cyanotic heart defect is a group-type of congenital heart defects (chds) that occurs due to deoxygenated blood bypassing the lungs and entering the systemic circulation or a mixture of oxygenated and unoxygenated blood entering the systemic circulation. it is caused by structural defects of the heart (i.e.:right-to-left, bidirectional shunting, malposition of the great arteries), or any condition which increases pulmonary vascular resistance. the result being the development of collateral circulation. == signs and symptoms == *clubbing *the patient assuming a crouching position *cyanosis - facial discolouration (particularly the lips) and digit discolouration (fingers & toes). *crying *crabbiness/irritability *tachycardia *tachypnea *a history of inadequate feeding. *unusually large toe & fingernails. *delayed development (both biological & psychological). == categories/classifications == *tetralogy of fallot (tof) *total anomalous pulmonary venous connection *hypoplastic left heart syndrome (hlhs) *transposition of the great arteries (d-tga) *truncus arteriosus (persistent) *tricuspid atresia *interrupted aortic arch *pulmonary atresia (pa) *pulmonary stenosis (critical) *eisenmenger syndrome (reversal of shunt due to pulmonary hypertension) . * patent ductus arteriosus may cause cyanosis in late stagepage  == pharmacological treatment & management == *morphine during tet spells to decrease associated infundibular spasm. *prophylactic: propranolol/inderall *prostaglandin e (to keep the ductus arteriosus patent) *prophylactic antibiotic to prevent endocarditis *surgery == non cyanotic heart defects == non cyanotic heart defects are more common because of higher survival. in these the shunt is initially from left (oxygenated) to right ( non oxygenated). these are * atrial septal defect * ventricular septal defect * coarctation of aorta (may cause cyanosis in some cases) * double outlet left/right ventricle  ==references== 
Congenital_heart_disease