Efficacy of Subcutaneous Electrocardiogram Leads for Synchronous Timing During Chronic Counterpulsation Therapy

Abstract

Counterpulsation devices (CPD) require an accurate, reliable electrocardiogram (ECG) waveform for triggering inflation and deflation. Surface electrodes are for short-term use and transvenous/epicardial leads require invasive implant procedure. A subcutaneous ECG lead configuration was developed as an alternative approach for long-term use with timing mechanical circulatory support (MCS) devices. In this study, efficacy testing was completed by simultaneously recording ECG waveforms from clinical-grade epicardial (control) and subcutaneous (test) leads in chronic ischemic heart failure (IHF) calves implanted with CPD for up to 30 days. Sensitivity and specificity of CPD triggering by R-wave detection was quantified for each lead configuration. The subcutaneous leads provided 98.9% positive predictive value and 98.9% sensitivity compared to the epicardial ECG leads. Lead migration (n=1) and fracture (n=1) were observed in only two of forty implanted leads, without adversely impacting triggering efficacy due to lead redundancy. These findings demonstrate the efficacy of subcutaneous ECG leads for long-term CPD timing and potential use as an alternative method for MCS device timing.

Effects of a Short-Term Left Ventricular Assist Device on Hemodynamics in a Heart Failure Patient-Specific Aorta Model: A CFD Study

“…To analyze hemodynamics in the aorta quantitatively, analyzing the fluid-dynamic variables is essential. However, traditional strategies using lumped parameter models using in vitro even in vivo studies are not adequate to fully understand geometric and functional properties and fluid-dynamic of the aorta (Gramigna et al, 2015 ; Carnahan et al, 2017 ; Wang et al, 2017 ). A crucial challenge facing such studies is that usually high fidelity pressure and/or flow measurements for hemodynamic analysis are extremely difficult because of the complex geometry and small dimensions of the aortic arch and blood vessels (Mazzitelli et al, 2016 ).…”