Subclinical hyperthyroidism and heart

Cardiovascular diseases (CVD) and thyroid dysfunction are two of the most prevailing disorders in the world that are closely interlinked. Actions of thyroid hormones are mediated via thyroid receptors present in the myocardium and the vascular tissue. Primary mechanism that links thyroid dysfunction with CVD is the modification of cardiovascular risk factors (dyslipidemia, blood pressure, coagulation parameters, etc.) resulting in endothelial and left ventricular systolic and diastolic dysfunction. Both overt and subclinical hyperthyroidism and hypothyroidism may cause adverse alterations in cardiac function...

The reversibility of HRV abnormalities in hyperthyroidism remains contradictory. The design of this study involves conducting a systematic review and meta-analysis on the effect of antithyroid treatments on HRV in hyperthyroidism. PubMed, Cochrane, Embase, and Google Scholar were searched until 4 April 2022. Multiple reviewers selected articles reporting HRV parameters in treated and untreated hyperthyroidism. Independent data extraction by multiple observers was stratified by degree of hyperthyroidism for each HRV parameter: RR intervals, SDNN (standard deviation of RR intervals), RMSSD (square root of the mean difference of successive RR intervals), pNN50 (percentage of RR intervals with >50 ms of variation), total power (TP), LFnu (low-frequency normalized unit) and HFnu (high-frequency), VLF (very low-frequency), and LF/HF ratio...

INTRODUCTION: Subclinical hyperthyroidism (SHT) is an endocrine disorder that is associated with abnormalities in heart structure and function. Oxidative stress plays an important role in the pathophysiology of cardiac disorders caused by SHT. Portulaca oleracea (P. Oleracea) is a herbaceous plant with many pharmacologic effects including antioxidant, and anti-inflammatory properties. In the present study, the effects of Portulaca oleracea and vitamin E on the biochemical, hemodynamic, and functional parameters of the cardiac tissue was studied in rats with subclinical hyperthyroidism...

INTRODUCTION: Thyroid disease is an independent predictor of heart failure in patients. This study aimed to investigate the prevalence of thyroid dysfunction among patients with heart failure in Mogadishu, Somalia. METHODS: From January 2019 to January 2021, a total of 250 patients diagnosed with heart failure admitted to the cardiology outpatient and emergency departments were evaluated retrospectively. The demographic characteristics, the cause of heart failure, and the kind of heart failure were recorded...

Hyperthyroidism directly affects the cardiovascular system, altering the heart's normal function and leading to high cardiovascular mortality. Excess thyroid hormones are associated with significantly increased risk and prevalence of cardiac arrhythmias, particularly atrial fibrillation (AF). This article reviewed the hemodynamic changes and the risk of cardiac arrhythmias, including atrial and ventricular arrhythmias associated with hyperthyroidism. It has also discussed the multi-level pathophysiology of thyrotoxic AF, sinus tachycardia, and different treatment modalities such as anti-thyroid drugs, beta-blockers, and the role of cardioversion and catheter ablation...

Objective: Cardiovascular effects of thyroid hormones may be measured through heart rate variability (HRV). We sought to determine the impact of hyperthyroidism on HRV. Design: A systematic review and meta-analysis on the impact of hyperthyroidism on HRV. Methods: PubMed, Cochrane, Embase and Google Scholar were searched until 20 August 2021 for articles reporting HRV parameters in untreated hyperthyroidism and healthy controls. Random-effects meta-analysis was stratified by degree of hyperthyroidism for each HRV parameter: RR intervals (or Normal-to-Normal intervals—NN), SDNN (standard deviation of RR intervals), RMSSD (square root of the mean difference of successive RR intervals), pNN50 (percentage of RR intervals with >50 ms of variation), total power (TP), LFnu (low-frequency normalized unit) and HFnu (high-frequency), VLF (very low-frequency), and LF/HF ratio...

Cardiovascular disease (CVD) remains the leading cause of death worldwide, representing a major health, social, and economic issue. Thyroid disorders are very common and affect >10% of the adult population in total. The aim of this review is to describe the physiologic role of thyroid hormones on cardiovascular system, to present cardiovascular manifestations in patients with thyroid disorders, emphasizing in molecular mechanisms and biochemical pathways, and to summarize current knowledge of treatment options...

IMPORTANCE: Thyroid disorders represent one of the most frequent complications of pregnancy associated with adverse obstetric, fetal, and neonatal outcomes, especially in case of delayed diagnosis and suboptimal management. OBJECTIVE: The aim of this study was to review and compare the recommendations of the most recently published guidelines on the diagnosis and management of these common conditions. EVIDENCE ACQUISITION: A descriptive review of guidelines from the Endocrine Society, the European Thyroid Association, the Royal Australian and New Zealand College of Obstetricians and Gynecologists, the American Thyroid Association, and the American College of Obstetricians and Gynecologists on thyroid disease in pregnancy was carried out...

Aim of the study : To assess the occurrence of cardiac arrhythmias caused by high doses of levothyroxine in patients with thyroid cancer with subclinical hyperthyroidism. Materials and Methods : This prospective study included 98 women divided into three groups according to plasma thyroid stimulating hormone (TSH) concentration: <0.1 µU/mL, 0.1-0.39 µU/mL, or 0.4-4.0 µU/mL (control group). All participants underwent laboratory tests and an electrocardiography (ECG) Holter test to assess their heart rate and the occurrence of arrhythmias...

