A woman died within seconds of her boyfriend touching a nerve on her neck, the Old Bailey heard today.
Michelle Creed, 34, collapsed during a row when Jason McKay, 36, put his hands round her neck for between five and 10 seconds.
Although his actions caused no obvious injury, it caused her death because of an unusual effect McKay did not know about, the court heard.
McKay, of no fixed address, pleaded guilty to Miss Creed's manslaughter at her home in West Kensington, London, in January last year and was jailed for five years and four months.
Her body lay undetected for a week after McKay, an unemployed clerk, panicked and went on the run before giving himself up in Poland.
Judge Charles Wide told McKay: "Death was caused by something unusual and not seen by you.
"You stopped applying force because you thought she had chosen to stop struggling."
The court was told Miss Creed died as the result of vagal inhibition, the suppression of a nerve linking the brain to the central nervous system, leading to a heart attack.