📘 Hypertension Physiology Masterclass

📋 Clinical Guideline: Assessment & Management

This algorithm synthesizes all the physiology we have learned into a practical, step-by-step guide for managing hypertension.

Step 1: Initial Assessment (Triage)

  1. Confirm the reading: Take 2-3 readings. Rule out White Coat HTN with ambulatory monitoring.
  2. Rule out Hypertensive Emergency: Check for chest pain, dyspnea, neurological deficits, papilledema, or aortic dissection.
    If present → Admit to ICU. Lower BP by 20-25% in the first hour using IV agents (Labetalol, Nicardipine). Do NOT drop to normal immediately.

Step 2: Identify the Physiological Phenotype

  1. High BP + High HR (>85): High Cardiac Output. Suspect Hyperthyroidism, Anemia, Sympathetic overdrive, or Pheochromocytoma.
  2. High BP + Normal/Slow HR: High TPR or High Volume. Suspect Essential HTN, Renal Artery Stenosis, or Hyperaldosteronism.
  3. Wide Pulse Pressure (e.g., 180/70): Stiff arteries (loss of elastin). Suspect Isolated Systolic HTN (Aging).
  4. Edema + Bounding pulses: High Preload (Volume overload). Suspect Heart Failure or Kidney Failure.

Step 3: Basic Labs & Secondary Workup

  1. Baseline: BMP (Creatinine, eGFR, Potassium), Glucose, Lipid panel, Urinalysis, ECG.
  2. If Low K⁺ + High BP: Check Aldosterone/Renin Ratio (ARR) → Suspect Conn's Syndrome.
  3. If Spiking BP + Sweating: Check 24-hour urine Metanephrines → Suspect Pheochromocytoma.
  4. If Cushingoid features: Check 24-hour urine Cortisol → Suspect Cushing's.

Step 4: Non-Pharmacological Management (The "Physiological Reset")

InterventionPhysiological TargetBP Reduction
Sodium Restriction (< 2g/day)Reduces volume & unloads Na/K pump~5-10 mmHg
DASH Diet (Fruits/Veggies)Increases NO & Potassium (Vasodilation)~10-12 mmHg
Weight Loss (BMI < 25)Reduces sympathetic tone~5-20 mmHg
Aerobic Exercise (150 min/wk)Increases NO, lowers HR~5-8 mmHg

Step 5: Pharmacological Management (Matching Drugs to Physiology)

💊 Step 1 (Mild HTN): Start 1 drug based on phenotype.

  • High HR / Sympathetic: Beta-Blocker (Metoprolol).
  • Edema / High Volume: Diuretic (Chlorthalidone).
  • High TPR / Stiff Vessels: CCB (Amlodipine) or ACEi/ARB (Lisinopril).

💊 Step 2 (Moderate HTN): Dual Therapy. Best combo: ACEi/ARB + CCB or ACEi/ARB + Diuretic.

💊 Step 3 (Resistant HTN): Triple Therapy. Add Spironolactone (Mineralocorticoid Receptor Antagonist) to block aldosterone.

Drug Class Cheat Sheet

Drug ClassPhysiological TargetBest For
Thiazide DiureticVolume / PreloadElderly, Edema, High Salt intake
ACE Inhibitor / ARBRAAS / TPRYounger, Diabetics, CKD
CCB (Amlodipine)Vascular Calcium / TPRIsolated Systolic HTN, African-American patients
Beta-BlockerCardiac Output / HRHigh HR, Angina, Heart Failure (not first-line for pure HTN)

Final Target Goals

✍️ Author: Ahmed Mohmad Rashyd Musleh Registered Staff Nurse