fibrillation

fibrillation /fi·bril·la·tion/ (fĭ″brĭ-la´shun)

1. the quality of being made up of fibrils.

2. a small, local, involuntary, muscular contraction, due to spontaneous activation of single muscle cells or muscle fibers whose nerve supply has been damaged or cut off.

3. the initial degenerative changes in osteoarthritis, marked by softening of the articular cartilage and development of vertical clefts between groups of cartilage cells.

---

atrial fibrillation  atrial arrhythmia marked by rapid randomized contractions of small areas of the atrial myocardium, causing a totally irregular, and often rapid, ventricular rate.

ventricular fibrillation  cardiac arrhythmia marked by fibrillary contractions of the ventricular muscle due to rapid repetitive excitation of myocardial fibers without coordinated ventricular contraction and by absence of atrial activity.

---

fib·ril·la·tion (fbr-lshn, fbr-)

n.

1. Fine, rapid twitching of individual muscle fibers with little or no movement of the muscle as a whole.

2. The formation of fibrils.

3. Vermicular twitching, usually slow, of individual muscular fibers, commonly occurring in the atria or ventricles of the heart and in recently denervated skeletal muscle fibers.

---

Fibrillation

Rapid, uncoordinated contractions of the upper or the lower chambers of the heart.

Mentioned in: Defibrillation, Electrocardiography, Electrophysiology Study of the Heart, Ventricular Ectopic Beats, Ventricular Tachycardia

---

fibrillation

[fī′brilā′shən]

Etymology: L, fibrilla, small fiber, atio, process

involuntary recurrent contraction of a single muscle fiber or of an isolated bundle of nerve fibers. Fibrillation of a chamber of the heart results in inefficient random contraction of that chamber and disruption of the normal sinus rhythm of the heart. Fibrillation is usually described by the part that is contracting abnormally, such as atrial fibrillation or ventricular fibrillation.

---

fibrillation (fī·br·lāˑ·shn),

n rapid localized contraction of a nerve fiber bundle or a solitary muscle fiber.

---

fibrillation (fib´rilā´shn),

n a local quivering of muscle fibers.

fibrillation, atrial,

n a cardiac arrhythmia caused by disturbed spread of excitation through atrial musculature.

Ibrillation, auricular

n an uncoordinated, independent contraction of the heart that results in marked irregularity of heart action.

fibrillation, ventricular,

n an uncoordinated, independent contraction of the ventricular musculature resulting in cessation of cardiac output.

---

fibrillation

1. a small, local, involuntary, muscular contraction, due to spontaneous activation of single muscle cells or muscle fibers.

2. the quality of being made up of fibrils.

3. the initial degenerative changes in osteoarthritis, marked by softening of the articular cartilage and development of vertical clefts between groups of cartilage cells.

---

atrial fibrillation

a cardiac arrhythmia marked by rapid randomized contractions of the atrial myocardium, causing a totally irregular, often rapid, ventricular rate. There is no synchronous atrial contraction and the ventricles beat irregularly. The heartbeat is irregular, the pulse is irregular in rhythm and amplitude. Common in the horse; an affected animal can still race but the performance is poor. Occurs in dogs in association with cardiac disease, particularly idiopathic congestive cardiomyopathy, and electrolyte disturbances.

ventricular fibrillation

a cardiac arrhythmia marked by fibrillatory contractions of the ventricular muscle due to rapid repetitive excitation of myocardial fibers without coordinated ventricular contraction. Ventricular fibrillation is a frequent cause of cardiac arrest. An apparatus called a defibrillator sometimes is used to alleviate fibrillation. The defibrillator delivers an electric shock to the heart muscle, depolarizing the muscle and ending the irregular contractions. The heart is then able to resume normal, regular contractions.

---

fibrillation

Cardiology Unsynchronized random and continuously changing electrical activity in the myocardium, causing inefficient pumping of blood. See Atrial fibrillation, Ventricular fibrillation.