tidal wave

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1. a uniformly advancing disturbance in which the parts undergo a change in direction, such as a progressing disturbance on the surface of a liquid.
2. variation in the transmission of electromagnetic energy, especially the periodic change in direction of a reading on a monitoring device.
A wave the wave on a His bundle electrogram that represents atrial activation.
alpha w's brain waves having a frequency of 8 to 13 per second, typical of a normal person awake in a quiet resting state; they occur primarily in the occipital region.
B wave a sharp rhythmic oscillation with a sawtooth pattern, occurring every 30 seconds to two minutes during intracranial pressure monitoring, associated with unstable increases in pressure.
beta w's brain waves having a frequency of 18 to 30 per second, typical during periods of intense central nervous system activity; they occur primarily in the parietal and frontal regions.
brain w's changes in electric potential of different areas of the brain, as recorded by electroencephalography. See also alpha, beta, delta, and theta waves.
C wave in intracranial pressure monitoring, a small rhythmic oscillation in pressure that occurs every four to eight minutes.
delta w's
1. brain waves having a frequency below 3½ per second, typical in deep sleep, in infancy, and in serious brain disorders.
2. an early QRS vector in the electrocardium in wolff-parkinson-white syndrome.
dicrotic wave the second portion of the tracing of a sphygmograph of the arterial pulse or arterial pressure after the dicrotic notch, attributed to the reflected impulse of closure of the aortic valves. Called also recoil wave
electromagnetic w's the entire series of ethereal waves, which are similar in character and move at the speed of light but vary enormously in wavelength. The unbroken series is known from radio waves that may be many kilometers in length through light waves, ultraviolet rays, x-rays, and gamma rays, to the cosmic rays, whose wavelength may be as short as 40 femtometers (4 × 10−14 m).
light w's the electromagnetic waves that produce sensations on the retina; see also vision.
P wave a positive deflection in the normal surface electrocardiogram produced by the wave of excitation passing over the atria; it represents atrial depolarization, an intrinsic atrial event.
papillary wave (percussion wave) the chief ascending portion of the tracing of a sphygmograph.
plateau wave a wave seen during intracranial pressure monitoring in advanced stages of increased pressure, signaling hypoxia of the brain cells.
pulse wave the elevation of the pulse felt by the finger or shown graphically in a recording of pulse pressure.
Q wave in the QRS complex, the initial electrocardiographic downward (negative) deflection, related to the initial phase of depolarization.
QRS wave QRS complex.
R wave in the normal surface electrocardiogram, the initial upward deflection of the QRS complex, following the Q wave; it represents ventricular depolarization. In cardiac pacing, it may be the entire native or intrinsic QRS complex.
radio w's electromagnetic waves of wavelength between 10−1 and 106 cm and frequency of about 1011 to 104 hertz.
recoil wave dicrotic wave.
S wave a downward deflection of the QRS complex following the R wave in the normal surface electrocardiogram.
sonic w's audible sound waves.
sound w's longitudinal waves of mechanical energy that transmit the vibrations interpreted as sound (def. 2).
T wave the second major deflection of the normal surface electrocardiogram, reflecting the potential variations occurring with repolarization of the ventricles.
theta w's brain waves having a frequency of 4 to 7 per second, occurring mainly in children but also seen in adults under emotional stress.
tidal wave the wave after the percussion wave on a sphygmograph recording; the second elevation of the tracing, preceding the dicrotic wave.
ultrasonic w's waves similar to sonic waves but of such high frequency (20,000 hertz or higher) that the human ear does not perceive them as sound; see ultrasonics.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

ti·dal wave

the wave between the percussion wave and the dicrotic wave in the downward limb of the arterial pulse tracing.
Farlex Partner Medical Dictionary © Farlex 2012
An abrupt rise of tidal water—due to atmospheric or geological activities—which moves rapidly inland from the mouth of an estuary or from a coast, resulting in an extremely large wave sweeping in from the sea like a massive tide
(1) Undersea earthquakes, resulting in tsunamis—seismic sea waves
(2) Hurricanes, cyclones, or storms at sea, resulting in storm surge-type tidal waves
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
References in periodicals archive ?
At that moment a tidal wave came in and swept him straight out to sea.'
26 Kyodo - At least 497 people were killed Sunday in Indonesia's Sumatra Island after a major earthquake off the island triggered a tidal wave, local military, government and hospital officials said.
Fisherman Zulkfli Mohd Noor, 42, and his wife lost their five children to the tidal waves.
The death toll has reached at least 11,300 and has risen almost hourly since the first tidal waves, which registered 8.9 on the Richter scale as the world's most powerful earthquake in 40 years- rocked large parts of the region Sunday, triggering tidal waves and killing thousands of people.
The earthquake behind the tidal wave which swamped parts of Asia was caused by one of the Earth's plates moving just 15 metres.
The new series underlines the threat of natural disasters such as tidal waves, hurricanes and freak storms.
Tidal waves at Yonagunijima Island reached up to 10 centimeters and up to 5 cm in Ishigakijima Island.
This new series, exploring the damage caused by extreme weather conditions around the globe, begins with on-the-spot footage and eyewitness testimony to probe the destruction caused by tidal waves.
For instance, tidal waves constantly crash against the continental shelf, losing energy and rolling back out to sea.
Briggs communicates an intimacy and humor in his tale of two ordinary folks who struggle to keep afloat through the extraordinary tidal waves of change wrought by the Depression, WWII, and the Cold War while negotiating the daily challenges of marriage, child rearing, and growing old together.
The finding could be taken to confirm the hypothesis the tidal waves were caused by the earthquake's aftershocks causing diastrophism around the seabed valley some 30 km off the Papua New Guinea coast, the center said.
The city, in which Cleopatra had a palace, sank more than 1,600 years ago after a series of earthquakes and tidal waves.