Doppler myocardial imaging to evaluate the effectiveness of pacing sites in patients receiving biventricular pacing.
OBJECTIVE
The goal of this study was to compare the efficacy of biventricular pacing (BIV) at the most delayed wall of the left ventricle (LV) and at other LV walls.


BACKGROUND
Biventricular pacing could provide additional benefit when it is applied at the most delayed site.


METHODS
In 31 patients with advanced nonischemic heart failure, the activation delay was defined, in blind before BIV, by regional noninvasive Tissue Doppler Imaging as the time interval between the end of the A-wave (C point) and the beginning of the E-wave (O point) from the basal level of each wall. The left pacing site was considered concordant with the most delayed site when the lead was inserted at the wall with the greatest regional interval between C and O points (CO(R)). After BIV, patients were divided into group A (13/31) (i.e., paced at the most delayed site) and group B (18/31) (i.e., paced at any other site).


RESULTS
After BIV, in all patients LV end-diastolic (LVEDV) and end-systolic (LVESV) volumes decreased (p = 0.025 and 0.001), LV ejection fraction (LVEF) increased (p = 0.002), QRS narrowed (p = 0.000), New York Heart Association class decreased (p = 0.006), 6-min walked distance (WD) increased (p = 0.046), the interval between closure and opening of mitral valve (CO) and isovolumic contraction time (ICT) decreased (p = 0.001 and 0.000), diastolic time (EA) and Q-P(2) interval increased (p = 0.003 and 0.000), while Q-A(2) interval and mean performance index (MPI) did not change. Group A showed greater improvement over group B in LVESV (p = 0.04), LVEF (p = 0.04), bicycle stress testing work (p = 0.03) and time (p = 0.08) capacity, CO (p = 0.04) and ICT (p = 0.02).


CONCLUSIONS
After BIV, LV performance improved significantly in all patients; however, the greatest improvement was found in patients paced at the most delayed site.
Ansalone
Gerardo
G
Department of Heart Diseases, San Filippo Neri Hospital, Rome, Italy. gansalone@iol.it
Giannantoni
Paride
P
Ricci
Renato
R
Trambaiolo
Paolo
P
Fedele
Francesco
F
Santini
Massimo
M
D002037:Bundle-Branch Block / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D006329:Heart Conduction System / Q000503:physiopathology; D006333:Heart Failure / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy; D006346:Heart Septum / Q000503:physiopathology; D006801:Humans; D009200:Myocardial Contraction / Q000502:physiology; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography