Detection of inflow obstruction in left ventricular assist devices by accelerometer: An in vitro study

Lilja, Didrik; Schalit, Itai; Espinoza, Andreas; Pettersen, Fred-Johan; Elle, Ole Jakob; Halvorsen, Per Steinar

doi:10.1016/j.medengphy.2022.103917

Cited by 4 publications

(2 citation statements)

References 28 publications

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“…The flow mechanics within the LV are altered during LVAD support, with the majority of flow exiting through the apex rather than the native AV. Application of this approach to patients supported with an HM3 necessitates a clear understanding of how to distinguish the impact of the unsynchronized artificial pulse of the LVAD from the changes produced by PO, which have significant overlap in their H-Q behavior [26].…”

Section: Discussionmentioning

confidence: 99%

Left Ventricular Assist Device Pump Obstruction Reduces Native Heart Efficiency

Montes,

Ueckert,

et al. 2023

Bioengineering

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Obstruction of the LVAD flow path can occur when blood clots or tissue overgrowth form within the inflow cannula, pump body, or outflow graft, and it can lead to thrombus, embolism, and stroke. The goal of this study was to measure the impact of progressive pump inflow obstruction on the pressure and flow dynamics of the LVAD-supported heart using a mock circulatory loop. Pump obstruction (PO) was produced by progressively blocking a fraction of the LVAD inlet area. Pressures, flows, and the midplane velocity field of the LV were measured for three LVAD speeds and six PO levels. Pressure and flow decreased with PO, shifting more of the flow through the aortic valve such that the total flow decreased by 6–11% and decreased the efficiency of the work of the native heart up to 60%. PO restricts diastolic flow through the LVAD, which reduces mitral inflow and decreases the strength and energy of the intraventricular vortices. The changes in flow architecture produced by PO include flow stasis and increased shear, which predispose the system to thromboembolic risk. Analysis of the contributions to external work may enable early detection, which allows time for therapeutic intervention, reducing the likelihood of pump replacement and the risk of complications.

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Section: Discussionmentioning

confidence: 99%

Left Ventricular Assist Device Pump Obstruction Reduces Native Heart Efficiency

Montes,

Ueckert,

et al. 2023

Bioengineering

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“…Complications such as thrombosis may also affect the results and it may alter the signal waveforms further in a CF-LVAD. However, it is also possible to detect obstruction in a CF-LVAD [34]. Therefore, again the proposed method can be utilised to detect and identify additional complications and it may be possible to monitor valvular functions in combination with the occurring complications in the patients implanted with CF-LVAD.…”

Section: Discussionmentioning

confidence: 99%

Sensor-Free Biosensing of Mitral and Aortic Valvular Function During Continuous Flow Left Ventricular Assist Device Support

Bozkurt

Bhalla

2023

IEEE Sensors J.

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Objective: Continuous Flow Left Ventricular Assist Devices (CF-LVADs) are miniaturised devices supporting the failing left ventricle and alter the blood flow in the cardiovascular system which may cause severe health complications. Regurgitation and stenosis in mitral and aortic valves may further aggravate complications and limit the efficiency of CF-LVAD support. Within this context, real-time monitoring of the blood flow in the CF-LVAD support will allow early detection of mitral and aortic valve problems and timely intervention before the valvular problems are worsened. Addressing these issues, this study detects mitral regurgitation, stenosis, and aortic regurgitation during CF-LVAD support by monitoring CF-LVAD electrical current. Methods: Patient-specific electrocardiograph RR interval time series with normal sinus rhythm were incorporated into a cardiovascular system model including CF-LVAD whilst simulating mild and moderate mitral regurgitation, stenosis, and aortic regurgitation. Spearman rank test was used to analyse the correlation between CF-LVAD electrical current signal waveforms over left ventricular systole and left atrial contraction. Results: Correlation coefficients between the CF-LVAD electrical current signals in normal heart valve function and mild and moderate mitral regurgitation were 0.07 and -0.68. In normal heart valve function and mild and moderate mitral stenosis were 0.82 and 0.68. Within the normal heart valve function and mild and moderate aortic regurgitation the correlation coefficients 0.86 and 0.61, respectively. Conclusion: These results suggest that CF-LVAD electrical current signal waveforms can be used for both diagnosis and prognosis of mitral and aortic disorders, thereby representing a potential innovation in the field of both bioelectronics and biosensors.

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