Chao Health Dictionary

the cessation of effective pumping action of the heart. This may be because the heart stops beating altogether (*asystole), because there is normal electrical activity without mechanical pumping activity (*pulseless electrical activity), or because there is rapid, chaotic, ineffective electrical and mechanical activity of the heart (ventricular *fibrillation or *ventricular tachycardia). There is abrupt loss of consciousness, absence of the pulse, and breathing stops. Unless treated promptly, irreversible brain damage and death follow within minutes. Some patients may be resuscitated by airway clearance and support, artificial ventilation, massage of the heart, and (if ventricular fibrillation or tachycardia is present) *defibrillation.... cardiac arrest

n. chaotic electrical and mechanical activity of a heart chamber, which results in loss of synchronous contraction. The affected part of the heart then ceases to pump blood.

Fibrillation may affect the atria or ventricles independently. In atrial fibrillation (a common type of *arrhythmia), the chaotic electrical activity of the atria is conducted to the ventricles in a random manner resulting in a rapid and irregular pulse rate. The main causes are atherosclerosis, chronic rheumatic heart disease, and hypertensive heart disease. It may also complicate various other conditions, including chest infections and thyroid overactivity. The heart rate is controlled by the administration of *digoxin; in some cases the heart rhythm can be restored to normal by *cardioversion. Anticoagulant therapy reduces the risk of blood-clot formation, which could cause a stroke.

When ventricular fibrillation occurs the ventricles stop beating (see cardiac arrest). It is most commonly the result of *myocardial infarction.... fibrillation

n. a disturbance of normal heart rhythm that – like *fibrillation – may affect the atria or ventricles. However, the arrhythmia is less rapid and less chaotic. The causes and treatment are similar to those of fibrillation. See also cardiac arrest; defibrillation.... flutter

a condition in which a person struggles to discard useless or worn-out possessions, acquires an excessive number of such items, and stores them in a chaotic manner resulting in unmanageable clutter. The items are nearly always of little or no monetary value, although valuable items are often found mixed indiscriminately with the rest. Hoarding disorder was included in DSM-5 in 2013 as a new disorder and has been considered for introduction in ICD-11.... hoarding disorder

n. a severe abnormality on an EEG (see electroencephalography) that demonstrates a chaotic pattern of brain activity. It is usually characteristic of *infantile spasms.... hypsarrhythmia