Coronary heart disease

Question 1

pathophysiology

Answer 1

1. Coronary arteries which deliver blood to the heart have atherosclerosis ( fatty plaques which narrow blood vessels)
   • 60% stenosis - blood flow not significantly altered, compensatory vasodilation
   •70% stenosis- resting blood flow is normal but inadequeate on demand
   • 90% > - myocardial ischaemia at rest

Question 2

other pathophys of coronary heart disease

Answer 2

1. inappropriate vasoconstriction of coronary arteries
   eg. physical activity stimulus -> impaired release of endothelial vasodilators leaves sympathetic nervous system activity unopposed.

Question 3

Stable angina

Answer 3

transient chest pain only during exertion

- subsides post exertion

Question 4

consequences of ischaemia

Answer 4

1. stable/unstable angina
2. variant angina - vasospasm of coronary artery in the absence of atherosclerosis which reduces blood flow
3. Stunned myocardium - tissue suffers from

Question 5

Myocardial oxygen demands

Answer 5

1. Ventricular wall stress
   • wall stress is inversely proportional to ventricular wall thickness
2. Heart rate
3. Contractility - measure of force of contraction