Hypertension

Why Hypertension Demands Exam Focus

Hypertension (HTN) is the most common primary diagnosis in the United States and a leading modifiable risk factor for cardiovascular disease (CVD), stroke, chronic kidney disease (CKD), and mortality.^[1] Often called the "Silent Killer" due to its asymptomatic nature, HTN affects nearly half of U.S. adults. For the FNP exam, mastering HTN staging, appropriate pharmacotherapy based on race and comorbidities, and lifestyle management is non-negotiable.

Why it matters on exams: HTN is a "core competency" topic tested heavily on the AANP and ANCC certification exams. Expect 5–10 questions on diagnostic criteria, first-line therapies, and management of hypertensive crises.

Hemodynamic Foundations and Hypertension Classification

Hemodynamic Foundations

• Blood Pressure (BP): The product of Cardiac Output (CO) and Systemic Vascular Resistance (SVR). BP = CO x SVR.
• Systolic BP (SBP): Pressure during ventricular contraction (left ventricular ejection). High SBP is the strongest predictor of CVD events in patients >50.
• Diastolic BP (DBP): Pressure during ventricular relaxation (filling phase).
• Pulse Pressure: SBP – DBP. Widened pulse pressure indicates arterial stiffness (common in older adults).

Classification of Hypertension

• Primary (Essential) HTN: No identifiable cause (95% of cases). Linked to genetics, obesity, high sodium intake, and aging.
• Secondary HTN: Caused by an underlying condition (renal artery stenosis, primary hyperaldosteronism, CKD, sleep apnea, pheochromocytoma). Suspect in resistant HTN (requiring 3+ meds), sudden onset, or onset age <30.
• White Coat HTN: Elevated BP in clinic but normal out-of-office readings.
• Masked HTN: Normal clinic BP but elevated out-of-office readings (higher risk for target organ damage).
• Resistant HTN: BP remains above goal despite using 3 antihypertensive agents of different classes, including a diuretic.
• Hypertensive Urgency: SBP >180 or DBP >120 without progressive target organ damage (TOD).
• Hypertensive Emergency: SBP >180 or DBP >120 with acute TOD (e.g., hypertensive encephalopathy, aortic dissection, acute MI).

Staging Thresholds and Underlying Mechanisms

ACC/AHA 2017 Staging Guidelines (High-Yield!)

The 2017 ACC/AHA guidelines lowered the threshold for Stage 1 HTN to 130/80 mm Hg.^[1] This is a critical update for the FNP exam. The JNC 8 (2014) threshold of 140/90 is considered outdated for most populations, though still referenced for specific groups like the elderly.

Pathophysiology (Succinct Overview)

• Renin-Angiotensin-Aldosterone System (RAAS): Increased renin release (renal hypoperfusion) → Angiotensin II (powerful vasoconstrictor) → Aldosterone release (Na+/H2O retention) → Increased BP.
• Sympathetic Nervous System (SNS): Overactivity increases heart rate and vasoconstriction.
• Endothelial Dysfunction: Reduced Nitric Oxide (NO) leads to vasoconstriction and arterial stiffness.
• Sodium Handling: Genetic salt sensitivity causes fluid retention and increased SVR.

Identifying Silent and Symptomatic Presentations

Asymptomatic Phase (Majority of Patients)

• Silent Killer: No symptoms until target organ damage occurs.
• Incidental Finding: Elevated BP discovered during a routine physical or screening.

Symptomatic HTN (Late or Severe)

• Headache: Dull, morning occipital headache (classic sign of severe HTN).
• Visual Disturbances: Blurred vision, scotomata (due to retinal damage).
• Epistaxis: Nosebleeds (often associated with very high BP).
• Dyspnea: Sign of left ventricular failure or pulmonary edema.
• Chest Pain: Potential for myocardial ischemia or aortic dissection.
• Neurologic Symptoms: Dizziness, confusion, or focal deficits (stroke/TIA).

BP Measurement Standards and Diagnostic Protocol

Accurate BP Measurement (Critical Skill)

1. Preparation: Patient sits quietly for 5 min, feet flat on floor, back supported, arm at heart level.
2. Cuff Size: Bladder must encircle 80% of the arm. Too small a cuff = falsely high BP.
3. Device: Aneroid (calibrated) or oscillometric. Auscultation (Korotkoff sounds) is the gold standard.
4. Confirmation: Take 2–3 readings at least 1 minute apart. Average if first is elevated.
5. Out-of-Office: Ambulatory BP monitoring (ABPM) or home BP monitoring (HBPM) for confirmation (White coat vs Masked HTN).

Diagnostic Workup for Target Organ Damage (TOD)

Routine Laboratory Evaluation

• BMP: Creatinine, eGFR (assess CKD), Na+, K+ (baseline before diuretics).
• Lipid Panel: Calculate ASCVD risk score.
• TSH: Rule out hyperthyroidism (secondary HTN).
• Hemoglobin A1c: Screen for Diabetes Mellitus.
• Urinalysis: Check for proteinuria (renal involvement).

