Abnormal coronary vasoreactivity in transient left ventricular apical ballooning (tako-tsubo) syndrome

Coronary microvascular dysfunction in patients with Takotsubo syndrome

BACKGROUND

The pathophysiology of Takotsubo syndrome (TTS) remains incompletely understood. While coronary microvascular dysfunction (CMD) is a potential pathophysiologic mechanism, evidence is limited.

OBJECTIVES

We sought to evaluate CMD in patients with TTS.

METHODS

Consecutive patients diagnosed with TTS were included and underwent coronary angiography with invasive microvascular function evaluation, including fractional flow reserve, Coronary Flow Reserve (CFR), Index of Microcirculatory Resistance (IMR), and Resistive Reserve Ratio (RRR). Patients had an echocardiography evaluation during their index admission and at approximately 6 weeks.

RESULTS

Thirty patients were included (mean age 74 ±9, 90 % female). Twenty-five patients (83 %) had at least one abnormal coronary microvascular function parameter. Abnormal parameters included CFR<2.5 in 20 patients (67 %), IMR>25 in 18 patients (60 %), and RRR<3.5 in 25 (83 %). Longer time from symptoms to angiography correlated with a higher CFR (r = 0.51, P<0.01), and had an area under the receiver operating characteristic curve of 0.793 (95 % CI 0.60-0.98) for pathologic CFR. Patients with emotional trigger had a lower rate of pathologic IMR compared with non-emotional trigger (36 % vs 81 %, p = 0.01). Follow up echocardiography performed at a median of 1.5 months (IQR 1.15-6) showed an improvement in left ventricular ejection fraction for all patients (from mean of 40 % to 57 %).

CONCLUSION

CMD was present in most patients with TTS. The role of microvascular function in TTS may vary according to the clinical presentation and RRR may be more sensitive for the diagnosis of CMD in TTS.

Transient stress-related hyperviscosity and endothelial dysfunction in Takotsubo syndrome: a time course study

Takotsubo syndrome (TTS) is an acute and usually reversible heart failure syndrome, frequently associated with emotional or physical stress. Its pathophysiology remains largely unclear, although several mechanisms related to catecholaminergic storm have been proposed. In this study we analyzed during the acute phase of TTS and at follow-up both hemorheological parameters and biomarkers of endothelial damage, whose time course has never been fully explored. In 50 TTS women, we analyzed several hemorheological parameters [whole blood viscosity (WBV) at 0.512 s^-1 and at 94.5 s^-1, plasma viscosity (PLV), erythrocyte deformability and aggregation index] as well as biomarkers of endothelial dysfunction [von Willebrand Factor (vWF), Plasminogen activator inhibitor-1 and factor VIII levels] during the acute phase and after a median 6 months follow-up. These variables were also assessed in 50 age-matched healthy women. Respect to follow-up, in the acute phase of TTS we observed higher values of white blood cell count, fibrinogen, WBV at low and high shear rates, PLV, erythrocyte aggregation index and lower values of erythrocyte elongation index. Moreover, all biomarkers of endothelial dysfunction resulted significantly higher in the acute phase. During follow-up WBV at 94.5 s^-1, erythrocyte elongation index and vWF resulted significantly altered with respect to controls. The results of this study confirm the role of hyperviscosity and endothelial dysfunction in TTS pathophysiology. Moreover, they suggest the persistence of alterations of erythrocyte deformability and endothelial dysfunction even beyond the acute phase that could be the target of therapeutic strategies also during follow-up.

Imaging Assessment of Endothelial Function: An Index of Cardiovascular Health

Endothelial dysfunction is a key early mechanism in a variety of cardiovascular diseases and can be observed in larger conduit arteries as well as smaller resistance vessels (microvascular dysfunction). The presence of endothelial dysfunction is a strong prognosticator for cardiovascular events and mortality, and assessment of endothelial function can aid in selecting therapies and testing their response. While the gold standard method of measuring coronary endothelial function remains invasive angiography, several non-invasive imaging techniques have emerged for investigating both coronary and peripheral endothelial function. In this review, we will explore and summarize the current invasive and non-invasive modalities available for endothelial function assessment for clinical and research use, and discuss the strengths, limitations and future applications of each technique.

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.

