Hypertensive Emergencies and Secondary Hypertension

Introduction to Hypertensive Emergencies

The European Society of Cardiology recommends that pheochromocytoma be considered as a primary differential diagnosis for blood pressure fluctuations between hypotension and hypertensive crisis, followed by medication non-adherence with rebound phenomena, autonomic dysfunction, and illicit drug use 1, 2
The American Heart Association suggests that pheochromocytoma is characterized by episodic hypertension with palpitations, diaphoresis, and headache, and can cause dramatic BP swings from catecholamine surges followed by depletion 1, 3

The Endocrine Society recommends screening for pheochromocytoma with plasma or 24-hour urine metanephrines, as it is a critical cause of episodic severe hypertension alternating with hypotension 2
The American College of Cardiology suggests that Cushing's syndrome can cause severe hypertension with periods of relative hypotension, and recommends screening with dexamethasone suppression test 2, 3

The European Society of Cardiology recommends that medication non-adherence be considered as a common trigger for hypertensive emergencies, and can create fluctuating BP patterns 1
The American Heart Association suggests that drug-induced hypertension with withdrawal periods can cause acute severe hypertension followed by hypotension during withdrawal, and recommends screening for sympathomimetics (cocaine, amphetamines) 2, 5

The American Autonomic Society recommends that autonomic failure syndromes be considered as a cause of dramatic orthostatic hypotension with supine hypertension, and suggests measuring supine and upright blood pressures to detect orthostatic changes 6
The European Society of Cardiology recommends that baroreflex failure following neck surgery or radiation be considered as a cause of labile hypertension, and suggests that it can present with severe BP swings throughout the day 1, 6

The American Society of Nephrology recommends that renal artery stenosis be considered as a cause of severe hypertension with episodes of flash pulmonary edema and relative hypotension, and suggests screening with duplex ultrasound or CT/MR angiography 2, 3
The National Kidney Foundation recommends that renal parenchymal disease be considered as a common secondary cause of hypertension, and suggests checking creatinine clearance and urinalysis 1, 3

The American College of Cardiology recommends that aortic coarctation be considered as a cause of upper extremity hypertension with lower extremity hypotension, and suggests checking for differential in brachial versus femoral pulses 3
The American Heart Association suggests that acute aortic dissection presents with severe hypertension that may alternate with hypotension if rupture occurs, and recommends immediate CT-angiography 1, 5

The Endocrine Society recommends that primary aldosteronism be considered as a cause of resistant hypertension with hypokalemia, and suggests screening with elevated aldosterone/renin ratio 2, 3
The American Academy of Sleep Medicine recommends that obstructive sleep apnea be considered as a contributor to difficult-to-control hypertension, and suggests looking for snoring, witnessed apnea, excessive daytime sleepiness 2, 3

The American College of Cardiology recommends determining if acute target organ damage is present to differentiate hypertensive emergency from urgency, and suggests checking for neurologic, cardiac, renal, vascular, and ophthalmologic signs 1, 5
The European Society of Cardiology recommends that basic screening include complete blood count, basic metabolic panel, lactate dehydrogenase, haptoglobin, urinalysis, TSH, and ECG 2, 5, 7

The American Heart Association recommends not assuming all BP fluctuations represent poor medication adherence without screening for secondary causes, as 20-40% of malignant hypertension cases have identifiable secondary causes 1, 5
The European Society of Cardiology recommends not overlooking pheochromocytoma in patients with episodic severe hypertension, palpitations, and diaphoresis, as this is the classic presentation requiring specific diagnostic workup 1, 3