Major aortopulmonary collateral arteries (or MAPCAs) are arteries that develop to supply blood to the lungs when native pulmonary circulation is underdeveloped. Instead of coming from the pulmonary trunk, supply develops from the aorta and other systemic arteries. Pathogenesis and anatomy
Major aortopulmonary collateral arteries (MAPCAs) develop early in embryonic life but regress as the normal pulmonary arteries (vessels that will supply deoxygenated blood to the lungs) develop. In certain heart conditions the pulmonary arteries do not develop. The collaterals continue to grow, and can become the main supply of blood to the lungs. Though it is usually associated with congenital heart diseases with decreased pulmonary blood flow like tetralogy of Fallot or pulmonary atresia it may be seen sometimes in isolation i.e. not associated with any congenital heart disease in that case it is termed as isolated aortopulmonary collateral artery. In these cases it may be one of the cause of congestive cardiac failure in neonates.Pulmonary arteries come from the right side of the heart, and usually carry deoxygenated blood from the body. These collateral arteries carry blood which has already been oxygenated by the lungs, so are of little use in helping the body to get oxygen. Associated conditions
Pulmonary atresia with ventricular septal defect (or Tetralogy of Fallot with pulmonary atresia) will result in the development of systemic collaterals. Implications of a systemic collateral supply
Major aortopulmonary collateral arteries come from the systemic circulation, because of this they will often have higher pressure than normal found in the lungs, leading to pulmonary hypertension.
The following progestogens are used:

350 μg norethisterone (norethindrone) (UK: Micronor, Janssen-Cilag; Noriday, Pfizer; US: Micronor, Ortho-McNeil; Nor-QD, Watson; Nora-BE, Watson; Jolivette, Watson; Camila, Barr; Errin, Barr; Heather, Glenmark; RU: Primolut-Nor, Bayer; Norkolut, Richter Gedeon)
4 mg drospirenone (Slynd)
75 μg desogestrel (UK: Cerazette, Loestrin; RU: Cerazette, Organon; Lactinette, Richter Gedeon; SE: Gestrina)
30 μg levonorgestrel (UK: Norgeston, Bayer; AUS, RU: Microlut, Bayer)
500 μg etynodiol diacetate (UK: Femulen, Pfizer)
500 μg lynestrenol (RU: Exluton, Organon)

Contraindications
Generally oral contraceptives should not be used in people who currently have the following conditions:

Thrombophlebitis or thromboembolic disorders
A history of deep vein thrombophlebitis or thromboembolic disorders
Cerebrovascular or coronary artery disease (current or history)
Valvular heart disease with thrombogenic complications
Severe hypertension
Diabetes with vascular involvement
Headaches with focal neurological symptoms
Major surgery with prolonged immobilization
Known or suspected carcinoma of the breast or personal history of breast cancer
Carcinoma of the endometrium or other known or suspected estrogen-dependent neoplasia
Undiagnosed abnormal genital bleeding
Cholestatic jaundice of pregnancy or jaundice with prior pill use
Hepatic adenomas or carcinomas, or active liver disease
Known or suspected pregnancy
Hypersensitivity to any component of the productMore comprehensive guidelines that include analysis of risks and benefits can be found in the World Health Organization Medical Eligibility for Contraceptive Use Guidelines which are reflected in the CDC Medical Eligibility for Contraceptive Use Guidelines. See also
Mestranol/noretynodrel (Enovid)—the first oral contraceptive
List of progestogens available in the United States
List of estrogens available in the United States


== References ==