Document Detail

Thoracic Spinal Cord Stimulation Improves Cardiac Contractile Function and Myocardial Oxygen Consumption in a Porcine Model of Ischemic Heart Failure.
MedLine Citation:
PMID:  22151312     Owner:  NLM     Status:  Publisher    
Thoracic Spinal Cord Stimulation. Background: Prior experimental studies show that thoracic spinal cord stimulation (SCS) improves left ventricular (LV) ejection fraction (LVEF). The mechanism of this improvement in the LV contractile function after SCS and its effects on the myocardial oxygen consumption remains unknown. Methods and Results: We performed thoracic SCS (T1-T2 level) followed by 4 weeks of rapid ventricular pacing in 9 adult pigs with ischemic heart failure (HF) induced by myocardial infarction (MI). At 24 hours off-pacing, detailed echocardiogram and invasive hemodynamic assessment were performed to determine LV contractile function and myocardial oxygen consumption. Serum norepinephrine level was measured before and after SCS. SCS was performed on 2 occasions for 15 minutes, 30 minutes apart (recovery) with 50 Hz frequency (pulse width 0.2 millisecond, 90% of motor threshold at 2 Hz output). Echocardiogram revealed significant decrease in LVEF (33.8 ± 1.8% vs 66.5 ± 1.7%, P < 0.01) after induction of MI and HF. Compared with MI and HF, acute SCS significantly increased LVEF and +dP/dt (all P < 0.05). Withdrawal of SCS during recovery decreased +dP/dt, but not LVEF that increased again with repeated SCS. Myocardial oxygen consumption also significantly decreased during SCS compared with MI and HF (P = 0.006) without any change in serum norepinephrine level (P = 0.9). Speckle tracking imaging showed significant improvement in global and regional circumferential strains over the infarcted mid and apical regions, decreased in time to peak circumferential strain over the lateral and posterior wall after SCS, and the degree of intraventricular dyssynchrony during SCS compared with MI and HF (P < 0.05). Conclusions: In a porcine model of ischemic HF, acute SCS improved global and regional LV contractile function and intraventricular dyssynchrony, and decreased myocardial oxygen consumption without elevation of norepinephrine level. (J Cardiovasc Electrophysiol, Vol. pp. 1-7).
Yuan Liu; Wen-Sheng Yue; Song-Yan Liao; Yuelin Zhang; Ka-Wing Au; Chika Shuto; Cary Hata; Euljoon Park; Peter Chen; Chung-Wah Siu; Hung-Fat Tse
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-12-8
Journal Detail:
Title:  Journal of cardiovascular electrophysiology     Volume:  -     ISSN:  1540-8167     ISO Abbreviation:  -     Publication Date:  2011 Dec 
Date Detail:
Created Date:  2011-12-13     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9010756     Medline TA:  J Cardiovasc Electrophysiol     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
© 2011 Wiley Periodicals, Inc.
Cardiology Division, Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, China St. Jude Medical, Inc., St. Paul, Minnesota, USA Research Center of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong, China.
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