Effect of heart rate modulation in Fontan circulation
Research type
Research Study
Full title
The hemodynamic response to heart rate modulation in Fontan circulation
IRAS ID
167517
Contact name
Reza Razavi
Contact email
Sponsor organisation
Kings College London
Duration of Study in the UK
2 years, 0 months, 1 days
Research summary
Fontan circulation is a surgically established solution for patients with complex congenital heart problems. Healthy people have two chambers that pump blood (one to the lungs and one to the body). Fontan patients lack a ventricle that supports the pulmonary circulation.
Survival rates of Fontan surgery have improved drastically over the last decades. But as patients grow into adulthood, they experience a slow decrease in cardiac function. This decrease results in ‘Fontan failure’ (death transplantation or severe heart failure) in up to 30% of the patients. So far, only marginal succes has been achieved in prevention of the decline in exercise capacity and cardiac performance.
Based on recent studies we know that, despite increasing heart rates, cardiac output in Fontan patients plateaus during stress. This blunted response to stress is caused by impaired filling, due to a limited supply of blood to heart (preload). We hypothyse that, if preload is the limiting factor of a cardiac output increase, high heart rates are non-beneficial in Fontan circulation, as a similar cardiac output can be reached at lower heart rates, due to better filling of the heart. This would result in lower energy demand to maintain cardiac output during stress.
Therefore, this study proposes to investigate the acute effect of heart rate
modulation in Fontan patients during stress. Patients and volunteers will perform physical exercise on a supine bicycle during a cardiac MRI scan at baseline and after a single dose of a heart rate lowering drug.
The results of this study will help to evaluate if heart rate modulating strategies could potentially play a role in prevention of the decline in cardiac performance in Fontan patients.REC name
London - Bloomsbury Research Ethics Committee
REC reference
15/LO/0522
Date of REC Opinion
27 May 2015
REC opinion
Further Information Favourable Opinion