Takotsubo cardiomyopathy: definition and clinical profile. Heart Fail Clin. 2013;9:111-122, vii. [PMID: 23562112 DOI: 10.1016/j.hfc.2012.12.007]

Takotsubo Cardiomyopathy in a Post-COVID Case

Takotsubo cardiomyopathy (TTC) is a unique heart disease that mimics the clinical presentation of acute coronary syndrome and is seen more commonly in post-menopausal females. Here, we report a case that presents an ideal documentation of TTC depicting its characteristic clinical features and possible outcomes. TTC usually culminates in a complete reversal of both systolic and diastolic dysfunctions, however in our case of a post-COVID scenario, the persisting, rather worsening diastolic dysfunction might be a residual manifestation of COVID-19 myocarditis. Recent reports have found an increasing prevalence of TTC amidst the COVID-19 pandemic possibly as a result of the emotional and physical stress, and subsequent catecholamine surge caused by the virus in such patients. There might exist an independent association between TTC and the COVID-19 virus. Increased clinical evidence is required to establish the strength of this relationship, if any.

Multicenter retrospective database evaluation of Takotsubo syndrome in subjects undergoing catheter ablation for atrial fibrillation

Background

Intracardiac catheter ablation for atrial fibrillation with pulmonary vein isolation may result in Takotsubo syndrome (TS), but the frequency, predisposing factors (age, sex, mental health disorders), and outcomes are currently unknown. This study sought to assess the frequency, predisposing factors, and outcomes of subjects who underwent intracardiac catheter ablation for atrial fibrillation with pulmonary vein isolation and were diagnosed with TS.

Methods

This was a retrospective observational cohort study utilizing TriNetX® electronic health record (EHR) data. We included subjects aged older than 18 years who underwent intracardiac catheter ablation for atrial fibrillation with pulmonary vein isolation. The study population was divided into two groups (no TS diagnostic code presence and TS diagnostic code presence). We analyzed the distributions of age, sex, race, diagnostic codes, common terminology procedures (CPT), and vasoactive medication codes and examined mortality rate within 30 days.

Results

We included 69,116 subjects. Of these, 27 (0.04%) had a TS diagnostic code, the cohort was comprised mostly of females [17 (63.0%)], and 1 (3.7%) death within 30 days was reported. There were no significant differences in age and frequency of mental health disorders between those patients in TS and non-TS cohorts. Adjusting for age, sex, race, ethnicity, patient regionality, and mental health disorder diagnostic code, those patients who developed TS had a significantly higher odds of dying in 30 days after catheter ablation compared to those without TS (OR = 15.97, 95% CI: 2.10-121.55, p = .007).

Conclusions

Approximately 0.04% of subjects who underwent intracardiac catheter ablation of atrial fibrillation by pulmonary vein isolation had a subsequent diagnostic code of TS. Further study is needed to determine whether there are predisposing factors associated with the development of TS in subjects who undergo catheter ablation of atrial fibrillation by pulmonary vein isolation.

Neutrophile-Lymphocyte Ratio and Outcome in Takotsubo Syndrome

Background: Takotsubo syndrome (TTS) is an important type of acute heart failure with significant risk of acute complications and death. In this analysis we sought to identify predictors for in-hospital clinical outcome in TTS patients and present long-term outcomes. Methods: In this analysis from the Austrian national TTS registry, univariable and multivariable analyses were performed to identify significant predictors for severe in-hospital complications requiring immediate invasive treatment or leading to irreversible damage, such as cardiogenic shock, intubation, stroke, arrhythmias and death. Furthermore, the influence of independent predictors on long-term survival was evaluated. Results: A total of 338 patients (median age 72 years, 86.9% female) from six centers were included. Severe in-hospital complications occurred in 14.5% of patients. In multivariable analysis, high neutrophile-lymphocyte-ratio (NLR; OR 1.04 [95% CI 1.02−1.07], p = 0.009) and low LVEF (OR 0.92 [0.90−0.95] per %, p < 0.001) were significant predictors of severe in-hospital complications. Both the highest NLR tercile and the lowest LVEF tercile were significantly associated with reduced 5-year survival. Conclusions: Low LVEF and high NLR at admission were independently associated with increased in-hospital complications and reduced long-term survival in TTS patients. NLR is a new easy-to-measure tool to predict worse short- and long-term outcome after TTS.

