QT interval

BACKGROUND: Thousands of people suffer from anxiety, depression, and insomnia every day, with benzodiazepines being one of the strategies used to treat these conditions. Withdrawal from its long-term use can lead to potentially life-threatening complications, including Takotsubo syndrome. The authors highlight an atypical case of Takotsubo syndrome secondary to benzodiazepine withdrawal, a rare life-threatening complication of acute substance withdrawal. CASE SUMMARY: A 58-year-old female presented to the emergency department with altered mental status and acute pulmonary oedema after discontinuing her prescribed benzodiazepines 3 days prior to presentation...

Identifying causal variants among tens or hundreds of associated variants at each locus mapped by genome-wide association studies (GWAS) of complex traits is a challenge. As vast majority of GWAS variants are noncoding, sequence variation at cis -regulatory elements affecting transcriptional expression of specific genes is a widely accepted molecular hypothesis. Following this cis -regulatory hypothesis and combining it with the observation that nucleosome-free open chromatin is a universal hallmark of all types of cis -regulatory elements, we aimed to identify candidate causal regulatory variants underlying electrocardiographic QT interval GWAS loci...

INTRODUCTION: Long QT syndrome (LQTS) is a common congenital cause of fatal cardiac arrhythmia. Characteristic clinical findings are prolonged QT interval and ventricular arrhythmia on electrocardiogram (ECG), syncope, seizure, and sudden death. It is a genetically heterogeneous disease. To date, disease-causing variant have been reported in seventeen genes. The AKAP9 is still considered controversial among those genes. CASE REPORT: We report the case of a 10-year-old female who was born from a non-consanguineous Turkish couple...

INTRODUCTION: Combination-based adjuvant chemotherapy utilising capecitabine and oxaliplatin is widely used in gastric cancer treatment. Rare but severe cardiac events such as prolonged QT, cardiac arrest and cardiogenic shock can result from their use. CASE DESCRIPTION: A 45-year-old female with gastric adenocarcinoma was started on capecitabine-oxaliplatin chemotherapy one week before presenting to the emergency department with weakness. Blood pressure was 78/56 mmHg, heart rate 140 bpm and oxygen saturation 85%...

BACKGROUND: Cholinesterase inhibitors (ChEIs) are regularly used in Alzheimer's disease. Of the three ChEIs approved for dementia, donepezil is among the most prescribed drugs in the United States with nearly 6 million prescriptions in 2020; however, it is classified as a "known risk" QT interval-prolonging medication (QTPmed). Given this claim is derived from observational data including single case reports, we aimed to evaluate high-quality literature on the frequency and nature of proarrhythmic major adverse cardiac events (MACE) associated with donepezil...

BACKGROUND: The control of the cardiovascular system depends on the autonomic nerve system. Chronic anabolic andorogenic steroids (AAS) use causes sympathovagal imbalance and increases sympathetic nerve activity. OBJECTIVE: The reduction in heart rate from the peak exercise rate following the end of the exercise stress test is known as the heart rate recovery index (HRRI). Several methods have been utilized to assess myocardial repolarization, such as QT interval (QT), corrected QT interval (QTc), and T-wave peak-to-end interval (Tp-e interval)...

A 69-year-old woman was admitted after a cardiac arrest. She developed status epilepticus and was later found to have variable morphologies of a "spiked helmet sign" (SHS) on ECGs in the setting of prolonged QT interval, raising the question of whether this sign is a manifestation of QT prolongation.

BACKGROUND: Ondansetron is one of the most commonly used drugs in the emergency department (ED) for treating nausea and vomiting, particularly in intravenous (IV) form. Nevertheless, it has been shown to prolong QT interval and increase the risk of ventricular dysrhythmias. This study evaluated the associations between single IV ondansetron dosage and subsequent QTc prolongation in the ED. METHODS: In this prospective observational study, a total number of 106 patients presenting to the ED in a 3-month period with nausea and vomiting treated with IV ondansetron were enrolled...

Congenital long QT syndrome (LQTS) is an inherited arrhythmia syndrome associated with sudden cardiac death. Accurate interpretation and classification of genetic variants in LQTS patients are crucial for effective management. All patients with LQTS with a positive genetic test over the past 18 years (2002-2020) in our single tertiary pediatric cardiac center were identified. Reevaluation of the reported variants in LQTS genes was conducted using the American College of Genetics and Genomics (ACMG) guideline after refinement by the US ClinGen SVI working group and guideline by Walsh et al...

BACKGROUND AND OBJECTIVES: Levetiracetam is a widely used antiseizure medication. Recent concerns have been raised regarding the potential prolongation of the QT interval by levetiracetam and increased risk of sudden cardiac death. This could have profound implications for patient safety and for prescribing practice. This study assessed the potential association of levetiracetam with cardiac outcomes related to QT interval prolongation. We compared outcomes of patients taking levetiracetam with those taking oxcarbazepine as a comparator medication that has not been associated with prolongation of the QT interval...

