CVS part 2 Flashcards
What are Korotkow sounds. Apparatus used
-Systolic when sounds appear (top pressure)
-Diastolic when they disappear (bottom pressure)
Pump cuff around arm so brachial pulse disappears. When deflates, pressure can be measured. Take average of 2 readings [Unobstructed and healthy blood flow is silent]
-be aware of white coat effect= higher when see doctor
What level of blood pressure constitutes hypertension. Values when they need meds. What value is severe hypertension
-120/80 is normal
>140/90 mmHg, consistently
>160/100 mmHg, in clinic
>180/110 mmHg, in clinic
Causes of essential hypertension. What % of hypertension is this
-90%
-no definitive cause
-Poly-causal = obesity, salt, lack of exercise, alcohol
Causes of secondary hypertension. What % of hypertension cases this is
-10%. A secondary cause of disease
-Renal artery stenosis
-Conn’s syndrome
-Adrenal adenoma
-Cushing’s syndrome
-Glomerulonephritis
-Fibromuscular disease
-medications
How Conn’s syndrome, adrenal adenoma and Cushing’s syndrome, kidney ischamia cause hypertension
-Conn’s and adrenal adenoma increase aldosterone (hyperaldosteronism) - increases sodium and fluid retention so increases BP. Also activates sympathetic system
-Cushing’s - too much cortisol causing vasoconstriction
-Ischamia of kidney - inappropriate activation of renin-angiotensin system, increasing aldosterone
List complications of hypertension
-Coronary heart disease- left ventricular dysfunction, MI, heart failure
-Peripheral vascular disease, Malignant hypertension, Dissection aneurysms, Renal failure, Aortic aneurysms
-Cerebral infarction and haemorrhage = Stroke. hypertensive encephalopathy - coma and seizures
What eye changes can occur in hypertension
-blood vessels weaken and cause haemorrhage areas in eye
-can be sight threatening
How to manage hypertension
-Lifestyle changes: weight reduction, exercise, decrease salt intake, alcohol reduction
-[reducing fat and smoking don’t reduce BP but reduce CVD risk]
-Meds = ACEI, ARBS, Beta blockers, Ca blockers, thiazide diuretics
General symptoms of a stroke
Symptoms depend on part of brain damaged
-unilateral face paralysis (opposite side to damaged brain)
-unilateral weak/ numb arms
-double vision
-slurred speech
-difficulty swallowing
-loss of sensation
-unsteady on feet
-Loss of ability to use and understand language (knows what something is but cannot name it)
FAST (Facial drooping, Arm weakness, Speech difficulties and Time)
Area of brain involved in speech, sight, understanding language,
-Speech = Broca’s area in frontal lobe
-Sight = Visual area, at the back
-Understanding = Wernicke’s area
Name some arteries involved in the circle of Willis
-Anterior, middle and posterior cerebral arteries
-Vertebral arteries and internal carotids supply the circle of willis
-Basilar arteries with pontine arteries
-Anterior and posterior communicating arteries
Risk factors for stokes. which is most common
-Hypertension - 52% = largest risk factor
-Vascular disease elsewhere - 38%
-Smoking - 45%
-Diabetes - 10%
-TIA - 14%
-Atrial fibrillation - 5% - Can cause a mural thrombus on the wall of the atria due to microstasis, which can then embolise and cause a stroke
Stroke prevention
-antihypertensives, lose weight, exercise, decrease salt intake, alcohol reduction
-Anti-platelet drugs (aspirin)
-Lipid lowering (statins)
-Anti-coagulants: Warfarin to reduce risk of thrombi-embolism
-Stop smoking
-Surgery
What drugs can cause hypertension
-Amphetamines -stimulant drugs
-Cocaine
-Oestrogens (e.g. oral contraceptive pill)
-Cyclosporin – (immunosuppressant)
-Sympathomimetic amines
-Erythropoetin
List drug classes used to reduce hypertension. Which are 4th line
-ACE inhibators
-Angiotensin receptor blockers
-Calcium channel blockers
-Diuretics (thiazide-like)
4th line:
-Beta blockers
-Anti-aldosterone
-Alpha blockers
Describe the renin angiotensin system - how its activated, hormone involved, what it causes
-low blood volume increases renin from kidney
-renin converts Ang to Ang I
-Ang I converts to Ang II (by ACE)
-Ang II causes vasoconstriction and stimulates aldosterone release from adrenal cortex
-This increases Na reabsorption, increased K secretion, increased fluid retention, increased blood volume = increased BP
Action of ACE inhibitors. Uses. Name drugs
-Inhibits ACE so inhibits conversion of Ang I to Ang II so reduced aldosterone (reducing water retention) Reduces BP. Renal vasodilation
-Inhibits breakdown of bradykinin, a vasodilator (releases nitric oxide and prostaglandins)
-1st line for hypertension. Used in heart failure
-Lisinopril, captopril, enalapril
Action of angiotensin receptor blockers. Uses. Name drugs
-Inhibit binding of Ang II at receptors, causing vasodilation
-very selective so not many adverse effects
-treats heart failure and hypertension
-Losartan, Irbesartan
Action of B blockers, atenolol, propranolol, bisoprolol. Uses Which is best for asthmatics
-Beta-adrenoceptor antagonist. Reduces sympathetic activity by blocking adrenaline on B1/B2.
