| Q wave | The initial deflection of the QRS complex when such deflection is negative (downward). (05 Mar 2000) |
|---|---|
| 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) |
| overflow wave | The descending wave of the sphygmogram from the apex to the first anacrotic break. (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) |
| theta wave | Brain waves in the electroencephalogram which have a frequency of 4 to 7 per second. They occur mainly in children but also in adults during periods of emotional stress. (12 Dec 1998) |
| tidal wave | The wave between the percussion wave and the dicrotic wave in the downward limb of the arterial pulse tracing. (05 Mar 2000) |
| electrocardiographic wave | <cardiology, physiology> A deflection of special shape and extent in the electrocardiogram representing the electric activity of a portion of the heart muscle. (05 Mar 2000) |
| electrohydraulic shock wave lithotripsy | Destruction of calculi (urinary tract or other) by fragmentation using shock waves sent transcutaneously. (05 Mar 2000) |
| electromagnetic wave | <physics> A wave of electric and magnetic fields that can move through space. Particles which make up the waves are called photons. (09 Oct 1997) |
| electrostatic wave | <radiobiology> Longitudinal oscillations appearing in a plasma due to a perturbation of electric neutrality. For a cold unmagnetised plasma, or at large wavelengths, the frequency of these waves is by definition the plasma frequency. (09 Oct 1997) |
| transverse wave | <radiobiology> Waves in which the direction of the oscillation is perpendicular (transverse) to the direction of the wave propagation. Examples include plucked strings and electromagnetic waves in free space or air. (09 Oct 1997) |