The effect of CRT on the hypercapnic ventilatory response
Research type
Research Study
Full title
Sleep-Disordered Breathing in patients with implanted cardiac devices: Assessment of the change in sensitivity to carbon dioxide with Cardiac Resynchronisation Therapy.
IRAS ID
142343
Contact name
Ali Vazir
Contact email
Sponsor organisation
Royal Brompton and Harefield NHS Trust
Research summary
Heart failure, where the output of blood from the heart is inadequate for the body’s requirements, is a common clinical problem with a poor prognosis despite advances in pharmacological, surgical and pacing therapy.
Around half of patients with heart failure suffer from sleep disordered breathing (SDB). This may be obstructive sleep opnoea (OSA - due to decreased muscle tone in the throat and associated with obesity, predisposing to hypertension, stroke and heart disease) or central sleep apnoea. Central sleep apnoea (CSA) is a type of SDB in which breathing may be excessively deep for a time and then very shallow or even cease for short periods. This pattern of breathing is associated with more severe heart failure and a poor prognosis. A novel algorithm (“ApneaScan“, Boston Scientific plc) has been developed on certain pacemakers to detect SDB. We are validating this algorithm in a parallel study.
The depth and frequency of breathing is predominantly influenced by the level of carbon dioxide in the blood. Rising levels of carbon dioxide stimulate the brain to make us breath harder, thereby restoring carbon dioxide levels back to baseline. One of the major causes of CSA is an exaggerated response to carbon dioxide, which is found in patients with heart failure. This sets in place a cycle of over-breathing followed by cessation of breathing. We aim to evaluate whether Cardiac Resynchronisation Therapy (CRT) via a biventricular pacemaker, which increases the efficiency of the heart and can improve heart failure symptoms and prognosis, has an effect on the brain’s response to carbon dioxide and whether this depends on the presence or absence of CSA.
REC name
London - Bromley Research Ethics Committee
REC reference
14/LO/0078
Date of REC Opinion
26 Feb 2014
REC opinion
Further Information Favourable Opinion