Noninvasive Neuromodulation to Reserve Diastolic Dysfunction

This is a 2x2 cross over pilot study using low level transcutaneous vagus nerve stimulation (LLTS) to reverse diastolic dysfunction in patients with diastolic dysfunction. All patients will receive 2 separate, 1-hour sequences, at least 1 day apart, of active and sham LLTS, but the sequence will be randomized. Patients will be randomly assigned (1:1) to active/sham or sham/active LLTS. LLTS will be performed using a transcutaneous electrical nerve stimulation (TENS) device with electrodes attached to the tragus of the ear, which is innervated by auricular branch of the vagus nerve. Echocardiography will be performed after 30 minutes of LLTS or sham stimulation to assess diastolic function. Five-minute ECGs will be obtained for HRV analysis every 15 minutes of stimulation (total of 4 recordings).