Optimal pacing sites for cardiac resynchronization therapy for patients with a systemic right ventricle with or without a rudimentary left ventricle.
OBJECTIVE
This study aims to assess the impact of pacing sites on the effectiveness of cardiac resynchronization therapy (CRT) in systemic right ventricle (sRV) patients with/without a rudimentary left ventricle (rLV).


RESULTS
We evaluated 13 procedures in 11 sRV patients with a wide QRS (>150 ms). Based on the digitalization results of ventriculography, long-axis dyssynchrony (LD) was defined as extremely delayed right ventricular (RV) outflow tract movement: ≥100 ms delay from the RV apical contraction, and short-axis dyssynchrony (SD) was defined as a paradoxical contraction between the rLV and sRV caused by a conduction delay between the two ventricles. During the follow-up period (2.1 ± 1.9 years), the response rates were 71% (5/7) and 33% (2/6) in the sRV patients with and without an rLV, respectively (P = ns). Following the CRT, the QRS duration remained similar between the responders and nonresponders. Among five responders with an rLV, the leads were placed in the longitudinal RV direction in two with LD, longitudinal RV direction with fusion of the intrinsic QRS in two with LD + SD, and laterally on opposite sides of both ventricles in one with SD. Among two responders without an rLV, the leads were placed in the longitudinal RV direction in those two with LD.


CONCLUSIONS
In sRV patients with LD with/without an rLV, the leads should be placed at furthest sites in the longitudinal RV direction. In patients with an rLV and SD, the leads should be placed laterally on opposite sides of both ventricles.
Department of Pediatric Cardiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan ayamiya@ncvc.go.jp.
Aya
A
Miyazaki
Department of Pediatric Cardiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
Heima
H
Sakaguchi
Department of Pediatric Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
Koji
K
Kagisaki
Department of Pediatric Cardiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
Nobuyuki
N
Tsujii
Department of Pediatric Cardiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
Michio
M
Matsuoka
Department of Pediatric Cardiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
Tetsuya
T
Yamamoto
Department of Pediatric Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
Takaya
T
Hoashi
Division of Arrhythmias and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan.
Takashi
T
Noda
Department of Pediatric Cardiology, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
Hideo
H
Ohuchi
D000328:Adult; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000002:abnormalities*; D006801:Humans; D008297:Male; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000517:prevention & control*; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis* / Q000517:prevention & control*; D055815:Young Adult
Cardiac resynchronization therapy; Congenital heart disease; Optimal pacing site; Systemic right ventricle