Pathophysiology of Takotsubo Cardiomyopathy: Reopened Debate

Takotsubo cardiomyopathy (TTC), a persistently obscure dysfunctional condition of the left ventricle, is uniquely transient but nevertheless dangerous. It features variable ventricular patterns and is predominant in women. For 30 years, pathophysiologic investigations have progressed only slowly and with inadequate focus. It was initially proposed that sudden-onset spastic obliteration of coronary flow induced myocardial ischemia with residual stunning and thus TTC. Later, it was generally accepted without proof that, in the presence of pain or emotional stress, the dominant mechanism for TTC onset was a catecholamine surge that had a direct, toxic myocardial effect. We think that the manifestations of TTC are more dynamic and complex than can be assumed from catecholamine effects alone. In addition, after reviewing the recent medical literature and considering our own clinical observations, especially on spasm, we theorize that atherosclerotic coronary artery disease modulates and physically opposes obstruction during spasm. This phenomenon may explain the midventricular variant of TTC and the lower incidence of TTC in men. We continue to recommend and perform acetylcholine testing to reproduce TTC and to confirm our theory that coronary spasm is its initial pathophysiologic factor. An improved understanding of TTC is especially important because of the condition's markedly increased incidence during the ongoing COVID-19 pandemic.

Takotsubo Syndrome: Impact of endothelial dysfunction and oxidative stress

Takotsubo Syndrome (TTS) is characterized by a transient left ventricular dysfunction recovering spontaneously within days or weeks. Although the pathophysiology of TTS remains obscure, there is growing evidence suggesting TTS to be associated with increased production of reactive oxygen species (ROS), which may be involved in causing transient coronary and peripheral endothelial dysfunction leading to a transient impairment of myocardial contraction due to stunning (apical ballooning). Endothelial dysfunction is mainly caused by decreased vascular and myocardial nitric oxide bioavailability in response to increased ROS production. Accordingly, studies in humans and animal models demonstrated increased myocardial dihydroethidium staining of the myocardium in endomyocardial biopsy specimens, increased levels of hydrogen peroxide and malondialdehyde as well as reduced glutathione levels compatible with increased oxidative stress. As significant superoxide sources the mitochondria and the NADPH oxidase isoform NOX-4 and the NOX-2 regulating cytosolic subunit p67phox have been identified. Treatment with antioxidants such as sodium hydrosulfide reduced superoxide production in mitochondria and reduced expression of NOX-4 and p67phox, respectively. The presence of superoxide and nitric oxide also provides the basis for the concept of nitro-oxidative as well as nitrosative stress in TTS.

A case of recurrent takotsubo-like cardiomyopathy associated with pheochromocytoma exhibiting different patterns of left ventricular wall motion abnormality and coronary vasospasm: a case report

Background

Takotsubo-like cardiomyopathy associated with pheochromocytoma (Pheo-TTS) is a recognized but uncommon disorder. While Pheo-TTS might more often recur and the pattern of left ventricular (LV) wall motion abnormality is more diverse compared with primary TTS, it remains to be elucidated whether coronary functional abnormalities are also involved.

Case summary

A 50-year-old woman was referred with a chief complaint of transient chest pain, dyspnoea, and paroxysmal thyroid swelling that usually developed after meals. In the past, she had been admitted to emergency rooms three times due to pulmonary oedema following the above attacks. Serial cardiac catheterizations showed normal coronary arteries and morphologically different types of LV dysfunction each time; apical LV ballooning at the first, basal LV ballooning at the second, and diffuse LV hypokinesis at the last admission. Acetylcholine (ACh) provocation testing for coronary vasospasm was negative at the second admission. During hospitalization in our department, abdominal ultrasonography for screening detected a right adrenal mass and the urinary normetanephrine level was increased. The adrenal tumour was urgently removed surgically and finally she was diagnosed as having norepinephrine-secreting pheochromocytoma. Acetylcholine testing was again performed just after the operation, showing both epicardial and microvascular coronary spasms. Since the operation, she has been free of symptoms. Importantly, ACh testing at 1-year follow-up showed that epicardial spasm was no longer noted, whereas coronary microvascular spasm persisted.

Discussion

Adrenal pheochromocytoma could cause recurrent attacks of catecholamine surges with different patterns of LV dysfunction, where coronary vasospasm may also be involved along the coronary arteries.

