Left Ventricular Assist Device Driveline Infections

Resonantly Coupled High-Efficiency Sensors for Assessment of Ventricular Chamber Size for Autonomous Control of Left Ventricular Assist Device

Current left ventricular assist devices (LVADs) are set to a fixed rpm and are unable to adjust to physiological demands irrespective of preload or afterload. Autonomous control of LVADs has the potential to reduce septal shift, preserve right ventricle function, and meet physiological demands. A highly innovative resonantly coupled regimen is presented which can achieve this goal. We introduce sensors based on a highly sensitive relationship between transmission coefficient and spatial separation in a resonantly coupled regimen. This relationship represents a polynomial regression. A regimen of an apical sensor and multiple outflow sensors is investigated. A range of separations varying from 50-200 mm was systematically investigated. These ranges consider anatomical & physiological variation(s) in cardiac chamber size. Validation was obtained in porcine heart preparation. The polynomial regression model predicted distance between the sensors with a mean absolute percentage error of 0.77%, 1.07%, and 5.75% for the three putative positions of the outflow sensors and apical sensor when compared with experimental results. A high degree of accuracy (95%) between the predicted and observed distance was obtained. Continuous measurements were done over 90 days to examine drift, with no statistically detectable change in measurements over million sampling cycles. We have demonstrated a reliable sensor methodology without drift for assessing ventricular chamber size in an LVAD setup. This has the potential to allow autonomous control of LVAD based on ventricular chamber size to address some of the adverse events.

Ventricular Assist Device Driveline Infections: A Systematic Review

Infection is the most common complication in patients undergoing ventricular assist device (VAD) implantation. Driveline exit site (DLES) infection is the most frequent VAD infection and is a significant cause of adverse events in VAD patients, contributing to morbidity, even mortality, and repetitive hospital readmissions. There are many risk factors for driveline infection (DLI) including younger age, smaller constitution of patients, obesity, exposed velour at the DLES, longer duration of device support, lower cardiac index, higher heart failure score, DLES trauma, and comorbidities such as diabetes mellitus, chronic kidney disease, and depression. The incidence of DLI depends also on the device type. Numerous measures to prevent DLI currently exist. Some of them are proven, whereas the others remain controversial. Current recommendations on DLES care and DLI management are predominantly based on expert consensus and clinical experience of the certain centers. However, careful and uniform DLES care including obligatory driveline immobilization, previously prepared sterile dressing change kits, and continuous patient education are probably crucial for prevention of DLI. Diagnosis and treatment of DLI are often challenging because of certain immunological alterations in VAD patients and microbial biofilm formation on the driveline surface areas. Although there are many conservative and surgical methods described in the DLI treatment, the only possible permanent solution for DLI resolution in VAD patients is heart transplantation. This systematic review brings a comprehensive synthesis of recent data on the prevention, diagnostic workup, and conservative and surgical management of DLI in VAD patients.

Chronic Heart Failure Treatment With the Left Ventricular Assist Device

The prevalence of chronic heart failure is increasing in the United States due to the increase in the number of older adults and because many people are surviving acute cardiac events and living longer with chronic heart disease. In end-stage heart failure, heart transplant was once the gold standard of treatment and patients had to wait for a matching heart donor. In the past, the left ventricular assist device (LVAD) was a mechanical circulatory support treatment used temporarily for those awaiting heart transplant. However, the LVAD is increasingly becoming the chosen treatment of patients in lieu of heart transplant. Home healthcare nurses and clinicians need to be familiar with LVADs in order to care for patients in end-stage heart failure who are using these devices. This article explains the mechanism, potential complications, and nursing implications of caring for the patient who is using an LVAD.

Current State and Future Perspectives of Energy Sources for Totally Implantable Cardiac Devices

There is a large population of patients with end-stage congestive heart failure who cannot be treated by means of conventional cardiac surgery, cardiac transplantation, or chronic catecholamine infusions. Implantable cardiac devices, many designated as destination therapy, have revolutionized patient care and outcomes, although infection and complications related to external power sources or routine battery exchange remain a substantial risk. Complications from repeat battery replacement, power failure, and infections ultimately endanger the original objectives of implantable biomedical device therapy - eliminating the intended patient autonomy, affecting patient quality of life and survival. We sought to review the limitations of current cardiac biomedical device energy sources and discuss the current state and trends of future potential energy sources in pursuit of a lifelong fully implantable biomedical device.