| intra-atrial | Within one or both of the atria of the heart. (05 Mar 2000) |
|---|---|
| intra-atrial block | Impaired conduction through the atria, manifested by widened and often notched P waves in the electrocardiogram. (05 Mar 2000) |
| intra-atrial conduction | Conduction of the cardiac impulse through the atrial myocardium, represented by the P wave in the electrocardiogram. (05 Mar 2000) |
| intra-atrial conduction time | The total duration of electrical activity of the atria in one cardiac cycle. (05 Mar 2000) |
| tachycardia, ectopic atrial | A tachycardia originating in the atrial myocardium and characterised by rates between 135 and 175 beats per minute. (12 Dec 1998) |
| tachycardia, paroxysmal atrial | Bouts of rapid, regular heart beating originating in the atrium (upper chamber of the heart). Often due to abnormalities in the av node relay station that lead to rapid firing of electrical impulses from the atrium which bypass the av node under certain conditions. These conditions include alcohol excess, stress, caffeine, overactive thyroid or excessive thyroid hormone intake, and certain drugs. Pat is an example of an arrhythmia where the abnormality is in the electrical system of the heart, while the heart muscle and valves may be normal. (12 Dec 1998) |
| fibrillation, atrial | An abnormal irregular heart rhythm whereby electrical signals are generated chaotically throughout the upper chambers (atria) of the heart. Although many persons with atrial fibrillation have no symptoms, the most common symptom is palpitations, an uncomfortable awareness of the rapid and irregular heartbeat. Atrial fibrillation can cause blood clots that travel from the heart to the brain, causing stroke. Treatment of atrial fibrillation involves controlling the risk factors, medications to slow the heart rate and/or convert the heart to normal rhythm, and preventing complications of blood clotting. (12 Dec 1998) |
| lateral atrial vein | A vein draining deep portions of the temporal and parietal lobes; it runs in the lateral wall of the lateral ventricle to terminate in the superior thalamostriate vein. Synonym: vena ventriculi lateralis lateralis, lateral atrial vein, lateral vein of lateral ventricle. (05 Mar 2000) |
| left atrial pressure | <radiology> 15-20 mm Hg redistribution 20-25 interstitial oedema 25-30 airspace oedema (12 Dec 1998) |
| adipokinetic hormone | An anterior pituitary hormone that causes mobilization of fat from adipose tissue. Synonym: adipokinetic hormone. (05 Mar 2000) |
| adrenal androgen-stimulating hormone | A putative pituitary hormone that may be responsible for increased secretion of adrenal androgens at the time of puberty. (05 Mar 2000) |
| adrenocorticotrophic hormone | <endocrinology> A peptide hormone that is produced by the anterior pituitary gland. It stimulates the adrenal cortex to secrete glucocorticoid hormones, which help cells synthesise glucose, catabolize proteins, mobilizefree fatty acids and inhibit inflammation in allergic responses. (10 May 1997) |
| adrenocorticotropic hormone | The hormone of the anterior lobe of the hypophysis which governs the nutrition and growth of the adrenal cortex, stimulates it to functional activity, and also possesses extraadrenal adipokinetic activity; it is a polypeptide containing 39 amino acids, but exact structure varies from one species to another; sometimes prefixed by a to distinguish it from beta-corticotropin. The first thirteen amino acids at the N-terminal region are identical to alpha-melanotropin. Synonym: adrenocorticotropin, adrenotropic hormone, adrenotropin, corticotropic hormone, corticotropin. (05 Mar 2000) |
| adrenotropic hormone | The hormone of the anterior lobe of the hypophysis which governs the nutrition and growth of the adrenal cortex, stimulates it to functional activity, and also possesses extraadrenal adipokinetic activity; it is a polypeptide containing 39 amino acids, but exact structure varies from one species to another; sometimes prefixed by a to distinguish it from beta-corticotropin. The first thirteen amino acids at the N-terminal region are identical to alpha-melanotropin. Synonym: adrenocorticotropin, adrenotropic hormone, adrenotropin, corticotropic hormone, corticotropin. (05 Mar 2000) |
| androgenic hormone | <endocrinology> A male (masculinising) hormone. These medications (testosterone, methyltestosterone, fluoxymesterone, danazol) are used to treat androgen deficiency, delayed puberty in males and some forms of breast cancer. (27 Sep 1997) |