Background

Cardiac sarcoidosis (CS) can present with various symptoms including heart failure, arrhythmias or sudden cardiac death. Due to this diverse presentation, the management can be challenging. We present a case of CS illuminating the significance of multimodality imaging techniques.

Case

26-year male with biopsy proven pulmonary sarcoidosis presented with palpitation and lightheadedness. EKG showed ventricular tachycardia (VT). Left Heart Catheterization showed nonobstructive coronaries. Cardiac MRI (CMR) with Delayed Hyper-Enhancement (DHE) images showed areas of fibrosis mostly in the septum and active inflammation mostly in the inferolateral and anterolateral wall consistent with CS. ICD was placed to prevent VT. Subsequently, Positron Emission Tomography (PET) scan was performed that showed significant diffuse uptake of the radiotracer in the left ventricular myocardium which demonstrated active CS. Patient was initially started on methotrexate and treatment was later escalated to infliximab with improvement of symptoms.

Discussion

Approximately 5% of patients with sarcoidosis experience CS. The clinical features, laboratory biomarkers, and traditional imaging findings have their limitations. The 2014 Heart Rhythm Society (HRS) Expert Consensus guideline includes both PET scan and CMR to increase diagnostic yield. CMR uses Late Gadolinium Enhancement (LGE) to assess function and identify fibrosis, while 18F-FDG PET scan uses 18F-FDG to assess myocardial inflammation. A study by Vita et.al showed that one third of LGE positive patients had no FDG uptake on PET scan. This concluded that CMR and PET provide complementary value in guiding further management as they assess different pathophysiology of the disease as evident in our case. Thus, our patient received a combination of ICD placement for scarring and anti-inflammatory agent for active inflammation. The amount of myocardial late enhancement detected during CMR is correlated with impaired left ventricular function and has prognostic implications. Blankstein et al. concluded that abnormal FDG uptake and perfusion defects are associated with higher risk of VT and death.

Conclusion

Randomized control trials are needed to standardize CS diagnostic criteria with PET and CMR, preventing under-diagnosis and guiding further management.

中文翻译：

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揭示心脏结节病之谜：先进成像方式的关键意义——病例报告

背景

心脏结节病 (CS) 可出现多种症状，包括心力衰竭、心律失常或心源性猝死。由于这种多样化的表现形式，管理可能具有挑战性。我们提出了一个 CS 案例来阐明多模态成像技术的重要性。

案件

26 岁男性，活检证实患有肺结节病，表现为心悸和头晕。心电图显示室性心动过速（VT）。左心导管插入术显示冠状动脉无阻塞。心脏 MRI (CMR) 和延迟超增强 (DHE) 图像显示纤维化区域主要位于隔膜，活动性炎症主要位于下外侧壁和前外侧壁，与 CS 一致。放置 ICD 是为了预防 VT。随后，进行正电子发射断层扫描(PET) 扫描，结果显示左心室心肌中放射性示踪剂显着弥漫性吸收，这证明了活性 CS。患者最初开始接受甲氨蝶呤治疗，随后升级为英夫利昔单抗治疗，症状有所改善。

讨论

大约 5% 的结节病患者经历 CS。临床特征、实验室生物标志物和传统影像学检查结果都有其局限性。2014 年心律协会 (HRS) 专家共识指南包括 PET 扫描和 CMR，以提高诊断率。CMR 使用晚期钆增强 (LGE) 来评估功能并识别纤维化，而 18F-FDG PET 扫描则使用 18F-FDG 来评估心肌炎症。Vita 等人的一项研究表明，三分之一的 LGE 阳性患者在 PET 扫描中未发现 FDG 摄取。结论是，CMR 和 PET 在指导进一步管理方面提供了互补价值，因为它们评估了疾病的不同病理生理学，正如我们的病例所示。因此，我们的患者接受了针对疤痕的 ICD 放置和针对活动性炎症的抗炎药物的组合治疗。CMR 期间检测到的心肌晚期增强量与左心室功能受损相关，并具有预后意义。布兰克斯坦等人。得出的结论是，FDG 摄取异常和灌注缺陷与 VT 和死亡风险较高相关。

结论

需要随机对照试验来标准化 PET 和 CMR 的 CS 诊断标准，防止诊断不足并指导进一步的治疗。