Clinical Study to Evaluate the Antihypertensive Efficacy and Changes of Neurohormonal Markers of Fimasartan and Atenolol With Exaggerated Blood Pressure Response During Exercise in Essential Hypertensive Patients

Inclusion Criteria: 1. Subjects who agreed to participate in this clinical trial and submitted the written informed consent 2. Subjects aged 20 to 75 years 3. Essential hypertension patients who are measured more 140mmHg, less than 170mmHg of sitting systolic blood pressure(SiSBP) or more 90mmHg, less than 110mmHg of sitting diastolic blood pressure(SiDBP) at baseline(Day 0) 4. men who are measured more 210mmHg, women who are measured more 190mmHg or increasing more than 50mmHg after exercise at baseline(Day 0) 5. Subject who considered to understand this clinical trial, be cooperative,and able to be followed-up whole of the clinical trial period Exclusion Criteria: 1. Patients who are measured the difference of mean blood pressure of one arm under sitting diastolic blood pressure(SiDBP) 10mmHg or SiSBP 20mmHg at screening and baseline visit 2. more 170mmHg of mean Sitting systolic blood pressure(SiSBP)or more 110mmHg of mean Sitting diastolic blood pressure(SiDBP) before exercise at baseline(Day 0) 3. Patients with secondary hypertension 4. Patients with orthostatic hypotension who has sign and symptom 5. Patients with severe insulin dependent or uncontrolled diabetes mellitus (HbA1c\>9, regimen change of oral hypoglycemic agent, using insulin) 6. Patients with severe heart disease, ischemic heart disease within 6 months, peripheral vascular disease, Percutaneous transluminal coronary angiography(PTCA), Coronary artery bypass graft(CABG) 7. Patients with significant ventricular tachycardia, atrial fibrillation, atrial flutter or other significant arrhythmia 8. Patients with hypertrophic obstructive cardiomyopathy, severe obstructive coronary artery disease, aortic stenosis, hemodynamically significant aortic valve or mitral valve disease 9. Patients with severe cerebrovascular disease 10. Patients with known severe or malignancy retinopathy 11. Patients with wasting disease, autoimmune disease, connective tissue disease at present and/or previous 12. Patients with significant investigations; abnormal renal function (Creatinine more 1.5 times than upper limit of normal), abnormal liver function(AST, ALT more 2 times than upper limit of normal), severe fatty liver disease needed medication 13. Patients with surgical and medical disease that is able to be affect to absorption, distribution, metabolism and excretion 14. Patients who have a story or evidence of alcohol or drug abuse within 2 years 15. Childbearing and breast-feeding women 16. Female who plan to become pregnancy or have a possibility of pregnancy but don't prevent conception with acknowledged methods 17. Patients with Bronchial Asthma 18. Patients expected to live less than 1 year with tumor or chronic disease 19. Patients with hepatitis B or C 20. Patients with history of allergic reaction to any angiotensin II antagonist 21. Patients who took medicine within 12 weeks from screening visit or is going on the progress of other clinical trial 22. Subject who are judged unsuitable to participate in this clinical trial by investigator