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Dual Diagnostic Role of 123I-MIBG Scintigraphy in Inverted-Takotsubo Pattern Cardiomyopathy Olivier Humbert, MD,*†‡ Karim Stamboul, MD,§|| Aurélie Gudjoncik, MD,§ Salim Kanoun, MD,*†‡ Carole Richard, MD, PhD,§|| Alexandre Cochet, MD, PhD,†‡ and Yves Cottin, MD, PhD§|| Abstract: We highlight the dual role of 123I-MIBG scintigraphy in inverted-Takotsubo pattern cardiomyopathy, the diagnosis of which is sometimes challenging: Firstly, 123I-MIBG scintigraphy can show myocardial sympathetic dysfunction (low 123I-MIBG uptake) in the hypokinetic basal segments, sparing the left ventricle apex. It is helpful in the imaging diagnosis of inverted-Takotsubo pattern cardiomyopathy and confirms that acute dysfunction of myocardial sympathetic nerve endings occurs with this cardiomyopathy. Secondly, 123I-MIBG scintigraphy is an accurate imaging examination to detect and localize pheochromocytoma; it can help in the search for an endogenous cause of this adrenergic stressrelated cardiomyopathy. (Clin Nucl Med 2015;40: 816–818) Received for publication January 7, 2015; revision accepted April 21, 2015. From the *Imaging Department, CHU, Dijon, France; †Nuclear Medicine Department, Centre GF Leclerc, Dijon, France; ‡Université de Bourgogne, UMR CNRS 6306, Dijon, France; §Cardiology Department, CHU, Dijon, France; and ||LPPCM, UMR INSERM 866, Dijon, France. Institution where work was performed: CHU Le Bocage, Dijon, France Conflicts of interest and sources of funding: none declared. Correspondence to: Olivier Humbert, MD, CHU Le Bocage, 1 bd Jeanne d’Arc, 21000 Dijon, France. E-mail: [email protected]. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0363-9762/15/4010–0816 DOI: 10.1097/RLU.0000000000000864

REFERENCES 1. Bybee KA, Kara T, Prasad A, et al. Systematic review: transient left ventricular apical ballooning: a syndrome that mimics ST-segment elevation myocardial infarction. Ann Intern Med. 2004;141:858–65. 2. Bybee KA, Prasad A. Stress-related cardiomyopathy syndromes. Circulation. 2008;118:397–409. 3. Wittstein IS, Thiemann DR, Lima JA, et al. Neurohumoral features of myocardial stunning due to sudden emotional stress. N Engl J Med. 2005;352:539–48. 4. Lyon AR, Rees PS, Prasad S, et al. Stress (Takotsubo) cardiomyopathy—a novel pathophysiological hypothesis to explain catecholamine-induced acute myocardial stunning. Nat Clin Pract Cardiovasc Med. 2008;5:22–9. 5. Haghi D, Papavassiliu T, Fluchter S, et al. Variant form of the acute apical ballooning syndrome (Takotsubo cardiomyopathy): observations on a novel entity. Heart. 2006;92:392–4. 6. Knuuti J, Sipola P. Is it time for cardiac innervation imaging? Q J Nucl Med Mol Imaging. 2005;49:97–105. 7. Agostini D, Carrio I, Verberne HJ. How to use myocardial 123I-MIBG scintigraphy in chronic heart failure. Eur J Nucl Med Mol Imaging. 2009;36:555–9. 8. Veltman C, Boogers M, Meinardi J, et al. Reproducibility of planar 123Imeta-iodobenzylguanidine (MIBG) myocardial scintigraphy in patients with heart failure. Eur J Nucl Med Mol Imaging. 2012;39:1599–608. 9. Di Valentino M, Balestra GM, Christ M, et al. Inverted Takotsubo cardiomyopathy due to pheochromocytoma. Eur Heart J. 2008;29:830. 10. Sanchez-Recalde A, Costero O, Oliver JM, et al. Images in cardiovascular medicine. Pheochromocytoma-related cardiomyopathy: inverted Takotsubo contractile pattern. Circulation. 2006;113:e738–739. 11. Kim S, Yu A, Filippone LA, et al. Inverted-Takotsubo pattern cardiomyopathy secondary to pheochromocytoma: a clinical case and literature review. Clin Cardiol. 2010;33:200–205.

