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Children (Basel, Switzerland) May 2024Congenital long QT syndrome (LQTS) represents a disorder of myocardial repolarization characterized by a prolongation of QTc interval on ECG, which can degenerate into... (Review)
Review
Congenital long QT syndrome (LQTS) represents a disorder of myocardial repolarization characterized by a prolongation of QTc interval on ECG, which can degenerate into fast polymorphic ventricular arrhythmias. The typical symptoms of LQTS are syncope and palpitations, mainly triggered by adrenergic stimuli, but it can also manifest with cardiac arrest. At least 17 genotypes have been associated with LQTS, with a specific genotype-phenotype relationship described for the three most common subtypes (LQTS1, -2, and -3). β-Blockers are the first-line therapy for LQTS, even if the choice of the appropriate patients needing to be treated may be challenging. In specific cases, interventional measures, such as an implantable cardioverter-defibrillator (ICD) or left cardiac sympathetic denervation (LCSD), are useful. The aim of this review is to highlight the current state-of-the-art knowledge on LQTS, providing an updated picture of possible diagnostic algorithms and therapeutic management.
PubMed: 38790576
DOI: 10.3390/children11050582 -
Children (Basel, Switzerland) Apr 2024CACNA1C gene encodes the alpha 1 subunit of the CaV1.2 L-type Ca2+ channel. Pathogenic variants in this gene have been associated with cardiac rhythm disorders such as... (Review)
Review
CACNA1C gene encodes the alpha 1 subunit of the CaV1.2 L-type Ca2+ channel. Pathogenic variants in this gene have been associated with cardiac rhythm disorders such as long QT syndrome, Brugada syndrome and Timothy syndrome. Recent evidence has suggested the possible association between CACNA1C mutations and neurologically-isolated (in absence of cardiac involvement) phenotypes in children, giving birth to a wider spectrum of CACNA1C-related clinical presentations. However, to date, little is known about the variety of both neurological and non-neurological signs/symptoms in the neurologically-predominant phenotypes. We conducted a systematic review of neurologically-predominant presentations without cardiac conduction defects, associated with CACNA1C mutations. We also reported a novel de novo missense pathogenic variant in the CACNA1C gene of a children patient presenting with constructional, dressing and oro-buccal apraxia associated with behavioral abnormalities, mild intellectual disability, dental anomalies, gingival hyperplasia and mild musculoskeletal defects, without cardiac conduction defects. The present study highlights the importance of considering the investigation of the CACNA1C gene in children's neurological isolated syndromes, and expands the phenotype of the CACNA1C related conditions. In addition, the present study highlights that, even in absence of cardiac conduction defects, nuanced clinical manifestations of the Timothy syndrome (e.g., dental and gingival defects) could be found. These findings suggest the high variable expressivity of the CACNA1C gene and remark that the absence of cardiac involvement should not mislead the diagnosis of a CACNA1C related disorder.
PubMed: 38790536
DOI: 10.3390/children11050541 -
JPMA. the Journal of the Pakistan... May 2024
Topics: Humans; Ondansetron; Long QT Syndrome; Antiemetics
PubMed: 38783462
DOI: 10.47391/JPMA.10825 -
BMC Neurology May 2024QT interval prolongation is one of the most common electrocardiographic (ECG) abnormalities in patients with aneurysmal subarachnoid hemorrhage (aSAH). Whether corrected... (Observational Study)
Observational Study
QTc prolongation after aneurysmal subarachnoid hemorrhage might be associated with worse neurologic outcome in patients receiving microsurgical clipping or embolization of the intracranial aneurysms: a retrospective observational study.
PURPOSE
QT interval prolongation is one of the most common electrocardiographic (ECG) abnormalities in patients with aneurysmal subarachnoid hemorrhage (aSAH). Whether corrected QT interval (QTc) prolongation is associated with perioperative cardiac events and dismal neurological outcome in mid to long-term follow-up in patients after aSAH is insufficiently studied and remains controversial.