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.

Role of Depression and Anxiety Disorders in Takotsubo Syndrome: The Psychiatric Side of Broken Heart

Takotsubo syndrome (TTS), also called broken heart syndrome, is an acute and transient cardiac wall motion abnormality of the left ventricle. The patient prototype is a post-menopausal woman with myocardial infarction-like symptoms (angina pectoris, breathlessness, palpitations, etc.) who has experienced sudden emotional or physical stress. Although prognosis is generally considered relatively benign, both complications and recurrence rates are not insignificant. Pathophysiological mechanisms underlying TTS are not entirely understood, but the sympathetic system over-activity has a leading role. Moreover, since emotional stress frequently triggers TTS and since precedent diagnosis of psychiatric disorders sometimes coexists, the psychological response to stress could be another potential therapeutic target. Indeed, this article aims to explore the association between underlying depression and anxiety disorders and TTS, as well as to find ideal therapeutic options useful to treat and prevent TTS. Thus in our review, we considered case reports, case-control studies, and review articles from PubMed. Papers dealing with Takotsubo syndrome and anxiety disorder or depression were selected. We included papers published since 2010 and whose abstract was in English. We concluded that anxiety disorders, but not depression, are associated with a higher occurrence of TTS. There is a link between anxiety, TTS, and inflammation leading to increased sympathetic activity. Nevertheless, patients with pre-admission psychiatric disorders have a higher risk of recurrent TTS. Importantly, the use of selective serotonin reuptake inhibitors (SSRIs) could be a potential therapeutic aid in preventing TTS's recurrence in selected patients.

Stress cardiomyopathy should be considered with unexpected hypotension in pregnant women

Stress-induced cardiomyopathy is expected that with the wide application of critical ultrasound, ICU doctors will find more cases, particularly among pregnant patients. Patients can actually survive the acute period of excessive stress, and their cardiac function can recover as long as effective treatment measures are taken.

Takotsubo cardiomyopathy and pituitary apoplexy: a case report

Background

Takotsubo cardiomyopathy (TTC) has been widely recognized in recent decades and is triggered by either physical or psychological stressors.

Case presentation

A 70-year-old woman presented to the Emergency Department due to confusion, hypotension, fever, chills, and cough. She had a one-year history of diabetes insipidus. Pituitary function examination at admission revealed decreased thyroid, sex and adrenal hormones. Pituitary MRI displayed findings suggestive of nonhemorrhagic pituitary apoplexy. Electrocardiogram (ECG) revealed T-wave inversion and extended QT interval. Transthoracic echocardiogram (TTE) showed left ventricular apical dysplasia and ballooning, accompanied by reduced left ventricular ejection fraction. Coronary angiography (CAG) revealed no obvious coronary arterial stenosis. The left ventriculogram demonstrated an octopus clathrate appearance. Most ECG and TTE changes recovered 10 days later.

Conclusions

To the best of our knowledge, this is the first report of newly diagnosed TTC associated with pituitary apoplexy.

Clinical Features and Outcomes of Patients with Chemotherapy-induced Takotsubo Syndrome

Chemotherapy treatment of malignancy accounts for 1–2% of takotsubo syndrome (TS) triggers. Women comprise 60–70% of patients with chemotherapy-associated TS, a distinctly lower prevalence than the 90% female prevalence in TS overall. Fluorouracil is the most commonly reported TS-triggering chemotherapeutic agent, although this must be interpreted in the context of the frequency of worldwide use of this agent. The onset of TS relative to chemotherapy initiation is quite variable, ranging from the initial administration to subsequent chemotherapy cycles several weeks beyond initiation. Limited information suggests chemotherapy can be safely reinitiated once the patient has recovered from the initial TS event. Having a TS event in the setting of chemotherapy treatment for malignancy is associated with substantial mortality.

