Final answer:
The pericardium can affect preload by conditions like pericarditis and cardiac tamponade, which restrict heart filling and reduce cardiac output.
Step-by-step explanation:
The pericardium is a membrane that envelops the heart and plays a critical role in affecting cardiac function, particularly the preload. Preload refers to the degree of stretch of the cardiac ventricles at the end of diastole, just before contraction, and is largely dependent on the end-diastolic volume (EDV). The pericardium can influence preload in several ways, but particularly through conditions that physically restrict the heart's ability to fill with blood.
Two serious conditions that can arise as complications include pericarditis, which is inflammation of the pericardium that can lead to excess fluid accumulation or scarring, and cardiac tamponade, where fluid accumulation within the pericardium exerts pressure on the heart, restricting ventricular filling and therefore reducing preload and cardiac output.
In summary, the pericardium, by virtue of its proximity to the heart, can significantly affect the preload either through inflammatory conditions or by fluid accumulation, both of which can impede the heart's capacity to fill properly and thus influence overall cardiovascular function.