In either instance, the apex of the heart will be poorly positioned, which should alert a clinician of the likelihood of atrial isomerism. It is estimated that 5–10% of isomeric patients have mesocardia, in which the heart is positioned at the center of the thorax, 25–50% have dextrocardia, in which the apex of the heart is pointed toward the right side of the thorax, and 50–70% have levocardia, in which the apex of the heart is pointed toward the left side of the thorax. Right atrial appendage isomerism
Right atrial appendage isomerism, also called right atrial isomerism, is a cardiac development defect in which the heart has bilateral right atria and atrial attachments in the muscle wall, as opposed to the normal right atrium and left atrium. In right atrial isomerism, the pulmonary blood oxygen tract is damaged due to right-left shunting of blood. In addition, the atrial septum which distinguishes the 2 atria is absent. These impairments, in addition to congestion in the pulmonary tract, allows deoxygenated blood to mix with oxygenated blood, contributing to cyanosis and possible respiratory distress. Poor systemic circulation also results due to improper positioning of the aorta. Left atrial appendage isomerism
Left atrial appendage isomerism, also called left atrial isomerism, is a cardiac development defect in which the heart has two bilateral left atria and atrial appendages in the muscle wall. Left atrial isomerism can have varied clinical manifestations, including a later onset of symptoms.
Orthostatic purpura is a skin condition that results from prolonged standing or even sitting with the legs lowered (as in a bus, airplane, or train), which produced edema and a purpuric eruption on the lower extremities. : 827

See also
Skin lesion


== References ==