Takotsubo syndrome occurring concomitantly with pre-eclampsia: A case report

Takotsubo syndrome (TTS) patients show transient ventricular dysfunction without coronary artery stenosis. We report a pregnant woman with TTS occurring concomitantly with severe pre-eclampsia (PE). A primiparous woman complained of dyspnea at 35 weeks of gestation. She showed severe PE, and cardiac ultrasound identified akinesis of the anterior lower wall. On the same day, emergent cesarean section was performed due to a nonreassuring fetus status, yielding a male infant with an umbilical artery pH of 6.851. Unfortunately, the neonate died of multiple organ failure. Following the delivery, her cardiac function markedly improved, and coronary angiography showed no coronary artery stenosis. Considering the clinical findings, we diagnosed the patient with TTS. Regarding antenatally occurring TTS, only six patients have been reported including the present one. Of the six patients, three had severe PE. Although previous reports on pregnancy-associated TTS described good maternal outcomes, antenatally occurring TTS complicated by severe PE may become critical for fetuses.

Stress Cardiomyopathy Diagnosis and Treatment: JACC State-of-the-Art Review

Stress cardiomyopathy is an acute reversible heart failure syndrome initially believed to represent a benign condition due to its self-limiting clinical course, but now recognized to be associated with a non-negligible rate of serious complications such as ventricular arrhythmias, systemic thromboembolism, and cardiogenic shock. Due to an increased awareness and recognition, the incidence of stress cardiomyopathy has been rising (15-30 cases per 100,000 per year), although the true incidence is unknown as the condition is likely underdiagnosed. Stress cardiomyopathy represents a form of neurocardiogenic myocardial stunning, and while the link between the brain and the heart is established, the exact pathophysiological mechanisms remain unclear. We herein review the proposed risk factors and triggers for the syndrome and discuss a practical approach to diagnosis and treatment of the patients with stress cardiomyopathy, highlighting potential challenges and unresolved questions.

[Acute Stress and Broken Heart Syndrome. A Case Report]

INTRODUCTION

Stress has been associated with an acute heart failure syndrome of important morbidity and mortality.

METHODS

Case report and non-systematic review of the relevant literature.

CASE PRESENTATION

A 65-year-old woman with a history of an untreated generalized anxiety disorder, whom after the violent death of her son presented with oppressive chest pain irradiated to neck and left superior extremity, lasting for more than 30minutes, initial clinical suspect suggests acute coronary syndrome.

LITERATURE REVIEW

Tako-tsubo cardiomyopathy is characterized by a reversible left ventricular dysfunction and wall movement abnormalities, without any compromise of the coronary arteries, associated to high plasma levels of catecholamines which in most cases correlates with an acute stress of emotional or physical type.

CONCLUSIONS

Tako-tsubo cardiomyopathy has to be considered by physicians among the differential diagnosis when facing a patient with suspected acute coronary syndrome, especially in post-menopausal women with a history of psychiatric comorbidities such as a generalized anxiety disorder.

Recurrent Stress Cardiomyopathy During COPD Exacerbation: Are Beta-adrenergic Agonists Only to Blame?

Takotsubo cardiomyopathy (TCM) is a variant of stress-induced cardiomyopathy, characterized by transient left ventricular dysfunction that may be associated with emotional or physical triggers. We present the case of a 51-year-old Caucasian female with severe chronic obstructive pulmonary disease (COPD) who presented with syncope and was found to have her second lifetime episode of stress-induced cardiomyopathy. Eight months prior, she had been admitted with a COPD exacerbation and was found to have left ventricular (LV) dysfunction with ejection fraction (EF) of 22% attributed to TCM with subsequent normalization of her left ventricular function. Recurrence of stress-induced cardiomyopathy associated with COPD is a rare phenomenon and its presentation raises the possibility of a common underlying mechanism.

