CV Medicine - 1 Flashcards
What are irreversble risk factors for cardiovascular disease?
age
sex
family history
Why do males have a larger risk of CVD?
females are protected by their sex hormones (estrogen)
the risk increases after menopause
What are reversible risk factors that patients can change?
smoking
obesity
diet
exercise
What are reversible risk factors that medicine can change?
- hypertension
- hyperlipidaemia (increased lipids in blood)
- diabetes
What is primary prevention and what does it include?
stopping a disease before it happens
* Exercise, diet & not smoking
* Assess total risk
* Medical treatment if high risk
What is secondary prevention and what does it include?
preventing further disease after a disease occurs i.e after a heart attack
all primary prevention
medicial treatment to reduce risk
What is the opportunistic approach to primary prevention that may be difficult?
- Family history
- Diet
- Smoking
- Test cholesterol
- Test blood pressure
- Test for diabetes (Type 2)
What are some CV diseases?
- Coronary artery disease (leads to MI)
- Heart failure
- Arrhythmias
- Congenital heart disease
- Valvular heart disease
- Peripheral arterial disease
- Aortic disease
- Deep vein thrombosis (DVT)
- Pulmonary embolism (PE)
- Stroke
What is the healthy cholestrol value?
<5.0mmol/L or 25%
What drug classes are used to prevent further CV disease?
- Anti platelet drugs
- Lipid lowering drugs
- Anti-arrhythmics
- Anticoagulants
- Diuretics
- Ace-inhibitors
What drug classes are used to reduce symptoms of current disease?
- Diuretics
- Anti-arrhythmics
- Nitrates
- Calcium channel blockers
- Ace-inhibitors
What are the main anti-platelet drugs?
How do they work?
Aspirin - alters balance between prostacyclin and thromboxane
Clopidogrel - inhibits ADP
Dipyridamole - inhibits phosphodiesterase
What is the platelet half-life in plasma?
7 days
What do anti-platelet cause to bleeding?
Prolong the bleeding time following dental extraction
- Not a significant problem individually
- Drug combinations increase the risk
How do anti-platelet drugs affect ‘at risk’ populations?
significantly reduce chance of heart attack/ stroke
When are the new anti-platelet drugs used?
- Only prescribed in conjunction with aspirin
- Only licenced for Acute Coronary Syndromes
When would oral anticoagulants cause a bleeding problem?
post-operation
How do oral anticoagulants work?
inhibit the clotting casade reducing fibrin formed
therefore clot will not stabilse as less fibrin is present
What phenolic substance is the base of warfarin?
coumarin
How does warfarin work?
Inhibits synthesis of Vitamin K dependent clotting factors
What clotting factors does warfarin inhibit sythesis of and what is the time period?
2, 7, 9, 10 (slow - 2 days)
protein c, protein s (quick)
What happens intially with warfarin?
Initial Hypercoagulation
* Anticoagulation takes 2-3 days
What is often used concurrently initially?
heparin
When does the effect of warfarin wear off after drug is used?
2-3 days
Why must warfarin be monitored?
Drug and food interaction with
* Plasma protein binding
* Liver metabolism
How is warfarin monitored?
with INR test
aim for 2-4
What is INR?
International Normalised Ratio
which is a Standardised prothrobin time (PT)
If out of INR range what could happen?
refer for medical advice
too high = risk of bleeding
too low = risk of clots, reduced protection
What are haemostatic measures used?
Absorbent gauze
Haemostatic packing material (e.g. oxidized cellulose, collagen sponge)
Suture kit (needle holders, tissue forceps, suture material, scissors)
LA with vasoconstrictor
What should you avoiding prescribing alongside warfarin?
NSAID analgesics
What are the new oral anticoagulants predictable in?
bioavalibility
What factor do most new oral anticoagulants inhibit?
factor 10
What factor does dabigatran inhibit?
thrombin
What is the duration of NOAC (new oral anticoagulants)?
short half life - effect rapidly lost
Why is no anticoagulant test used with NOAC?
bioavilability predictable (warfin interacts with food therefore bioavalibity is unpredicatable)
What are statins?
lipid lowering drugs - reduce cholosterol synthesis in the liver
What drugs are HMG coA Reductase inhibitors?
-statin ending drugs
What do statins reduce?
Reduce total cholesterol and LDL-cholesterol
What are the side effects of statins?
if plasma drug levels becomes high/ interacts, this can cause inflammation in the muscle (myositis)
What drug do statins interact with that has a significance in dentistry?
fluconazole
What are beta-adrenergic blockers (beta-blockers)?
drugs that stop arrhythmias leading to cardiac arrest (Ventricular fibrillation – VF)
* Reduces heart muscle excitability
Why is asthma relevant to beta blockers?
Salbutamol is used to relieve symptoms of asthma by relaxing muscles of airways
it works on beta-2 receptors
however if patient takes non selective beta-blocker, salbutamol is not effective as it cannot work on receptors
What do b-blockers cause that can be dangerous?
- Cause postural hypotension (decreased circulation)
- Reduce heart efficiency, make heart failure worse
- Block beta receptors in the lungs
What are diuretics used for?
antihypertensive
heart failure
What are the two types of diuretics?
thiazide
loop
What do diuretics do systemically?
Increase salt and water LOSS
* Reduce plasma volume
* Reduce cardiac workload
What are the side effects of diuretics?
- Can lead to Na+/K+ imbalance if not monitored carefully
- Can lead to dry mouth in the elderly
What is an example of a short acting nitrate?
GTN
Why is GTN administered sub-lingually/dermal patches?
extensively metabolised (inactivated) on first pass metabolised through liver
When are short acting nitrates used?
Emergency management of angina pectoris
What are long acting nitrates used?
Prevention of angina pectoris
What is an example of a long-acting nitrate (transdermal patch)?
isosorbide mononitrate
How are nitrates inactivated?
Inactivated by first pass metabolism–administer
by
Sublingual
Transdermal
Intravenous
What do nitrates do systemically?
- Vasodilation: This is the primary action. Nitrates work by relaxing smooth muscle cells in blood vessels, causing them to widen (dilate). This widens blood vessels throughout the body, particularly those supplying the heart (coronary arteries).
- Reduced Blood Pressure:
- Improved blood flow to the heart:
- Reduced workload on the heart:
What oral disease can calcium channel blockers lead to?
Can lead to gingival hyperplasia in some
- Oral hygiene dependent – need to keep good OH
What do calcium channel blockers do systemically and what are they used for?
Block Calcium channels in smooth muscle causing slow conduction of pacing impulses
* Relaxation and vasodilation
Used to treat hypertension and migranes
What do ACE inhibitors do?
- Inhibit conversion of angiotensin I to angiotensin II
- Prevents aldosterone dependent reabsorption of salt and water.
What do ACE inhibiotrs do systemically?
- Reduce blood pressure
- Reduce excess salt and water retention
What are the side effects of ACE inhibitors?
cough (inhibit other enzymes causing irritation)
hypotension
What do angiotensin 2 blockers do?
Directly block
Inhibit same system but by a different mechanism
do not cause ACE side effects
What drug is most likely to be given to someone having an acute myocardial infarction FIRST?
aspirin
How does aspirin work?
Aspirin works by irreversibly inhibiting an enzyme called COX-1 in platelets.
COX-1 helps make chemicals that promote clotting.
By blocking COX-1, aspirin reduces platelet clumping, helping to prevent further blood clot formation in heart attacks and reduce inflammation. This can limit damage to the heart muscle.
