Hypertension

Question 1

Hypertension

Answer 1

• A systolic blood pressure greater than 140mm Hg and a diastolic
pressure greater than 90mm Hg over a sustained period
• Heart is working harder putting heart & blood vessels under strain
• High BP can contribute to atherosclerosis, myocardial infarction,
stroke & renal failure

Question 2

Risk Factors

Answer 2

• Genetic & environmental factors
• Family history
• Advancing age
• Smoking
• Obesity
• Heavy alcohol consumption
• Males more @ risk than females before age 55 years
• Females more @ risk than males after 55 years
• High dietary sodium intake
• Low dietary intake of potassium, calcium, magnesium
• Glucose intolerance

Question 3

Primary (Essential) Hypertension

Answer 3

Combined systolic &
diastolic hypertension
•Specific cause has not
been identified
•Accounts for 90 – 95%
of all cases

Question 4

Review of Normal Regulation of BP

Answer 4

BP is the force exerted by the blood against the walls of blood vessels.
• BP is a function of Cardiac Output & Systemic Vascular Resistance
• BP regulation is a complex process involving functions of:
• Nervous, Cardiovascular, Renal & Endocrine systems

Question 5

Pathophysiology of Primary

Hypertension

Answer 5

Multiple pathophysiological mechanisms contribute to
primary hypertension
• Sympathetic nervous system
• ↑ activity causes ↑ heart rate & systemic vasoconstriction = ↑
BP
•Renin-angiotensin-aldosterone system
• Angiotensin II is a potent vasoconstrictor & increases
vascular resistance = ↑BP
•Natriuretic peptides (secreted by cardiac cells)
• Dysfunction of these hormones leads to Na+ & H2O
retention = ↑BP

Question 6

Secondary Hypertension

Answer 6

• Caused by an underlying disease or medication that
raises peripheral vascular resistance or cardiac
output
•If the cause can be identified & corrected before
damage occurs BP will return to normal
• Causes include: narrowing of aorta, renal diseases,
endocrine disorders, neurological disorders,
medications & pregnancy-induced hypertension

Question 7

Clinical Manifestations

Answer 7

Frequently asymptomatic until severe
• Symptoms secondary to effects on blood vessels,
increased workload of the heart and organs affected.
• Severe hypertension may produce symptoms such as:
• fatigue, reduced activity tolerance, dizziness, palpitations,
angina & dyspnoea
•Headaches, nosebleeds & dizziness usually only occur
with very high or very low BP

Question 8

Complications

Answer 8

• Atherosclerosis / CHD / MI
• Left ventricular hypertrophy
• Heart failure
• TIA / Stroke
• Peripheral vascular disease
• Aortic aneurysm
• Renal failure
• Retinal damage

Question 9

Pharmacology

Hypertension

Answer 9

• ACE inhibitors
• Prevents the conversion of angiotensin I into angiotensin II
• Captopril, Cilazapril, Enalapril
• β – blockers
• Mechanism of action in hypertension unclear. ? Renin release mediated by β1
receptors. Blocking these receptors prevents angiotensin II formation.
• Metoprolol, Atenolol, Sotalol

Question 10

Pharmacology

Hypertension cotinued…

Answer 10

Calcium channel blockers
• Decrease entry & availability of calcium within the heart
& blood vessels which affects cardiac contraction,
conduction & vascular tone
• Diltiazem, Felodipine, Verapamil
• Diuretics
• Increasing the amount of water excreted by the kidneys
therefore reducing blood volume
• Bendrofluazide, Spironolactone, Hydrochlorothiazide