Simantirakis Emmanuel N, Prassopoulos Vasilios K, Marketou Maria E, Chrysostomakis Stavros I, Koukouraki Sophia I, Lekakis John P, Karkavitsas Nikolaos S, Vardas Panos E
Cardiology Department, University Hospital of Heraklion, Crete, Greece.
Pacing Clin Electrophysiol. 2003 May;26(5):1202-7. doi: 10.1046/j.1460-9592.2003.t01-1-00169.x.
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.
本研究的目的是调查室内传导障碍患者的心肌灌注和肾上腺素能神经支配情况，并检测右心室心尖部起搏导致心室激动顺序改变所引起的任何变化。我们研究了15例右束支传导阻滞（RBBB）合并左前分支阻滞（LAFB）的患者，同时15名健康个体作为对照。所有患者在静脉注射5mCi 123I-间碘苄胍（123I-MIBG）后接受平面和单光子发射计算机断层扫描（SPECT）心肌显像，并在起搏器植入前和植入后3个月进行SPECT铊201心肌灌注研究。在123I-MIBG研究期间计算心脏与纵隔比值，以评估整体心脏交感神经活性，患者的该比值显著低于对照组（P<0.001）。RBBB和LAFB患者存在局部肾上腺素能神经支配缺陷，主要位于下壁和后壁。在中期起搏期后，检测到123I-MIBG摄取重新分布，心尖部和后壁的肾上腺素能神经支配缺陷加重，而间隔和前壁有所改善。5例患者起搏后灌注缺陷无变化。另外2例患者出现轻度心肌灌注缺陷，起搏前不存在。总之，RBBB和LAFB患者存在心肌肾上腺素能神经支配的整体和局部紊乱，这是由于心室电激动传播改变导致的重新分布。这些患者在较小程度上存在心肌灌注紊乱，起搏的中期效果有限。