FIGURE 1. A 41-year-old woman underwent hysterectomy because of endometriosis. Few hours after the surgical procedure, cardiogenic pulmonary edema and confusion appeared. Brain CT scan revealed an ischemic stroke. Trans-esophageal echocardiography showed a low left ventricular ejection fraction (LVEF) at 25% with thrombi in the left ventricle (LV). Heparin was started. Few days later, cardiac magnetic resonance (CMR) was performed. The cine-CMR sequences revealed apical hyperkinesis, basal hypokinesis, and a LVEF at 40% (A, B). Using inversion recovery sequence, no late gadolinium enhancement was assessed in the LV, ruling out myocardial infarction (C). Myocarditis or a Takotsubo cardiomyopathy with atypical pattern were 2 diagnostic hypotheses. Takotsubo cardiomyopathy (TTC) is a syndrome with an acute and transient left ventricular dysfunction, in the absence of obstructive coronary artery disease.1 It can occur under the influence of predisposing factors, such as severe emotional or physical stress.1,2 A toxic effect of a catecholamine excess is the hypothesis of choice to explain its pathophysiology.3,4 The concentration of β2-adrenoreceptors in the LV apex could explain why focal wall-motion abnormalities usually involve the apical segments.4 However, other TTC subtypes have been described, including an inverted type with akinesis of basal LV segments, sparing the apex.1,5 Pheochromocytoma-related cardiomyopathy is excluded from the Mayo clinic Takotsubo definition.1 Nonetheless, because of their similar transient focal wall-motion abnormalities,6 some authors have included both TTC and pheochromocytoma-related cardiomyopathies in the group of stress-related cardiomyopathies.2 Despite the help of CMR, the diagnosis of inverted stress cardiomyopathy is difficult. 816

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Clinical Nuclear Medicine • Volume 40, Number 10, October 2015

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I-MIBG Scintigraphy in Inverted Takotsubo

FIGURE 2. Because the 24-hour urinary metanephrines were measured at 30-fold the normal values, a 123I-MIBG scintigraphy was performed to search for pheochromocytoma. Indeed, 123I-MIBG is a tracer that presents the same uptake, storage, and release characteristics as endogenous norepinephrine in sympathetic nerve endings.6 It is an accurate examination to localize pheochromocytoma but can also provide information on sympathetic nervous function in the LV.7 Thus, myocardial scintigraphic studies were performed 15 minutes (early images) and 4 hours (delayed images) after the administration of 123 I-MIBG, with both planar and single-photon emission computed tomography (SPECT) acquisitions (A–C). The heart/mediastinum (H/M) ratios were calculated on planar images.8 Low H/M ratios, at 1.6 (early images) and 1.7 (delayed images), were obtained, reflecting a dysfunction of cardiac sympathetic nerve endings (A, B). On SPECT studies, regional uptake of 123I-MIBG was only reduced in the hypokinetic LV basal segments (C). For this patient with inverted-Takotsubo pattern cardiomyopathy, myocardial 123I-MIBG SPECT scintigraphy showed that, contrary to the usual apical pattern, the decrease in 123 I-MIBG uptake on SPECT images was mainly found in the hypokinetic basal LV segments, sparing the apex. It supports the notion of a sympathetic cardiac dysfunction in the hypokinetic LV base of the inverted-Takotsubo pattern cardiomyopathy and facilitates its diagnosis.

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FIGURE 3. Whole-body planar scintigraphic study was performed 24 hours after the same 123I-MIBG injection and showed a high uptake of the right adrenal mass with no abnormal extra-adrenal uptake; pheochromocytoma was strongly suggested and confirmed by surgical excision. The final diagnosis was inverted stress-related cardiomyopathy secondary to pheochromocytoma.9–11

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© 2015 Wolters Kluwer Health, Inc. All rights reserved. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Dual Diagnostic Role of 123I-MIBG Scintigraphy in Inverted-Takotsubo Pattern Cardiomyopathy.

We highlight the dual role of I-MIBG scintigraphy in inverted-Takotsubo pattern cardiomyopathy, the diagnosis of which is sometimes challenging: First...
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