Angina

Question 1

What are the characteristics of these types of angina

• stable
• mixed
• vasospastic (Prinzmetals)
• microvascular (Syndrome X)
• unstable

Answer 1

Stable

• Stenosis >70%
• tight crushing pain on physical/emotional exertion (supply demand mismatch => adenosine, bradykinin release => pain)

Mixed

• stenosis + vasospasm
• unpredictable exertion

Vasospastic (Prinzmetals)
-no stenosis, coronary spasm

Microvascular (Syndrome X)

• can’t VD enough due to endothelial dysfunction
• no stenosis, linked to post/perimenopause

Unstable
-transient thrombus => partial occlusion

Question 2

What are the main aims of drug treatment

-2 reasons

Answer 2

Decrease future attacks

• decrease coronary O2 demand
• increase coronary flow

Protect against future CV events

• decrease risk factors via
  
  • Bblockers
  • Statins
  • ACEi
  • Aspirin

Question 3

Describe the mechanism behind B blockers
What are the SE and why
What are the CI

Answer 3

Decreased SNS => decreased contractility and renin release => increase flow, diastole

SE due to VD inhibition

• cold extremities
• hypoglyacaemia due to dampened SNS dominated adrenaline reaction
• exercise intolerance
• fatigue

CI due to VD inhibition

• asthma
• VS angina

Question 4

Describe the mechanism behind Ca channel blockers

What are the 3 main drugs in this group

Answer 4

VD CORONARIES

Amilodipine
-increase VD arteries => decrease after load => decrease cardiac stress

Verapamil, Diltiazem
-decreased inotropy => increase diastole

Question 5

Describe the mechanism behind organic nitrates
What are the SE and why
Why can you develop a tolerance to this

Answer 5

Decreased CVP (decreaseSM, depolarization => venous VD) => decrease wall stress => decrease O2 demand

Decrease TPR
VD of coronaries

SE due to VD

• low BP, reflex tachycardia
• headache, facial flush

Tolerance due to increased oxygen radicals

Question 6

Describe the mechanism behind ranalazine

Answer 6

Ischemia => increased ROS => increased late Na I

Normally

• APs more likely
• afterdepolarization arrhythmias

-increased [Ca] I => myocardial stunning => decreased diastolic period => increased work, decreased coronary flow

Ranalazine inhibitions late Na I

Question 7

Describe the mechanism behind ivabradine
What are the SE and why
What are the CI

Answer 7

Blocks If => decreased HR => increased diastole, decreased after load, O2 demand

SE due to reflex increases

• headache, dizzy
• bradycardia
• luminous phenomena

CI
-renal, hepatic impairment

Question 8

Describe the mechanism behind nicorandil
What are the SE and why
What are the CI

Answer 8

KATP channel activator => opens channels in SM => hyper polarization and Ca removal/desensitization
=> VD => decreased pre/afterload => decreased work/O2 demand

SE due to VD
-headache, dizzy, flushed

CI

• hypotension
• PDE5 inhibitor (synergistic VD)

Question 9

What are the 2 physical treatments for angina

How would you do this

Answer 9

PCI

• guide catheter via femoral/radial vein
• balloon inflates stent open

CABG

• saphenous/int mammary for serious cases
• more invasive, increase survival
• needs thoracotomy, CP bypass