-atenolol and bisoprolol = cardio-selective, only acting on B1, causing reduced HR, CO, BP. Also Inhibits RAS. No B2 bronchoconstriction so fine for asthmatics.
-Used for 4th line in hypertension, tremors, rate control in AF, heart failure
-propranolol = non-selective, acting on B1 and B2 so not used in asthmatics. Mainly used for anxiety and stress related hypertension, migraine prophylaxis
Action of calcium channel blockers. Uses. Name drugs
Act on L-type voltage calcium channels.
-Reduces Peripheral resistance: slows Ca entry into smooth muscle cells, causing vasodilation.
-Reduced coronary resistance: Slow Ca reduces SA node firing so reduces rate and force of contraction of myocardium, decreasing HR, BP
-used for hypertension. Sometime arrhythmias. Not used in heart failure
-amlodipine, nifedipine, diltiazem, verapamil
Action of diuretics (thiazide-like and loop) Name drugs
-Inhibit ADH, decrease blood sodium, decreased fluid retention and blood volume, increase urine
-This lowers BP to treat hypertension (weaker, thiazide-like) = indapamide
-Removes oedema to treat heart failure (more powerful loop diuretics) = furosemide
Action of aldosterone antagonists. Use. Name drugs
-Inhibit aldosterone, which is involved in increasing Na and fluid retention. Therefore less fluid retention and reduced BP
-4th line for hypertension
-spironalactone, eplerenone
Action of alpha blockers. Use. Name drugs
-Blocks a1 adrenoreceptors, sympatholytic.
-causing vasodilation, reducing BP
-4th line for hypertension
- Doxazosin
For step 1, which hypertensives to give <55 years. Which to give if >55 of African/ carribean. Then which ones to add (step 2, 3, 4)
<55= ACEI or ARBs
>55 or black= Ca blocker or Diuretics
Step 2 = A+C, or A+ thiazide D
Step 3 = A+C+thiazide D
Step 4= add extra thiazide D, or B blocker
Propranolol use. Side effects
-Blocks B1 and B2 adrenoreceptors, causing blocking sympathetic activity on heart (and lungs)
-used for anxiety and stress related hypertension, migraine prophylaxis, tremors
-not used for heart failure
-side effects: bronchoconstriction, heart failure, bradyarrhythmias, fatigue, dry mouth, blunting of recognising hypoglycaemia in diabetes, lichenoid eruptions, increased tooth demineralisation
Uses of Ca channel blockers. Name dihydroyridine and non-dihydropyridines. Which vasodilator, which slow heart contraction.
-used for treating hypertension, sometimes arrhythmias. Not used in heart failure
- Dihydropyridine – peripheral vessel dilation, lowering BP
-Amlodipine and Nifedipine
2.Non – slows HR, slows contraction force
-Verapamil
Side effects of calcium channel blockers for hypertension, and in particular verapamil
In general: flushing (vasodilation), headache, oedema (increased capillary permeability), bradycardia, heart block
-verapamil: hypotension, heart failure, constipation
Side effects of thiazide-like diuretics for hypertension
- Gout flare
- Impaired glucose tolerance
- Increased LDL cholesterol
- Hypercalcemia
- Lichenoid reactions
- Steven Johns syndrome
- Thrombocytopenia
- Hyponatraemia (low Na)
- Pancreatitis
Adverse effects of ACE inhibitors for hypertension
- Renal failure, Hyperkalaemia
- Dry cough - due to increased tissue bradykinin levels
- Angioedema – increased bradykinin. Glossitis, anaphylaxis
- Urticaria - hives
- Burning mouth syndrome
- Fetal injury - congenital malformations so AVOID IN PREGNANCY
- Erythema multiforme
- Lichenoid reactions
Adverse effects of alpha blockers for hypertension
-Not first choice for hypertension as causes deterioration in heart failure (baroreceptor mediated increased heart rate), peripheral oedema, postural hypotension (so avoided in elderly)
Which combination of anti-hypertensives to avoid
Avoid combination Beta blockers and Diuretics – ↑ risk of developing new-onset diabetes
Name long-acting and short-acting nitrates for angina
-Short-acting: GTN spray
-Long-acting: Isosorbide, mononitrate, dinitrate
Action of nitrates. use
-Nitric oxide causes vasodilation by increasing cGMP, reducing BP and CO. Dilates coronary arteries so increases blood flow to heart. Redistribution of coronary blood flow to ischamic myocardium. Reduce oxygen demand.
-Used for stable angina
what is nitrate tolerance
nitrate tolerance: Decreased effect after repeated doses. May be due to depletion of sulfhydryl groups necessary to produce active intermediate metabolite of nitrates
What ion channels in the SA node affect SA node firing
calcium channels, IF channels, potassium channels, sodium channels
What type of drug is Nicorandil and what does it treat. Side effects
-It is a potassium channel activator (in SA node), with a nitrate component
-anti-anginal
-causes vasodilation
-adverse effects= dizzy, headache, flushing, oral ulceration, myalgia, angioedema
What drugs are used for heart failure and their general functions
-Inotropes = increase force of contraction
-Diuretics = increase urine out – try to remove oedema
-Beta blockers- stabilise heart beat
-ACE inhibitors, ARBS – block RAS, reduce BP