Thyrotoxic Cardiomyopathy: State of the Art

Reversible acute heart failure induced by thyrotoxic cardiomyopathy: A case report

RATIONALE

Thyrotoxic cardiomyopathy is a rare but severe complication of thyrotoxicosis, leading to episodes of acute heart failure. This case report highlights a rare presentation of thyrotoxic cardiomyopathy with low-output heart failure, emphasizing the importance of early diagnosis and comprehensive management. The report aims to increase awareness among clinicians about the potential reversibility of this condition and the effective strategies for managing such complex cases.

PATIENT CONCERNS

This patient presented with dyspnea and chest constriction, without any antecedent predisposing factors. Subsequently, the patient abruptly manifested symptoms indicative of acute heart failure during outpatient consultation. Electrocardiography revealed rapid atrial fibrillation with type A preexcitation syndrome, whereas cardiac ultrasonography demonstrated global cardiac enlargement with a diminished ejection fraction (EF).

DIAGNOSES

After a comprehensive evaluation, the patient was diagnosed with thyrotoxic cardiomyopathy, acute heart failure, and atrial fibrillation with preexcitation syndrome.

INTERVENTIONS

Immediate interventions comprised diuretic administration, oxygen therapy, and antiarrhythmic agents, addressing acute heart failure concomitant with preexcitation syndrome. Following a fortnight of comprehensive therapeutic measures, the patient was discharged with a prescription for oral medications, notably methimazole.

OUTCOMES

Following the intervention, the patient showed significant improvement with the resolution of heart failure symptoms and dyspnea, restoration of sinus rhythm, improved left ventricular ejection fraction (LVEF improved from 36% to 45%), and normalization of thyroid function. These outcomes underscore the efficacy of the intervention strategy and offer a hopeful prognosis for similar cases.

LESSONS

Thyrotoxicosis may cause cardiomyopathy in patients with heart failure that manifests as dilated cardiac chambers. Clinicians should carefully screen patients for this reversible condition. Diagnosis requires a comprehensive assessment of various tests, and the therapeutic goal is to restore normal thyroid function.

Cardiac evaluation in amiodarone-induced thyroid dysfunction with suspected cardiac ischemia?: a case report and review of the literature

BACKGROUND

Amiodarone-induced thyroid dysfunction (AIT) is a side-effect associated with the use of Amiodarone for the treatment of refractory arrythmias. Resulting hyperthyroidism can precipitate cardiac complications, including cardiac ischemia and myocardial infarction, although this has only been described in a few case reports.

CASE PRESENTATION

We present here a clinical scenario involving a 66-year-old male Caucasian patient under Amiodarone for atrial fibrillation, who developed AIT. In the presence of dyspnea, multiple cardiovascular risk factors and ECG abnormalities, a transthoracic echocardiogram was performed, showing inferobasal hypokinesia. This led to further investigations through a cardiac PET-CT, where cardiac ischemia was suspected. Ultimately, the coronary angiography revealed no abnormalities. Nonetheless, these extensive cardiologic investigations led to a delay in initiating an emergency endovascular revascularization for acute-on-chronic left limb ischemia. Although initial treatment using Carbimazole was not successful after three weeks, the patient reached euthyroidism after completion of the treatment with Prednisone so that eventually thyroidectomy was not performed. Endovascular revascularization was finally performed after more than one month.

CONCLUSIONS

We discuss here cardiac abnormalities in patients with AIT, which may be due to relative ischemia secondary to increased metabolic demand during hyperthyroidism. Improvement of cardiac complications is expected through an optimal AIT therapy including medical therapy as the primary approach and, when necessary, thyroidectomy. Cardiac investigations in the context of AIT should be carefully considered and may not justify delaying other crucial interventions. If considered mandatory, diagnostic procedures such as coronary angiography should be preferred to functional testing.

Thyrotoxic Cardiomyopathy: A Rare Case of Thyroid Storm Presenting as De Novo Heart Failure

Thyroid storm and heart failure represent formidable challenges in clinical practice. Their coexistence, however, poses an even greater threat to the patient's well-being. To facilitate early recognition and appropriate management, an understanding of the complex interplay between these two conditions is crucial. Through comprehensive assessment, vigilant monitoring, and prompt intervention, outcomes can be improved and the morbidity and mortality mitigated. We present a rare case of a 40-year-old male who presented with severe de novo heart failure and a concurrent thyroid storm. Despite an initial left ventricular systolic ejection fraction of 20% and evidence of global dilatation and hypokinesis on echocardiography, appropriate management resulted in improved clinical status and ultimately recovery of cardiac function.

Thyrotoxic Cardiomyopathy Unveiled: Insights From a Compelling Case Report

Thyrotoxicosis is a clinical condition characterized by inappropriately elevated thyroid hormone levels in the bloodstream, leading to systemic effects on the body. In fact, the thyrotoxic state has tight regulatory control over the cardiovascular system through genomic and non-genomic mechanisms. This study highlights a rare presentation of thyrotoxic cardiomyopathy (TCM), which, to the best of our knowledge, is one of the very few case reports involving heart failure with preserved ejection fraction (HFpEF) and only atrial involvement, compared to the previous literature. A 37-year-old female presented to the outpatient clinic with abdominal distention and neglected signs and symptoms consistent with thyrotoxicosis for a year. Investigations revealed high N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels of 1788 pg/mL. Cardiac MRI and trans-thoracic echocardiogram (TTE) revealed bilateral atrial dilatation, a left ventricular ejection fraction (LVEF) of 60%, and diastolic dysfunction. Additionally, severe free-flowing tricuspid and mitral valve regurgitation were observed, with no evidence of pericardial effusion or ventricular abnormalities. Therefore, a diagnosis of TCM was suspected and eventually confirmed by excluding other differential diagnoses. Besides a diffuse goiter on ultrasonography, the thyroid panel test revealed low thyroid-stimulating hormone (TSH) levels of <0.01 mIU/L, a free thyroxine T4 of >100 pmol/L, and positive anti-thyroid peroxidase (TPO) and TSH receptor antibodies. Accordingly, a team of endocrinologists, cardiologists, and internists managed the patient with anti-thyroid medications alongside symptomatic treatment. A few days later, she was discharged in good condition, and a follow-up visit was arranged with the endocrinology and cardiology clinics. It is crucial to maintain a high level of suspicion to detect and treat TCM promptly, and a multidisciplinary approach should ideally be employed. This is not only important for the prevention of but also reversing potentially life-threatening cardiovascular complications.