Pathophysiological Mechanisms of Activity-Related Dyspnea in Heart Failure: A Pilot Study

• Conditions: Heart Failure
• Interventions: Other: Cardiopulmonary Exercise Testing

• Registration Number: NCT02007486
• Lead Sponsor: McGill University

Brief Summary

Dyspnea (breathlessness) on exertion is the most prevalent and distressing symptom of heart failure (HF). Nevertheless, the mechanisms of dyspnea in HF remain poorly understood. Thus, the general aim of this pilot study is to advance our understanding of the mechanisms of activity-related dyspnea in patients with HF. Studies will be performed in patients with mild, moderate and severe HF (n=24) as well as in healthy, age- and sex-matched control subjects (n=8). We will test the hypothesis that the increased prevalence and severity of activity-related dyspnea in HF reflects the interaction between an exaggerated drive to breathe and the inability of the respiratory system to meet this increased demand. Detailed physiological and perceptual responses to bicycle exercise will be examined and compared, first, between HF patients and healthy control subjects and, second, across patients with varying degrees of HF severity. The results from this preliminary study will be used to help design future studies in this patient population.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2013-11-28
• Study First Submitted QC: 2013-12-05
• Study First Posted: 2013-12-10
• Study Start: 2014-01
• Status Verified: 2017-02
• Last Update Submitted: 2017-02-10
• Last Update Posted: 2017-02-14
• Primary Completion: 2017-12
• Study Completion: 2017-12

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 32

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Heart Failure: NYHA functional class I	Cardiopulmonary Exercise Testing	Ambulatory and clinically-stable patients with New York Heart Association Functional Class I heart failure and a left ventricular ejection fraction (LVEF) on echocardiography of \<45%.
Heart Failure: NYHA functional class III	Cardiopulmonary Exercise Testing	Ambulatory and clinically-stable patients with New York Heart Association Functional Class III heart failure and a left ventricular ejection fraction (LVEF) on echocardiography of \<45%.
Heart Failure: NYHA functional class II	Cardiopulmonary Exercise Testing	Ambulatory and clinically-stable patients with New York Heart Association Functional Class II heart failure and a left ventricular ejection fraction (LVEF) on echocardiography of \<45%.
Healthy Control Subjects	Cardiopulmonary Exercise Testing	Healthy, sedentary, non-smoking, age- and sex-matched control subjects.

Primary Outcome Measures

Name	Time	Method
Sensory intensity (Borg 0-10 scale) ratings of dyspnea at a standardized sub-maximal work rate during exercise	Patients will be followed until all study visits are complete, an expected average of 2 weeks

Secondary Outcome Measures

Name	Time	Method
Power output (measured in watts) at the symptom-limited peak of incremental cycle ergometer exercise testing	Patients will be followed until all study visits are complete, an expected average of 2 weeks.	The highest power output (measured in watts) that the study participants are able to sustain for greater than or equal to 30 seconds will be defined as the "symptom-limited peak power output" and used as a secondary outcome measure in this study.
Esophageal electrode catheter-derived measurements of the diaphragm EMG at a standardized sub-maximal work rate during exercise.	Patients will be followed until all study visits are complete, an expected average of 2 weeks

Trial Locations

Locations (1)

McConnell Centre for Innovative Medicine, Research Institute of the McGill University Health Centre; 🇨🇦 Montreal, Quebec, Canada