Interatrial septum pacing avoids the adverse effect of interatrial delay in biventricular pacing: an echo-Doppler evaluation.
OBJECTIVE
Biventricular pacing (BVP) can improve haemodynamics in patients with dilated cardiomyopathy (DCM) and left bundle branch block by reducing interventricular delay (IVD). Since in DCM interatrial delay (IAD) and IVD frequently coexist, the aim of this study was to test the hypothesis that IVD reduction associated with IAD produces an imbalance between the programmed right atrioventricular (AV) delay and the effective AV delay on the left, and that interatrial septum pacing (IASP) combined with BVP overcomes this adverse effect.


RESULTS
IAD, IVD, left and right mechanical atrioventricular delay (L-RMAVD) were measured by echo-Doppler in 29 patients with BVP: 17 patients (Group A) had the atrial lead in the right atrial appendage, 12 patients (Group B) who experienced paroxysmal atrial fibrillation had the atrial lead on the interatrial septum. In Group A, LMAVD was significantly shorter than RMAVD (172 +/- 24 vs 207 +/- 24 ms, P<0.002), IAD was significantly longer than IVD (52 +/- 24 vs 21 +/- 18 ms, P<0.0001). In Group B, no differences were observed between LMAVD and RMAVD (187 +/- 32 vs 185 +/- 28 ms, NS), and between IAD and IVD (11 +/- 12 vs 13 +/- 16 ms, NS).


CONCLUSIONS
IAD produces different left and right atrioventricular sequences in BVP. IASP combined with BVP, by resynchronizing both atria and ventricles, is able to avoid this adverse effect.
Institute of Internal Medicine and Cardiology, University of Florence, Italy. c.porciani@dfc.unifi.it
Maria Cristina
MC
Porciani
Alessandra
A
Sabini
Andrea
A
Colella
Antonio
A
Michelucci
Nicola
N
Musilli
Paolo
P
Pieragnoli
Luigi
L
Padeletti
D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015150:Echocardiography, Doppler; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction