Cardiovascular disorders

• Primary (Essential) hypertension

  High blood pressure of unknown aetiology (i.e. there is no known cause)

  
• Secondary hypertension

  High blood pressure caused by an identifiable underlying secondary cause

  
• Resistant hypertension

  High blood pressure that doesn't respond to antihypertensive medications

  
• Heart Foundation of Australia (2016) Classification of clinic blood pressure levels in adults

  • Optimal
  • Normal
  • High-normal
  • Grade 1 (mild hypertension)
  • Grade 2 (moderate hypertension)
  • Grade 3 (severe hypertension)
  • Isolated systolic hypertension

  
• 90% of hypertension cases are primary HTN or do not have a discernible cause

  
• The initial management of hypertension should focus on the non-pharmacological measures
• Modifiable risk factors for hypertension

  • Unhealthy diet rich in salt, saturated fats and trans fats, poor fiber intake
  • Physical inactivity
  • Consumption of tobacco and alcohol
  • Being overweight and obese
• Non-modifiable risk factors for hypertension

  • Positive family history of hypertension
  • Age over 65 years
  • Comorbidities like diabetes and kidney disease
• Treatment of hypertension

  1. Reducing and eliminating risk factors

  2. Lifestyle modifications

  3. Medication regimen
• Lifestyle modifications to prevent hypertension

  • Restrict sodium intake to 2.4g/d
  • Increase potassium intake
  • Restrict saturated fat intake
  • Adjust calorie intake to maintain optimum body weight
  • Exercise program that promotes endurance and relaxation
  • Smoking cessation
• First line antihypertensive medication options

  • Angiotensin-Converting Enzyme (ACE) inhibitors
  • Angiotensin-II receptor blockers (ARB)
  • Beta-blockers
  • Calcium channel blockers
  • Diuretics
• Second line antihypertensive medication options

  • Potassium-sparing diuretics
  • Alpha blockers
  • Centrally acting antiadrenergic drugs
• Angiotensin Converting Enzyme Inhibitors (ACE inhibitors)

  Prevent the conversion of angiotensin I to angiotensin II, reducing peripheral vascular resistance and blood pressure

  
• Angiotensin Converting Enzyme Inhibitors (ACE inhibitors)

  • Decrease the oxygen demand of the heart by decreasing the afterload (blood pressure)
  • Used in the treatment of ACS and as an antihypertensive
• Side effects of ACE inhibitors

  • Hypotension
  • Palpitations
  • Tachycardia
  • Chest pain
  • Dizziness
  • Vertigo
  • Rash
  • Elevated potassium levels
  • Raised liver enzymes
  • Proteinuria
  • Renal impairment
  • Jaundice
  • Abdominal pain
• Angiotensin-receptor antagonists (ARBs)

  Antagonise angiotensin II receptors on vascular smooth muscles and adrenal cortex, increasing renal blood flow and maintaining/increasing glomerular filtration rate

  
• Angiotensin-receptor antagonists (ARBs)

  • Used as antihypertensive for patients unable to tolerate ACEIs
• Side effects of ARBs

  • Hypotension
  • Palpitations
  • Tachycardia
  • Chest pain
  • Dizziness
  • Headache
  • Nausea
  • Vomiting
  • Abdominal pain
  • Raised liver enzymes
  • Peripheral oedema

  
• Beta Blockers

  Provide beta-adrenergic sympathetic inhibition, reducing heart rate, slowed conduction of impulses, decreased blood pressure, and reduced cardiac contractility
• Beta Blockers

  • Reduce cardiac output and myocardial oxygen demand
  • Used as secondary therapy for treatment of atrial fibrillation

  
• Side effects of Beta Blockers

  • Bronchospasm
  • Dyspnea on exertion
  • Bradycardia
  • Heart block
  • Hypotension
  • Nausea
  • Vomiting
  • Diarrhea
  • Cold extremities
  • Fatigue
  • Sleep disturbance
  • Oedema
  • Blurred vision
  • Hallucinations
  • Hypoglycemia
• Calcium Channel Blockers

