This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiac Cycle, Subject name: Physiology
Which of the following best describe Anrep effect ? 
Select and explain. 
A. Increased preload decreases cardiac contractility, B. Increased after load increases cardiac contractility, C. Increased preload decreases cardiac relaxation, D. Decreased after load decreases cardiac relaxation
B: Increased after load increases cardiac contractility
Answer: B: Increased after load increases cardiac contractility 
Explanation: Anrep effect: - Increased afterload increases cardiac contractility. Autoregulation method in which myocardial contractility increases with afterload. It was experimentally determined that increasing afterload caused a propoional linear increase in ventricular inotropy For instance, when LV has to pump against the aoa pressure, & the aoa pressure is after load on LV. If the after-load increases, then against the increasing resistance LV has to contract & eject out the blood, therefore it needs to go on increasing its contractility, this effect has been called as the Anrep effect. Such contractions are called as - Auxotonic contraction.