eart failure is a disease with high morbidity and mortality. It is also the commonest cause of medical ward admission. The incidence of heart failure has been increasing world-wide in the past decade.Studies observed that about 25 - 50 % of patients with heart failure had evidence of electromechanical delay,commonly in the form of left bundle branch block or intraventricular conduction delay on surface electrocardiogram. This condition results in dyssynchronous contraction, mitral regurgitation and was associated with a worse prognosis. These patients may therefore benefit from cardiac resynchronization therapy.