Hypertension

Risk factors

• Non-modifiable: age, family history, Black race (earlier onset, more severe)
• Modifiable: high sodium diet, low potassium intake, obesity, sedentary lifestyle, alcohol use, smoking, chronic stress, poor sleep / OSA
• Secondary causes (~5-10% of cases) to consider especially in young, resistant, or rapidly accelerating HTN:
• • Renal: renal artery stenosis (FMD in young women; atherosclerotic in older), CKD, glomerular disease
• • Endocrine: primary hyperaldosteronism (Conn's — low K, metabolic alkalosis), pheochromocytoma (paroxysmal HTN, headache, sweating, palpitations), Cushing syndrome, hyperthyroidism
• • Coarctation of aorta — upper-extremity HTN, lower-extremity hypotension, radio-femoral delay
• • Obstructive sleep apnea (very common, under-recognized)
• • Medications: NSAIDs, OCPs, decongestants, stimulants, SNRIs

Pathophysiology

Multifactorial: increased peripheral vascular resistance from inappropriate RAAS activation, sympathetic overactivity, endothelial dysfunction, vascular remodeling, and renal sodium handling abnormalities. Genetic predisposition interacts with dietary and lifestyle exposures.

Clinical presentation

Differential diagnosis

• White-coat hypertension — Office BP elevated, ambulatory or home BP normal; ~20% of office HTN patients; no end-organ damage on workup
• Masked hypertension — Office BP normal, out-of-office BP elevated; carries worse cardiovascular prognosis than white-coat; suspect with end-organ damage despite 'normal' office readings
• Pseudohypertension (elderly) — Calcified non-compressible arteries cause falsely elevated cuff readings; persistent palpable radial pulse with cuff inflated above SBP (Osler maneuver)
• Renal artery stenosis — Abdominal bruit, refractory HTN, ↑ creatinine after ACEi/ARB; FMD in young women, atherosclerotic in older men; renal artery Doppler or MRA
• Primary hyperaldosteronism (Conn syndrome) — Hypokalemia, metabolic alkalosis, suppressed renin, elevated aldosterone-to-renin ratio; adrenal CT
• Pheochromocytoma — Paroxysmal HTN with the '5 H's' — headache, hypertension, hyperhidrosis, heart palpitations, hyperglycemia; plasma or 24-h urine metanephrines
• Cushing syndrome — Central obesity, moon facies, abdominal striae, easy bruising, proximal muscle weakness; 24-h urine free cortisol or dexamethasone suppression
• Coarctation of the aorta — Upper-extremity HTN with weak/delayed femoral pulses; radio-femoral delay; rib notching on CXR (children/young adults)
• Obstructive sleep apnea — Snoring, witnessed apneas, daytime somnolence, obesity; polysomnography; CPAP can lower BP
• Drug or substance-induced — NSAIDs, OCPs, decongestants (pseudoephedrine), stimulants (cocaine, amphetamines), SNRIs, corticosteroids, licorice (mineralocorticoid effect)

Diagnostic workup

Diagnostic algorithm

Treatment

Complications

• Atherosclerotic cardiovascular disease: MI, stroke, peripheral arterial disease
• Hypertensive heart disease: LVH → HFpEF → HFrEF, AFib
• Chronic kidney disease — second leading cause of ESRD after diabetes
• Hypertensive retinopathy
• Aortic dissection
• Hypertensive emergency with end-organ damage (encephalopathy, pulmonary edema, AKI)

PANCE pearls

• Proper BP measurement: seated, back supported, feet flat, arm at heart level, no caffeine/exercise/smoking 30 min prior, appropriate cuff size. Average of ≥2 readings on ≥2 occasions.
• ACEi cough (10-20% of patients, bradykinin-mediated) → switch to ARB. Angioedema → avoid both ACEi AND ARB (cross-reactivity ~10%).
• Hypertensive urgency (≥180/120 no end-organ damage): oral therapy, gradual reduction over 24-48 h. Hypertensive emergency: IV therapy, reduce MAP 10-20% in first hour, then more gradually. Acute dissection: aggressive — SBP <120 in minutes.
• Avoid sublingual nifedipine — unpredictable, can cause stroke or MI from rapid hypotension. Pulled from US market for this use decades ago.
• Lower 'goal' to <130/80 in most patients per SPRINT (intensive control reduces CV events but increases AKI, syncope, electrolyte abnormalities).

Images

References

• ACC/AHA 2017 — 2017 ACC/AHA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults (Whelton et al., Hypertension 2018)
• SPRINT — A Randomized Trial of Intensive versus Standard Blood-Pressure Control (SPRINT Research Group, NEJM 2015)
• ALLHAT — Major Outcomes in High-Risk Hypertensive Patients Randomized to ACEi, CCB, or Thiazide (ALLHAT Officers, JAMA 2002)
• PATHWAY-2 — Spironolactone vs Placebo, Bisoprolol, Doxazosin for Resistant HTN (Williams et al., Lancet 2015)
• JNC 8 — 2014 Evidence-Based Guideline for the Management of High Blood Pressure (James et al., JAMA 2014)