Atrial fibrillation and flutter â€” epidemiology and mechanisms
Shared by: cqe15118 940ftxt06 14/7/04 11:22 am Page 104 104
ARRHYTHMIAS Atrial ﬁbrillation and ﬂutter — epidemiology and
mechanisms within the pulmonary vein oriﬁces, are commonly
responsible Atrial ﬁbrillation for episodes of atrial
ﬁbrillation in patients with otherwise Atrial ﬁbrillation is a
supraventricular arrhythmia characterised apparently normal
hearts (Fig. 3). Once initiated, the by rapid, chaotic
depolarisation of the atria. The atrial rhythm arrhythmia is
maintained by re-entry (pp. 98–99). Macro re- is irregular, with
rate from 300–500 per minute. Although the entry occurs when a
continuous loop of atrial depolarisation is AV node limits the
number of these impulses that reach the set up around an
anatomical or functional conduction barrier ventricles, atrial
ﬁbrillation usually produces a rapid, irregular (e.g. vein
oriﬁce, zone of diseased atrial tissue). During atrial
ventricular rhythm (Fig. 1; Table 1). Since the AV node ﬁbrill