Acute Pulmonary Edema in an Eclamptic Pregnant Patient: A Rare Case of Takotsubo Syndrome

Patient: Female, 35

Final Diagnosis: Takotsubo cardiomyopathy

Symptoms: Seizures

Medication: —

Clinical Procedure: Cesarean section

Specialty: Critical Care Medicine

Stress cardiomyopathy: Is it limited to Takotsubo syndrome? Problems of definition

In 2006, Takotsubo syndrome (TTC) was described as a distinct type of stress-induced cardiomyopathy (stress cardiomyopathy). However, when thinking about Takotsubo cardiomyopathy from the viewpoints of the AHA and ESC classifications, 2 possible problems may arise. The first potential problem is that a forecast of disease outcome is lacking in the ESC classification, whereas the AHA only states that 'outcome is favorable with appropriate medical therapy'. However, based on the literature data, one can make a general conclusion that occurrence of myocardial lesions in TTC (i.e., myocardial fibrosis and contraction-band necrosis) causes the same effects as in other diseases with similar levels of myocardial damage and should not be considered to have a lesser impact on mortality. To summarise, TTC can cause not only severe complications such as pulmonary oedema, cardiogenic shock, and dangerous ventricular arrhythmias, but also damage to the myocardium, which can result in the development of potentially fatal conditions even after the disappearance of LV apical ballooning. The second potential problem arises from the definition of TTC as a stress cardiomyopathy in the AHA classification. In fact, the main factors leading to TTC are stress and microvascular anginas, since, as has been already discussed, coronary spasm can cause myocardium stunning, resulting in persistent apical ballooning. Thus, based on this review, 3 distinct types of stress cardiomyopathies exist (variant angina, microvascular angina, and TTC), with poor prognosis. Adding these diseases to the classification of cardiomyopathies will facilitate diagnosis and preventive prolonged treatment, which should include intensive anti-stress therapy.

Current state of knowledge on Takotsubo syndrome: a Position Statement from the Taskforce on Takotsubo Syndrome of the Heart Failure Association of the European Society of Cardiology

Takotsubo syndrome is an acute reversible heart failure syndrome that is increasingly recognized in modern cardiology practice. This Position Statement from the European Society of Cardiology Heart Failure Association provides a comprehensive review of the various clinical and pathophysiological facets of Takotsubo syndrome, including nomenclature, definition, and diagnosis, primary and secondary clinical subtypes, anatomical variants, triggers, epidemiology, pathophysiology, clinical presentation, complications, prognosis, clinical investigations, and treatment approaches. Novel structured approaches to diagnosis, risk stratification, and management are presented, with new algorithms to aid decision-making by practising clinicians. These also cover more complex areas (e.g. uncertain diagnosis and delayed presentation) and the management of complex cases with ongoing symptoms after recovery, recurrent episodes, or spontaneous presentation. The unmet needs and future directions for research in this syndrome are also discussed.

Management of Takotsubo cardiomyopathy in non-academic hospitals in France: The Observational French SyndromEs of TakoTsubo (OFSETT) study

BACKGROUND

Takotsubo cardiomyopathy (TTC) is a rare condition characterized by a sudden temporary weakening of the heart. TTC can mimic acute myocardial infarction and is associated with a minimal release of myocardial biomarkers in the absence of obstructive coronary artery disease.

AIMS

To provide an extensive description of patients admitted to hospital for TTC throughout France and to study the management and outcomes of these patients.

METHODS

In 14 non-academic hospitals, we collected clinical, electrocardiographic, biological, psychological and therapeutic data in patients with a diagnosis of TTC according to the Mayo Clinic criteria.

RESULTS

Of 117 patients, 91.5% were women, mean ± SD age was 71.4 ± 12.1 years and the prevalence of risk factors was high (hypertension: 57.9%, dyslipidaemia: 33.0%, diabetes: 11.5%, obesity: 11.5%). The most common initial symptoms were chest pain (80.5%) and dyspnoea (24.1%). A triggering psychological event was detected in 64.3% of patients. ST-segment elevation was found in 41.7% of patients and T-wave inversion in 71.6%. Anterior leads were most frequently associated with ST-segment elevation, whereas T-wave inversion was more commonly associated with lateral leads, and Q-waves with septal leads. The ratio of peak B-type natriuretic peptide (BNP) or N-terminal prohormone BNP (NT-proBNP) level to peak troponin level was 1.01. No deaths occurred during the hospital phase. After 1 year of follow-up, 3 of 109 (2.8%) patients with available data died, including one cardiovascular death. Rehospitalizations occurred in 17.4% of patients: 2.8% due to acute heart failure and 14.7% due to non-cardiovascular causes. There was no recurrence of TTC.

