CRT In Narrow QRS Heart Failure: Mechanistic Insights From Cardiac MRI And Electroanatomical Mapping

Cardiac Resynchronisation Therapy (CRT) is a specialist pacemaker procedure that aims to improve the efficiency of the heartbeat. This treatment is used routinely in patients with heart failure and a delay in electrical conduction across the heart seen on the surface ECG (heart tracing). Also CRT has been seen to improve some heart failure patients with a normal electrical conduction (seen on the ECG as a narrow QRS complex). The investigators aim to see if cardiac MRI can be used to select patients with normal electrical conduction for CRT, therefore expanding the number of people who would stand to benefit from this treatment.