Prospective Study on Prognosis of Cardiac Resynchronized Therapy (CRT), Implantable Cardioverter Defibrillator (ICD) Implantation in Patients With Congestive Heart Failure (CHF)

CRT and ICD has known as decreasing cardiac mortality in patient with heart failure. Especially, it has reported that CRT improved cardiac systolic function, quality of life of patients with heart failure. However, CRT and primary ICD was not generalized in Korea. So the investigators will register patients who implant CRT or ICD (primary), and follow them up. During scheduled follow up, all patients will perform echocardiography, 6 minute walking test, EKG, Holter monitoring and questionnaire on QOL.

Inclusion Criteria:

1. Age >=18
2. LV ejection fraction <40% or Clinical HF Symptom with (LV ejection fraction >40%)
3. medication for at least 3month

Exclusion Criteria:

1. patient who refuse to enroll the study