M. Efremidis et al., Effect of atrial pressure increase on effective refractory period and vulnerability to atrial fibrillation in patients with lone atrial fibrillation, J INTERV C, 3(4), 1999, pp. 307-310
Citations number
13
Categorie Soggetti
Cardiovascular & Respiratory Systems
Journal title
JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY
Background: There is evidence suggesting that atrial fibrillation (AF) may
be induced by acute increase of atrial pressure. The aim of the present stu
dy was to investigate the effect of alterations in atrial pressure, induced
by varying the atrioventricular (AV) interval, on atrial refractoriness, a
nd on the frequency of induction of (AF), in patients with a history of lon
e atrial fibrillation (LAF).
Methods and Results: Twenty-five patients were included in this study. The
patients were divided in two groups: the LAF group, and the control group.
None of the patients in either group had organic heart disease. Effective r
efractory period (ERP) and duration of atrial extrastimulus electrogram (A(
2)) were measured at two right atrial sites (high lateral wall, atrial appe
ndage) during AV pacing (cycle length: 500 msec) with different AV interval
s. Peak, minimal and mean atrial pressure increased from 8.57 +/- 2.37 to 1
8.14 +/- 4.74 mm Hg, 2 +/- 2.23 to 5.14 +/- 2.60 mm Hg (p = 0.0001) and fro
m 4.28 +/- 1.6 mm Hg to 9.77 +/- 2.9 mm Hg (p = 0.001), respectively during
AV interval modification. During lateral and atrial appendage pacing, with
a progressive decrease of AV interval to 160, 100, 80, 40, 0 msec, the ERP
, the dispersion of ERP, functional refractory period (FRP), A2 and latency
period (LP) did not change significantly, in both groups. The frequency of
induction of AF was not statistically different in both lateral atrial wal
l and appendage, during pacing in different AV intervals.
Conclusions: This study demonstrates that alterations in the intraatrial pr
essure does not have important effects on atrial refractoriness and does no
t increase vulnerability to AF in patients with a history of LAF.