The purpose of this research study is to determine whether atenolol or controlled release carvedilol lower blood pressure in the body as effectively as in the arm. Blood pressure measured in the aorta, a large blood vessel carrying blood away from the heart, may be a better measure of the harmful effects of high blood pressure on the body's organs. In the past, blood pressure has only been measured in the arms. However, blood pressure in the arms may not accurately reflect the blood pressure in the aorta and thus may mislead doctors treating high blood pressure. For this reason, we are testing whether two different medications for blood pressure, both in a class called beta blockers, have similar effects on blood pressure in the arm and aorta.

Carvedilol reduces aortic wave reflection and improves left ventricular/vascular coupling: a comparison with atenolol (CENTRAL Study) is a prospective, open-label, comparative, randomized control trial that evaluated brachial and central hemodynamic profiles in patients taking atenolol or controlled-release carvedilol.

Inclusion Criteria:

• At least 18 years of age
• Hypertension (untreated or treated with no more then one anti-hypertensive drug)

Exclusion Criteria:

• Secondary forms of hypertension (including sleep apnea)
• Patients currently treated with two or more antihypertensive drugs
• Patients taking antihypertensive drugs with properly measured clinic systolic blood pressure greater then 170mmHg
• Isolated systolic hypertension
• Other diseases requiring treatment with blood pressure lowering medications
• Heart rate less then 55 beats/min (in the absence of beta-blocker therapy)
• Known cardiovascular disease including history of angina pectoris, heart failure, presence of a cardiac pacemaker, history of myocardial infarction or revascularization procedure, or cerebrovascular disease (including stroke and TIA)
• Known diabetes mellitus (Type 1 or 2)
• Renal insufficiency defined as a serum creatinine greater then 1.5mg/dL in males and 1.4mg/dL in females
• Primary renal disease
• Pregnancy or lactation
• History of Raynaud's syndrome
• Alcoholism and recreational drug use (due to compliance concerns)

Small sample size, short duration.