Selective Coronary Vein Sampling in Dyssynchronous Heart Failure and Cardiac Resynchronisation Therapy to Assess Physiological Response to Exercise and Characterise Regional Release of Novel Biomarkers

Cardiac resynchronisation therapy (CRT) prolongs the life and improves the symptoms in patients with heart failure and electrical dyssynchrony. 30-50% of patients do not improve with the treatment which is both expensive and not without complication. Despite much research, we cannot accurately predict who will not respond. Furthermore, most heart failure patients gets symptoms on exercise and most studies have examined patients at rest. We propose to investigate the effect of exercise on different parts of the left ventricle by sampling various biomarkers of metabolism, myocardial injury and gene expression. We will then repeat the protocol following device insertion to look for changes. This novel work will require a small cohort of patients with heart failure and no electrical dyssynchrony and normal patients to act as controls. We will also measure novel biomarkers at different venous sites relating to different parts of the myocardium to determine whether they can be used to prognosticate or even predict response to CRT.