The purpose of this study is to compare the impact of inspiratory muscle training (IMT) combined with cardiac rehabilitation (CR) on cardiovascular function in patients with heart failure.

Inclusion Criteria

HFrEF Patients: (≥18 yrs) receiving guideline directed pharmacologic medical therapy for >6 weeks (those with contraindications to medical therapy will meet inclusion criteria), NYHA symptoms I-III, no hospitalizations in the >3 months, have a body mass index ≤45 kg/m2, currently be non-smokers with <30 pack year history and be able to exercise (i.e. without significant orthopedic limitations or musculoskeletal disorders limiting their ability to exercise).

Exclusion Criteria

1. sustained ventricular tachycardia and/or ventricular fibrillation within 21 days of visit 1;
2. second or third degree heart block;
3. body mass index >45 kg/m2;
4. current smokers and/or smoking history >30 pack years;
5. pregnant women (testing will be done by research team if requested);
6. 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);
7. individuals who are not able to engage in exercise;
8. symptomatic peripheral artery disease;
9. asthmatic patients with a low symptom perception and suffer frequency, severe exacerbations or with an abnormally low perception of dyspnea;
10. ruptured eardrum or any other condition of the ear;
11. history of spontaneous pneumothorax or osteoporosis with a history of rib fractures;
12. history of lung disease.

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.