Hypothyroidism-induced reversible dilated cardiomyopathy

Utilities and Limitations of Cardiac Magnetic Resonance Imaging in Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is one of the most common types of non-ischemic cardiomyopathy. DCM is characterized by left ventricle (LV) dilatation and systolic dysfunction without coronary artery disease or abnormal loading conditions. DCM is not a single disease entity and has a complex historical background of revisions and updates to its definition because of its diverse etiology and clinical manifestations. In cases of LV dilatation and dysfunction, conditions with phenotypic overlap should be excluded before establishing a DCM diagnosis. The differential diagnoses of DCM include ischemic cardiomyopathy, valvular heart disease, burned-out hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy, and non-compaction. Cardiac magnetic resonance (CMR) imaging is helpful for evaluating DCM because it provides precise measurements of cardiac size, function, mass, and tissue characterization. Comprehensive analyses using various sequences, including cine imaging, late gadolinium enhancement imaging, and T1 and T2 mapping, may help establish differential diagnoses, etiological work-up, disease stratification, prognostic determination, and follow-up procedures in patients with DCM phenotypes. This article aimed to review the utilities and limitations of CMR in the diagnosis and assessment of DCM.

The Autosomal Short Tandem Repeat Polymorphisms Are Potentially Associated with Cardiovascular Disease Predisposition in the Latin American Population: A Mini Review

According to the World Health Organization, cardiovascular diseases (CVDs) are the leading cause of death worldwide across nearly all ethnic groups. Inherited cardiac conditions comprise a wide spectrum of diseases that affect the heart, including abnormal structural features and functional impairments. In Latin America, CVDs are the leading cause of death within the region. Factors such as population aging, unhealthy diet, obesity, smoking, and a sedentary lifestyle have increased the risk of CVD. The Latin American population is characterized by its diverse ethnic composition with varying percentages of each ancestral component (African, European, and Native American ancestry). Short tandem repeats (STRs) are DNA sequences with 2-6 base pair repetitions and constitute ~3% of the human genome. Importantly, significant allele frequency variations exist between different populations. While studies have described that STRs are in noncoding regions of the DNA, increasing evidence suggests that simple sequence repeat variations may be critical for proper gene activity and regulation. Furthermore, several STRs have been identified as potential disease predisposition markers. The present review is aimed at comparing and describing the frequencies of autosomal STR polymorphisms potentially associated with cardiovascular disease predisposition in Latin America compared with other populations.

The therapeutic effect of glucocorticoids on type II respiratory failure, heart failure, and massive pericardial effusion caused by hypothyroidism: A case report

Background: Hypothyroidism is a disease commonly observed in outpatient clinics but can occasionally cause severe cardiovascular and respiratory diseases requiring hospitalization.

Case report: The patient reported herein suffered from heart failure, massive pericardial effusion, type II respiratory failure, and hypothyroidism. There was no related basic diseases of respiratory and cardiovascular system in the past. She failed to be weaned from invasive ventilation multiple times after routine treatment and was finally successfully weaned on day five of receiving the combination therapy of a high-dose methylprednisolone intravenous drip and levothyroxine oral administration.

Conclusion: This case report indicates that hypothyroidism may be a cause of type II respiratory failure, heart failure, and massive pericardial effusion without cardiac tamponade and that a combination of levothyroxine and corticosteroids could effectively treat the disease. Clinical workers should consider the role of thyroid function in diagnosis, and the admission team should include this aspect in the monitoring scope. Moreover, the role of hormones in the treatment of patients with severe hypothyroidism should not be ignored, and timely treatment should be provided.

Non-Cardiac Cause of Death in Selected Group Children with Cardiac Pathology: A Retrospective Single Institute Study

Background: Pediatricians and pediatric surgeons often face children with cardiomegaly and dilatative or hypertrophic cardiomyopathies presenting with or without symptoms. Some of these patients have already been diagnosed and received medication, and some present with completely unrelated pathologies. Methods: We performed a 4-year retrospective study on the causes and mechanisms of death of children with cardiac pathology who died outside the cardiology clinic of our hospital by studying the hospital charts and necropsy reports. All children who were in this situation in our hospital were included. Results: Most children in our study group were infants (81.82%), most were boys (81.82%), and in most cases, the cause or mechanism of death was unrelated to their heart condition, whether it had already been diagnosed or not (one case probably died as a result of a malignant ventricular arrhythmia). Additionally, 27.27% of children died as a consequence of bronchopneumonia, the same percentage died as a consequence of an acquired non-pulmonary disease or after surgery, and 18.18% died as a consequence of congenital malformations. Conclusions: Cardiac disease needs to be thoroughly investigated using multiple tools for all children presenting with heart failure symptoms, those with heart murmurs, and children scheduled for surgery of any type. The intensive care specialist and surgeon need to be aware of any heart pathology before non-cardiac surgical interventions.

