| NPC | nasopharyngeal carcinoma; near point of convergence; nodal premature contractions; nonparenchymal [l... |
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| PNB | p-nitrobiphenyl; perineal needle biopsy; peripheral nerve block; premature nodal beat |
| PNC | penicillin; peripheral nucleated cell; pneumotaxic center; premature nodal contracture |
| SANDR | sinoatrial nodal reentry |
| TNI | total nodal irradiation |
| sinus tachycardia | A fast heartbeat (tachycardia) occurring because of rapid firing by the sa node, the natural pacemaker of the heart. Electrical signals initiated in the sa node are transmitted to the atria and the ventricles to stimulate heart muscle contractions heartbeats. Sinus tachycardia is usually a rapid contraction of a normal heart in response to a condition, drug, or disease as, for examples, pain, fever, excessive thyroid hormone, exertion, excitement, low blood oxygen level (hypoxia), or stimulant drugs such as caffeine, cocaine, and amphetamines. However, in some cases, it can be a sign of heart failure, heart valve disease, or other illness. (12 Dec 1998) |
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| supraventricular tachycardia | <cardiology> An abnormally accelerated rhythm that results from a rapidly firing electrical focus above the A-V node. Rates may be in the rage of 150-250 beats/minute. Origin: Gr. Kardia = heart (27 Sep 1997) |
| double tachycardia | The simultaneous tachycardia of two ectopic pacemakers, e.g., atrial and junctional tachycardia. (05 Mar 2000) |
| orthostatic tachycardia | Increased heart rate on assuming the erect posture. (05 Mar 2000) |
| tachycardia | <clinical sign> The excessive rapidity in the action of the heart, the term is usually applied to a heart rate above 100 per minute and may be qualified as atrial, junctional (nodal) or ventricular and as paroxysmal. Origin: Gr. Kardia = heart (18 Nov 1997) |
| tachycardia-bradycardia syndrome | <syndrome> A disorder consisting of abnormalities of supraventricular impulse generation and conduction which produce a wide variety of intermittent rapid and slow supraventricular arrhythmias. Common symptoms include palpitations, faintness and fainting. Diagnosis is generally by 24 hour cardiac monitoring. A permanent pacemaker is indicated for those who are unresponsive to drug therapy. (27 Sep 1997) |
| 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, ectopic junctional | A tachycardia arising in the conduction tissues surrounding the atrioventricular node. It usually occurs during myocardial infarction, after heart surgery, or in digitalis intoxication. The rate may range from 140 to 250 beats per minute. (12 Dec 1998) |
| tachycardia en salves | Short runs of paroxysmal tachycardia of the Gallavardin type. Compare: Gallavardin's phenomenon. Origin: Fr. Tachycardia in salvos (05 Mar 2000) |
| tachycardia exophthalmica | Rapid heart action occurring as one of the symptoms of exophthalmic goiter. (05 Mar 2000) |
| tachycardia, paroxysmal | Condition marked by attacks of rapid action of the heart having sudden onset and cessation. (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) |
| tachycardia, sinus | Fast heartbeat (tachycardia) occurring because of rapid firing by the sa node, the natural pacemaker of the heart. Electrical signals initiated in the sa node are transmitted to the atria and the ventricles to stimulate heart muscle contractions heartbeats. Sinus tachycardia is usually a rapid contraction of a normal heart in response to a condition, drug, or disease. For examples, pain, fever, excessive thyroid hormone, exertion, excitement, low blood oxygen level (hypoxia), or stimulant drugs such as caffeine, cocaine, and amphetamines can cause tachycardia. However, in some cases, it can be a sign of heart failure or heart valve disease or other illness. (12 Dec 1998) |
| tachycardia, supraventricular | A generic expression for any tachycardia that originates above the bundle of his. (12 Dec 1998) |
| tachycardia, ventricular | An abnormal heart rhythm that is rapid, regular and originates from an area of the ventricle, the lower chamber of the heart. Ventricular tachycardias are life threatening arrhythmias most commonly associated with heart attacks or scarring of the heart muscle from previous heart attack. (12 Dec 1998) |