Atrial Fibrillation, April 20, 1985

Atrial Fibrillation, April 20, 1985

Atrial fibrillation is divided into paroxysmal and persistent types. The former has a rapid rhythm, while the latter has a slow rhythm. The former is commonly referred to as acute atrial fibrillation, and the latter as chronic atrial fibrillation. The electrocardiographic characteristics include disappearance of the P wave, replaced by f waves with a frequency of 350–600 times per minute, normal QRS complexes, or variations due to differences in intraventricular conduction, bundle branch block, or pre-excitation syndrome. The f waves may overlap with the QRS complexes, ST segments, and T waves, causing deformation. During atrial fibrillation, intraventricular conduction differences and ventricular premature beats are common. The former is more likely to occur when the ventricular rhythm is faster, with intraventricular conduction differences having no coupling interval with the basic heart rhythm R wave, and QRS complexes often showing right bundle branch block deformity, followed by no long pauses. Intraventricular conduction differences may appear after long R-R intervals, while ventricular premature beats are more common when the ventricular rate is slower, often with fixed coupling intervals and longer compensatory pauses.