Cardiovascular disease Flashcards
What innervates parasympathetic and sympathetic nerves?
Vagus nerve
Circulating catecholamines
What causes systolic failure?
Coronary heart disease - which is ineffective ejection of blood
What causes diastolic failure?
- Fibrosis or hypertrophy of ventricles
- Hypertension
- Pericarditis
What are the signs / symptoms of heart failure?
Dyspnea - difficulty breathing
Fatigue
Exercise intolerance
Peripheral oedema - RHS failure
Pulmonary oedema - LHS failure
What are the causes of heart failure? (5)
- Coronary artery disease and myocardial infarction
- Hypertension
- Faulty heart valves
- Dilated cardiomyopathy (heart muscle)
- Arrhythmia
How does coronary artery disease and MI lead to heart failure?
- Atherosclerotic plaque build up in coronary arteries
- Occlusion of arteries
- Increases BP
- Increases risk of plaque rupturing
How does hypertension cause heart failure?
- Heart pumping harder to circulate blood
- Extra exertion leads to fibrosis or or hypertrophy of myocardium
How can valves become faulty and cause heart failure?
- Congenital defect / rheumatic fever / stenosis
- E.g. aortic valve stenosis - left ventricle works harder to force blood through narrow valve, leads to left ventricular hypertrophy
What can lead to dilated cardiomyopathy (heart muscle)?
Genetics
Infection
Alcoholism
Cocaine
How can arrhythmia lead to heart failure?
- HR increase
- Not enough time for heart to fill with blood
- Can lead to sudden death
What are the TX for heart failure? (3)
- Lifestyle changes
- Pharmacological agents
- Surgery
Which lifestyle changes can treat heart failure?
- Exercise
- Limit alcohol
- Stop smoking
- Immunisations (against influenza, pneumonia etc)
What pharmacological agents can treat heart failure?
- Diuretics (aid kidneys to remove XS salt and water, making it easier for the heart to pump)
- ACE (angiotensin converting enzymes) inhibitors (dilate blood vessels)
- Beta-blockers (slow down HR)
- Digoxin (increases force of heart contractions)
Which surgeries can treat heart failure?
- Coronary artery bypass graft CABG - treats atherosclerosis, restores normal blood flow to heart
- Heart valve repairs / replacements
- Implantable cardiac defibrillator ICD - continually monitors heart rhythm
What should you consider when giving oral healthcare to pt with heart failure? (4)
- Meds e.g. anti-platelets / anti-coagulants, bleeding risk
- Ability to lay flat in chair - possible pulmonary oedema
- Medical care may be prioritised over oral care
- Infective endocarditis risk for valve replacement pts
What is IE? What causes it?
- Infection of hearts lining
- Involves heart valves
- Caused by bacteria entering blood from outside the body
What increases risk of IE / bacteria entering blood stream?
- Invasive dental procedure e.g. XLA
- Poor OH
What is the guidance on antibiotic prophylaxis and IE?
- Dental procedures are no longer main cause of IE
- Unclear if antibiotic prophylaxis prevents IE
- Antibiotics give side effects e.g. allergies, nausea, diarrhoea, antibiotic resistance
- No longer given prior to invasive dental procedures
What is peripheral arterial disease related to?
Atherosclerosis
What common areas of the body are affected by peripheral arterial disease?
- Legs primarily
- Ulcers on feet / gangrene
What are the impacts / effects of peripheral arterial disease? (3)
Intermittent claudication i.e. tightness
- Calf / thigh muscle pain with exercise
- Relieves with rest
Pain at rest
- Spontaneously
- Worsens with time
Critical ischaemia
- Pain and sensory loss
- Blue and cold limbs
- Ulceration
- Wet / dry gangrene
What is an aneurysm?
Localised, blood-filled dilation of a blood vessel caused by a disease or weakened vessel wall
What is an Abdominal Aortic Aneurysm?
- Aorta up to 10cm + in diameter
- Often asymptomatic until they dissect
- Dissection is life threatening, causes death by massive blood loss, few people reach hospital in time
What is carotid artery stenosis?
What is it a risk factor for?
- Atherosclerosis of carotid artery
- Can involve both carotids
- RF for stroke and TIA (transient ischaemic attack)
What are the management options for carotid artery stenosis? (2)
- Lifestyle changes e.g. stop smoking, reduce BP, exercise, diet
- Revascularise arteries by carotid endarterectomy +/- vascular graft
What is coronary artery disease and what does it lead to?
- Ischaemia to myocardium
- Due to atherosclerosis
- Leads to angina and MI
What are the risk factors for coronary artery disease?
