Myocardial Ischaemia As A Drug Target

Question 1

Heart beat

Answer 1

60-100bpm
Normally around 70 bpm

Question 2

Features of ordinary circulation

Answer 2

• Maintain high basal rate of O2 supply - high capillary density + high oxygen extraction - 80% aerobic
• increase proportional to an increased cardiac demand

Question 3

Two factors limit blood supply in the endocardial region

Answer 3

Intrventricular pressure
Cardiomyocyte shortening

Question 4

Poor myocardial perfusion

Answer 4

1. Coronary artery narrowing : Atheroma formation
   2.aortic valve stenosis
2. Increased HR

Question 5

Treatment of reversible ischaemia (angina)

Answer 5

Reduce HR- beta-adrenoceptor blocker + block pacemaker (inhibit funny current =slows HR + improves coronary perfusion)
Reduces cardiac filling pressure - nitrates

Question 6

Calcium channel blocker

Answer 6

Inhibit ca influx to vascular smooth muscle
Slows HR