Heart failure is a condition that occurs when the heart muscle weakens and no longer
contracts normally. Half of these patients have an irregularity of heart rhythm called atrial
fibrillation (AF). Patients with both heart failure and AF spend more time in hospital, and
die earlier than those with heart failure alone. AF is difficult to treat with conventional
methods in patients with heart failure. Radiofrequency ablation is a new technique used to
cure AF. The investigators aim to establish if radiofrequency ablation for atrial
fibrillation in patients with advanced heart failure can result in marked improvement in the
function of the heart.