Dyslipidaemia - high LDL and low HDL (should be other way)
High BP (systolic >140)
Smoking
Diabetes
What happens in stable angina when active?
Insufficient blood flow to myocardium
O2 demands not met
Causes pain, breathlessness, dizziness and sweating
Pain radiates to central chest, left arm / neck / mandible
Predictable
Relieved by short acting nitrate e.g. GTN
What are short acting nitrates, how do they work? Give example
- Relax vascular muscles
- Dilate coronary arteries
- Improve o2 supply to myocardium
- Glyceryl trinitrate
What is beta-blocker, how does it work? Give example
- Block effects of adrenaline / epinephrine
- Cause HR to decrease, lowers BP
- Help widen vessels
- Drugs ending in -olol
How does unstable angina differ pathologically to stable angina?
- There are cracks in luminal surfaces of plaques, these fissures are thrombogenic (can cause thrombi AKA clots to form)
How can unstable angina lead to MI?
• Thrombus forms around fissure, occluding vessel more
• Further angina symptoms
• Emboli shed from fissured plaque and can further impact narrowed vessel
• If emboli block significant portion of end vessel then no oxygenation of tissue = MI
What is a MI?
Critically reduced blood flow to myocardium
No oxygenation
Leads to death of tissue
How can you diagnose an MI? (2)
- ECG - ST elevation
- Cardiac enzyme levels - Troponin
How to manage MI? (4)
Analgesia - morphine
Anti-platelet - aspirin
Anti-coagulant - low molecular weight heparin e.g. Enoxaparin
Thrombolysis - streptokinase
What considerations should be made for pt with arterial disease when treating them?
What considerations should be made for pt with arterial disease when treating them? Triggers?
Possible triggers for stable angina - Stress / anxiety / pain
How long should you wait post MI? And why?
- 6 months
- Potential for arrhythmia
- Arrhythmia can be induced by vasoconstrictors in LA
What is a normal systolic BP? and diastolic BP?
Less than 120 mmHg
Less than 80 mmHg
What are the 4 determinants of normal BP?
Cardiac output
Total peripheral resistance
Circulating volume
Blood viscosity
What receptors and where can detect blood flow and signal to autonomic NS?
Arterial baroreceptors in aortic arch and carotid artery
What effect does the autonomic NS have on CO? What are its 2 branches?
Increase CO
Sympathetic branch can increase BP (by increasing TPR, SV and HR via SAN)
Parasympathetic branch can decrease BP (by decreasing TPR, SV and HR via SAN)
How do arterial baroreceptors respond to BP changes?
- Hypertension - can increase BP if low
- Hypotension - can decrease BP if high
How is BP regulated long term? (4)
- Low pressure baroreceptors
- Renin-angiotensin system RAS
- Aldosterone from adrenal cortex
- Anti-diuretic hormone ADH from posterior pituitary gland
What are risk factors for hypertension? (6)
- Diet - high fat / salt intake
- Age - TPR increases and vessel elasticity decreases with age
- Ethnicity - Afro-caribbeans and South asians
- FH - genetic predisposition
- Obesity
- Pharmacological - alcohol / cocaine / chronic use of NSAIDs / corticosteroids
- Stress
Which RFs are non modifiable?
Age
Ethnicity
Genetics / FH
What are the pharmacological treatments for hypertension? (3)
- ACE inhibitors (angiotensin converting enzyme)
- Calcium channel blocker
- Diuretics
Example of ACE inhibitor? (-suffix)
Benazepril
-pril
Example of Calcium channel blocker? -suffix?
Amlodopine
-dipine
What are the potential complications from hypertension tx? (4)
- Cardiac - angina / MI / heart failure / arrhythmia
- Renal - impairment / failure
- Cerebral - TIA / stroke
- Retinal - impairment / blindness
What is atrial fibrillation the leading cause of?
Stroke
Which type of drugs can prevent further complications from atrial fibrillation?
Therapeutics:
- NOACs (novel oral anticoagulants) e.g. Apixaban, Rivaroxaban, Dabigastran
- Warfarin - older its still on, NOACs / DOACs safer
What are NOACs?
Novel oral anticoagulant drugs
Work by preventing formation of thrombus (blood clotting) - inhibit factor Xa
Safer than Warfarin
What are examples of long term anti-arrhythmic meds?
Beta blockers - e.g. Bisprolol / Metoprolol
-olol
Amidarone
Which medications are pts who have recurrent episodes of atrial fibrillation on?
Flecanide
Propafenone
Which procedure can re-establish sinus rhythm?
Cardioversion - low energy shocks
80% success rate
What should you be aware of when delivering oral healthcare to pt with AF?
- How AF currently managed
- Which anticoagulant pt on
