Baskerville effect: A fatal heart attack triggered by extreme psychological stress. The effect is named after Charles Baskerville, a character in the Arthur Conan Doyle story "The Hound of the Baskervilles," who suffers a fatal heart attack due to extreme psychological stress.
The term "Baskerville effect" was coined in 2001 in the course of a research study that found Chinese Americans and Japanese Americans had a 7% greater death rate from heart disease on the 4th day of the month (BMJ 2001;323:1443-1446). There was no such peak mortality for white Americans. Since both Chinese and Japanese regard the number four as unlucky, it appears that heart fatalities increase on psychologically stressful occasions.
(The stressful nature of the number 4 for Chinese and Japanese comes from the fact that in Chinese (both Mandarin and Cantonese) and Japanese the words "four" and "death" are pronounced almost identically. Some Chinese and Japanese hospitals do not have a fourth floor or number any rooms "4." Mainland Chinese omit the number 4 in designating military aircraft. Japanese people may avoid traveling on the 4th of the month.)
Arthur Conan Doyle was born in Edinburgh in 1859. He received his medical degree from the University there and practiced briefly as a doctor but left medicine to write full-time. This he was able to do because of the popularity of his Sherlock Holmes stories. However, he tired of Holmes and in 1893 he tried to "kill" him in "The Final Problem." However, because of public mourning for Holmes, he brought him briefly back to life in 1901 in "The Hound of the Baskervilles." Conan Doyle was knighted in 1902 for his work in Boer War propaganda and, some said, because of "The Hound of the Baskervilles." Sir Arthur died in 1930.