Document Detail

Myocardial perfusion and adrenergic innervation in patients with RBBB and LAfB: the effect of altering the activation sequence with right ventricular apical pacing.
MedLine Citation:
PMID:  12765447     Owner:  NLM     Status:  MEDLINE    
The aim of this study was to investigate myocardial perfusion and adrenergic innervation in patients with intraventricular conduction disturbances and to detect any changes caused by alteration of the ventricular activation sequence as a result of right ventricular apical pacing. We studied 15 patients with right bundle branch block (RBBB) and left anterior fascicular block (LAFB), while 15 healthy individuals served as controls. All patients underwent planar and single-photon emission computed tomography (SPECT) myocardial imaging after intravenous infusion of 5mCi 123I-metaiodobenzylguanidine (123I-MIBG) and a SPECT thallium201 myocardial perfusion study before and 3 months after pacemaker implantation. The heart to mediastinum ratio was calculated during the 123I-MIBG study in order to assess the global cardiac sympathetic activity and was significantly smaller in patients than in controls (P < 0.001). Patients with RBBB and LAFB revealed regional adrenergic innervation defects, mostly in the inferior and posterior walls. After a medium-term pacing period, a redistribution of 123I-MIBG uptake was detected, with aggravation of adrenergic innervation defects in the apical and posterior walls and amelioration in septal and anterior walls. Five patients showed perfusion defects that remained unchanged after pacing. Two others displayed mild myocardial perfusion defects that did not exist before pacing. In conclusion, patients with RBBB and LAFB reveal global and regional disturbances of myocardial adrenergic innervation, which shows redistribution as a result of the altered propagation of the ventricular electrical activation. To a smaller degree these patients reveal myocardial perfusion disturbances in which pacing has a limited medium-term effect.
Emmanuel N Simantirakis; Vasilios K Prassopoulos; Maria E Marketou; Stavros I Chrysostomakis; Sophia I Koukouraki; John P Lekakis; Nikolaos S Karkavitsas; Panos E Vardas
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Pacing and clinical electrophysiology : PACE     Volume:  26     ISSN:  0147-8389     ISO Abbreviation:  Pacing Clin Electrophysiol     Publication Date:  2003 May 
Date Detail:
Created Date:  2003-05-26     Completed Date:  2003-10-02     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  7803944     Medline TA:  Pacing Clin Electrophysiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1202-7     Citation Subset:  IM    
Cardiology Department, University Hospital of Heraklion, Crete, Greece.
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MeSH Terms
Analysis of Variance
Bundle-Branch Block / physiopathology,  radionuclide imaging*,  therapy*
Case-Control Studies
Coronary Circulation*
Heart Ventricles / innervation*,  physiopathology,  radionuclide imaging
Iodine Radioisotopes / diagnostic use
Middle Aged
Pacemaker, Artificial*
Prospective Studies
Radiopharmaceuticals / diagnostic use
Thallium Radioisotopes / diagnostic use
Tomography, Emission-Computed, Single-Photon
Reg. No./Substance:
0/Iodine Radioisotopes; 0/Radiopharmaceuticals; 0/Thallium Radioisotopes

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