matched cohort balanced for pre-implant risk factors showed that HVAD was associated with higher probabilities of major NAEs (% freedom from NAE: 82% vs. 92%, p <0.001). Device type was not significantly associated with NAEs in the early hazard phase, but HVAD was associated with higher incidence of major NAEs during the constant hazard phase (hazard ratio: 5.71, confidence interval: 3.90-8.36). Conclusions: HM3 is associated with lower hazard of major NAEs than is HVAD beyond the early post-implantation period and during the constant hazard phase. Defining the explanation for this observation will inform device selection for individual patients.

Outpatient use of left ventricular assist devices: nursing, technical, and educational considerations

1997 ◽  
Vol 6 (5) ◽  
pp. 355-362 ◽  
Author(s):  
DA Moroney ◽  
K Powers
Keyword(s):  
Clinical Training ◽  
Left Ventricular ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Left Ventricular Assist Devices ◽  
Hospital Data ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Left Ventricular Assist ◽  
Permanent Implants

Improvements in technology and in the selection, care, and treatment of patients have led to wider clinical use of mechanical circulatory support. Considerable progress has been made with the use of left ventricular assist devices. Patients are currently maintained in outpatient facilities until a donor heart becomes available; recently, left ventricular assist devices have started to be used as permanent implants. This article outlines the steps that are taken to prepare the patient, the patient's family, and the medical staff for discharge from the hospital of a patient supported with a left ventricular assist device. Extensive technical and clinical training of the primary caregiver and the patient is required to prepare for discharge from the hospital. Data are rapidly accumulating that show that left ventricular assist devices are safe and efficacious for outpatient use. Similar success is expected in clinical trials of permanent left ventricular assist devices, suggesting that many more patients will benefit from this technology in the future.

scholarly journals Driveline Infection in Ventricular Assist Devices and Its Implication in the Present Era of Destination Therapy

2017 ◽  
Vol 9 ◽  
pp. 117906521771421 ◽  
Author(s):  
Gabriel A Hernandez ◽  
Jonatan D Nunez Breton ◽  
Sandra V Chaparro
Keyword(s):  
Treatment Options ◽  
Left Ventricular ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Destination Therapy ◽  
Left Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Bridge To Transplant ◽  
Innovative Therapy

Advances in mechanical circulatory support devices provided the technology to develop long-term, implantable left ventricular assist devices as bridge to transplant, destination therapy, and in a lesser group of patients, as bridge to recovery. Despite the benefits from this innovative therapy, with their increased use, many complications have been encountered, one of the most common being infections. With the driveline acting as a portal to the exterior environment, an infection involving this structure is the most frequent one. Because patients with destination therapy are expected to receive circulatory support for a longer period of time, we will focus this review on the risk factors, prevention, and treatment options for driveline infections.

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