rhythm-, rhythmo- +
(Greek: regularly recurring motion; measured motion)
2. An irregular heartbeat that recurs repeatedly.
2. The normal brainwave in the electroencephalogram of a person who is awake but relaxed.
3. A pattern of smooth, regular electrical oscillations in the human brain that occur when a person is awake and relaxed.
As recorded by the electroencephalograph, alpha waves have a frequency of 8 to 13 hertz.
2. An agent that prevents or alleviates cardiac arrhythmia.
2. An irregularity in the rhythm of the heartbeat.
In an arrhythmia the heartbeats may be too slow, too rapid, too irregular, or too early.
Rapid arrhythmias (greater than 100 beats per minute) are called tachycardias. Slow arrhythmias (slower than 60 beats per minute) are called bradycardias. Irregular heart rhythms are called fibrillations (as in atrial fibrillation and ventricular fibrillation).
When a single heartbeat occurs earlier than normal, it is called a premature contraction.3. Any variation from the normal rhythm of the heartbeat; it may be an abnormality of either the rate, regularity, or site of impulse origin or the sequence of activation.
The term encompasses abnormal regular and irregular rhythms as well as loss of rhythm.
Rapid arrhythmias (greater than 100 beats per minute) are called "tachycardias" while slow arrhythmias (slower than 60 beats per minute) are called "bradycardias"; and sometimes, irregular heart rhythms are called fibrillations or muscular twitching in the heart that involves individual muscle fibers that move without coordination.
2. In electroencephalography, a rapid rhythm usually of low voltage, which can be recorded in the motor areas of the brain and sometimes in the frontal regions; especially, during states of stress or anxiety or after the administration of certain drugs such as barbiturates.
3. The second most common waveform occurring in electroencephalograms of the adult brain, characteristically having a frequency from 13 to 30 cycles per second.
It is associated with an alert waking state but can also occur as a sign of anxiety or apprehension.