RESynchronisation in Patients With Heart Failure and a Normal QRS Duration

Patients who have heart failure and have electrical evidence of delay in the contraction of the left ventricle on an ECG tracing of the heart are eligible for biventricular pacing. Recent work has suggested that patients with heart failure who do not have electrical evidence of conduction delay (normal QRS) may benefit from biventricular pacing. The reliance on ECGs to determine the presence of dyssynchrony is widespread, although the ECG alone is not 100% sensitive and specific. ECG criteria for de-synchrony in heart failure patients are estimated to pick up only 30% of patients with dyssynchrony, and results in patients missing out on a potentially important treatment advance. We would like to study patients with heart failure who have normal ventricular activation on their ECGs to see whether we can predict those patients who will respond to biventricular pacing.