Cardiovascular conditions Flashcards
What diseases fall under acute coronary syndrome (ACS)
- Unstable angina (not stable angina)
- ST-elevation myocardial infarction (STEMI)
- Non-ST-elevation myocardial infarction (NSTEMI)
What causes acute coronary syndromes
Supply/demand mismatch of oxygen to the myocardium
-Blockage of blood flow (narrowing or occlusion of a coronary artery)
-Increased demand (e.g. arrythmia, during acute illness)
What are the symptoms of ACS
Central, crushing chest pain ***
Pain radiating to the jaw or arms
Nausea and vomiting
Sweating and clamminess
A feeling of impending doom
Shortness of breath
Palpitations
What is the name of the substance that builds up on vessel walls
Atherosclerotic plaque
What does embolise mean
Plaque breaks off (or blood clot forms) and travels down the vessel
What is unstable angina
Partial occlusion of coronary artery
Ischaemia
No infarction
What is NSTEMI
Partial occlusion
Ischaemia
Infarction
What occurs with STEMI
Total occlusion
Infarction
What complications does ACS pose
Death (cardiac arrest) – Basic Life Support!
Arrythmia
Heart failure
Rupture of heart wall
New valvular disease (papillary muscle infarction)
What tests are used to diagnose ACS
ECG
Troponin (blood test)
-high troponin levels are bad as it is released when the heart muscle infarcts (dies)
How is ACS (heart failure) managed
Minimise tissue loss from infarction
Re-establish blood flow (reperfusion)
-break up and remove clot/dissolve
Prevent further episodes
-lifestyle management/medication
What is the procedure if a patient have acute onset of chest pain in the dental practice
At this point we do not know if stable angina, unstable angina, NSTEMI or STEMI
PHONE AN AMBULANCE AND GET TO HOSPITAL
100% oxygen via non-rebreather mask
Glyceryl trinitrate spray (GTN), 2 puffs, sublingual
-Repeated after 3 minutes if no improvement
Aspirin 300mg oral tablet
-Chewed
Why is oxygen given to patients with ACS
increase oxygen delivery to the ischemic myocardium and thereby limit infarct size
What is GTN
Glyceryl trinitrate spray
Why is GTN given to patients with chest pain
Vasodilator
Release of nitrous oxide (NO) in vascular smooth muscle
Dilates veins – reduces preload on heart (less hard work)
Dilates arteries – increases blood flow through coronary arteries
What role does aspirin do in releiving chest pain and reducing infarction risk
Prevents thrombus enlarging
Reduces platelet aggregation at clot
“inhibits COX enzyme, to reduce production of thromboxane A2, thereby reducing platelet aggregation”
What is reperfusion/types
Break-up/remove clot by a procedure
-Percutaneous coronary intervention (PCI)
-Access via coronary artery from peripheral artery
-Break-up clot
-Widen the artery (angioplasty)
-Place stent to maintain width
-Within 120 minutes of onset**
Dissolve blood clot
-“Thrombolysis”
-Clot-busting drug (alteplase), given IV
What ,medication can be prescribed to prevent ACS
Aspirin (75mg)
Another antiplatelet (e.g. clopidogrel for 12 months)
Atorvastatin (lipid lowering)
ACE-inhibitor (blood pressure)
Atenolol (or another beta blocker like bisoprolol)
Why is adrenaline risky for patients with ACS
Supply/demand mismatch of oxygen to the myocardium
Blockage of blood flow (narrowing or occlusion of a coronary artery)
Increased demand (e.g. arrythmia, during acute illness)
What is PAD
Peripheral arterial disease
What does PAD refer to
PAD refers to narrowing of arteries suppling limbs
Commonly legs
What do PAD and ACS have in common
Pathophysiology and risk factors
What are the symptoms of PAD
Leg, thigh, buttock, calf cramping pain particularly when walking (intermittent claudication)
Non-healing ulcers on toes, foot, leg
One leg cooler than the other
One leg paler than the other
Hair loss on leg
Necrosis of skin on digits
How is PAD diagnosed
CT angiography of limb
What surgical procedures can be carried out for PAD
Angioplasty and stent
Endartectomy
Bypass surgery
Amputation
What dental implications may arise for patients with PAD
Shared risk factor with periodontal disease
Smoking
Antiplatelet medication
Bleeding risk
Cardiovascular health
Risk of ACS increased
What is the difference between ACS and PAD
ACS is reduction/absence of blood supply to myocardium
PAD is reduction/absence of blood supply to leg tissue