Lifestyle Foundation and Race-Specific Pharmacotherapy

Lifestyle Modifications (The Foundation)

• DASH Diet: High in fruits, vegetables, low-fat dairy; low in saturated fats and cholesterol.
• Sodium Restriction: Aim for 1500 mg/day (about ¾ tsp salt).
• Physical Activity: At least 30 minutes of moderate-intensity exercise (brisk walking) most days.
• Weight Loss: Aim for BMI <25. A 5-10% reduction in body weight can significantly lower BP.
• Alcohol Moderation: Limit to 1 drink/day for women, 2 drinks/day for men.
• Other: Smoking cessation, stress management.

Pharmacologic Therapy (Step-by-Step Algorithm)

General First-Line Options (Based on ACC/AHA/ISH Guidelines):^[1][3]

• Thiazide Diuretics: Chlorthalidone (preferred over HCTZ for 24-hr duration), HCTZ.
• ACE Inhibitors (ACEi): Lisinopril, Enalapril.
• Angiotensin II Receptor Blockers (ARBs): Losartan, Valsartan.
• Calcium Channel Blockers (CCB): Amlodipine (dihydropyridine), Diltiazem/Verapamil (non-dihydropyridine).

Race and Comorbidity-Specific Strategies (High-Yield!)

Resistant HTN

• Rule out secondary causes (sleep apnea, hyperaldosteronism, renal artery stenosis).
• Add Spironolactone (Aldosterone Antagonist) after optimizing Thiazide, ACEi/ARB, and CCB.
• Ensure proper medication adherence and correct BP measurement technique.

Side Effect Profiles and Complication Prevention

Common Medication Side Effects (Must-Know)

• Thiazides: Hypokalemia, hyponatremia, hyperuricemia (gout), hyperglycemia.
• ACEi: Dry cough, hyperkalemia, angioedema (airway emergency!), acute kidney injury.
• ARBs: Similar to ACEi but no cough (fewer angioedema cases).
• CCB (Dihydropyridine): Ankle edema, headache, flushing, gingival hyperplasia.
• CCB (Non-DHP): Bradycardia, constipation (Verapamil), heart block.
• Beta-Blockers: Bradycardia, bronchospasm (avoid in asthma/COPD), fatigue, masking of hypoglycemia.

Complications of Untreated or Poorly Controlled HTN

• Cardiovascular: MI, HF, LVH, Aortic dissection, Atrial Fibrillation.
• Cerebrovascular: Ischemic/Hemorrhagic Stroke, Vascular Dementia.
• Renal: Nephrosclerosis, ESRD requiring dialysis.
• Vascular: PAD, Aortic Aneurysm.
• Ocular: Retinopathy, vision loss.

Critical Safety Alerts

• Do not lower BP too rapidly in chronic HTN (risk of cerebral hypoperfusion).
• Hypertensive Emergency: Admit to ICU. Use IV agents (Nitroprusside, Labetalol, Nicardipine). Goal is to reduce mean arterial pressure by 25% in the first hour.
• Check K+ and Creatinine within 1–2 weeks of starting an ACEi or ARB.
• Avoid NSAIDs in patients on ACEi/ARB or diuretics (causes sodium retention and reduces efficacy).

Critical Facts for AANP and ANCC Mastery

• Memorize the 2017 ACC/AHA Staging: Specifically that Stage 1 HTN starts at 130/80 (not 140/90).
• First-Line Drugs by Race: If the question says "African American patient with HTN," pick Thiazide diuretic or CCB as monotherapy.
• Comorbidities:
  • HTN + CKD + Proteinuria → ACEi or ARB.
  • HTN + DM + Microalbuminuria → ACEi or ARB.
  • HTN + Pregnancy → Labetalol, Nifedipine, Methyldopa. (NEVER ACEi/ARB).
• Resistant HTN: Add Spironolactone.
• Side Effects: ACEi → Cough. CCB (Amlodipine) → Ankle Edema. Thiazide → Hypokalemia.
• Lifestyle First: Always consider lifestyle modifications first in Elevated and Stage 1 (low ASCVD risk) before starting meds.
• Treatment Goals: General goal <130/80. In frail elderly, a slightly higher goal (<140/90) may be acceptable to avoid falls.

References & Sources

1. Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. Hypertension. 2018;71(6):e13-e115. https://doi.org/10.1161/HYP.0000000000000065
2. James PA, Oparil S, Carter BL, et al. 2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults (JNC 8). JAMA. 2014;311(5):507-520. https://doi.org/10.1001/jama.2013.284427
3. Unger T, Borghi C, Charchar F, et al. 2020 International Society of Hypertension Global Hypertension Practice Guidelines. Hypertension. 2020;75(6):1334-1357. https://doi.org/10.1161/HYPERTENSIONAHA.120.15026
4. American Diabetes Association. Standards of Medical Care in Diabetes—2023. Diabetes Care. 2023;46(Suppl 1):S1–S291. https://diabetesjournals.org/care/issue/46/Supplement_1
5. Lewis SL, Bucher L, Heitkemper MM, Harding MM. Lewis's Medical-Surgical Nursing: Assessment and Management of Clinical Problems. 11th ed. Elsevier; 2022.
6. Silvestri LA, Silvestri AE. Saunders Comprehensive Review for the NCLEX-RN Examination. 9th ed. Elsevier; 2022.
7. Mancini M, Collawn C. Hypertension. In: Kellerman RD, Rakel DP, eds. Conn's Current Therapy 2023. Elsevier; 2023:151-163.