CONCLUSIONS

This observational study of TTC included primarily women with atherosclerotic risk factors and mental stress. T-wave inversion was more common than ST-segment elevation. There were few adverse cardiovascular outcomes in these patients after 1-year follow-up.

Ischemic heart disease in women: a focus on risk factors

Heart disease remains a major contributor to morbidity and mortality in women in the United States and worldwide. This review highlights known and emerging risk factors for ischemic heart disease (IHD) in women. Traditional Framingham risk factors such as hypertension, hyperlipidemia, diabetes, smoking, as well as lifestyle habits such as unhealthy diet and sedentary lifestyle are all modifiable. Health care providers should be aware of emerging cardiac risk factors in women such as adverse pregnancy outcomes, systemic autoimmune disorders, obstructive sleep apnea, and radiation-induced heart disease; psychosocial factors such as mental stress, depression, anxiety, low socioeconomic status, and work and marital stress play an important role in IHD in women. Appropriate recognition and management of an array of risk factors is imperative given the growing burden of IHD and need to deliver cost-effective, quality care for women.

Recurrent Tako-Tsubo cardiomyopathy (TTC) in a pre-menopausal woman: late sequelae of a traumatic event?

Background

“Tako-Tsubo cardiomyopathy” (TTC) is a syndrome characterized by left ventricular (LV) wall motion abnormalities, usually without coronary artery disease, mimicking the diagnosis of acute coronary syndrome. It most often affects post-menopausal women and TTC tends to run a benign course with very low rates of recurrence, complications or mortality. The condition is also called “stress-induced cardiomyopathy” because acute physical or emotional stress appears to be frequently related to its onset. The pathogenic role of premorbid or comorbid psychiatric illnesses has been discussed controversially. For the first time, we present a case of fourfold recurrent TTC with severe complications in a pre-menopausal woman. Furthermore, a long history of flaring posttraumatic stress symptoms anteceded the first event.

Case presentation

A 43-year old, pre-menopausal Caucasian woman was hospitalized with symptoms of acute coronary syndrome. Clinical examination revealed hypokinetic wall motion in the apical ventricular region with no signs of coronary artery disease and diagnosis of TTC was established. She experienced recurrence three times within the following ten months, which led to thrombembolism and myocardial scarring among others. The circumstances of chronic distress were striking. 16 years ago she miscarried after having removed a myoma according to her doctor’s suggestion. Since then, she has suffered from symptoms of posttraumatic distress which peaked annually at the day of abortion. Chronic distress became even more pronounced after the premature birth of a daughter some years later. The first event of TTC occurred after a family dispute about parenting.

Conclusion

This is the first case report of fourfold TTC in a pre-menopausal woman. From somatic perspectives, the course of the disease with recurrences and complications underlines the fact that TTC is not entirely benign. Furthermore, it is the first case report of long lasting symptoms of traumatic stress anteceding TTC. Close connections between adrenergic signaling and late onset of clinical stress symptoms are well known in the psychopathology of traumatization. Although larger clinical trials are needed to elucidate possible interactions of premorbid psychiatric illnesses and TTC, cardiologists should be vigilant especially in cases of recurrent TTC.

Takotsubo Cardiomyopathy: Typical and Atypical Variants, A Two-Year Retrospective Cohort Study

Background

Typical or classical takotsubo cardiomyopathy (TCM) is associated with the characteristic abnormality of a ballooned left ventricular apex with basal segmental hyperkinesis. TCM may not present with the “classical” wall motion abnormalities but can have a variety of segmental wall motion abnormalities. The aim of our work was to assess for any unique identifying factors that can help distinguish typical and atypical variants of TCM.

Methods

We studied 11 consecutive patients between 2010 and 2012 admitted with chest pain, electrocardiographic and cardiac biomarker changes consistent with acute coronary syndrome (ACS) who underwent left heart angiography and were clinically diagnosed to have TCM.

