Ischaemic Heart Disease Flashcards
What is another name for Ischaemic Heart Disease?
Coronary heart disease (CHD) or
Coronary artery disease
What is Ischaemic Heart disease?
Heart’s blood supply is blocked or interrupted due to atherosclerosis in the coronary arteries
What are the main symptoms of ischaemic heart disease?
Angina
SOB
Pain in neck, shoulders, jaw or arms
Feeling faint
Nausea
What is stable angina (3 parts)?
1) Central crushing chest pain radiating to neck and jaw
2) Brought on with exertion
3) Relieved with 5 mins rest or GTN spray
What does stable angina progress to?
Unstable angina
Then NSTEMI (partial infarction)
then STEMI (transmural infarction)
What is unstable angina (3 parts)?
1) Central crushing chest pain radiating to neck or jaw
2) Pain at rest
3) Pain not relieved with inactivity or GTN spray
What is Prinzmetal’s?
Type of angina due to coronary vasospasm rather than atherogenesis in coronary arteries.
Which group of people is Prinzmetal’s angina seen in?
Cocaine users particularly
What is an ECG finding in Prinzmetal’s angina?
ST elevation
What would it mean for an angina to be decubitus?
Induced by lying flat
How is a venous thrombosis diagnosed?
D-dimer (sensitive but not specific, is a fibrin degradation product and may be elevated due to infection, malignancy or trauma)
Imaging like duplex ultrasonography or Venous Doppler ultrasound
May take PT, aPTT and TT
What does an atherosclerotic plaque consist of?
Lipid
Necrotic core
Connective tissue
Fibrous cap
What are some risk factors for IHD?
Age
Smoking
Male
Family history
DMT2
Cocaine use
Hyperlipidaemia
Hypertension
Kidney disease
Obesity
Physical inactivity
Stress
Name some environmental factors which exacerbate IHD
Cold weather
Heavy meals
Emotional stress
Name some types of angina
Prinzmetal’s angina
Microvascular angina
Crescendo angina
Unstable angina
For describing pain, what does OPQRST stand for?
Onset
Position (site)
Quality (nature/character)
Relationship (with exertion, posture, meals, breathing and with other symptoms),
Radiation
Relieving or aggravating factors
Severity
Timing
Treatment
Name a calcium channel blocker
Amlodipine
Beta blockers reduce heart rate, ___ ventricular c_____, CO and oxygen demand
left ventricular contractility
Side effects of beta blockers
Tiredness, nightmares, bradycardia, erectile dysfunction, cold hands and feet
When would you not prescribe a beta-blocker?
Patients with asthma
How do nitrates help?
Venodilators meaning reduced venous return and reduced preload and afterload
How does aspirin help?
COX inhibitor, decreased prostaglandin synthesis including thromboxane, decreased platelet aggregation, antipyretic, anti-inflammatory, analgesic
What is a complication of aspirin
Gastric ulceration
Statins inhibit which enzyme?
HMG CoA Reducatase
What is PCI?
Percutaneous coronary intervention
same as coronary angioplasty
same as stenting
Why is Fondaparinux used instead of heparin?
Fandoparinux specifically inhibits factor Xa while heparin binds to antithrombin III to enhance its inhibition of thrombin and Xa.
Longer half life so administered once daily so more convenient. heparin needs frequent dose adjustments.
Lower risk of heparin-induced thrombocytopenia (low platelets) and osteoporosis.
(However, Fondaparinux cannot easily be reversed in bleeding emergencies and contraindicated in severe renal impairment.)
Is heparin used for treating an arterial thrombus?
Not typically, often arterial thrombi are rich in platelets and fibrin. Heparin works by promoting activity of antithrombin III which inhibits thrombin and factor Xa, primarily affecting thrombi in veins.
Increases risk of bleeding.
Slower onset of action.
What is used to treat an arterial thrombus?
May be antiplatelet agent like aspirin or P2Y12 inhibitor and anticoagulants.
Thrombolytic therapy like tissue plasminogen activator
Surgical thrombectomy
What are the 3 components of Virchow’s triad?
Blood stasis
Hypercoagulability
Endothelial injury
What factors might cause blood stasis and increase chance of a venous thrombosis?
Immobilisation:
Surgery
Long haul flight
Trauma
What is used to treat venous thrombosis?
Heparin or LMWH
Warfarin
DOAC
Surgery
When would the treatment of DVT be more aggressive?
History of DVT or PE
Cancer
Thrombophilia
Severe obesity
Immobilisation
Heart failure
Chronic kidney disease
Heparin is a g_______ which binds to and promotes antithrombin which inhibitors factors _, _ and _
glycosaminoglycan
2 (thrombin), 9 and 10
What is used to monitor heparin?
aPTT (intrinsic pathway involves all factors that are inhibited by antithrombin which heparin promotes)
True or false, heparin is given by continuous infusion
True
How is LMWH given?
Once daily, weight-adjusted dose given subcutaneously
Is Heparin Induced Thrombocytopenia more common after LMWH or UFH?
UFH although can occur rarely in either.
How does warfarin work?
Antagonist of vitamin K. Vitamin K is needed for synthesis of factors 2, 7, 9 and 10 and also protein C and S. Therefore interferes with clotting cascade so acts as anti-coagulant
How is warfarin monitored?
PT (prothrombin time)
Extrinsic pathway involves 7 - blocked by warfarin as requires vitamin K to be made
Which factors do DOACs act on?
Factor II (thrombin) and X
True or false: DOACs require blood tests and monitoring
False
Can DOACs be used in pregnancy?
No
Why are DOACs not used in metal heart valves?
Mechanical valves create turbulent blood flow and increase risk of thrombus formation. Vitamin K more traditional choice as inhibits more coagulation factors.
Also DOACs aren’t reversible in case of bleeding or emergency surgery.
How is aspirin an anti-platelet?
Inhibits cyclo-oxygenase irreversibly
Inhibits thromboxane formation so platelets don’t adhere to each other so lack of platelet aggregation and platelet plug formation.
How does Clopidogrel work?
Prevent ADP (released by platelet bound to VWF) binding to P2Y12 receptors on platelets inhibiting further signalling for platelet aggregation. Prevents platelet plug.
What is the gold standard diagnosing tool for stable angina?
CT angiography showing stenosed atherosclerotic arteries
What is the order of meds given for stable angina?
GTN spray
(lifestyle modifications)
1) CCB (not if also have HF) or Beta-blocker (not for asthmatics)
2) CCB and Beta-blocker
Make sure CCB is non-rate limiting or could cause bradycardia
3) CCB and BB and another antianginal like trabradine or nitrates
Consider patient starting ACE-i, aspirin, statin or htn treament
Revascularisation surgically
What are surgical options for severe angina?
PCI (Balloon stent coronary artery)
CABG (bypass graft, LAD bypassed by LMA)
What is a positive for PCI over CABG?
Less invasive
What is a negative of PCI over CABG?
Risk of stenosis
What is a positive of CABG over PCI?
Better prognosis
What is a negative of CABG over PCI?
More invasive
