Bowditch Revisited: Defining the Optimum Heart Rate Range in Chronic Heart Failure

Not Applicable

• Conditions: Chronic Heart Failure
• Interventions: Device: Tailored pacemaker settings

• Registration Number: NCT02563873
• Lead Sponsor: University of Leeds

Brief Summary

The investigators are examining the relationship between heart rate and heart contraction in patients with heart failure and pacemakers, aiming to improve quality of life.

Detailed Description

Heart rate lowering is a cornerstone of the management of chronic heart failure (CHF) and the degree of lowering is closely related to improvements in longevity, hospitalisation rate and heart function. The investigators have shown that increasing heart rates using pacemakers does not increase exercise capacity in CHF patients. This might be because the optimal heart rate range for contraction is narrower for patients with CHF. At higher heart rates, heart contraction might be less strong. The investigators now want to examine the relationship between heart rate and heart contraction in patients with heart failure and pacemakers. Tailored pacemaker heart rate setting's, individually optimised for heart contractility as assessed by cardiac ultrasound, will be investigated to examine the effects on exercise tolerance .

Study Timeline

• Study First Submitted: 2015-07-22
• Study First Submitted QC: 2015-09-28
• Study First Posted: 2015-09-30
• Study Start: 2015-10
• Status Verified: 2016-05
• Last Update Submitted: 2016-05-10
• Last Update Posted: 2016-05-11
• Primary Completion: 2017-07
• Study Completion: 2018-07

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 110

Inclusion Criteria

• stable CHF
• Cardiac Resynchronisation Therapy (CRT) device for >3 months,
• able to walk on treadmill

Exclusion Criteria

• unable to walk on treadmill,
• unstable angina pectoris
• uncontrolled heart rate
• prescribed calcium channel blocker
• significant aortic stenosis
• significant airways disease

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Tailored pacemaker settings	Tailored pacemaker settings	The pacemaker settings will be altered to match optimal heart rate range with respect to cardiac contractility, as determined by echocardiography. This will be programmed and the patient will complete a symptom limited exercise tolerance test with metabolic gas exchange.

Primary Outcome Measures

Name	Time	Method
Change in Exercise Time	Assessed following the second treadmill test, 1 week later	Exercise duration in seconds

Secondary Outcome Measures

Name	Time	Method
Change in Peak Oxygen Consumption (pVO2)	Assessed following the second treadmill test, 1 week later	Peak Oxygen Consumption (pVO2) measured by metabolic gas exchange

Trial Locations

Locations (1)

Leeds Institute of Cardiovascular and Metabolic Medicine; 🇬🇧 Leeds, West Yorkshire, United Kingdom