takotsubo

Serial changes of myocardial perfusion imaging in takotsubo and reverse takotsubo cardiomyopathy

BACKGROUND

Takotsubo cardiomyopathy (TTC) shows reversible hypokinesis in the left ventricular (LV) apical-half segment and hyperkinesis in the LV basal-half segment. However, the precise pathophysiological mechanism of TTC is unclear. Therefore, this study sought to clarify the nuclear characteristics, degree of myocardial damage, and serial change of TTC and rTTC using myocardial perfusion imaging.

METHODS

We performed myocardial perfusion scintigraphy in 28 patients (TTC: 20, rTTC: 8) using Tc-99m sestamibi and assessed minimum percentage uptake (min-%-uptake), extent score (ES) and summed rest score (SRS) at acute and chronic phases.

RESULTS

Min-%-uptake improved from the acute to the chronic phase (TTC: 54 [48-59]% vs 87 [81-90]%, P  < 0.01; rTTC: 60 [55-64]% vs 77 [71-79]%, P < 0.01), as did the ES (TTC: 32 [26-41]% vs 0.0 [0.0-6.0]%, P < 0.01; rTTC: 16 [12-34]% vs 0.0 [0.0-0.0]%, P = 0.02) and SRS (TTC: 4.5 [3.9-5.3] vs 0.0 [0.0-0.2], P < 0.01; rTTC: 3.6 [3.3-3.8] vs 0.0 [0.0-0.0], P = 0.01).

CONCLUSION

Tc-99m sestamibi uptake was reduced in hypokinetic regions in the acute phase and improved in the chronic phase. TTC and rTTC may involve a reversible disorder of the myocardial cell membrane, mitochondria, and microcirculation.

Takotsubo Syndrome: Translational Implications and Pathomechanisms

Takotsubo syndrome (TTS) is identified as an acute severe ventricular systolic dysfunction, which is usually characterized by reversible and transient akinesia of walls of the ventricle in the absence of a significant obstructive coronary artery disease (CAD). Patients present with chest pain, ST-segment elevation or ischemia signs on ECG and increased troponin, similar to myocardial infarction. Currently, the known mechanisms associated with the development of TTS include elevated levels of circulating plasma catecholamines and their metabolites, coronary microvascular dysfunction, sympathetic hyperexcitability, inflammation, estrogen deficiency, spasm of the epicardial coronary vessels, genetic predisposition and thyroidal dysfunction. However, the real etiologic link remains unclear and seems to be multifactorial. Currently, the elusive pathogenesis of TTS and the lack of optimal treatment leads to the necessity of the application of experimental models or platforms for studying TTS. Excessive catecholamines can cause weakened ventricular wall motion at the apex and increased basal motion due to the apicobasal adrenoceptor gradient. The use of beta-blockers does not seem to impact the outcome of TTS patients, suggesting that signaling other than the beta-adrenoceptor-associated pathway is also involved and that the pathogenesis may be more complex than it was expected. Herein, we review the pathophysiological mechanisms related to TTS; preclinical TTS models and platforms such as animal models, human-induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) models and their usefulness for TTS studies, including exploring and improving the understanding of the pathomechanism of the disease. This might be helpful to provide novel insights on the exact pathophysiological mechanisms and may offer more information for experimental and clinical research on TTS.

Stepwise approach for diagnosis and management of Takotsubo syndrome with cardiac imaging tools

Takotsubo syndrome is featured by transient left ventricle dysfunction in the absence of significant coronary artery disease, mainly triggered by emotional or physical stress. Its clinical presentation is similar to acute coronary syndrome; therefore, cardiac imaging tools have a crucial role. Coronary angiography is mandatory for exclusion of pathological stenosis. On the other side, transthoracic echocardiography is the first non-invasive imaging modality for an early evaluation of left ventricle systolic and diastolic function. Left ventricle morphologic patterns could be identified according to the localization of wall motion abnormalities. Moreover, an early identification of potential mechanical and electrical complications such as left ventricle outflow tract obstruction, mitral regurgitation, thrombus formation, right ventricular involvement, cardiac rupture, and cardiac rhythm disorders could provide additional information for clinical management and therapy. Because of the dynamic evolution of the syndrome, comprehensive serial echocardiographic examinations should be systematically performed. Advanced techniques, including speckle-tracking echocardiography, cardiac magnetic resonance, and nuclear imaging can provide mechanistic and pathophysiologic insights into this syndrome. This review focuses on these aspects and provide a stepwise approach of all cardiac imaging tools for the diagnosis and the management of Takotsubo syndrome.

