| endocardial cushion defect | <radiology> Persistence of primitive atrioventricular canal and anomalies of AV valves associated with: Down syndrome: in 25% of Trisomy 21 an ECD is present; in 45% of ECD Trisomy 21 is present, asplenia/polysplenia types: complete (AV canal), partial findings: gooseneck deformity on angiogram, increased pulmonary vascularity, enlarged pulmonary artery, enlarged RV, LV, RA; normal LA (secondary to atrial septal defect) (12 Dec 1998) |
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| enzyme defect | A disorder resulting from a deficiency (or functional abnormality) of an enzyme. In 1902 Archibald Garrod first attributed a disease to an enzyme defect: an inborn error of metabolism. Today, newborns are routinely screened for certain enzyme defects such as PKU (phenylketonuria) and galactosaemia, an error in the handling (metabolism) of the sugar galactose. (12 Dec 1998) |
| fibrous cortical defect | A common 1 to 3 cm defect in the cortex of a bone, most commonly the lower femoral shaft of a child, filled with fibrous tissue. Nonosteogenic or nonossifying fibroma by convention refers to lesions greater than 3 cm in diameter. See: nonossifying fibroma. Synonym: nonosteogenic fibroma. (05 Mar 2000) |
| uterine filling defect | <radiology> Technical, bubble, blood clot, mucoid material, congenital fold, pseudoadhesions / ridging -- folds long axis, neoplasm, submucosal leiomyoma, adenoma, endometrial carcinoma, pregnancy-related, pregnancy, molar pregnancy, retained conceptus, polyp, septated uterus, synechiae, IUD, iatrogenic (post-op) (12 Dec 1998) |
| filling defect | Displacement of contrast medium by a space-occupying lesion in a radiographic study of a contrast-filled hollow viscus, such as a polyp on a barium enema; also applied to defects in the otherwise uniform distribution of radionuclide in an organ, such as a metastasis in the liver on a 99mTc-sulfur colloid scan. (05 Mar 2000) |
| filling defect in renal collecting system | <radiology> Common causes: transitional cell carcinoma, blood clot, lucent calculus (urate) less common causes: fungus ball, sloughed papilla, fibroepithelial polyp, invasion by hypernephroma, malakoplakia, vessel impression, metastases (12 Dec 1998) |
| lambdoid suture defect | <radiology> Well-defined lucent lesion, classically unilateral, associated with neurofibromatosis (12 Dec 1998) |
| luteal phase defect | Inadequate function of the corpus luteum that may prevent a fertilized egg from implanting in the uterus or may lead to early pregnancy loss. (09 Oct 1997) |
| aberrant ventricular conduction | Abnormal intraventricular conduction of a supraventricular beat, especially where surrounding beats are normally conducted. Synonym: ventricular aberration. (05 Mar 2000) |
| accelerated conduction | Any pathologically increased speed of conduction; usually occurs between the atrium and ventricles as in the Wolff-Parkinson-White and Lown-Ganong-Levine syndromes; such accelerated pathways provide the bases for particular forms of reentry tachycardia. (05 Mar 2000) |
| A-H conduction time | Forward conduction of the cardiac impulse from atria to ventricles via the A-V node or any bypass tract, represented in the electrocardiogram by the P-R interval. P-H conduction time is from the onset of the P wave to the first high frequency component of the His bundle electrogram (normally 119 ± 38 msec); A-H conduction time is from the onset of the first high frequency component of the atrial electrogram to the first high frequency component of the His bundle electrogram (normally 92 ± 38 msec); P-A conduction time is from the onset of the P wave to the onset of the atrial electrogram (normally 27 ± 18 msec). (05 Mar 2000) |
| air conduction | In relation to hearing, the transmission of sound to the inner ear through the external auditory canal and the structures of the middle ear. (05 Mar 2000) |
| anomalous conduction | Conduction of cardiac electrical impulses through any abnormal pathway. (05 Mar 2000) |
| antegrade conduction | Conduction in the expected normal direction between any cardiac structures. Synonym: antegrade conduction, forward conduction, orthograde conduction. (05 Mar 2000) |
| anterograde conduction | Conduction in the expected normal direction between any cardiac structures. Synonym: antegrade conduction, forward conduction, orthograde conduction. (05 Mar 2000) |