Takotsubo cardiomyopathy in the setting of a myasthenic crisis

BACKGROUND

Myasthenic crisis is characterized by severe weakness in bulbar and respiratory muscles leading to respiratory failure and can be a natural result of myasthenia gravis or precipitate due to infections, surgeries, and pregnancy. It has been shown that stressful emotional events can lead to stress, or takotsubo cardiomyopathy. Takotsubo cardiomyopathy is characterized by transient reversible left ventricular dysfunction in the absence of obstructive artery disease with hypo- or akinesis of the apex with hypercontractility of the base.

METHODS

Case report and review of literature.

RESULTS

We report a 77-year old man with myasthenia gravis that was admitted to the neurological intensive care unit due to a myasthenic crisis. During the course of his treatment with plasma exchange, he developed hypotension with a reduced cardiac ejection fraction found on transthoracic electrocardiography. Repeat echocardiography 2 and 8 days later showed a normal ejection fraction and resolved cardiac function.

CONCLUSION

While takotsubo cardiomyopathy rarely presents concurrently with a myasthenic crisis, its consideration is warranted in the face of cardiovascular decompensation. Given that several cardiac complications are known to be associated with myasthenic crisis, cardiac monitoring is advised. Nine reports describe takotsubo cardiomyopathy occurring concurrently with a myasthenic crisis; however, only one report demonstrates this association in the absence of concomitant comorbidities or significant emotional distress.

Is Transient Takotsubo Syndrome Associated With Cancer? Why, and With What Implications for Oncocardiology?

See Article Cammann et al.

Heterogeneity of clinical presentation in Tako-Tsubo syndromes: the prevalence of normal segmental wall motion and normal ECG pattern

AIM

The aim of this study is to report the heterogeneity of clinical presentation in Tako-Tsubo syndrome (TTS), including a significant prevalence of normal ECG and echocardiographic patterns in a series of consecutive patients from a single center.

METHODS AND RESULTS

From our database we selected a total of 168 cases of TTS. A total of 140 of these (Group A); 14 men (10%), mean age 60.3 years, range 39-87; 126 women (90%), mean age 66.1 years, range 43-93; matched the following reported criteria: typical stenocardic pain immediately following an emotional acute stress, or acute medical or surgical event within the preceding 12 h; acute rise and fall of troponin release; absence of significant coronary disease at coronary angiography. ECG findings at presentation ranged from T wave abnormalities (41 cases, 29.3%) to ST elevation (52 cases, 37.1%) and ST depression (11 cases, 7.9%), whereas in 36 cases (25.7%) the ECG was normal. Echocardiography at presentation showed akinesia of the total apical or medium-apical segments in 74 patients (53%), whereas it showed akinesia of left ventricular wall segments in other locations in 30 patients (21%) and even normal regional wall motion and thickening in 36 patients (26%). We described also a series of 13 female patients (mean age 70.2 years; age range 45-85 years) (Group B) who did not complain of chest pain at presentation, but showed a classical Tako-Tsubo evolution of wall motion abnormalities at echocardiography. Finally we selected 15 female patients (mean age 69.3 years; age range 49-89 years) (Group C) who formally did not report acute stress immediately preceding their presentation to the hospital for chest pain. They showed a classical Tako-Tsubo evolution of wall motion abnormalities at echocardiography and only one case of normal ECG pattern at presentation.

CONCLUSION

In this series of acute TTS, a wide variability of ECG and echocardiographic patterns are observed, ranging from ST elevation with coexisting segmental wall motion abnormalities of the typical TTS to a clinical presentation characterized by normal ECG and normal segmental wall motion pattern.

Takotsubo Cardiomyopathy Mimicking Myocardial Infarction in a Man with Myasthenic Crisis: A Case Report and Literature Review

Takotsubo Cardiomyopathy is a syndrome characterized by transient and reversible regional myocardial dysfunction in the absence of obstructive coronary artery disease classically resulting in ventricular apical ballooning. It has a strong female predominance with onset generally in seventh decade of life, with hypothesized pathophysiology related to excess of catecholaminergic stimulation, particularly during episodes of physical or emotional stress. Takotsubo cardiomyopathy has been previously reported during myasthenic crisis, the acute deterioration of myasthenia gravis typically involving respiratory failure that is also associated with physical or emotional stress. We present the case of an atypically young male patient with classical takotsubo cardiomyopathy in the setting of myasthenic crisis after thymectomy initially concerning for ST segment elevation myocardial infarction, and a review of the literature of takotsubo cardiomyopathy in myasthenic crisis.