In this condition, the normal heartbeat passing from the upper chambers of the heart to the lower chambers is interrupted. This results in a condition called a "heart block." When a heart block occurs, the heart rate usually slows considerably. This can cause inadequate blood flow to the brain and result in fainting.
This condition goes by a baffling number of names including the Adams-Stokes, Morgagni, Morgagni-Adams-Stokes, Spens syndrome, and Stokes-Adams disease or syndrome. William Stokes (1804-1878) and Roberts Adams (1791-1875) were Irish physicians. Stokes is also remembered for Cheyne-Stokes respiration, a pattern of breathing characteristically seen in coma. Thomas Spens (1764-1842) was a Scottish physician. Giovanni Battista Morgagni (1682-1771) was an Italian anatomist and pathologist. Although Adams, Stokes, and Spens did describe the syndrome (separately) in the early 19th century, the first description was, in fact, recorded in 1761 by Morgagni. All of these eponyms are now declining in use as our understanding of the disease process advances.
The preferred name for the condition now is cardiovascular syncope.