Multivessel Coronary Artery Vasospasm-Induced Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy is associated with a constellation of cardiac findings including reversible left ventricular dysfunction and an acute triggering stressor. Epicardial coronary vasospasm is a rarely reported etiology for takotsubo cardiomyopathy, and its pathophysiologic mechanisms still remain incompletely understood. We present the case of a 54-year-old female with chest pain and ST-elevation myocardial infarction who was found to have takotsubo cardiomyopathy due to diffuse multivessel coronary artery vasospasm in the absence of obstructive coronary artery disease. To our knowledge, this is the first angiographically confirmed case of this rare phenomenon to be reported, as most literature involves focal, segmental, or single coronary artery involvement. Moreover, we review current literature and develop a discussion on the targeted treatment of vasospastic disease as part of the multimodal approach to the management of takotsubo syndrome.

Case Report: Acute Heart Failure Induced by the Combination of Takayasu's, Takotsubo and Coronary Vasospasm in an Elementary School Teacher-A Reaction to Return-to-Work Stress After COVID-19?

INTRODUCTION

Takayasu's arteritis (TA) is a systemic inflammatory disease that affects aorta and its major branches. There are several cardiac manifestations of TA and an association with Takotsubo syndrome (TTS) - but not coronary vasospasm - has been previously reported. The role of emotional stress in this context is unknown.

CASE PRESENTATION

A 58-year-old Caucasian female elementary school teacher, with a history of generalized anxiety disorder (GAD), severe asymptomatic aortic regurgitation (AR), and TA in remission under corticosteroids, was admitted in the emergency department with worsening chest pain and dyspnea, initiated after a period of intense emotional stress (increased workload during COVID-19 pandemic). Physical examination revealed signs of heart failure (HF) with hemodynamic stability and an early diastolic heart murmur. The electrocardiogram showed sinus tachycardia, T wave inversion in left precordial and lateral leads, and a corrected QT of 487 ms. Laboratorial evaluation presented high values of high-sensitivity troponin I (3494 ng/L) and B-type natriuretic peptide (4759 pg/mL). The transthoracic echocardiogram revealed severe dilation of left ventricle (LV) with moderate systolic dysfunction, due to apical and midventricular akinesia, and severe AR. The coronary angiography showed normal coronary arteries. An acetylcholine provocative test induced spasm of both the left anterior descending and circumflex arteries, accompanied by chest pain and ST depression, completely reverted after intracoronary nitrates administration. The patient was switched to diltiazem and a drug multitherapy for HF was started. A cardiac magnetic resonance revealed severe dilation of the LV, mild apical hypokinesia, improvement of ejection fraction to 53%, signs of myocardial edema and increased extracellular volume in apical and mid-ventricular anterior and anterolateral walls, and absence of myocardial late gadolinium enhancement, compatible with TTS. At discharge, the patient was clinically stable, without signs of HF, and a progressive reduction of troponin and BNP levels was observed. A final diagnosis of TTS and coronary vasospasm in a patient with GAD and TA was done.

DISCUSSION

We present the first case of acute HF showing coexistence of TA, TTS and coronary vasospasm. TA is a rare inflammatory disease that can be associated with TTS and coronary vasospasm. Besides that, coronary vasospasm may also be involved in TTS pathophysiology, suggesting a complex interplay between these diseases. Mood disorders and anxiety influence the response to stress, through a gain of the hypothalamic-pituitary-adrenal axis and an increased cardiovascular system sensitivity to catecholamines. Therefore, although the mechanisms behind these three pathologies are not yet fully studied, this case supports the role of inflammatory and psychiatric diseases in TTS and coronary vasospasm.