Cardiovascular- hypertension Flashcards
Lowering blood pressure reduces risk of what?
stroke, coronary events, HF and renal impairment
What is stage 1 hypertension?
BP>140/90 (home 135>85)
Who do we treat with stage 1 hypertension?
patients under 80 with target organ damage, diabetes, 10 year CV risk >20%
What is stage 2 hypertension?
BP>160/100 (home 150/95)
What is severe hypertension?
Systolic BP>180 or diastolic BP>110. HYPERTENSIVE CRISIS
What is the target blood pressure for under 80s?
<140/90
What is the target blood pressure in diabetes?
<140/80 (<130/80 with kidney, eye, cerebrovascular damage)
How long should you trial each stage of anti-hypertensive treatment?
4 weeks to determine response
Step 1 treatment for under 55s
ACE inhibitor. If not tolerated ARB. If both not toelrated consider a beta blocker
Step 2 treatment for under 55s
Step 1 + CCB. If not tolerated or HF give thiazide related diuretic i.e. chlortalidone or indapamide.
Step 3 treatment
ACE inhibitor (ARB) + CCB + thiazide
Step 4 treatment
Add low dose spironolactone (unlicensed) or high dose thiazide if potassium >4.5mmol/L
Monitor RF and electrolytes
If diuretic therapy contraindicated, use beta blocker or alpha blocker
Step 1 treatment for over 55 or Afro-Caribbean
CCB. If not tolerated or HF give thiazide related diuretic
Step 2 treatment for over 55 or Afro-Caribbean
Step 1 + ACE inhibitor (ARB preferred in Afro-Caribbean patients)
What is the target blood pressure for over 80s
150/90
What is isolated systolic hypertension and what does it increase the risk of?
Systolic >160 but diastolic <90. Increased CV risk
What is the role of ACE inhibitors in diabetes?
Management of diabetic nephropathy.
T2DM can delay progression of microalbuminuria to nephropathy
When should you consider ACE inhibitors in renal disease?
patients with proteinuria
What is the problem with diuretics in renal impairment?
thiazides may be ineffective. High dose loop diuretics may be required
What drugs can be used for hypertension in pregnancy?
methyldopa, labetalol, nifedipine MR (unlicensed)
What is the target BP in pregnancy?
<150/100
How do ACE inhibitors work?
inhibit conversion of angiotensin 1 to angiotension 2
What is the role of ACE inhibitors in HF?
all grades, usually combined with beta blockers.
stop potassium sparing diuretics- risk of hyperkalaemia. Low dose spironolactone beneficial in sever HF. monitor potassium.
If already taking high dose loop diuretics, may get profound first dose hypotension.
What are the renal effects of ACE inhibitors?
RF and electrolytes should be monitored before treatment, when doses are increased and during treatment.
Treatment with NSAIDs increases risk to kidneys
How do ARBs differ to ACE inhibitors?
They don’t inhibit breakdown of bradykinin- less likely to cause cough
Name 3 centrally acting antihypertensives
clonidine, methyldopa. moxonidine
What happens if you suddenly withdraw clonidine?
rebound hypertension
What are the side effects of clonidine and methyldopa?
dry mouth, constipation, bradycardia, drowsiness
What patient info do you need to give for clonidine and methyldopa?
may affect skilled tasks and enhance alcohol
When is methyldopa contraindicated?
depression
What monitoring is needed for methyldopa?
blood counts and LFTs before treatment and during intervals of first 6-12 weeks, or unexplained fever
Where do beta blockers work?
heart, peripheral vasculature, bronchi, pancreas, liver
What beta blockers have intrinsic sympathomimetic activity and what does this mean?
Oxoprenolol, acebutolol, pindolol, celiprolol- less bradycardia and cold extremities
What are the most waters soluble beta blockers and what does this mean?
Celiprolol, atenolol, nadolol, sotalo- less likely to cross BBB, cause less sleep disturbances and nightmares. Excreted by the kidneys
Which beta blockers have a longer duration of action and once daily dosing?
atenolol, bisoprolol, celiprolol and nadilol
When are beta blockers contraindicated?
2nd/3rd degree heart block
Which beta blockers are cardioselective
atenolol, bisoprolol, metoprolol, nebivolol
How do beta blockers were in hypertension?
reduce cardiac output, alter baroceptor reflex sensitivity, block peripheral adrenoreceptors
How do beta blockers work in angina?
Reduce cardiac work, improve exercise tolerance, relieve symptoms.
Risk of precipitating HF is verapamil and beta blocker used together in IHD.
What do beta blockers reduce after MI?
Reduce recurrence risk
How do beta blockers work in arrhythmias?
Reduce effects of sympathetic system on automaticity and conductivity
How do beta blockers work in HF?
Block sympathetic activity. Bisoprolol and carvedilol reduce mortality in any grade stable HF
Why should you avoid abrupt withdrawal of beta blockers?
Rebound worsening myocardial ischaemia
Name some dihydropyridine CCBs
amlodipine, felodipine
When should you avoid verapamil and diltiazem?
HF. May further depress cardiac function causing deterioration
What can verapamil be used for?
Angina, HTN, arryhthmias
Verapamil is a highly …. ionotrope
negative
How does verapamil work?
reduces cardiac output., slows HR
How does nifedipine work?
relaxes vascular smooth muscle, dilates coronary and peripheral arteries
What is nifedipine used for?
HTN and angina
How do CCBs affect calcium ions?
Interfere with inwards displacement of calcium ions through slow channels of active cell membranes.
What effect do CCBs have?
Reduce myocardial contractility, depress the formation and propagation of electrical impulses within the heart, diminish coronary or systemic vascular tone
Name some peripheral vasodilators
Hydralazine, minoxidil, sildenafil
What should you monitor with Hydralazine?
Proteinurea every 6 months and antinuclear factor.
Acetylator status for doses >100mg
Name a renin inhibitor
Aliskiren
How does renin work?
converts angiotensin to angiotensin 1
When are thiazides contraindicated?
Addisons, hypercalcaemia, hyponatraemia, hypokalaemia
What condition might thiazides cause?
gout
What should you avoid giving thiazides with?
Lithium- sodium depletion increases risk of toxicity
What electrolyte disturbances can thiazides cause?
Low potassium, sodium, and high calcium and glucose.