When the heart lies on the right side of the thorax instead of the left, the condition is called dextrocardia. This condition occurs when the heart loop bends to the left instead of right (to understand this points, the reader is advised to refer back to the subject of formation of cardiac loop discussed under the topic of establishment of external form). Dextrocardia entails a transposition in which the heart and its vessels are reversed left to right as in a mirror image. This malformation may occur as an isolated anomaly or may be the part of a more generalized anomaly called situs inversus, in which there is transposition of all the thoracic and abdominal viscera. Isolated dextrocardia is usually associated with other serious cardiac defects.