Hypertension Flashcards
Definition
that blood pressure above which the benefits of treatment outweigh the risks in terms of morbidity and mortality
Complications of hypertension
Haemorrhage, stroke, cognitive decline
Retinopathy
Peripheral vascular disease
Renal failure, dialysis, transplantation, proteinuria
Left ventricular hypertrophy, coronary heart disease, congestive heart failure, myocardial infarction
What are the clinical systolic and diastolic blood pressures for stage 1, stage 2 and severe hypertension?
Stage 1 - 140/90 mmHg
Stage 2 - 160/100 mmHg
Severe - systolic: 180mmHg or higher
diastolic: 110mmHg or higher
Primary and secondary?
Primary - no obvious cause
Secondary - underlying cause eg chronic renal disease, renal artery stenosis, endocrine diseases
How is blood pressure normally controlled?
Integrated system - sympathetic and renin-angiotensin-aldosterone.
How does the sympathetic system increase blood pressure?
Increases heart rate by activating sinoatrial node
Increased stroke volume by increased contractility of myocytes
Increases peripheral vascular resistance by vasoconstriction
Increases cardiac output
How can the sympathetic system, which normally controls blood pressure in the short term, cause hypertension?
If it is over activated on a daily basis then it will remain high
What does renin do?
Convert angiotensinogen to angiotensin I.
How does angiotensin II increase blood pressure?
Potent venoconstrictor
Anti-natriutretic peptide
Stimulator of aldosterone from adrenal glands
What are the two likely pathological causes of high blood pressure?
A sodium homeostatic effect - kidneys unable to excrete appropriate amounts of sodium and fluid is retained
Increased reactivity of resistance vessels so increased peripheral resistance
Risk factors
Age Genetics Environment Weight Alcohol intake Smoking Race Sodium intake and diet Birth weight
Secondary hypertension risk factors
Renal disease Diabetes Previous MI or stroke Drug induced - oral contraceptive, NSAIDS, corticosteroids Pregnancy Endocrine diseases Vascular - coarctation of the aorta Sleep apnoea
Symptoms
Asymptomatic
Flushed, headaches, syncope, tinnitus, fatigue, blurred vision
Investigations
ABPM (ambulatory blood pressure monitoring)
HBPM (home blood pressure monitoring)
ECG, fasting blood lipids, U&Es, creatine, urine, fundoscopy (looks at eye), TFTs, renal ultrasound
When you think someone has high blood pressure, what do you do before treatment?
Assess risk factors
Assess end organ damage
Screen for treatable causes
If under 40 then specialist evaluation
Why do we treat hypertension if generally no symptoms?
Reduces cerebrovascular disease by 40-50%
Reduce MI by 15-30%
What is the difference in blood pressure target between young and old?
Old has higher target as if too low there is a risk of falls
Lifestyle modification?
Weight loss Reduce salt Smoking cessation Increase omega 3 More exercise
Stepped approach treatment for those under 55 years old
- ACEI/ ARB (but not to Afro-Caribbean or women of child bearing age)
- Add thiazide-type diuretic
- Add calcium channel blocker
- Consider further diuretic therapy with low dose spironolactone if potassium lower than 4.5mmol/l or higher-dose thiazide diuretic if high potassium
Stepped approach treatment for those over 55 years of age
Start CCB Add Thiazide-type diuretic Add ACE inhibitor Add Beta-blocker Add one of the less commonly used agents
Angiotensin converting enzyme inhibitor example
RAMIPRIL
perindopril
Contraindications of ACEI
renal artery stenosis
renal failure
hyperkalemia
Angiotensin II antagonists
LOSARTAN, VALSARTAN, CANDESARTAN, IRBESARTAN
Calcium channel blockers
Vasodilator - Amlodipin, Felodipine
Rate limiting - Verapamil, Diltiazem
Contraindications of CCB
Acute MI
Heart failure, bradycardia
Thiazide-type duiretics
Indapamide
Clortalidone
Dangers of hypertension in pregnancy
Preeclampsia
How is high blood pressure represented in children
BP > 98th centile
What is accelerated/malignant hypertension?
Increase in levels >180mmHg in systolic or >110mmHg diastolic. Hypertensive emergency.
Commonest cause of accelerated hypertension
Non-adherence to medication
