Angina (General) Flashcards
Myocardial Ischemia
Decreased ratio of O2 Supply : O2 Demand
–> Inadequate blood supply
Myocardial Infarction
Tissue death
Myocardial Ischemia (Therapy)
Lifestyle changes
Revascularization
- PCI (Percutaneous Coronary Intervention)
–> Insert a balloon to open closed artery
- CABG (Coronary Bypass Graft Surgery)
–> Redirect blood flow around damaged area
Determinants of Supply
Coronary Diameter (Blood supplying heart)
Collateral Blood Flow (Back up vessels)
Perfusion Pressure (Pressure that supplies body with blood)
Heart Rate / Diastole (Pumps blood to body)
Determinants of Demand
More energy = More oxygen
- Heart rate
- Systolic Blood Pressure
- Myocardial Wall Stress + Contractility
Angina
- What is it?
- Caused by?
Chest Pain
- When heart muscle does not get enough oxygen
How to treat Angina
Decrease O2 demand
- Slow down heart rate
- Decrease heart contractility
Beta Blockers (VSMC)
- Agonist
Promotes Relaxation
Beta Blockers (VSMC)
- Antagonist
Promotes contraction
Beta Blockers (Cardiac Cell)
- Agonist
Promotes Contraction
Beta Blockers (Cardiac Cell)
- Antagonist
Inhibits Contraction
Calcium Channel Blocker (VSMC)
DHP
- Promote Relaxation
Calcium Channel Blocker (Cardiac Cell)
Non-DHP
- Inhibit Contraction
Increasing Myocardial Contraction
- When?
- Reduce risk of low cardiac output
- Following cardiac surgery
- Cases of cardiogenic / septic shock
Arterial Dilators
Decrease vascular resistance
- Decreases afterload on left ventricle
–> Reduces demand of oxygen
Venous Dilators
Reduce venous pressure
- Decreases preload on heart
–> Decreases cardiac output
Nitrate Chronic Use
Nitrates are abossrbed qickly, have short half lives
Not used chronically, patients are quick to develop resistance
- Impaired conversion to NO active form
- Dysfunction of endothelial
- Forms free radicals
- Increased release of vasoconstrictors in response
Stable Angina
Classic
- Atherosclerosis
–> Fatty Plaque causes narrowing of vessel
Unstable Angina
Crescendo
- Atherosclerosis + Blood Clot
–> Plaque is unstable and releases stuff causing thrombosis
Variant Angina
Prinzmetal
- Coronary Spasm
