Hypertension (HT)

General Information

Classification: Cardiovascular

What is it?

Persistent elevation in arterial blood pressure (BP)

HT Stages

Table 1 Categories/stages of HT according to systolic and diastolic pressures (Source: Wikimedia Commons)

Hypotension: <90/60

Normal: <120/80

Elevated (undepicted in Table 1): when systolic BP is 120-129 mmHg

Stage 1: 130-139/80-89

Stage 2 (Resistant): >140/90

Hypertensive crisis/Critical stage: >180/110

Blood Pressure

Is the force exerted by blood flow against your vessels, and is typically measured using both systolic and diastolic pressure values, yielding one ratio of SP/DP (e.g. 120/80) in mmHg.

  • Systolic BP: blood pressure when heart is beating
  • Diastolic BP: blood pressure when heart is at rest

BP calculations

  • BP = CO (cardiac output) * SVR (systemic vascular resistance)
    • This indicates that BP depends on both the total volume of blood the heart pumps, as well as vessel blood flow resistance

How is BP measured?

  • A sphygmomanometer, or more traditionally by listening to Korotkoff sounds using a stethoscope

Risk Factors: advanced age, smoking, high sodium diet and/or low potassium, diabetic, high alcohol consumption, low or middle income countries

Evaluation:

  • BP readings:
    • Recording an elevated/hypertensive BP measurement at least on two separate occasions
  • Symptoms: nausea, headaches, dyspnea, vomiting
  • Blood test, CBC (for electrolyte abnormalities)
  • For Secondary HT, check for differentials based on the presumed primary cause

Types of HT (broad level)

  1. White Coat HT: HT only at physician or HCP setting (due to clinical stress, nervousness/agitation)
    • Use 24h BP monitor to diagnose
  2. Mask HT: HT out of office

Categorization & Etiology

Essential HT Idiopathic origin

Most commonly seen from ages 25-50 with accompanying family history

Causes: increased SNS activity (e.g., epinephrine release), increased renin (dysregulation of RAAS system), increased Na+ retension, older age (which leads to decreased elastin)

Secondary HT Falls secondary to prior conditions

In ages <30, presenting with sudden, severe, refractory onset (higher stage orders)

5% of all HT cases

*Renal disorders–neuropathy, polycystic disease

Drugs–sympathomimetics, oral contraceptives with estrogen (increases production of angiotensinogen), NSAIDS (inhibit Cox2, decreasing production of the vasodilator PGI2), antacids with sodium, anti-depressants, systemic corticosteroids

Endocrine origin–hyperaldosteronism, Cushing’s disease (increases cortisol and SNS activity); more rare: hyper or hypothyroidism (increases sympathetic tone, inducing vasoconstriction), hyperparathyroidism (increases cardiac muscle contraction via increasing [Ca2+])

Vascular disorders–atherosclerosis in renal vessels, coarctation of the aorta (increases BP in upper extremities, head, neck)

Miscellaneous–sleep apnea, preeclampsia

Complications

Coronary heart disease, congestive heart failure, atherosclerosis, ventricular hypertrophy, arrhythmias

Stroke, seizures, subarachnoid hemorrhage

AV nicking, papilledema, cotton wool spots

Renal/kidney failure

Treatment

Anti-hypertensives: ACE inhibitors, ARBs, Ca-channel blockers,

If Secondary HT: address primary causes

  • E.g…beta/alpha-adrenergic drugs or thyroid/hormone therapy for endocrine causes, revascularization for renovascular causes, CPAP for sleep apnea

Lifestyle modifications: quit/reducing smoking and drinking frequency, dietary changes (reduce sodium intake), exercise

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