A Novel Subcutaneous Counterpulsation Device: Acute Hemodynamic Efficacy During Pharmacologically Induced Hypertension, Hypotension, and Heart Failure

Abstract

The miniaturization of mechanical assist devices and less invasive implantation techniques may lead to earlier intervention in patients with heart failure. As such, we evaluated the effectiveness of a novel, minimally invasive, implantable counterpulsation device (CPD) in augmenting cardiac function during impaired hemodynamics. We compared the efficacy of a 32-mL stroke volume CPD with a standard 40-mL intra-aortic balloon pump (IABP) over a range of clinically relevant pathophysiological conditions. Male calves were instrumented via thoracotomy, the CPD was anastomosed to the left carotid artery, and the IABP was positioned in the descending aorta. Hemodynamic conditions of hypertension, hypotension, and heart failure were pharmacologically simulated and data were recorded during CPD and IABP support (off, 1:2, 1:1 modes) for each condition. In all three pathophysiological conditions, the CPD and IABP produced similar and statistically significant (P < 0.05) increases in coronary artery blood flow normalized to the left ventricular (LV) workload. During hypotension and heart failure conditions, however, the CPD produced significantly greater reductions in LV workload and myocardial oxygen consumption as compared with the IABP. A novel 32-mL CPD connected to a peripheral artery produced equivalent or greater hemodynamic benefits than a standard 40-mL IABP during pharmacologically induced hypertension, hypotension, and heart failure conditions.

Nonphysiologic blood flow triggers endothelial and arterial remodeling in vivo: Implications for novel left ventricular assist devices with a peripheral anastomosis

“…Anastomosis of the outflow graft to the subclavian artery was initially described by DeBakey when he implanted the first LVAD 19 and has become a common site for less-invasive therapy. For example, the continuous-flow CircuLite Synergy Pocket Micro-Pump 6 and the Symphony pump 5 have adopted this configuration. This approach forces a medium-sized peripheral artery to accommodate non-physiologic hemodynamics and the volumetric flow of a larger artery.…”

“…A number of novel circulatory support devices are being developed that require an end-to-side anastomosis to a peripheral artery 5, 6 . This anatomical configuration forces a medium-sized artery to accommodate significant increases in blood flow and blood pressure, and with certain devices, bidirectional blood flow.…”

“…This results in improved coronary and systemic blood flow. By these mechanisms, the myocardial oxygen supply/demand relationship improves 5 , and end-organ perfusion increases. A clinical trial with the Symphony pump is currently underway in Canada and France 7 .…”

Extracorporeal Membrane Oxygenation Versus Counterpulsatile, Pulsatile, and Continuous Left Ventricular Unloading for Pediatric Mechanical Circulatory Support*

“…Total arterial flow during VAD and ECMO support was calculated as the sum of LVCO and VADF mean . LADF mean normalized to LVEW was used as an index of the left ventricular blood supply/demand relationship[18]. Total myocardial blood flow (MBFtotal, as determined by microspheres) normalized to MVO 2 was used as an index of the global myocardial oxygen supply/demand relationship.…”

Feasibility of Subcutaneous ECG Leads for Synchronized Timing of a Counterpulsation Device

“…Symphony (SCR, Louisville KY) is a counterpulsation device that can be placed via a limited operative approach, thereby avoiding thoracotomy or sternotomy approaches typically associated with ventricular assist devices (LVAD). 2 Symphony is a 30-mL stroke volume device with a polyurethane-lined pumping chamber that is designed to fit comfortably in a pacemaker-like pocket on the right side of a patient (Fig. 1).…”