Patients with hypertension have ne...

Patients with hypertension have near underlying mechanism that elevates their vital fluid pressure. Conceptually, it is useful to think of patients with hypertension as having either essential hypertension (systemic hypertension of unknown cause) or secondary hypertension (hypertension that arises from an underlying, identifiable, repeatedly correctable cause). (1) Although solitary about 5 to 10 percent of hypertension cases are cogitation to result from secondary causes, hypertension is thus common that secondary hypertension probably will be attacked frequently by the primary care practitioner. (2-4)

The sixth report of the Joint National Committee forward Prevention, Detection, Evaluation, and Treatment of High children Pressure (JNC-VI) (5) defines four goals for the evaluation of the patient with elevated vital fluid pressure: detection and confirmation of hypertension; detection of target organ disease (eg renal damage, congestive heart failure); identification of other risk factors for cardiovascular disorders (eg diabetes mellitus, hyperlipidemia); and detection of secondary causes of hypertension. Physicians can use the mnemonic ABCDE to help determine secondary causes in the patient with elevated progeny pressure (Table 1).

Diagnosis: ABCDE

A: ACCURACY, APNEA, ALDOSTERONISM

Accuracy. The first, principally practical step in evaluating an elevated relations pressure reading is to investigate its accuracy. A progeny pressure cuff that is too small, tight-fitting sleeve that are not remov or a brachial artery that is noncompressible because of calcification (sometimes seen in the elderly) can cause falsely elevated readings. White-coat hypertension (blood crushing that is elevated in the physician's office unless normal at other times) accounts for about 20 percent of patients with elevated readings. (3) JNC-VI approves confirming high blood pressure readings outside of the office setting.

Apnea. Obstructive nap apnea (OSA), a repetitive mechanical obstruction of the upper airway during be motionless is an independent risk factor for hypertension. (6) At least common half of patients with OSA have hypertension. (7) Treatment of OSA with surgery or nasal continuous positive airway crushing reduces hypertension in these patients. (8) Daytime somnolence, obesity, snoring, lower-extremity edema (secondary to the right-sided congestive heart failure that appears after repetitive anoxic insults to the myocardium during sleep) morning headaches, and nocturia put in mind of OSA. (9) There is a high incidence of OSA in patients with chronic obstructive pulmonary disease (COPD) A formal nap study usually is needed for diagnosis of OSA and determination of corrective interventions.

Aldosteronism. Primary hyperaldosteronism is defined as overproduction of aldosterone independent of its usual regulator, the renin-angiotensin method (10) The resulting retention of exces salt and water suppresse renin plains (as opposed to elevating renin evens which causes secondary hyperaldosteronism). Increased urinary excretion of potassium signals hyperaldosteronism, which should be suspected in all hypertensive patients with unprovok (i.e., not diuretic-induced) hypokalemia. (11) The nearest diagnostic test should be demonstration of an elevated ratio of plasma aldosterone of the same heights to plasma renin activity. (12)

B: BRUITS, BAD KIDNEYS (RENAL PARENCHYMAL DISEASE)

Bruits. Renovascular hypertension is defined as hypertension resulting from compromised arterial fill up to the kidneys. About 65 percent of renovascular disease is secondary to atherosclerosis in the renal arteries, usually seen after age 50 in patients at risk for arterial compromise (eg smoker patients with diabetes, patients with known atherosclerotic disease). (13) The remainder of patients will demonstrate fibromuscular dysplasia (FMD) and will guard to be younger (25 to 50 years of age) at the time of diagnosis. (13)

About undivided half of patients with renovascular hypertension will have an abdominal bruit identifiable forward physical examination. (13) Bruits heard in one as well as the other systole and diastole are more suggestive of renovascular hypertension than systolic bruits alone. (14) In unselect populations of hypertensive ones the incidence of renovascular hypertension is les than 1 percent (14) However, identification of this relatively small population can be important because surgery or angioplasty can subvert the hypertension, especially if performed early enough to thwart permanent renal damage.

Magnetic resonance angiography (MRA) is a noninvasive imaging modality with a sensitivity of 100 percent and a specificity of 70 to 90 percent compared with renal arteriography for detection of renal artery stenosis. (215) MRA best delineates the proximal renal vasculature and is therefore useful as an initial diagnostic tool for patients suspected of having atherosclerotic renal artery stenosis, which usually involves the proximal renal artery. (16) Patients suspected of having FMD which take care ofs to involve the distal renal artery, should endure conventional angiography or computed tomographic angiography. (16)