Investigations

1st investigations to order

Test
Result
Test

Normal result does not rule out coronary artery disease.

Result

may show evidence of left ventricular hypertrophy or old infarction

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Result
Test

Risk of hypertension is increased if there are features of the metabolic syndrome.

Unprovoked hypokalemia suggests hyperaldosteronism.

GFR is calculated according to the Modification of Diet in Renal Disease (MDRD) formula[51][ Glomerular Filtration Rate Estimate by the IDMS-Traceable MDRD Study Equation ] or the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.[ Glomerular Filtration Rate Estimate by CKD-EPI Equation ]

Result

may show renal insufficiency, hyperglycemia, hypokalemia, hyperuricemia, or hypercalcemia

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Result
Test

Risk of hypertension is increased in setting of the metabolic syndrome.

Result

may show high LDL, low HDL, or high triglycerides

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Result
Test

Increased albumin excretion suggests end-organ damage.

Result

may show proteinuria

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Result
Test

Anemia accompanies chronic renal failure.

Polycythemia may be seen with pheochromocytoma.

Result

anemia or polycythemia suggests secondary cause or complication

Test
Result
Test

Indicated if signs/symptoms of hypo- or hyperthyroidism.

Result

high or low if thyroid dysfunction

Investigations to consider

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Result
Test

Indicated when unprovoked hypokalemia present.

Result

low renin suggests hyperaldosteronism

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Result
Test

Indicated in the following situations: BP is sustained above 150/100 mmHg on 3 measurements over different days, with hypertension resistant to 3 conventional antihypertensive drugs (including a diuretic), or controlled BP (140/90 mmHg) on 4 or more antihypertensive drugs; hypertension and spontaneous or diuretic-induced hypokalemia; hypertension and adrenal incidentaloma; hypertension and sleep apnea; hypertension and a family history of early-onset hypertension or cerebrovascular accident at a young age (40 years); hypertensive first-degree relatives of patients with primary aldosteronism.[55]

Result

high aldosterone or failure to suppress with salt loading suggests hyperaldosteronism

Test
Result
Test

Young patients (age <40 years) with severe hypertension or renal artery bruits.

Ultrasound provides hemodynamic information and magnetic resonance angiogram (MRA) provides anatomic information, in lieu of renal angiogram. CT angiography is accurate in atherosclerotic disease.

Result

may show renal artery stenosis, renal scarring, or lesions

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Result
Test

Indicated with symptoms/signs of catecholamine excess.

Result

elevated catecholamines if pheochromocytoma

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Result
Test

Indicated with signs/symptoms of catecholamine excess. This test is easier to perform than 24-hour urine screen, but has a higher rate of false positives.

Result

elevated metanephrines if pheochromocytoma

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Result
Test

Indicated when stigmata of Cushing disease present.

Result

elevated in Cushing disease

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Result
Test

Sleep study may be considered in cases of resistant hypertension and also for patients with signs or symptoms of obstructive sleep apnea.

Result

may show results consistent with obstructive sleep apnea

Test
Result
Test

Assesses left ventricular hypertrophy and left ventricular function.

Echocardiogram may have prognostic implications, but is not routinely recommended except as recommended by guidelines.[5][56]

There was increased risk of mortality and cardiovascular events in patients with increased left ventricular mass and abnormal geometric left ventricular hypertrophy on echocardiogram.[52][53] 

Result

increased left ventricular mass, decreased left ventricular systolic function, impaired left ventricular diastolic function, and increased left atrial size and decreased function

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