What causes cardiovascular diseases
Impairment of any of:
heart
arteries
veins
capillaries
Movement of blood through the heart
In via superior vena cava
right atrium
tricuspid valve
right ventricle
pulmonary valve
pulmonary artery
lungs
pulmonary vein
left atrium
mitral
left ventricle
aortic valve
Out via aorta
What is atherosclerosis
Refers to the deposition of fatty deposits in the artery walls
Creates “stiffening” of the arteries
Narrowing results in “stenosis”
What can atherosclerosis cause
Myocardial infarction
Angina
Stroke / TIA
Peripheral arterial disease
Mesenteric ischaemia
What are the risk factors for cardiovascular diseases
Older age
Male
Family history
Ethnicity
Hypertension
Obesity
Diabetes
Lipids
Smoking
Alcohol
Stress
Poor sleep
How does plaque form in vessel walls
Damage to vessel wall (e.g. hypertension and smoking)
High lipid content of blood (LDL cholesterol)
High circulating glucose (diabetes)
Immune cells
Why is Atorvastatin prescribed to patients with cardiovascular disease or at risk of infarction
It lowers the lipid content (cholesterol) within the blood to reduce plaque build up
What is hypertension
High blood pressure
When is hypertension diagnosed
With a Bp >140/90
What complications can arise from existing hypertension
Atherosclerosis
Chronic kidney disease
Heart failure
Stroke
Retinopathy
Vascular dementia
What non-modifiable risk factors exist for hypertension
Age
Gender
Ethnicity (black African, black Caribbean)
Genetic factors (family history)
Family history
What medications treat hypertension
ACE-inhibitors
Angiotensin-II-receptor blockers
Beta blockers
Calcium channel blockers
Diuretics
What does angina refer to
collection of symptoms due to myocardial ischaemia
What is the difference between stable and unstable angina
Stable angina – only experienced during exertion
Unstable angina – experienced at rest (see Acute CVS Disease lecture)
How is coronary artery disease managed
Lifestyle modifications
-E.g. weight loss, healthy diet, stop smoking, reduce alcohol…
Immediate symptom management
-GTN (glyceryl trinitrate) spray
Long term secondary prevention
-Covered more in Medications lecture
-Manage hypertension, lipids, aspirin
Interventional management
-Widen the narrowed bit of artery
-Bypass narrowed bit of artery
What is PCI
Percutaneous coronary intervention
-Inserting a ballon to widen diseased coronary arteries
-Inserting a stent to maintain the arteries
-Via the radial or femoral artery
What is a CABG
Coronary artery bypass graft
What does a CABG surgery involve
Blood flow through damaged coronary artery is by-passed
Harvest a vessel from elsewhere in body (commonly leg)
What is heart failure
where the heart fails to work effectively in its role of pumping blood
What does right or left sided heart failure heart failure indicate
right sided-heart cant pump from right ventricle
Left sided-heart cant pump blood from right ventricle
What are some common causes of heart failure
Hypertension
Coronary artery disease (e.g. previous MI)
Valvular heart disease
Arrythmias
Congenital heart defects
What is the result of left or right sided heart failure
Left-sided heart failure means congestion of blood from the heart into the pulmonary vein and backing up into the lungs
**Results in fluid in the lungs (pulmonary oedema)
Right-sided heart failure means congestion of blood from the heart into the vena cava and backing up into the systemic circulation
**Results in fluid in the abdomen and legs (peripheral oedema)
What is orthopnea
Shortness of breath when lying flat
What are the symptoms of heart failure
Shortness of breath (SoB)
Cough (frothy sputum)
Orthopnoea – SoB when lying flat
Paroxysmal nocturnal dyspnoea – suddenly waking at night with SoB
Peripheral oedema – fluid in the legs, abdomen, sacrum
Fatigu
What are arrythmias
Abnormal heart rhythmns
Due to interrupted electrical signals that coordinate heart muscle contraction
What is atrial fibrillation
Disorganised electrical activity in the atria, resulting in fibrillation (random muscle twitching) and an irregular pulse
What is the major health risk with atrial fibrillation
Blood clots
Due to the uncoordinated heart muscle activity, blood flow is not smooth through the heart. This makes blood more likely to clot.
