Renovascular hypertension

Definition

Renovascular hypertension is high blood pressure due to narrowing of the arteries that carry blood to the kidneys. It is a form of secondary hypertension.

See also:

• Drug-induced hypertension
• Essential hypertension
• Malignant hypertension

Alternative Names

Causes

When the kidney arteries become narrow, less blood flows to the kidneys. The kidneys mistakenly respond as if your blood pressure is low and give off hormones that tell the body to retain salt and water. This causes your blood pressure to rise.

Many different diseases can cause narrowing of the renal arteries. Renal artery stenosis is one of the most common.

Symptoms

Usually, high blood pressure causes no symptoms. Occasionally you may have a mild headache. If your headache is severe, or if you have any of the symptoms below, see a doctor right away. These may be a sign of malignant hypertension.

• Blood in urine
• Confusion
• Crushing, angina-like chest pain
• Ear noise or buzzing
• Irregular heartbeat
• Nosebleed
• Tiredness
• Vision changes

Exams and Tests

Persons with renovascular hypertension usually have severe, difficult-to-control high blood pressure. Elevated blood pressure measurements, repeated over time, confirm hypertension.

Your doctor may hear a "whooshing" noise, or bruit, when placing a stethoscope over your belly area.

Other signs of this disease include:

• Episodes of heart failure (flash pulmonary edema)
• Rapid progression of kidney failure
• Acute kidney failure occurs when starting blood pressure medicines called ACE-I or ARBs
• Hypertension in an elderly patient whose blood pressure was previously well controlled

There may be signs of complications, such as:

• Left ventricular hypertrophy (swelling of the heart)
• Hypertensive retinopathy

Your doctor may order blood tests to check your renin and aldosterone levels. Imaging tests may be done see if the kidney arteries have narrowed. They include:

• Renal arteriography
• Doppler ultrasound of the renal arteries
• Magnetic resonance angiography (MRA)
• Angiotensin converting enzyme (ACE) inhibition renography

Treatment

Renovascular hypertension is often difficult to treat.

Medications may be used to help control blood pressure. There are a variety of high blood pressure medications available. You and your doctor will decide which type is best for you.

Everyone responds to medicine differently. Your blood pressure should be checked frequently. The amount and type of medicine you take may need to be changed from time to time.

Further treatment depends on what causes the narrowing of the kidney arteries. In some cases, surgery to reconstruct the damaged artery may be done. Persons with renal artery stenosis may have a stent placed in the artery to hold it open.

Most nephrologists will perform a surgical bypass of the renal arteries (revascularization) to restore blood flow in patients who have severe hypertension, episodes of flash pulmonary edema, or rapid progression of kidney failure.

Possible Complications

• Early death
• Hypertensive heart disease
• Heart attack
• Congestive heart failure
• Blood vessel damage
• Kidney damage
• Kidney failure
• Stroke
• Loss of vision

When to Contact a Medical Professional

Call for an appointment with your health care provider if you think you have high blood pressure.

Call your health care provider if you have renovascular hypertension and symptoms get worse or do not improve with treatment. Also call if new symptoms develop.

Prevention

Preventing atherosclerosis may prevent the development of renal artery stenosis.

Lifestyle changes may reduce your risk of high blood pressure. Lose weight if you are overweight. Excess weight makes the heart work harder. Check with your doctor before starting a rigorous exercise program.

Changes in your diet may help to control your blood pressure. Reduce the amount of salt (sodium)you use. Salt, MSG, and baking soda all contain sodium.

See also: Heart disease and diet

Taylor AT Jr, Blaufox MD, Dubovsky EV, et al. Procedure guideline for diagnosis of renovascular hypertension, 3.0. Reston, Va: Society of Nuclear Medicine; 2003 Jun 20.

Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). Rockville, Md. National Heart, Lung, and Blood Institute, US Department of Health and Human Services; August 2004. National Institutes of Health Publication No. 04-5230.

Berg AO. Screening for High Blood Pressure Recommendations and Rationale U.S. Preventive Services Task Force. USPSTF Guide to Clin Preventive Services. June 1, 2003; 1.