A common genetic risk factor for bipolar disorder is CACNA1C , a gene that is also critical for cardiac rhythm. The impact of CACNA1C mutations on bipolar patient cardiac rhythm is unknown. Here, we report the cardiac electrophysiological implications of a bipolar disorder-associated genetic risk factor in CACNA1C using patient induced pluripotent stem cell-derived cardiomyocytes. Results indicate that the CACNA1C bipolar disorder-related mutation causes cardiac electrical impulse conduction slowing mediated by impaired intercellular coupling via connexin 43 gap junctions...

Several empirical and theoretical studies suggest presence of multiple enhancers per gene that collectively regulate gene expression, and that common sequence variation impacting on the activities of these enhancers is a major source of inter-individual variability in gene expression. However, for vast majority of genes, enhancers and the underlying regulatory variation remains unknown. Even for the genes with well-characterized enhancers, the nature of the combined effects from multiple enhancers and their variants, when known, on gene expression regulation remains unexplored...

High-degree atrioventricular node block is a known cause of bradycardia. Heart rate and QT interval have an inverse relation. Therefore, bradycardia can lead to prolonged QT interval, which can predispose patients to Torsades de Pointes, a life-threatening arrhythmia. Correcting the underlying etiology can often reverse the arrhythmia and prevent recurrence. For this reason, recognizing the etiology of this arrhythmia plays an essential role in management.

Although long-QT syndrome (LQTS) with a normal range QT interval at rest leads to fatal ventricular arrhythmias, it is difficult to diagnose. In this article, we present a rare case of a patient who suffered a cardiac arrest and was recently diagnosed with LQTS and coronary vasospasm. A 62-year-old man with no syncopal episodes had a cardiopulmonary arrest while running. During coronary angiography, vasospasm was induced and we prescribed coronary vasodilators, including calcium channel blockers. An exercise stress test was performed to evaluate the effect of medications and accidentally unveiled exercise-induced QT prolongation...

Tebuconazole (TEB), a widely used pesticide in agriculture to combat fungal infections, is commonly detected in global food, potable water, groundwater, and human urine samples. Despite its known in vivo toxicity, its impact on heart function remains unclear. In a 28-day study on male Wistar rats (approximately 100 g), administering 10 mg/kg/day TEB or a control vehicle revealed no effect on body weight gain or heart weight, but an increase in the infarct area in TEB-treated animals. Notably, TEB induced time-dependent changes in in vivo electrocardiograms, particularly prolonging the QT interval after 28 days of administration...

Nasal vasoconstrictors are some of the most widely used over-the-counter drugs, considered by many consumers as relatively safe with few significant adverse effects. At recommended dosage, the drug produces local vasoconstriction in nasal mucous membranes. However, the use of such drugs has been linked to cardiovascular adverse effects, including hypertension, arrhythmias, prolongation of the QT interval, and angina pectoris.1 The various cardiovascular adverse effects may occur with both oral and nasal administration and after a single dose or prolonged treatment, without dose-effect and independently of vascular status and age...

A systematic literature review was conducted to determine the incidence and mortality of QT-interval prolongation (QTp), torsades de pointes (TdP), and heart failure (HF) in patients with non-small cell lung cancer (NSCLC) who received epidermal growth factor receptor (EGFR) TKIs. Of 296 identified publications, 95 met eligibility criteria and were abstracted for QTp/TdP and HF outcomes (QTp/TdP: 83 publications, including 5 case study publications; HF: 79 publications, including 6 case study publications [involving 8 patients])...

BACKGROUND: The indication for this assessment is the use of the KardiaMobile six-lead electrocardiogram device for the assessment of QT interval-based cardiac risk in service users prior to the initiation of, or for the monitoring of, antipsychotic medications, which are associated with an established risk of QT interval prolongation. OBJECTIVES: To provide an early value assessment of whether KardiaMobile six-lead has the potential to provide an effective and safe alternative to 12-lead electrocardiogram for initial assessment and monitoring of QT interval-based cardiac risk in people taking antipsychotic medications...

BACKGROUND: Eating disorders (EDs) often develop during adolescence with high mortality rates. Sudden cardiac death in these patients has been associated with corrected QT (QTc) interval prolongation. The significance of extrinsic factors on QTc prolongation in populations with EDs remains controversial. This study assessed the relationship between QTc prolongation in paediatric patients with EDs and extrinsic factors, such as QTc-prolonging medications and electrolyte abnormalities to investigate whether an ED alone is associated with an increased prevalence of QTc prolongation...

The hallmark of acute promyelocytic leukemia (APL) is the presence of the characteristic fusion transcript of the promyelocytic leukemia gene with the retinoic acid receptor α gene (PML::RARA). The PML::RARA fusion is a molecular target for all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Therapies based on ATRA plus ATO have excellent outcomes in terms of complete remission rates, overall survival, and achievement of deep and durable molecular responses with a very low incidence of relapse...