Giordano A, Calcagni M L, Rufini V, Colivicchi F, Melina D, Melina G, Pristipino C, Nori S, Trani C, Santarelli P
Department of Nuclear Medicine, Catholic University of the Sacred Heart, Rome, Italy.
Q J Nucl Med. 1995 Dec;39(4 Suppl 1):44-8.
[123I]MIBG has been proposed as a suitable tracer of the adrenergic system of the heart. The aims of this study was to investigate the adrenergic functional status of the heart in hypertensive patients with left ventricular hypertrophy (LVH), and to evaluate the distribution of neuroadrenergic terminals in patients with left ventricular aneurysms (LVA) presenting complex arrhythmias. We studied 21 patients (4 normals, 11 with LVH and hypertension, and 6 with previous myocardial infarction, LVA and complex arrhythmias) who underwent series of [123I]MIBG planar scans (from 0.5 to 24 hours p.i.) and SPECT scans using both [123I]MIBG and 201Tl. Data quantification was performed by calculating the heart/mediastinum ratio (planar scan) and the percent uptake in 5 myocardial regions (SPECT scan). No significant differences between normals and hypertensive patients were found either in the heart/mediastinum ratio or in the regional distribution of [123I]MIBG and 201Tl. In hypertensive patients the uptake of [123I]MIBG was significantly higher than that of 201Tl in the septal wall while in the lateral and inferior walls it was significantly lower. In patients with anteroapical myocardial infarction (MI), the size of the [123I]MIBG defect was slightly smaller than the 201Tl defect; moreover a constant, severe [123I]MIBG defect was observed in the inferior walls whereas 201Tl uptake was normal. We conclude that while in hypertensive patients adrenergic innervation seems to be slightly impaired as compared to myocardial perfusion, in patients with MI a large area of functional or anatomical denervation may be detected despite the preserved perfusion and viability; this mismatch may be the trigger of complex arrhythmias.
[123I]间碘苄胍已被提议作为心脏肾上腺素能系统的一种合适示踪剂。本研究的目的是调查左心室肥厚（LVH）高血压患者心脏的肾上腺素能功能状态，并评估出现复杂心律失常的左心室室壁瘤（LVA）患者神经肾上腺素能末梢的分布。我们研究了21例患者（4例正常者、11例LVH合并高血压患者以及6例既往有心肌梗死、LVA和复杂心律失常患者），这些患者接受了一系列[123I]间碘苄胍平面扫描（注射后0.5至24小时）以及使用[123I]间碘苄胍和201铊的单光子发射计算机断层扫描（SPECT）。通过计算心脏/纵隔比值（平面扫描）和5个心肌区域的摄取百分比（SPECT扫描）进行数据定量分析。在心脏/纵隔比值以及[123I]间碘苄胍和201铊的区域分布方面，正常者与高血压患者之间均未发现显著差异。在高血压患者中，[123I]间碘苄胍在室间隔壁的摄取显著高于201铊，而在侧壁和下壁则显著低于201铊。在前壁心尖心肌梗死（MI）患者中，[123I]间碘苄胍缺损的大小略小于201铊缺损；此外，在下壁观察到持续、严重的[123I]间碘苄胍缺损，而201铊摄取正常。我们得出结论，与心肌灌注相比，高血压患者的肾上腺素能神经支配似乎略有受损，而在MI患者中，尽管灌注和存活能力得以保留，但仍可检测到大面积的功能性或解剖性去神经支配；这种不匹配可能是复杂心律失常的触发因素。
