Atrial Fibrillation ECG Review | 農藥百科
ThismeansanECGshowingatrialfibrillationwillhavenovisiblePwavesandanirregularlyirregularQRScomplex.Theventricularrateisfrequentlyfast, ...
Atrial fibrillation occurs when action potentials fire very rapidly within the pulmonary veins or atrium in a chaotic manner.
The result is a very fast atrial rate — about 400 to 600 beats per minute. Because the atrial rate is so fast, and the action potentials produced are of such low amplitude, P waves will not be seen on the ECG in patients with atrial fibrillation.
At times, the P wave activity may be observed as “coarse fibrillatory waves,” and the term “coarse atrial fibrillation” is used, though there is no clinical significance to this finding.
The atrial action potentials all attempt to conduct through the atrioventricular node; however, the AV node becomes intermittently refractory and will only allow a certain number of atrial action potentials to reach the ventricles. This is the reason the ventricular rate is not also 400 to 600 bpm, but rather around...