Renovascular Hypertension

What is renovascular hypertension? its an acute or chronic elevation of systemic blood pressure caused by partial or complete occlusion of one or more renal arteries or their branches. 

Etiology and Pathophysiology of Renovascular Hypertension

Renovascular hypertension is the clinical consequence of renin angiotensin aldosterone (RAA) activation. Stenosis or occlusion of one or both main renal arteries or their branches or an accesory renal artery or its branches can cause hypertension by inciting the release of the enzyme renin from the juxtaglomerular cells of the affected kidney. Presumably, the decrease in pulse amplitude rather than the decrease in blood flow stimulates renin secretion. The area of the lumen must be decreased by at least 65% before the occlusion is hemodynamically significant. In patients over 50 years old and usually men, the most frequent cause of renal arterial stenosis is atherosclerosis. In younger patients (usually women), it is one of the fibrous dysplasis. Rarer cause of renal arterial stenosis or obstruction include emboli, trauma, inadvertent ligation during surgery, and extrinsic compression of the renal pedicle by tumors.

Renovascular Hypertension symptoms and Diagnosis

Renovascular hypertension should be suspected when hypertension first develops in patient under 30 or over 50 year of age or whenever previously stable hypertension abruptly accelerates. Rapid progression to malignant hypertension within 6 month of onset is suggestive of renal artery disease.

An epigastric bruit transmitted to one or both upper quadrants is the most important physical symptoms and is especially significant if there is a diastolic component. About 50 percents of patient with renovascular hypertension, however, do not have bruits. Trauma to the back or flank or acute pain in this region with or without hematuria should alert the patient to possibility of renovascular hypertension, but this historic features are rare. Renovascular hypertension is characterized by both high cardic output and high peripheral resistance. Both renovascular and primary hypertension are usually asymptomatic, and only difference in history.

Renovascular Hypertension Epidemiology

Mortality. Patients with hypertension, the atherosclerotic renal artery disease is would increased mortality relative to the general population. Renovascular Hypertension in the setting of renal dysfunction is associated cause the greatest mortality.
Race, in particular, Renovascular Hypertension are less common among the black than the white population.
Sex, Renovascular Hypertension is most common in younger women and older men.
Age, The onset of Renovascular Hypertension tends to occur in patients under 30 years or over 50 years of age.