| umls-concept:C0004238 | skos:definition | MSH: Abnormal cardiac rhythm that is characterized by rapid, uncoordinated firing of electrical impulses in the upper chambers of the heart (HEART ATRIA). In such case, blood cannot be effectively pumped into the lower chambers of the heart (HEART VENTRICLES). It is caused by abnormal impulse generation.,CSP: disorder of cardiac rhythm characterized by rapid, irregular atrial impulses and ineffective atrial contractions.,NCI: A supraventricular arrhythmia characterized by uncoordinated atrial myocardium activation due to multiple reentry circuits with consequent deterioration of atrial mechanical function. Instead of intermittently contracting, the atria quiver continuously in a chaotic pattern, causing a totally irregular, often tachycardia ventricular rate. On the ECG it is described by the replacement of consistent P waves by rapid oscillations or fibrillatory waves that vary in size, shape, and timing, associated with an irregular, frequently rapid ventricular response when atrioventricular conduction is | lld:umls |
