Heart failure Circulatory System Heart failure
Conditions
Interventions
1. Carotid body chemosensitivity testing: brief, intermittent lowering of inhaled oxygen levels to test hypoxic ventilatory response at rest.
2. Muscle Sympathetic Nerve Activity measu
Sponsors
University of Bristol
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: All participants: 1. Aged 18-90 years HFrEF participants: As per the European Society of Cardiology (ESC) guidelines: 1. Signs and symptoms of heart failure AND 2. Raised natriuretic peptides AND 3. Evidence of reduced ejection fraction (EF 50%) AND 4. Objective evidence of cardiac functional and structural alterations
Exclusion criteria
Exclusion criteria: All participants: 1. Requirement for oxygen therapy to maintain oxygen saturation 2. Oxygen saturations at rest 28 units/week 18. Febrile illness/clinically significant infection within two weeks of participation 19. Contraindications to dopamine administration: 19.1. Known phaeochromocytoma 19.2. Known hyperthyroidism 19.3. Known uncontrolled atrial or ventricular tachyarrhythmias 19.4. Known hypersensitivity to dopamine or any of the excipients 19.5. Participants on the following medications: 19.5.1. Monoamine oxidase I inhibitors 19.5.2. Phenytoin 19.5.3. Ergot alkaloids 19.5.4. Tricyclic antidepressants 19.5.5. Guanethidine Healthy controls: 1. No history of hypertension
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 1. CB chemosensitivity and tonicity and levels of sympathetic activity in HFrEF & HFpEF patients compared to healthy controls at rest: 1.1. Hypoxic ventilatory response (HVR) in litre/minute/%SpO2 1.2. Change in minute ventilation during dopamine infusion (l/min) 1.3. Muscle sympathetic nerve activity (burst frequency, usually quantified as bursts per 100 heartbeats) at baseline 2. Change in exercise tolerance and perceived rate of exertion in HFpEF patients as a result of dopamine administration vs saline during VO2 Peak Test: 2.1. BORG score at peak 2.2. VO2 peak measurement, overall VE/VCO2 slope | — |
Secondary
| Measure | Time frame |
|---|---|
| Differences between healthy controls, HFrEF & HFpEF groups at rest during carotid body chemosensitivity testing: 1. BP responses to hypoxia 2. BP response to dopamine and hypoxia (small subset of participants) 3. HR responses to hypoxia 4. HR responses to dopamine and hypoxia (small subset of participants) 5. Inflammatory markers 6. Pulse Wave Analysis | — |
Countries
United Kingdom
Outcome results
None listed