Tachycardia (from the Greek takhys, meaning "swift", and kardia, meaning heart) means a swift heart rate.By this definition, junctional ectopic tachycardia is an abnormally swift heart rhythm due to cells firing within the heart near the AV node. References


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The incidence has been reported to be about 1:3,000 to 1:7,000 deliveries. History
In 1614 Mercier (also shown as Mercerus) described ovarian pregnancy for the first time, as a condition separate from a tubal pregnancy. Once the study of physiology emerged, Boehmer classified extra-uterine pregnancy into three classes: abdominal, ovarian, and tubal. There were many doubters that such a condition existed, particularly Mayer, who wrote an essay not only denying the existence of ovarian pregnancy, but demonstrating that recorded cases to that time were other conditions. Then Cohnstein proposed four criteria that would need to be present for ovarian pregnancy exist. His requirements were: 1) absence of the ovary on the side in which the alleged pregnancy was located; 2) connection of the uterus and sac via an ovarian ligament; 3) cylindrical tissue must line the layers of the sac with direct connection between the tunica albuginea and sac wall; and 4) evidence of the amniotic cavity connection to the ovarian follicle or corpus luteum. These were replaced by Otto Spiegelbergs criteria in 1878, which have been used into the 20th century with additions and modifications.Up to 1845, about 80 cases of ovarian pregnancy were proposed. With Mayers 1845 denial that ovarian pregnancy could exist, physicians began taking more care in their descriptions and analysis of cases. Though numerous cases were evaluated, some failed to provide microscopic evidence and others failed to show the necessary histological changes of pregnancy, or failed on one or more of the criteria.