Systemic Hypertension

Definition & Thresholds - Hypertensive Hurdles

• Hypertension: BP ≥95th percentile for age, sex, height (on ≥3 occasions).
• BP Categories:
  • Normal: <90th percentile.
  • Prehypertension: 90th to <95th percentile OR BP >120/80 mmHg.
  • Stage 1 HTN: ≥95th percentile to ≤(99th percentile + 5 mmHg).
  • Stage 2 HTN: >(99th percentile + 5 mmHg).

    ⭐ Children <6 yrs or Stage 2 HTN: suspect secondary causes.

• Accurate Measurement:
  • Correct cuff: bladder width ~40% arm circumference, length 80-100%.
  • Calm child; average ≥3 readings on separate occasions.

Etiology & Red Flags - Root Cause Roundup

Primary (Essential) HTN: Prevalence ↑ with age; common in adolescents. Secondary HTN: More common in younger children, especially <6-10 years.

Common Causes of Secondary HTN:

• Renal (Most common overall): Parenchymal disease (e.g., glomerulonephritis, reflux nephropathy), renovascular disease.
• Coarctation of Aorta.
• Endocrine: Pheochromocytoma, CAH, hyperthyroidism, Cushing's syndrome.
• Drugs: Corticosteroids, NSAIDs, OCPs, sympathomimetics.
• Neurologic (e.g., ↑ICP), Genetic syndromes (e.g., Turner, Williams).

Common Causes by Age Group:

• Age <6 years (especially <3 years).
• Stage 2 HTN, symptomatic HTN, or acute severe rise.
• Electrolyte imbalance (e.g., hypokalemia).
• Physical findings suggestive of underlying cause (e.g., abdominal bruit, delayed femoral pulses, virilization, café-au-lait spots).
• Poor response to standard antihypertensive therapy.

⭐ Renal parenchymal disease is the single most common identifiable cause of secondary hypertension in children.

Evaluation & Workup - Detective Diagnosis

• History Taking:
  • Perinatal: UAC, prematurity.
  • Family Hx: HTN, renal/endocrine disease.
  • Meds: Steroids, NSAIDs, sympathomimetics.
  • Symptoms: Headache, visual changes, epistaxis, palpitations, FTT, seizures.
• Physical Examination:
  • Accurate BP: Correct cuff, 4-limb BP.
  • Fundoscopy: Retinopathy.
  • Palpation: Kidneys, abdominal bruits, radio-femoral delay.
  • Syndromic/Endocrine features (Turner, NF1, Cushingoid).
• Initial Investigations:
  • Urinalysis (proteinuria, hematuria), Culture.
  • Serum: Electrolytes (K+), BUN, Creatinine, Uric acid.
  • Lipid profile, Fasting glucose. TSH.
• Further Investigations (Targeted):
  • Renal USG + Doppler, DMSA. Echo (LVH, coarctation).
  • Endocrine: PRA, Aldosterone, Catecholamines, Cortisol. Genetic tests.
• Ambulatory BP Monitoring (ABPM):
  • Indications: White coat HTN, masked HTN, nocturnal dip, drug efficacy.

⭐ A significant BP difference (>10-20 mmHg) between upper and lower limbs suggests Coarctation of the Aorta.

Management & Meds - Pressure Protocol

• Non-Pharmacological: Lifestyle: DASH diet, weight management, regular physical activity, salt restriction.
• Pharmacotherapy Indications: Symptomatic HTN, Stage 2 HTN, Stage 1 HTN unresponsive to LSM or with End-Organ Damage (EOD), secondary HTN, Diabetes (DM), Chronic Kidney Disease (CKD).
• Choice of Antihypertensives:
  • ACE inhibitors (e.g., Enalapril; SE: cough, hyperK, angioedema)
  • ARBs (e.g., Losartan; SE: similar to ACEi, less cough)
  • Long-acting Calcium Channel Blockers (e.g., Amlodipine; SE: edema, flushing)
  • Diuretics (e.g., Hydrochlorothiazide/HCTZ; SE: hypoK, hypoNa)
  • (Beta-blockers less preferred first-line unless specific indication e.g. coarctation)
• Hypertensive Urgency/Emergency:
  • Urgency: Severe HTN, no acute EOD. Emergency: Severe HTN + acute EOD.

  ⭐ For hypertensive emergencies, BP should be lowered gradually to avoid cerebral hypoperfusion; aim for a 25% reduction in the first 8 hours, then normalize over 24-48h.

  • IV Meds (Emergency): Labetalol, Nicardipine, Sodium Nitroprusside.

High‑Yield Points - ⚡ Biggest Takeaways

• Definition: BP > 95th percentile for age, sex, height on ≥3 occasions.
• Secondary HTN: Renal parenchymal disease (most common); Coarctation of Aorta (cardiac).
• Screening: Annually from 3 years of age.
• ABPM: Gold standard to confirm diagnosis, rules out white-coat HTN.
• LVH: Most common target organ damage.
• Treatment: Lifestyle changes; ACEIs/ARBs preferred if drugs needed.
• Hypertensive Emergency: IV Labetalol or Nicardipine for rapid control.