Vascular Flashcards
Where are baroreceptors?
Carotid sinuses (glossopharyngeal) and aortic arch (vagus)
What is the average pulse pressure?
40 mm Hg
Why does the pulse pressure increase in ageing?
SBP increases due to less elastic aorta
DBP decreases due to lack of elastic recoil
When does the pulse pressure decrease?
haemorrhage
How often should BP be measured?
Every 5 years in adults
Annually over 80
How to investigate hypertension?
ECG - LVH
Fundoscopy - hypertensive retinopathy
Urinalysis
Cardiovascular risk assessment
Bloods: U&Es, glucose, lipids
NICE hypertension criteria
Stage 1: 140/90 clinic, 135/85 ABPM/ HBPM
Stage 2:160/100, 150/95
Stage 3: 180/110
If BP elevated in clinic, how is hypertension confirmed?
ABPM (2 readings every hour)
HBPM (2 readings daily)
What are the hypertensive crises?
MALIGNANT (ACCELERATED) HTN: stage 3 + accompanied with end-organ damage - refer hospital same day
SUSPECTED PHAECHROMOCYTOMA: refer same day
HYPERTENSIVE URGENCY: stage 3 without impending organ damage - refer within few days
Secondary causes of hypertension
Renal: intrinsic or renovascular
Endocrine: Cushing’s - Conn’s - thyroid - phaechromocytoma - acromegaly - hyperparathyroidism
Coarctation of the aorta
Obstructive sleep apnoea
Pre-eclampsia and HTN in pregnancy
Drugs: alcohol, cocaine, amphetamines, antidepressants, COCP, etc.
Management of hypertension
Young + non-black // Black or over 55
STEP 1: A (or B if contra-indicated) // C (or D if contra-indicated)
STEP 2: A + C (AIIRA in black)
B + C if initially started on B
A + D (if C contraindicated)
STEP 3: A + C + D
STEP 4: Consider fourth agent/ specialist
Mx HTN: HF
Normally already on A + B
Add D - refer to specialist for spiro
Mx HTN: DM
A is first-line, regardless of age/ race
Then add D
Then add C
Mx HTN: AF
If rate control needed, add B or CCB (diltiazem better than amlodipine)
MoA beta-blockers
B1 mainly in heart
B2 mainly smooth muscle of vessels and airway
Blockade reduces speed of contraction and speed of conduction
Five 5 indications for beta-blockers
IHD (symptoms + prognosis) HF (prognosis) AF (reduce ventricular rate) SVT (restores sinus rhythm) HTN
Who requires a low dose of beta-blockers?
Hepatic failure
In whom should beta-blockers be avoided?
Asthma (in COPD use B1-selective, not propranolol)
Heart block
Avoid in haemodynamically unstable
Which medication should not be given with beta-blockers?
Non-dihydropyridine CCB (eg verapamil, diltiazem) –> HF, bradycardia, asystole
Needs specialist supervision
What are the classes of CCBs?
Dihydropyridines (more vasc-selective): nifedipine, amlodipine
Non-dihydropyridines (more heart-selective): diltiazem, verapamil
3 indications for CCBs
HTN (amlodipine, nifedipine less oftten)
Stable angina (beta-blockers main alternative)
Rate control in SVT arrhythmias (diltiazem and verapamil)
MoA CCBs
reduced calcium entry into vascular and cardiac muscle –> less contraction
ADRs of CCBs
Dihydropyridines: ankle swelling, flushing, headaches, palpitations (vasodilataion + compensatory tachycardia)
Verapamil: constipation - bradycardia, heart block, cardiac failure
Diltiazem has both as less selective
When should dihydropyridines not be given?
Unstable angina (don't want to increase O2 demand of heart) Severe AS (provokes collapse)