Pathophysiology

• What is the pathophysiology of HTN?

  Multifactorial & complex

  Involves impairment of renal pressure natriuresis -> feedback system - high BP = increase Na+ & H2O excretion by kidney -> reduction in BP (involved RAAS, baroreceptors & ANS)
• What heart problems does untreated HTN cause?

  Left ventricular hypertrophy - due to high systemic BP -> left ventricle overworks to push blood into aorta

  Coronary heart disease & angina

  MI

  Arrhythmia
• How does untreated HTN lead to stroke?

  Blood vessels damaged by HTN can narrow, leak or rupture -> blood clot formation -> blocks blood flow -> stroke
• Why is there decreased eGFR in HTN?

  High BP -> vasoconstriction in kidney -> damages & scars blood vessels -> decreased blood flow to kidneys -> less blood flow -> decreased eGFR
• What are the different catecholamines?

  Dopamine

  Noradrenaline

  Adrenaline
• What do catecholamines act as?

  Hormones & neurotransmitters
• How is adrenaline synthesised from noradrenaline?

  Noradrenaline methylated to form adrenaline
• What does hyperparathyroidism lead to, in terms of BP?

  Activates osteoblasts -> more RANKL -> stimulates osteoclasts to reabsorb bone -> releases Ca+2 in blood -> more smooth muscle contraction -> vasoconstriction
• What does hyperreactive RAAS cause?

  More renin release -> more angiotensin II -> increase BP
• What does hypersensitive sympathetic NS lead to, in terms of BP?

  Vasoconstriction -> increased BP

  OR

  Acts on heart -> increases CO, HR & BP
• What is the pathophysiology of HTN?

  Multifactorial

  Anything that increases cardiac output or total peripheral resistance -> leads to increased BP

  Some factors increase both CO & TPR

  
• What can HTN increase the risk of developing?

  Strokes

  Coronary artery disease

  Atheroma

  MI

  Aneurysms

  Heart failure

  Peripheral arterial disease

  Aortic aneurysms

  Kidney disease

  Vascular dementia
• What can uncontrolled HTN lead to?

  Hypertensive Target Organ Damage -> can cause structural or functional changes in heart, kidney & CNS
• What are the common causes of secondary HTN?

  Primary hyperaldosteronism

  Obstructive sleep apnoea

  Obesity

  Pregnancy