Selecting the best site for pacing leads after cardiac surgery by evaluating the asynchrony of myocardial deformation observed with different pacing sites.
OBJECTIVE
After cardiac surgery, temporary pacing leads are routinely implanted in the right ventricle (RV). The objective was to investigate the effect of different ventricular pacing locations on cardiac synchrony (by evaluating myocardial deformation, or strain) and efficiency in patients undergoing cardiac surgery.


METHODS
Interventricular asynchrony (i.e. the difference in the time of onset of deformation between right and left ventricles; Tε-R/L) and intraventricular asynchrony (i.e. the standard deviation and maximum difference in the time of onset of deformation in six segments of the left ventricle [LV]; Tε-SD and Tε-MD, respectively) were assessed in 19 patients. Doppler echocardiography was used to evaluate these parameters and cardiac output after pacing in the RV and in three different LV segments.


RESULTS
Pacing in the RV resulted in the greatest increases in asynchrony parameters from baseline: Tε-R/L 59.8 ms (standard deviation [SD] 40.5 ms) vs. 28.23 ms (SD 56.9 ms), P=.002; Tε-SD 53.2 ms (SD 34.4 ms) vs. 36.6 ms (SD 34.9 ms), P=.007; and Tε-MD 135.3 ms (SD 82.9 ms) vs. 90.5 ms (SD 87.4 ms), P=.007. Pacing in the LV resulted in less asynchrony: for anterior LV pacing, Tε-R/L was 17.2 ms (SD 53.8 ms), Tε-SD was 35.8 ms (SD 17.9 ms), and Tε-MD was 91.3 ms (SD 45.2). The change from baseline was not significant. Cardiac output was lower after RV pacing than after anterior LV pacing: 4.36 (SD 1) vs. 4.70 (SD 1); P=.001.


CONCLUSIONS
Pacing in the LV produced less asynchrony than RV pacing. In addition, anterior LV pacing resulted in a higher cardiac output than RV pacing. These findings suggest that the location normally used for temporary leads after cardiac surgery should be changed.
Moya-Mur
José Luis
JL
Servicio de Cardiología, Hospital Ramón y Cajal, Madrid, España. jmoya.hrc@salud.madrid.org
Oliva-De Anquin
Enrique
E
Centella-Hernández
Tomasa
T
Ruiz-Leira
Soledad
S
Megías-Sáez
Alicia
A
Tomás-Zarlenga
Juan Pablo
JP
Hernández-Madrid
Antonio
A
García-Galloway
Eva
E
Moro
Concepción
C
D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D006348:Cardiac Surgical Procedures; D004452:Echocardiography; D004562:Electrocardiography; D004567:Electrodes, Implanted; D005260:Female; D006321:Heart / Q000502:physiology; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D010138:Pacemaker, Artificial; D015203:Reproducibility of Results