The triad of palpitation, angina, and murmur is a classical feature of cardiac pathology. However, their presence sometimes uncovers a thyroid etiology. Identification well in time decreases out-of-pocket expenditures on illness and suffering. We report a case of a 40-year-old woman who presented with fever with chills, vomiting, palpitations, and shortness of breath for the past month. Also, she described chest pain as typical of angina. Multiple diagnoses were made elsewhere, but none of the treatments resulted in the resolution of symptoms...

Background: The relationship between thyroid function and cardiac disease is complex. Both hypothyroidism and thyrotoxicosis can predispose to ventricular arrhythmia and other major adverse cardiovascular events (MACE), so that a U-shaped relationship between thyroid signaling and the incidence of MACE has been postulated. Moreover, recently published data suggest an association between thyroid hormone concentration and the risk of sudden cardiac death (SCD) even in euthyroid populations with high-normal FT4 levels...

COVID-19 vaccines are the most critical measure for controlling the COVID-19 pandemic; however, we have little information on their complications. We experienced a case of a patient who developed hyperthyroidism complicated with atrial fibrillation and heart failure on the sixth day after the first dose of COVID-19 vaccination. This case report shows the importance of considering hyperthyroidism as a possible complication after COVID-19 vaccination.

PRACTICAL RELEVANCE: Hypertrophic cardiomyopathy (HCM) is the most common form of feline cardiomyopathy observed clinically and may affect up to approximately 15% of the domestic cat population, primarily as a subclinical disease. Fortunately, severe HCM, leading to heart failure or arterial thromboembolism (ATE), only occurs in a small proportion of these cats. PATIENT GROUP: Domestic cats of any age from 3 months upward, of either sex and of any breed, can be affected...

BACKGROUND: Thyroid crisis is a life-threatening condition in thyrotoxic patients. Although differentiated thyroid cancer is one of the causes of hyperthyroidism, reports on thyroid crisis caused by thyroid cancer are quite limited. Here, we describe a case of thyroid crisis caused by metastatic thyroid cancer. CASE PRESENTATION: A 91-year-old woman was admitted to our hospital because of loss of appetite. Two years prior to this hospitalization, she presented with subclinical thyrotoxicosis and was diagnosed with histologically unidentified thyroid cancer with multiple metastases, and she refused aggressive medical interventions...

Objective: To evaluate if subclinical thyroid dysfunction is associated with cardiovascular (CV) risk in patients with atrial fibrillation (AF). Methods: Swiss-AF is a prospective cohort of community-dwelling participants aged ≥ 65 years with AF. Primary outcome was a composite endpoint of CV events (myocardial infarctions, stroke/transitory ischemic events, systemic embolism, heart failure (HF) hospitalizations, CV deaths). Secondary outcomes were component endpoints, total mortality, and AF-progression...

BACKGROUND: Thyroid disorders, both overt and subclinical, are highly prevalent conditions in the general population. Although a clear relationship between overt thyroid dysfunctions and cardiovascular complications has long been established, data regarding subclinical thyroid dysfunction are by far more controversial. PURPOSE: The present review will be aimed at providing a summary of most recent evidence coming from meta-analyses regarding the complex relationship between thyroid dysfunction and cardiovascular disease...

OBJECTIVE: Subclinical hyperthyroidism (SHyper), defined as reduced thyrotropin with free hormones within the reference range, is a common medical finding, in particular in elderly people. In the last years has gained attention due to its health-related conditions, in particular at the cardiovascular level. MATERIALS AND METHODS: We searched electronic database (PubMed) and search engines (Google Scholar) of articles and reviews using the terms "subclinical hyperthyroidism", "Atrial fibrillation", Ischemic stroke", "Hypertension", Heart failure", and "Mortality"...

Thyroid dysfunction (TD) is common in metabolic disorders such as diabetes mellitus (DM), cardiovascular disease (CVD), obesity, dyslipidemia, hyperuricemia, kidney and liver dysfunctions, and polycystic ovary syndrome (PCOS). Subclinical hypothyroidism (SHypo) worsens glycemic control in patients with DM, and these patients, especially those with Type-1DM, have higher prevalence of TD. Both TD and DM increase CVD risk. Even minor alteration in thyroid hormone (TH) levels can alter cardiovascular function. While hyperthyroidism increases systolic blood pressure and leads to high-output heart failure, hypothyroidism increases diastolic blood pressure and leads to low-output heart failure...

OBJECTIVE: After an intravenous bolus injection of 100 mL of iodinated contrast agent (370 mgI/mL), the amount of iodine atoms entering the blood is tens of thousands of times the daily dose of iodine recommended by the World Health Organization. However, the effect of iodinated contrast in patients with nonthyroidal illness, manifested as reduced serum total triiodothyronine (TT3) concentrations, is unclear. We studied the effect of iodinated contrast on thyroid function and auto-antibodies in patients with reduced TT3 after diagnosis and treatment of coronary heart disease...

Thyroid hormone stimulates cardiac inotropy and chronotropy via direct genomic and non-genomic mechanisms. Hyperthyroidism magnifies these effects, resulting in an increase in heart rate, ejection fraction and blood volume. Hyperthyroidism also affects thrombogenesis and this may be linked to a probable tendency towards thrombosis in patients with hyperthyroidism. Patients with hyperthyroidism are therefore at higher risk for atrial fibrillation, heart failure and cardiovascular mortality. Similarly, TSH suppressive therapy for differentiated thyroid cancer is associated with increased cardiovascular risk...