Abstract 19667: Vagus Nerve Stimulation Normalizes Autonomic Neural Processing and Reduces Cardiac Hypertrophy in a Canine Model of Preserved Ejection Fraction Heart Failure

Objective: To determine whether vagus nerve stimulation (VNS) influences hypertensive-induced changes in cardiac function. Methods: A model of preserved ejection fraction heart failure (HFpEF) was created in adult canines (n=23) via bilateral, non-restrictive renal wrapping (RW) with woven silk pouches. Cardiac echocardiographic and hemodynamic responses were measured longitudinally over 35±1 weeks. Nine animals were untreated; 14 animals received VNS implants (10 right- and 4 left-sided). VNS was initiated at 19±2 weeks of RW by systematically titrating over a 2 week period to an optimal intensity based on real-time measurement of heart rate dynamics [10 Hz, 2.5±0.2 mA, 250 μs pulse width, 22% duty cycle (18 s-ON, 66 s-OFF, continuously-cyclic)]. At termination, after 3 months of VNS therapy, hemodynamic profile and the evoked cardiac responses to stimulation of autonomic inputs (sympathetic and parasympathetic) to the heart were determined. Results: The hemodynamic responses to the RW procedure (mean bl...