  Block calcium channels in smooth muscle of the vasculature, causing smooth muscle relaxation and vasodilation
• Calcium Channel Blockers

  • Decrease the afterload and blood pressure
  • Decrease sinoatrial node automaticity and atrioventricular node conduction, resulting in a slower heart rate
  • Used as treatment for angina and class IV antiarrhythmic

  
• Side effects of Calcium Channel Blockers

  • Headache
  • Dizziness
  • Nausea
  • Vomiting
  • Abdominal pain
  • Rash
  • AV block
  • Palpitations
  • Hypotension
  • Oedema
  • Gingivitis
• Diuretics (thiazides)

  Increase the excretion of sodium, chloride, water, potassium, magnesium, and bicarbonate ions
• Diuretics (thiazides)

  • Used as primary therapy for hypertension in those above 65 years of age, or combined with other antihypertensives
  • Used for oedema including ascitis, and mild to moderate stable heart failure
• Side effects of Diuretics (thiazides)

  • Electrolyte disturbances: hypokalemia, hyponatremia, hypomagnesemia, hypochloremia
  • Hypovolemia
  • Dehydration
  • Dizziness
  • Blurred vision
  • Reversible tinnitus
  • Hypotension
  • Polyurea
  • Rash
• Vasodilators (with nitrates)

  Relax smooth muscle causing vasodilation of peripheral arteries and veins
• Vasodilators (with nitrates)

  • Used for prophylaxis and treatment of angina pectoris
  • Used to control post-operative hypertension and produce prolonged hypotension during neurosurgery and orthopaedic surgery

  
• Side effects of Vasodilators (with nitrates)

  • Throbbing headache
  • Facial flushing
  • Orthostatic hypotension
  • Nausea and vomiting
  • Bradycardia
  • Rash
  • Abrupt withdrawal angina
  • Skin irritation
• Organic nitrates


  Relax smooth muscle causing vasodilation of peripheral arteries and veins. At low doses the effect is venodilation, whereas at large doses arterial dilation occurs.

  
• General use of organic nitrates

  Prophylaxis and treatment of angina pectoris, control of post-operative hypertension, to produce prolonged hypotension during neurosurgery and orthopaedic surgery

  
• General side effects of organic nitrates

  • Throbbing headache
  • Facial flushing
  • Orthostatic hypotension
  • Nausea and vomiting
  • Bradycardia
  • Rash
  • Abrupt withdrawal angina
  • Skin irritation
• General interactions of organic nitrates

  • Increased risk of hypotension if used with alcohol
  • Effect may decrease if given with NSAIDs
  • May decrease the effect of noradrenaline, heparin, morphine metabolism
• Nursing considerations for organic nitrates

  Contraindicated in acute circulatory failure, pronounced hypotension, and cardiogenic shock. Hypovolemia should be corrected before starting therapy. Patient should sit or lie down after taking tablets to avoid dizziness. Continuous monitoring of heart rate and blood pressure required. Compatibility with IV infusion solution and administration set must be checked.
• To lower blood pressure, you should aim to decrease the cardiac output or the heart rate

  
• Orthostatic hypotension (OH)

  Decrease in systolic and diastolic arterial blood pressure on standing, usually at least 20mmHg decrease in systolic or 10mmHg decrease in diastolic

  
• Causes of acute orthostatic hypotension

  • Altered body chemistry
  • Drug actions
  • Prolonged immobility
  • Starvation
  • Physical exhaustion
  • Volume depletion
  • Venous pooling
• Causes of chronic orthostatic hypotension

  • Idiopathic
  • Endocrine disorders
  • Metabolic disorders
  • CNS/PNS disorders
• Orthostatic hypotension is a significant risk factor for falls and associated injuries and increased cardiovascular events