# Cardiac Nuclear Imaging Findings in Atypical Variants of Takotsubo Cardiomyopathy
## 3 Results
### Analysis of the Evidence
#### 3.3.2 Cardiac Nuclear Imaging Findings in Basal/Inverted/Reverse TTC  
Three out of five papers concerning basal/inverted/reverse TTC were performed using 123I-mIBG scintigraphy as a single cardiac nuclear imaging technique. In 2011, [PERSON] and colleagues [76] published a rare case of dobutamine-induced inverted TTC, which occurred with an atypical presentation including no chest pain, no ECG abnormalities, and a lack of increase in cardiac troponin. A 48-year-old female patient was referred to their echo laboratory due to a long history of atypical precordial chest pain. During a dobutamine/atropine stress echocardiogram, hypokinesia of the mid-basal anterior wall was noted and the test was interrupted. The recovery images showed a progressive worsening of the kinetic pattern withkinesia of all the left ventricular mid-basal segments and severe impairment of the global systolic function (LVEF = 25%). 123I-mIBG myocardial scintigraphy performed two months later showed decreased uptake in the whole left ventricle with increased washout in late images. A few years later, an interesting image by [PERSON] et al. [82] highlighted the dual role of 123I-mIBG scintigraphy in TTC through the case of a 41-year-old woman showing ischemic stroke and cardiogenic pulmonary edema a few hours after hysterectomy due to endometriosis. TTE showed a low LVEF at 25% with thrombi in the left ventricle. CMR performed a few days later revealed apical hyperkines and basal hypokinesis, as well as no late gadolinium enhancement. 123I-mIBG scintigraphy confirmed the presence of the acute dysfunction of the myocardial sympathetic nerve endings and revealed decreased uptake in the hypokinetic basal segments, sparing the apex, suggesting an atypical pattern of TTC. The whole-body planar scintigraphy performed 24 h after injection showed a high uptake of the right adrenal mass consistent with the presence of a pheochromocytoma, a possible endogenous cause of adrenergic stress related cardiomyopathyopathy. In this case, 123I-mIBG allowed for the final diagnosis of inverted stress-related cardiomyopathy secondary to pheochromocytoma. Following this paper, a year later, [PERSON] and colleagues [83] reported the case of a 40-year-old woman admitted to the Emergency Department for syncope associated with severe oppressive pain in the epigastric region. According to the Mayo Clinic criteria, the absence of coronary lesions, the presence of dyskinesia of the basal and middle segments, as well as the absence of myocarditis as confirmed by CMR, strongly suggested the diagnosis of inverted takotsubo cardiomyopathy which was confirmed through 123I-mIBG scintigraphy revealing increased adrenergic receptor activity in the apex, with simultaneous reduction in the basal region (See Figure 3). Myocardial scintigraphy with 99 mTc-sestamibi was performed as a single cardiac nuclear imaging modality to assess the left ventricular perfusion in the remaining two publications. A fixed midventricular and basal circumferential area of hypoperfusion and hypokinesis with preservation of the ventricular apex was revealed during a rest-stress dipyridamole Tc-99m secatinib myocardial perfusion G-SPECT by [PERSON] and coworkers [84] in a 49-year-old black male admitted to the intensive care unit with acute respiratory failure with anoxic encephalopathy and elevated cardiac biomarkers. In this case, as the anatomical distribution of the specific perfusion defects did not appear to represent obstructive epicardial coronary pathology, immediate coronary angiography was not performed and a final diagnosis of atypical stress-induced cardiomyopathy was made. In a recent study published in 2021, [PERSON] et al. [75] prospectively enrolled 20 patients with typical TTC and 8 patients (6 females, 2 males) with reverse TTC and assessed the minimum percentage uptake (min-%-uptake), extent score (ES), and summed rest score (SRS) at acute and chronic phases through myocardial perfusion scintigraphy with 99 mTc-sestamibi.