aortic septal defect

defect /de·fect/ (de´fekt) an imperfection, failure, or absence.defec´tive

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acquired defect  a non-genetic imperfection arising secondarily, after birth.

aortic septal defect  a congenital anomaly in which there is abnormal communication between the ascending aorta and pulmonary artery just above the semilunar valves.

atrial septal defects , atrioseptal defects congenital anomalies in which there is persistent patency of the atrial septum, owing to failure of the ostium primum or ostium secundum.

Atrial septal defects; cutaway composite view showing possible locations of ostium primum and secundum defects in the right atrium.

birth defect  one present at birth, whether a morphological defect (dysmorphism) or an inborn error of metabolism.

congenital defect  birth d.

congenital ectodermal defect  anhidrotic ectodermal dysplasia.

cortical defect  a benign, symptomless, circumscribed rarefaction of cortical bone, detected radiographically.

endocardial cushion defects  a spectrum of septal defects resulting from imperfect fusion of the endocardial cushions, and ranging from persistent ostium primum to persistent common atrioventricular canal; see atrial septal d. and atrioventricularis communis.

fibrous cortical defect  a small, asymptomatic, osteolytic, fibrous lesion occurring within the bone cortex, particularly in the metaphyseal region of long bones in childhood.

filling defect  any localized defect in the contour of the stomach, duodenum, or intestine, as seen in the radiograph after a barium enema.

genetic defect  see under disease.

luteal phase defect  inadequate secretory transformation of the endometrium during the luteal phase of the menstrual cycle; it can cause habitual abortion.

metaphyseal fibrous defect 

1. fibrous cortical d.

2. nonossifying fibroma.

neural tube defect  a developmental anomaly of failure of closure of the neural tube, resulting in conditions such as anencephaly or spina bifida.

retention defect  a defect in the power of recalling or remembering names, numbers, or events.

septal defect  a defect in a cardiac septum resulting in an abnormal communication between the opposite chambers of the heart.

ventricular septal defect  a congenital cardiac anomaly in which there is persistent patency of the ventricular septum in either the muscular or fibrous portions, most often due to failure of the bulbar septum to completely close the interventricular foramen.

Abnormal communication between the ventricles in ventricular septal defect.

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aortic septal defect

n.

A small congenital opening between the aorta and pulmonary artery just above the semilunar valves. Also called aorticopulmonary septal defect.

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aortic

pertaining to or emanating from the aorta. See also aortic arch.

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aortic aneurysm

occurs most often in dogs, where it is caused by Spirocerca lupi larvae, turkeys and primates, causing dyspnea, cyanosis and coughing. May be congenital affecting the aortic trunk and the arch sometimes associated with aneurysm of an aortic sinus. See also copper nutritional deficiency.

aortic aneurysm, inherited

see inherited aortic aneurysm.

aortic annulus fibrosus

the fibrous ring in the wall of the root of the aorta. In the bovine heart the ring carries the ossa cordis (see os² cordis).

aortic base rupture

rupture of the vessel just above the semilunar valves.

aortic bodies

small neurovascular structures on either side of the aorta in the region of the aortic arch. The left body is located at the angle between the left subclavian artery and the aorta, and the right at the junction of the right subclavian and right common carotid arteries. They contain chemical receptors which send impulses through the afferent branches of the vagus nerve and are involved in regulating respiration so as to ensure an appropriate partial pressure of oxygen in the arterial blood.

aortic body tumors

single or multiple nodules within the pericardial sac near the base of the heart. Malignant tumors may invade the anterior mediastinum. Called also heart base tumor.

aortic bulb

the dilated part of the aorta at its origin, caused by the swellings of the aortic sinuses.

aortic coarctation

constriction of the aorta at the site of entry of the ductus arteriosus causing a syndrome similar to that of stenosis of the aortic valve.

aortic cystic medionecrosis

pools of ground substance within the elastic media of the aorta. May predispose to arterial aneurysm but this material is present in the aortas of normal horses.

