Upgrading to biventricular pacing guided by pressure-volume loop analysis during implantation.
BACKGROUND
cardiac resynchronization therapy (CRT) may improve prognosis in patients with chronic right ventricular (RV) pacing, and optimal lead position can decrease nonresponders. We evaluated the clinical and echocardiographic response to CRT in patients with previous chronic RV pacing, using pressure-volume loop analyses to determine the optimal left ventricular (LV) lead position during implantation.


RESULTS
In this single-blinded, randomized, controlled crossover study, 40 patients with chronic RV apical pacing and symptoms of heart failure, decreased LV ejection fraction (LVEF) or dyssynchrony were included. During implantation, stroke work (SW), LVEF, cardiac output, and LV dP/dt(max) were assessed by a conductance catheter. Clinical and echocardiographic response was studied during a 3-month period of RV pacing (RV period, LV lead inactive) and a 3-month period of biventricular pacing (CRT period). At the optimal LV lead position, SW (37 ± 41%), LVEF (16 ± 13%), cardiac output (29 ± 16%), and LV dP/dt(max) increased (11 ± 11%) significantly during biventricular pacing compared to baseline. Additional benefit could be achieved by pressure-volume loop guided selection of the best left-sided pacing location. RV outflow tract pacing did not improve hemodynamics. During follow-up, symptoms improved during CRT, VO(2,max) increased 10% and significant improvements in LVEF, LV volumes, and mitral regurgitation were observed as compared to the RV period.


CONCLUSIONS
CRT in patients with chronic RV pacing causes significant improvement of both LV function as measured by pressure-volume loops during implantation and clinical and echocardiographic improvement during follow-up. Pressure-volume loops during implantation may facilitate selection of the most optimal pacing site.
Department of Cardiology, Isala klinieken, Zwolle, The Netherlands. v.r.c.derks@isala.nl
Peter Paul H M
PP
Delnoy
Jan Paul
JP
Ottervanger
Dick H S
DH
Vos
Arif
A
Elvan
Anand R Ramdat
AR
Misier
Willem P
WP
Beukema
Paul
P
Steendijk
Norbert M
NM
van Hemel
D000368:Aged; D001795:Blood Pressure Determination; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002306:Cardiac Volume; D018592:Cross-Over Studies; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000150:complications / Q000175:diagnosis* / Q000517:prevention & control*; D013813:Therapy, Computer-Assisted / Q000379:methods; D016896:Treatment Outcome