IJCS | Volume 32, Nº2, March/April 2019

199 Barbosa et al. Inverted takotsubo syndrome Int J Cardiovasc Sci. 2019;32(2)197-200 Case Report Discussion Clinically indistinguishable from classic ACS, TTS can present with or without variable changes on ECG, 2 as well as with elevation in myocardial lesion markers, 3,8 as seen in this report. Therefore, although TTS may be suspected through epidemiological data (postmenopausal women) and emotional stress as an event trigger, it may be difficult to distinguish TTS fromACS due to atherothrombosis in the initial assessment. 3 TTSmay also be triggered, although less frequently, by positive and pleasant emotions, which can make it even more difficult to identify. While the clinical presentation is usually similar, a greater prevalence of midventricular involvement is observed in cases of TTS resulting from positive emotions, compared to TTS caused by negative emotions (35.0% vs. 16.3%; p = 0.030). 9 Coronary angiography and left/echocardiographic ventriculography showed normal coronary arteries and involvement of ventricular walls which extended beyond one specific arterial territory. These conditions, associated with evidence of emotional or physical stress as precipitating factors, are considered criteria for the diagnosis of TTS, although not exclusively. 1,3 This report brings a case of ITS inwhich the diagnosis was made soon after the coronary anatomy had been defined on coronary angiography, confirmed by the classic appearance revealed by left ventriculography. Among the causes of non-obstructive coronary failure, TTS has presented increasing incidence, with variable evolution. The management of this syndrome with angiotensin converting enzyme inhibitors, angiotensin receptor blockers and beta-blockers is also reported; the latter, particularly due to evidence of adrenergic excess in its physiopathology. However, the benefits of these drugs to treat TTS and its variations lack solid scientific evidence. 8 The variant forms of TS, such as ITS, still have no well- established occurrence, clinical course or recurrence index in the world literature. Population differences are little known. A recent study has shown four morphological types of TTS: apical form, mid-ventricular form, basal (or inverted) form and focal form. 3 The estimated incidence of the different ventricle involvements were, respectively, 81.7%, 14.6%, 2.2% and 1.5%. The ITS is distinguished from the typical form through imaging tests that reveal basal akinesia or hypokinesia with apical LV compensatory hyperkinesia. Even though the cause of this variation is not defined yet, it has been proposed that its morphology is a direct result of the apex containing a higher density of adrenoreceptors in postmenopausal women, predisposing this group to this type of involvement. 6 In spite of these data, the reason why this type is rarer than the classical form of TTC is unknown. Some cases of ITS reported were considered secondary to pheochromocytoma, but this association, as well as its mechanism, are not cleared yet. 10,11 It is worth highlighting that TTS is just one among several possible causes of myocardial infarction with nonobstructive coronary arteries (MINOCA). Other possibilities should be considered, such as coronary spasm, rupture of atherosclerotic plaque, spontaneous coronary dissection, microvascular disorders, coronary embolism, use of sympathomimetic agents, myocarditis, cardiotoxic drugs and cardiac trauma. 12 A detailed analysis is recommended in unclear cases of MINOCA, with special attention to indications for magnetic cardiac resonance, 12,13 since it can distinguish types and patterns of myocardial lesions and is useful to confirm or rule out myocarditis. In addition, it can provide the basis for pathophysiological reasoning and clinical conduction in each case. 12,14 Other complementary methods may be necessary according to individual clinical findings, such as intracoronary ultrasound and echocardiogram with microbubbles. 15 Once considered a syndrome of benign course, because of spontaneous reversion of ventricular dysfunctionwithin weeks in most cases, the acute phase of TTS can lead to complications and death due to left ventricular outflow tract obstruction, ventricular arrhythmias, cardiogenic shock, ventricular rupture, ventricular thrombus formation and embolization. 7 In the long run, there may be TTS recurrences in about 14%of cases, and highmortality rate, usually attributed to comorbidities often found in TTS, such as neoplasms, intracranial hemorrhage, psychiatric disorders and lung diseases. 16,17 Clinical differences related to the subtypes and variations of TTS requiremore studies to be clarified, in order to obtain more long-run data for the different types of involvement. We reported a rare variant form of TTS: a diagnosis that has gained attention because of the growing stress in the modern world and increasing life-expectancy. Future scientific data shall turn to more accurate identification of possible patterns, the genetic changes involved, determination of degree of severity and more appropriate therapy.