Coronary Artery Disease: SAQ Solutions

Listed below are the solutions to the SAQ on Coronary Artery Disease:

1. Any 3 of the following are acceptable: Chest pain (angina), heart attack, heart failure, abnormal heart rhythm (arrhythmia), shortness of breath.
   Consult the video for these symptoms. All of these are due to a lack of blood flow to the heart muscle through the coronary arteries.
2. True.
   Q = P/R is similar to I = V/R, where fluid flow (Q) approximates current flow, the pressure difference (P) approximates the potential difference (V) that cause fluid and charge flow, respectively, and there is a resistance (R) to that flow in both cases.
3. True.
   Vessel radius is the most important factor of the Poiseuille’s law variables in determining flow rate as it is raised to the fourth power.
4. Any of the following are acceptable: The fluid is Newtonian, flow is laminar, blood vessel tube is cylindrical with a cross section; circular walls, rigid walls on the tube, tube is long compared to entrance length.
   Poiseuille’s law does not apply when these conditions are not met. Thus, these equations are approximations for modeling blood flow in the coronary arteries in which a perfectly rigid walled, cylindrical tube cannot be assured.