Breathing workouts may boost exercise in heart failure patients

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * ≥18 yrs of age * Receiving SGLT2 inhibitors and spironolactone (and beta-blocker use for HFpEF patients with hypertension) for \>3 months * NYHA symptoms I-III * Body mass index ≤40 kg/m2 * Currently non-smokers with \<20 pack year history * Able to exercise (i.e. without significant orthopedic limitations or musculoskeletal disorders limiting their ability to exercise) Exclusion Criteria: * Sustained ventricular tachycardia and/or ventricular fibrillation within 21 days of visit 1 * Second or third degree heart block * Body mass index \>40 kg/m2 * Current smokers and/or smoking history \>20 pack years * Pregnant women (testing will be done by research team if requested) * Glomerular filtration rate of \<30 mL/min/1.73m2 (initial screen via clinical record within the past 6 months and this will be assessed on Visit 1) * Individuals who are not able to engage in exercise * Uremia, history of allergy to iodides * Peripheral artery disease * Alanine transaminase and/or aspartate transaminase greater than 2 times the upper limit of normal (via clinical record within the past 6 months) * Asthmatic patients with a low symptom perception and suffer frequency, severe exacerbations or with an abnormally low perception of dyspnea * Ruptured eardrum or any other condition of the ear * History of spontaneous pneumothorax or osteoporosis with a history of rib fractures * History of lidocaine allergy. For individuals agreeing to undergo dual energy x-ray absorptiometry (DEXA) scanning for measurement of body composition as part of their study visit, additional exclusion criteria apply: recently administered gastrointestinal contrast or radionuclides; severe degenerative changes or fracture deformity in measurement areas; or inability to attain correct position and/or remain motionless for the measurement period.