21% of candidates passed this question.

It was expected the answer would start with a definition of afterload and then proceeded to indicate what effects this increase in afterload would have on ventricular end-systolic pressure, ventricular end-diastolic pressure, left atrial pressure, cardiac output, myocardial oxygen demand and myocardial work, coronary blood flow and systemic blood pressure.

Most candidates who failed to pass this question submitted answers that were just too brief, only including a small subset of the material required. Very few candidates included any mention of myocardial oxygen demand or myocardial work or the impact upon the cardiac output. A number of candidates included a detailed description of the Sympathetic Nervous System and the Renin-Angiotensin system, material which was not asked for. There were quite a number of incorrect perceptions about what effect a sudden increase in afterload would have on the systemic blood pressure. Candidates who mentioned the baroreceptor response and the stretch receptor response where rewarded with additional credit.