Results

Our study found no specific features distinguishing typical and atypical variants of TCM. In our study, all patients were female and all had excellent outcome. One patient was in fourth decade of life, three patients in fifth and sixth decade of life, while remaining were older. One patient had diabetes mellitus, five had hypertension, four had concurrent coronary artery disease, but no patient had any family history of TCM. Nine of 11 patients had immediate clear-cut stressors. Three patients had normal ECG, two with ST segment elevation, with nine patients having only modest troponin elevations. One patient had an anomalous RCA take-off from the right coronary cusp, otherwise remaining patients had normal anatomy. One patient had only apical involvement, remaining had multiple wall motion abnormalities, and all patients had involvement of the anterior wall. Four patients had apical sparing. No inverted TCM pattern with basal akinesis with normal wall motion in the midventricular and apical regions was found among our patients.

Conclusions

We report that the classification of TCM as typical versus atypical is probably not clinically meaningful. The regional wall motion abnormalities are related to catecholamine excess and to the susceptibility of that particular region to excess catecholamine. We do not know why such differences in regional susceptibility exist, and agree with the other authors that sub-classification would only add to confusion, and a delay in understanding of the disease process.

Diagnosis of Takotsubo cardiomyopathy

Takotsubo cardiomyopathy, also known as left ventricular apical ballooning syndrome and stress-induced cardiomyopathy, is typically characterized by transient systolic dysfunction of the apical and mid-segments of the left ventricle, in the absence of obstructive coronary artery lesions. Patients may present with symptoms and signs of acute coronary syndrome, and the provider is challenged to differentiate between these conditions. In this review, we guide the reader through the diagnostic pathway, focusing on differential diagnoses and diagnostic criteria for takotsubo cardiomyopathy.

Epidemiology and clinical profile of Takotsubo cardiomyopathy

First described in Japan over 2 decades ago, takotsubo cardiomyopathy (TTC) has emerged as a unique cardiomyopathy with world-wide recognition, mimicking acute coronary syndrome. In early TTC experience, typical patients were older women, with a triggering emotional event, ST-segment elevation, and apical ballooning left ventricular (LV) contraction pattern. However, TTC is now more heterogeneous, occurring in males and younger individuals, without ST-segment elevation, as a spontaneous event in the absence of a trigger, and with diverse LV contraction patterns. Furthermore, TTC is more common than initially thought, now constituting 10% of women with suspected acute coronary syndrome. TTC is also associated with a broader range of psychological or physical triggers, including presentation during outpatient medical evaluations or hospitalization for acute illness. Although TTC has been considered a benign condition, it now carries a small but important risk for adverse outcomes, including cardiac arrest in 5%. Hemodynamic instability requiring intervention with vasopressor drugs or intra-aortic balloon pump is necessary in 15% and in-hospital mortality is approximately 5%, largely because of refractory cardiogenic shock or irreversible major comorbid conditions. Although complete cardiac recovery usually occurs rapidly, post-hospital survival may be less than the general population of similar age, largely because of concomitant illnesses. TTC may reoccur in up to 10% of patients, but β-blocking drugs are not absolutely preventive for initial or subsequent events.

Heart and lung, a dangerous liaison-Tako-tsubo cardiomyopathy and respiratory diseases: A systematic review

AIM: To investigate the possible association between Tako-tsubo cardiomyopathy (TTC)-a reversible clinical condition mimicking an acute myocardial infarction characterized by multifactorial pathophysiologic mechanisms- and respiratory system diseases.

METHODS: We systematically searched PubMed and EMBASE medical information sources, to identify the different triggering causes, limiting our search to articles in English. The search keywords were: “tako-tsubo cardiomyopathy”, “takotsubo”, “takotsubo cardiomyopathy”, “broken heart syndrome”, “stress-induced cardiomyopathy”, “apical ballooning syndrome”, and “ampulla cardiomyopathy in combination with respiratory diseases, lung, pulmonary disease. For each kind of disease, we registered: author, year and country of study, patient sex, age, concurring situation, and outcome.

RESULTS: Out of a total of 1725 articles found, we selected 37 papers reporting a total of 38 patients. As expected, most patients were women (81.6%), mean age was 65 ± 10 years. Outcome was favorable in 100% of cases, and all the patients have been discharged uneventfully in a few days.

CONCLUSION: An association between respiratory diseases and TTC is likely to exist. Patients with severe respiratory diseases, due to the high dosages of β₂-agonists used or to the need of invasive procedures, are highly exposed to the risk of developing TTC.