Malignant Hypertension Workup

Updated: May 26, 2020
  • Author: John D Bisognano, MD, PhD, FACP, FACC; Chief Editor: Vecihi Batuman, MD, FASN  more...
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Laboratory Studies

Initial laboratory studies include a complete blood cell (CBC) count and electrolytes (including calcium), blood urea nitrogen (BUN), creatinine, glucose, coagulation profile, and urinalysis. Other laboratory studies are indicated only as directed by the initial workup. These may include measurements for cardiac enzymes, urinary catecholamines, and thyroid-stimulating hormone (TSH), and 24-hour urine collection for vanillylmandelic acid (VMA) and catecholamines.

Renal function should be evaluated through urinalysis, complete chemistry profile, and CBC count. Expected findings include elevated BUN and creatinine, hyperphosphatemia, hyperkalemia or hypokalemia, glucose abnormalities, acidosis, hypernatremia, and evidence of microangiopathic hemolytic anemia and azotemic oliguric renal failure. Urinalysis may reveal proteinuria, microscopic hematuria, and red blood cell or hyaline casts.

Diffuse intrarenal ischemia results in increased levels of plasma renin, angiotensin II, and aldosterone, with resulting hypovolemia and hypokalemia. Sodium depletion is common and may be severe. [12]


Imaging Studies

Routine screening consists of chest radiography, which is useful for assessment of cardiac enlargement, pulmonary edema, or involvement of other thoracic structures, such as rib notching with aortic coarctation or a widened mediastinum with aortic dissection. Other studies, such as computed tomography (CT) of the head, transesophageal echocardiography (TEE), and renal angiography, are indicated only as directed by the initial workup.


Electrocardiography and Echocardiography

Electrocardiography (ECG) is an essential part of the evaluation to screen for ischemia, infarct, or evidence of electrolyte abnormalities or drug overdose. In the earliest stages of malignant hypertension, ECG and echocardiography reveal left atrial enlargement and left ventricular hypertrophy.