TY - JOUR
T1 - Spatial heterogeneity of protein expression induced by dyssynchronous right ventricular pacing in the left ventricle of dogs with preserved systolic function
AU - Lin, Jih Min
AU - Lai, Ling Ping
AU - Chou, Nai Kuan
AU - Lin, Jiunn Lee
PY - 2010/8/1
Y1 - 2010/8/1
N2 - Background: Right ventricular (RV) apical pacing may result in ventricular dyssynchrony, which is associated with functional and morphological changes in the left ventricle (LV). Our aim is to assess contraction and hypertrophy-related protein expression changes in the LV after RV apical pacing. Methods and Results: Six dogs underwent dual chamber pacemaker (DDD) implantation and atrioventricular nodal catheter ablation. The pacing group received atria-sensed RV apical pacing for 12 weeks. LV dyssynchrony was assessed with speckle tracking technique. Subsequently, hearts were processed for Western blotting. Four sham-operated dogs were included for comparison. After 12 weeks of RV pacing, cardiac chamber size and LV ejection fraction remained unchanged. Both electrical and mechanical dyssynchrony were evident in RV-paced dogs compared with sham-operated dogs. The late-activated LV lateral wall of paced dogs displayed a 23% reduction in the amount of sarcoplasmic reticulum Ca2+ ATPase, a 32% reduction in phospholamban levels, but a 3.6-fold increase in phospho-JNK expression, a 2.2-fold increase in phospho-p38, and 1.9-fold increase in phospho-ERK expression. There were no significant differences in the early-activated LV septum between paced and sham dogs. Conclusions: Temporal dispersion of mechanical activation by RV apical pacing induced spatial dispersion of protein expression in the LV.
AB - Background: Right ventricular (RV) apical pacing may result in ventricular dyssynchrony, which is associated with functional and morphological changes in the left ventricle (LV). Our aim is to assess contraction and hypertrophy-related protein expression changes in the LV after RV apical pacing. Methods and Results: Six dogs underwent dual chamber pacemaker (DDD) implantation and atrioventricular nodal catheter ablation. The pacing group received atria-sensed RV apical pacing for 12 weeks. LV dyssynchrony was assessed with speckle tracking technique. Subsequently, hearts were processed for Western blotting. Four sham-operated dogs were included for comparison. After 12 weeks of RV pacing, cardiac chamber size and LV ejection fraction remained unchanged. Both electrical and mechanical dyssynchrony were evident in RV-paced dogs compared with sham-operated dogs. The late-activated LV lateral wall of paced dogs displayed a 23% reduction in the amount of sarcoplasmic reticulum Ca2+ ATPase, a 32% reduction in phospholamban levels, but a 3.6-fold increase in phospho-JNK expression, a 2.2-fold increase in phospho-p38, and 1.9-fold increase in phospho-ERK expression. There were no significant differences in the early-activated LV septum between paced and sham dogs. Conclusions: Temporal dispersion of mechanical activation by RV apical pacing induced spatial dispersion of protein expression in the LV.
KW - calcium handling protein
KW - Dyssynchrony
KW - heart failure
KW - mitogen-activated protein kinase
KW - ventricular pacing
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U2 - 10.1016/j.cardfail.2010.04.001
DO - 10.1016/j.cardfail.2010.04.001
M3 - Article
C2 - 20670849
AN - SCOPUS:77955509811
SN - 1071-9164
VL - 16
SP - 700
EP - 706
JO - Journal of Cardiac Failure
JF - Journal of Cardiac Failure
IS - 8
ER -