Thyroid Hormones-An Underestimated Player in Dilated Cardiomyopathy?

Dilated cardiomyopathy (DCM) is the most prevalent cardiomyopathy, typified by left ventricular dilation and systolic dysfunction. Many patients with DCM have altered thyroid status, especially lower levels of free triiodothyronine (T3) and elevated levels of thyroid-stimulating hormone. Moreover, growing evidence indicates that even subtle changes in thyroid status (especially low T3) are linked with a worse long-term prognosis and a higher risk of mortality. Notably, recent discoveries have shown that not only local myocardial thyroid hormones (THs) bioavailability could be diminished due to impaired expression of the activating deiodinase, but virtually all genes involved in TH biosynthesis are also expressed in the myocardium of DCM patients. Importantly, some studies have suggested beneficial effects of TH therapy in patients suffering from DCM. Our aim was to discuss new insights into the association between TH status and prognosis in DCM, abnormal expression of genes involved in the myocardial synthesis of TH in DCM, and the potential for TH use in the future treatment of DCM.

Review of canine dilated cardiomyopathy in the wake of diet-associated concerns

Dilated cardiomyopathy (DCM) has been in the literature and news because of the recent opinion-based journal articles and public releases by regulatory agencies. DCM is commonly associated with a genetic predisposition in certain dog breeds and can also occur secondary to other diseases and nutritional deficiencies. Recent communications in veterinary journals have discussed a potential relationship between grain-free and/or novel protein diets to DCM, citing a subjective increase in DCM in dog breeds that are not known to have a genetic predisposition for the disease. This literature review describes clinical presentations of DCM, common sequelae, treatment and preventative measures, histopathologic features, and a discussion of the varied etiological origins of the disease. In addition, current literature limitations are addressed, in order to ascertain multiple variables leading to the development of DCM. Future studies are needed to evaluate one variable at a time and to minimize confounding variables and speculation. Furthermore, to prevent sampling bias with the current FDA reports, the veterinary community should be asked to provide information for all cases of DCM in dogs. This should include cases during the same time period, regardless of the practitioner's proposed etiology, due to no definitive association between diets with specific characteristics, such as, but not limited to, grain-free diets and those containing legumes, novel protein diets, and those produced by small manufacturers to DCM in dogs. In summary, in order to determine if certain ingredients, categories of diets, or manufacturing processes are related to an increased risk of DCM, further studies investigating these variables are necessary.

HYPOTHYROIDISM INCREASES EXPRESSION OF STERILE INFLAMMATION PROTEINS IN RAT HEART TISSUE

Purpose

In this study, we aimed to investigate the relationship between hypothyroidism and sterile inflammation in rat heart tissue.

Methods

Groups; control group (fed with standard rat chow diet and tab water) and the hypothyroid group (fed with a standard rat chow diet and tap water containing 0.05% 6-n-propyl-2-thiouracil for 6-weeks). At the end of the experiment, histopathologic examination was performed. The T3, T4, TSH and myocardial malondialdehyde (MDA) measurements were performed with an ELISA kit. TUNEL assay was performed to demonstrate apoptosis. Sterile inflammation markers, caspase-1 and NLRP3, were investigated by immunohistochemistry and western blot.

Results

In histopathological examination, we observed leukocyte infiltration, myocardial atrophy, pyknotic nucleated cells and cytoplasmic vacuolization in hypothyroid group whereas the control group showed normal structure. MDA levels in myocardial tissue were significantly high in hypothyroid group when compared to the control group (P<0.05). Myocardial apoptosis increased in hypothyroid group when compared to the control group. NLRP3 and caspase-1 immunoreactivity was higher in the hypothyroid group. In ELISA results, we found significantly higher level of TSH and lower levels of T3 and T4 in hypothyroid group when compared to the control group.

Conclusion

Hypothyroidism increased oxidative stress, and caused inflammatory alterations in cardiac tissue. In addition, our study also suggested that thyroid hormone deficiency would increase the amounts of cardiac NLRP3 and caspase-1 protein, which indicates that hypothyroidism exerts its destructive effects through sterile inflammation. Elucidation of sterile inflammation-associated pathways may produce promising results in the treatment of hypothyroidism-induced cardiac damage.