Blood clot can travel to brain – 5x higher risk of stroke in AF
Name an arrythmia
Atrial fibrillation
What devices can be placed into the body to manage arrythmias
Pace makers
What are the 4 heart valves
Aortic
Pulmonary
Tricuspid
Mitral
Why is it important to be aware if the patient has a pacemake
Can interact with bipolar diathermy (used in oral surgery)
What are some diseases of the valves
Stenosis – means valve is stiff and does not fully open
Regurgitation – means the valve does not fully close, and is leaky
What can cause valvular disease
Aging (aortic stenosis)
Congenital (bicuspid aortic valve)
Damage following myocardial infarction
Rheumatic heart disease
Infective endocarditis
What is a bicuspid aortic valve
3 leaflets instead of 2 – can be stenotic or leaky
Congenital (from birth)
Spectrum of severity
Management with medications and/or surgery
What is the most common valvular pathology
Aortic stenosis
How does aortic stenosis occur and how is it managed
Due to age - narrowing of aortic valve
managed through valve replacement
When does valve disease often occur
Following myocardial infarction
-infarction of valves leads to disfunction (most commonly mitral valve)
How can rheumatic heart disease cause valve disease
Damage to heart valves by body’s immune system, following streptococcal throat infection
Group A streptococcus infects throat - untreated
Bacteria cell wall has M protein antigen
Immune system produces antibodies against M protein
However, cardiac valves have proteins which resemble M protein
Immune system attacks heart valves
Fibrosis and vegetation forms on valves
Valves become leaky or stenotic
Valve replacement required
What conditions lead to valve replaced
Severe aortic stenosis
Rheumatic heart disease
Papillary muscle rupture
Congenital valvular disease
What are the types of valve replacements and the adv and disadv
Bioprosthetic
-Less likely to have a blood clot, no need for anticoagulation
-Reduced lifespan
-Commonly derived from pig tissue
Metallic
-Longer lifespan
-Higher risk of blood clot, need anticoagulation with warfarin
What is infective endocarditis
Infection of the lining of the heart (endocardium), particularly heart valves
Why is there a risk of infective endocarditis developing due to dental procedures
Invasive dental procedures introduce bacteria to bloodstream
In predisposed patients, this can result in bacteria colonising and infecting the endocardium
Antibiotic prophylaxis (before a procedure) is recommended in some patients
Bacteria – most commonly Staphylococcus aureus.
How does infective endocarditis develop
Altered heart valve morphology (to provide suitable site for bacterial colonisation)
Bacteria into the bloodstream (e.g. from dental procedure, IV drug use… )
Bacteria circulates in blood and deposits on valve
Formation of vegetation on valve leaflets
What does infective endocarditis cause
Impaired heart valve function – heart failure
Focus of infection - sepsis
Source of emboli – stroke
How is infective endocarditis managed
4-6 weeks of IV antibiotics
Surgery may be required
What patients are predisposed to infective endocarditis
Patients:
-With a heart valve replacement
-Have previously had infective endocarditis
-Born with a congenital heart defect
-Who currently have valvular heart disease
What is the procedure when opperating on patients at risk of infective endocarditis
Give antibiotic 60 mins prior to procedure (amoxicillin powder sachet/clindamycin capsules, penicillin alergy)
Why is prevention of dental diseases so important in patients with infective endocarditis
Reduce risks involved with dental procedures
What dental implications does chronic CVS disease have
Medications
-Anticoagulants in AF and metallic valve replacement
-Polypharmacy – dry mouth
-Lichenoid tissue reactions to anti-hypertensive medications
Appointments
-Stress-inducing – angina (medical emergency)
-Heart failure – lying patients back (orthopnea)
Infective endocarditis
-High risk patients / high risk procedures
-Dental pre-assessment of patients before cardiac surgery***
What drugs are anti-hypertensives
ACE-inhibitors
Angiotensin-II-receptor blockers
Beta blockers
Calcium channel blockers
Diuretics
What are the types of anti-platelets
Aspirin
Clopidogrel
Ticagrelor
Dipyramidole
What are anti-anginals
Nitrates
Nicorandil
What are lipid lowering medications classed as
Statins
What is the equation of blood pressure
Cardiac output x total peripheral resistance
What increases total peripheral resistance
Vasocontriction of peripheral blood vessels
How is cardiac output, stroke volume and TPH calculated
(Cardiac output = heart rate x stroke volume)
(Stroke volume = volume of blood being pumped by left ventricle)
(Total Peripheral Resistance = how much vasoconstriction vs. vasodilation is present in peripheral circulation)
How is blood pressure reduced
by lowering any of:
Heart rate
Stroke volume
Total peripheral resistance
Which areas of the body will anti-hypertensives target
Heart (reduce heart rate or contractility)