aortic depressor nerve

pressure receptors in the aortic arch and thoracic aorta which assist in maintaining circulatory equilibrium by communicating pressure changes through the aortic depressor nerve, an afferent branch of the vagus nerve; stimulation causes heart slowing and vasodilation.

aortic dextraposition

the aorta receives blood from the right ventricle. There are a number of variations of the basic defect. The common one is the aorta overriding the septum, which is defective, so that the aorta receives blood from both ventricles. The clinical syndrome includes dyspnea and cyanosis from birth, usually with a loud systolic murmur. Affected animals are not viable.

aortic embolism

occurs in cats in association with feline cardiomyopathy and rarely in dogs. Acute pain with paresis to paralysis in the hindlegs, cold, cyanotic feet and no femoral pulse are signs of the condition.

aortic hiatus

an opening in the diaphragm through which the aorta, thoracic duct, the right and/or left azygos veins pass.

aortic-ilial embolism

see iliac artery thrombosis.

aortic mineralization

is one of the early lesions in poisoning by plants that induce mineralization of tissues, e.g. solanummalacoxylon. In combination with lesions in the myocardium causes a syndrome of congestive heart failure.

aortic nerve

see cardiac depressor nerve.

aortic palpation

the aorta is easily palpable per rectum in cattle and horses; valuable as a clinical sign only in cases of thrombosis at the bifurcation; incision at this point has been used as a means of euthanasia in an emergency.

aortic-pulmonary window

an anomaly of the aorta in which there is an opening between the ascending portion of the aorta and the pulmonary artery; clinical signs are similar to those of patent ductus arteriosus, but surgical correction is much more difficult.

aortic regurgitation

see valvular regurgitation.

aortic root

the part of the aorta attached to the atrioventricular fibrous rings and myocardium.

aortic rupture

1. in horses is caused by weakening of the wall of the aorta by migrating strongyle larvae. In cattle the cause may be onchocerciasis, in pigs experimental diets deficient in copper. Sudden death results from cardiac tamponade or dissecting aneurysm into the ventricular muscle.

2. sudden death in growing turkeys due to dissecting aneurysmal rupture of the aorta and death due to internal hemorrhage; the cause is unknown. Copper deficiency is suspected as a cause in several animal species.

aortic sac

the merged ventral aortae of the embryo which supplies blood to the aortic arches.

aortic septal defect

a congenital anomaly in which there is abnormal communication between the ascending aorta and the pulmonary artery just above the semilunar valves.

aortic sinus

the three pouch-like dilatations of the aortic bulb which carry the cusps of the aortic valve. The coronary arteries arise from the left caudal and the cranial sinuses.

aortic subvalvular stenosis

in dogs and pigs is possibly an inherited defect. Characterized by stenosis of the aorta just below the semilunar valves. In pigs, it causes congestive heart failure in the newborn, but in affected dogs severity increases with age so that clinical effects may not be apparent until the patients are older.

aortic thromboembolism

thrombosis is the usual forerunner of embolism, pieces of the thrombus breaking off the main mass and lodging in more distal parts of the vascular system. See also aortic embolism (above), verminous mesenteric arteritis, iliac artery thrombosis.

Aortic thromboembolism in a cat. By permission from Nelson RW, Couto CG, Small Animal Internal Medicine, Mosby, 2003

aortic valve

the valve at the entrance to the aorta from the left ventricle made up of three semilunar leaflets or valvulae.

aortic valve rupture

rupture of the medial cusp is recorded as a cause of sudden death in horses usually as a sequel to endocarditis.

aortic valvular disease

stenosis is rarely an acquired disorder, but may be an inherited defect in several species. In cats and rarely dogs, restrictive cardiomyopathy may be a cause of subvalvular aortic obstruction. Valvular incompetence may be congenital or acquired and results in diastolic overloading of the left ventricle with a characteristic water-hammer pulse and diastolic murmur. See also aortic stenosis, aortic subvalvular stenosis (above).

aortic vestibule

the cranial part of the left ventricular cavity leading to the root of the aorta in the avian heart.