In its classic definition, by FranÃ§ois-Louis Ganshof (1944), feudalism describes a set of reciprocal legal and military obligations among the warrior nobility revolving around the three key concepts of lords, vassals and fiefs.
The exact cause of intracardiac echogenic foci remains unclear; however, they appear to be caused by small deposits of calcium in the papillary muscle of the fetal heart.
The pathophysiology behind noncardiac causes of tachyarrhythmias depends on the underlying pathology. In the case of hypovolaemia and hypotension, the increase in heart rate is a reflex response to a decrease in cardiac output. Vasodilation or haemorrhaging results in a reduction in the stroke volume (SV) of the heart.