Inclusion Criteria:  Patients with ischemic and non-ischemic cardiomyopathy, EF < 40 % Patient haemodynamically stable Patients accept to make test  Exclusion Criteria:  Patients with underlying arrhythmia ex heart block or atrial arrhythmia like PACs, AF. Patients on arrhythmogenic drugs ex digitalis, amiodarone. Patients on underlying Pacemaker device or CRT-D. Patients with MI in less than 40 days Patients refuse to make test .