Takotsubo syndrome in patients with myasthenia gravis: a systematic review of previously reported cases

Cardiac implications in myasthenia gravis

This editorial aimed to consolidate the current evidence in literature on the association between myasthenia gravis (MG) and cardiac involvement, focusing on the impact of thymoma, antistriational antibodies, and late-onset MG. Additionally, the study aimed to explore the influence of genetic differences among populations on the association with cardiac disease. We conducted a review of existing literature in PubMed and Google Scholar to find relevant studies on cardiac involvement in MG. We created search criteria using a combination of free text words, including MG, antistriational antibodies, thymectomy, cardiomyopathy, myocarditis, arrhythmias, autonomic dysfunction. Relevant articles published in English language were analyzed and incorporated. The findings indicate a strong association between thymoma, myasthenic crisis, antistriational antibodies, and late-onset MG with cardiac involvement. The study also revealed that genetic differences among populations influence the risk of cardiac disease and electrocardiography (ECG) abnormalities in MG patients. Autonomic dysfunctions altered cardiac autonomic response and increased susceptibility to arrhythmias and sudden cardiac death in MG patients. The study supports the significance of thymoma, antistriational antibodies, and late-onset MG as key factors associated with cardiac involvement in MG patients. It emphasizes the importance of ECG as the initial test in managing MG patients, particularly in the perioperative period, to identify and genetic testing if needed to address their cardiac risk effectively.

Myasthenic crisis-induced Takotsubo cardiomyopathy: a case report

Introduction and importance

Myasthenic crisis (MC) is characterized by severe weakness in the bulbar and respiratory muscles. Takotsubo cardiomyopathy (TC) is a rare clinical entity mainly associated with postmenopausal women. We report a case of both these conditions in a premenopausal woman.

Case presentation

A 31-year-old woman with hypothyroidism presented with dyspnea. Bedside echocardiography in the ICU revealed an apical ballooning with an ejection fraction of 25%, and she was treated with losartan, furosemide, and spironolactone. She was intubated after 2 days as she developed respiratory distress and type II respiratory failure. Upon investigation, the patient tested positive for anti-acetylcholine receptor antibody. Treatment with five doses of IVIG (intravenous immunoglobulin) was given, and she made a remarkable recovery. Repeat echocardiography revealed her ejection fraction is normal and cardiac function is resolved.

Clinical discussion

The association between TC and MC is unusual and not commonly observed. MC can be a natural progression of myasthenia gravis or due to stressors, such as infection, medicine, pregnancy, and surgery. Stressful events can lead to TC. This leads to the possibility of TC, along with other cardiac complications, in patients with MC.

Conclusion

Patients with MC may be at potential risk of developing TC, thus careful cardiac monitoring is necessary while treating them for a better prognosis.

Identification and Management of Acute Neuromuscular Respiratory Failure in the ICU

Respiratory failure is a common and potentially life-threatening complication of neuromuscular diseases. Prompt recognition and accurate diagnosis of new or worsening chronic neuromuscular disease have important clinical management and prognostic implications. In this article, we present an approach to the acute presentation of undifferentiated neuromuscular respiratory failure in the ICU and guidance for determination and respiratory management of the underlying disorder.

An Unfortunate Case of Takotsubo Cardiomyopathy During Plasmapheresis for Myasthenia Crisis

A literature review shows scarce reports of myasthenic crises (MC) complicated by Takotsubo cardiomyopathy (TC). This patient cohort (0.11%) has higher all-cause mortality and prolonged in-hospital course. We present a rare case of a 72-year-old man who developed cardiogenic shock post-plasmapheresis for myasthenia crisis. He became hemodynamically unstable and developed acute respiratory failure requiring intubation 30 minutes after completion of plasma exchange. Serum troponin peaked at 3.19 ng/mL while an emergent 12-lead electrocardiogram (EKG) showed new-onset diffuse ST-segment elevation. Hypokinesis of the entire apex, anterior septum, mid-and apical inferior septum, and mid-and apical inferior wall consistent with Takotsubo cardiomyopathy was seen on bedside echocardiogram. The patient received a continuous infusion of norepinephrine and vasopressin. The hospital course was complicated by multiorgan failure and eventual demise. This case highlights MC and the potential of plasma exchange therapy to induce TC.