Blood vessels (vasodilation)
Kidneys (reduce how much fluid is being reabsorbed into circulation)
What do anti-hypertensive drugs do
Reduce blood pressure
What are some ACE-inhibitors
Ramipril, lisinopril, perindopril
Why are ACE-inhibitors classed as anti-hypertensives
ACE-inhibitors stop the formation of angiotensin-II (by inhibiting Angiotensin Converting Enzyme)(RAAS)
This means that less aldosterone is produced, resulting in less fluid reabsorption in kidneys
Thereby reducing blood pressure
How do ACE-inhibitors affect the oral cavity
Dry mouth
Lichenoid tissue reaction
How do ARB’s reduce blood pressure
ARBs bind to angiotensin-II receptors on:
Smooth muscle of blood vessels (prevent vasoconstriction)
Cortical cells of adrenal gland (prevent aldosterone production)
Thereby reducing blood pressure
Name some ARBs
Candesartan, losartan, valsartan
What receptors are found on the heart, lungs and blood vessels (smooth muscle)
Blood vessels - alpha 1
Heart - beta 1
Lungs - beta 2
What medications are classed as beta blockers
Atenolol, bisoprolol, propranolol, carvedilol
What action do beta blockers prevent
Increases in heart rate and contractility
How do beta blokers reduce hypertension
Competitively inhibit beta 1 receptors on cardiac muscle cells
Prevent stimulation by adrenaline which would increase heart rate
Why should beta blockers be avoided in patients with asthma
Broncho-constriction
How do calcium channel blockers affect the cardiovascular system
- Inhibit calcium channels on smooth muscle around peripheral blood vessels – thereby reducing vasoconstriction, reducing TPR
- Inhibit calcium channels at sino-atrial node (pacemaker of the heart) – thereby reducing heart rate
- Inhibit calcium channels on cardiac muscle cells – thereby reducing heart contractility
Name 3 calcium channel blockers
Amlodipine, nifedipine, felodipine
What drugs can cause gingival enlargement
Nifedipine (calcium channel blocker)
Ciclosporin (immunosuppressant)
Phenytoin (anti-convulsant)
What drugs are types of diuretics
Furosemide, bendroflumethiazide, bumetanide
How do diuretics work to reduce blood pressure
Work at different parts of the nephron to decrease fluid reabsorption
Increased urination = reduced circulating fluid
Reduced blood pressure
What anti-hypertensive drugs cause dry mouth
Diuretics
ACE-inhibitors
Why might a patient be presribed anti-platelet drugs
Coronary artery disease
Secondary prevention following MI
Peripheral artery disease
Secondary prevention following stroke/TIA
Name 4 anti-platlet drugs
Aspirin*
Clopidogrel
Ticagrelor
Dipyramidole
How does aspirin work
- inhibits COX-1 enzyme, to reduce production of thromboxane A2, thereby reducing platelet aggregation
What dose of aspirin is used for acute MI/stroke
300mg
What are the dental implications of anti-platelets
Patient likely to have prolonged bleeding times
Patients on DAPT (two anti-platelets) likely to have higher bleeding risk than single drug
Often only for 12 months – can treatment be delayed?
No need to stop anti-platelet for dental treatment
Risk / benefit
What drugs are classed as anti-coagulants
DOACs – used in atrial fibrillation (stroke prevention)
-Edoxaban, rivaroaxaban, apixaban
-Dabigatran
Warfarin – metallic valve replacement
Why is it possible to remain taking DOACs while undergoing dental procedures such as extractions
Rapid onset of action and short half lives
What is the recomendation for operating on patients taking warfarin
Do not delay or miss dose
-Long half-life and onset of action
INR checked ideally < 24 hours before dental treatment
-If stable readings, 72 hours is acceptable
If INR < 4 – can proceed with dental treatment
What are the types of cholesterol
LDL and HDL cholesterol
Low-density lipoprotein (“bad”)
High-density lipoprotein (“good”)
Why is LDL cholesterol worse
High levels of LDL contribute to atherosclerotic process
What is the main lipid-lowering medication
Statins
What are the names of some statins
Atorvastatin, simvastatin, rosuvastatin
How do statins work
Works by inhibiting enzyme in liver (HMG-CoA reductase), which halts production of LDL cholesterol
What dental implications do statins present
Interaction with fluconazole, miconazole and clarithromycin to cause rhabdomyolysis (breakdown of skeletal muscle)
How do nitrates reduce affects of angina
Nitrates relax smooth muscle within coronary vessels, thereby causing vasodilation and improving blood flow
Also, dilate veins returning to heart, to reduce preload and therefore reduce the work being done by heart
What types of nitrates do patients with angina take
GTN spray (glycerlyltrinitrate) - taken for acute relief
Isosorbide mononitrate (ISMN) - taken daily for prevention
What is Nicorandil used for
Treatment of angina
What are the dangers of taking nicorandil
Can cause severe oral ulceration (up to 5%)
Heals on withdrawal of medication
Lead by medical team!
What is given to patients suffering from side effects of nicorandil
Symptomatic relief
Benzydamine mouthwash
