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

University of Leeds

Status: Unknown

Conditions: Chronic Heart Failure

Treatments: Device: Tailored pacemaker settings

Study type: Interventional

Funder types: Other

Identifiers

NCT02563873

12/YH/0097

Details and patient eligibility

About

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.

Full 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 .

Enrollment: 110 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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110 participants in 2 patient groups

Standard pacemaker settings

No Intervention group

Description:

Standard pacemaker settings will be programmed and the patient will complete a symptom limited exercise tolerance test with metabolic gas exchange

Tailored pacemaker settings

Experimental group

Description:

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.

Treatment:

Device: Tailored pacemaker settings