Oxidative Stress in Takotsubo Syndrome-Is It Essential for an Acute Attack? Indirect Evidences Support Multisite Impact Including the Calcium Overload-Energy Failure Hypothesis

Indirect evidences in reviews and case reports on Takotsubo syndrome (TTS) support the fact that the existence of oxidative stress (OS) might be its common feature in the pre-acute stage. The sources of OS are exogenous (environmental factors including pharmacological and toxic influences) and endogenous, the combination of both may be present, and they are being discussed in detail. OS is associated with several pathological conditions representing TTS comorbidities and triggers. The dominant source of OS electrones are mitochondria. Our analysis of drug therapy related to acute TTS shows many interactions, e.g., cytostatics and glucocorticoids with mitochondrial cytochrome P450 and other enzymes important for OS. One of the most frequently discussed mechanisms in TTS is the effect of catecholamines on myocardium. Yet, their metabolic influence is neglected. OS is associated with the oxidation of catecholamines leading to the synthesis of their oxidized forms - aminochromes. Under pathological conditions, this pathway may dominate. There are evidences of interference between OS, catecholamine/aminochrome effects, their metabolism and antioxidant protection. The OS offensive may cause fast depletion of antioxidant protection including the homocystein-methionine system, whose activity decreases with age. The alteration of effector subcellular structures (mitochondria, sarco/endoplasmic reticulum) and subsequent changes in cellular energetics and calcium turnover may also occur and lead to the disruption of cellular function, including neurons and cardiomyocytes. On the organ level (nervous system and heart), neurocardiogenic stunning may occur. The effects of OS correspond to the effect of high doses of catecholamines in the experiment. Intensive OS might represent "conditio sine qua non" for this acute clinical condition. TTS might be significantly more complex pathology than currently perceived so far.

The Synergy of ADAM17-Induced Myocardial Inflammation and Metabolic Lipids Dysregulation During Acute Stress: New Pathophysiologic Insights Into Takotsubo Cardiomyopathy

Due to its reversible nature, Takotsubo cardiomyopathy (TTC) is considered an intriguing and fascinating cardiovascular disease characterized by a transient wall motion abnormality of the left ventricle, affecting more than one coronary artery territory, often in a circumferential apical distribution. Takotsubo cardiomyopathy was discovered by a Japanese cardiovascular expert and classified as acquired primary cardiomyopathy by the American Heart Association (AHA) in 1990 and 2006, respectively. Regardless of the extensive research efforts, its pathophysiology is still unclear; therefore, there are no well-established guidelines specifically for treating and managing TTC patients. Increasing evidence suggests that sympatho-adrenergic stimulation is strongly associated with the pathogenesis of this disease. Under acute stressful conditions, the hyperstimulation of beta-adrenergic receptors (β-ARs) resulting from excessive release of catecholamines induces intracellular kinases capable of phosphorylating and activating “A Disintegrin and Metalloprotease 17” (ADAM17), a type-I transmembrane protease that plays a central role in acute myocardial inflammation and metabolic lipids dysregulation which are the main hallmarks of TTC. However, our understanding of this is limited; hence this concise review provides a comprehensive insight into the key role of ADAM17 in acute myocardial inflammation and metabolic lipids dysregulation during acute stress. Also, how the synergy of ADAM17-induced acute inflammation and lipids dysregulation causes TTC is explained. Finally, potential therapeutic targets for TTC are also discussed.

Myasthenic crisis-induced Takotsubo cardiomyopathy in an elderly man: A case report of an underestimated but deadly combination

BACKGROUND

Patients with myasthenia gravis (MG) are at a higher risk of developing Takotsubo cardiomyopathy (TTC), particularly during a myasthenic crisis. Myasthenic crisis-associated TTC occurs predominantly in women. In this case report, we present a man with metastasized prostate carcinoma who developed TTC after new-onset MG.

CASE SUMMARY

An 81-year-old man with non-insulin dependent diabetes mellitus and metastasized prostate carcinoma presented with dyspnea. During primary assessment examination at the emergency department, there was evident blepharoptosis of his right eye. His electrocardiograms were suggestive of an acute anterior wall myocardial infarction, for which he underwent emergency coronary angiography. No obstructive coronary artery disease was found. During the coronary angiography, the patient developed respiratory failure and was admitted to the Intensive Care Unit for non-invasive respiratory support. The following day, diagnostic neostigmine test revealed a myasthenic crisis. Bedside echocardiography revealed left ventricular apical ballooning with a typical appearance of TTC. Despite the potentially reversible character of both MG and TTC, the patient and family requested an end of support in the Intensive Care Unit due to age and chronic malignancy with reduced quality of life in recent months after non-chemo-responding prostate carcinoma. The patient died soon after treatment withdrawal.

CONCLUSION

Elderly men should be carefully evaluated for TTC when new-onset MG is diagnosed.