METHODS
We retrospectively studied the adult (≥ 18 years) patients admitted to our institution between Jan 2018 and Dec 2020 for aSAH who underwent intracranial aneurysm clipping or embolization. The patients were divided into 2 groups (normal and QTc prolongation groups) according to their QTc. To minimize the confounding bias, a propensity score matching (PSM) analysis was performed to compare the neurologic outcomes between patients with normal QTc and QTc prolongation.
RESULTS
After screening, 908 patients were finally included. The patients were divided into 2 groups: normal QTc groups (n = 714) and long QTc group (n = 194). Female sex, hypokalemia, posterior circulation aneurysm, and higher Hunt-Hess grade were associated with QTc prolongation. In multiple regression analysis, older age, higher hemoglobin level, posterior circulation aneurysm, and higher Hunt-Hess grade were identified to be associated with worse outcome during 1-year follow-up. Before PSM, patients with QTc prolongation had higher rate of perioperative cardiac arrest or ventricular arrhythmias. After PSM, there was no statistical difference between normal and QTc prolongation groups in perioperative cardiac events. However, patients in the QTc prolongation group still had worse neurologic outcome during 1-year follow-up.
CONCLUSIONS
QTc prolongation is associated with worse outcome in patients following SAH, which is independent of perioperative cardiac events.
Topics: Humans; Male; Female; Retrospective Studies; Subarachnoid Hemorrhage; Middle Aged; Intracranial Aneurysm; Long QT Syndrome; Embolization, Therapeutic; Adult; Aged; Microsurgery; Treatment Outcome; Electrocardiography
PubMed: 38783204
DOI: 10.1186/s12883-024-03679-z -
Stem Cell Research Aug 2024Long QT Syndrome (LQTS) is a genetic heart disorder that can induce cardiac arrhythmias. The most prevalent subtype, LQT1, stems from rare variants in the KCNQ1 gene....
Long QT Syndrome (LQTS) is a genetic heart disorder that can induce cardiac arrhythmias. The most prevalent subtype, LQT1, stems from rare variants in the KCNQ1 gene. Utilizing induced pluripotent stem cells (iPSCs) enables detailed cellular studies and personalized medicine approaches for this life-threatening condition. We generated two LQT1 iPSC lines with single nucleotide nonsense mutations, c.1031 C > T and c.1121 T > A in KCNQ1. Both lines exhibited typical iPSC morphology, expressed high levels of pluripotent markers, maintained normal karyotype, and possessed the capability to differentiate into three germ layers. These cell lines serve as important tools for investigating the biological mechanisms underlying LQT1 due to mutations in the KCNQ1 gene.
Topics: Humans; KCNQ1 Potassium Channel; Induced Pluripotent Stem Cells; Long QT Syndrome; Cell Line; Heterozygote; Mutation; Male; Female; Cell Differentiation
PubMed: 38763038
DOI: 10.1016/j.scr.2024.103443 -
Global Cardiology Science & Practice Mar 2024Hydroxychloroquine (HCQ), which was initially used as an antimalarial drug, is now being used to treat other illnesses, especially rheumatic autoimmune disorders such... (Review)
Review
Hydroxychloroquine (HCQ), which was initially used as an antimalarial drug, is now being used to treat other illnesses, especially rheumatic autoimmune disorders such as systemic lupus erythematosus, primary Sjögren's syndrome, and rheumatoid arthritis, because it is safe, effective, and cost efficient. This drug has shown high efficacy and has become the first-line treatment for many of these diseases. Although HCQ has many therapeutic effects, it has unfortunately shown some complications, especially with its long-term use. One of these side effects is arrhythmia through prolongation of the QT interval. This narrative literature review focuses on the effects of HCQ on the QT interval in patients with rheumatologic diseases who have been prescribed this drug. In particular, we will focus on the increased risk of arrhythmia when HCQ is administered with other drugs, such as azithromycin and many others, along with drug-drug interactions. In addition, we investigated the safety of this drug in pregnant women.
PubMed: 38746066
DOI: 10.21542/gcsp.2024.17 -
Frontiers in Pharmacology 2024Prolonged QT intervals are extremely common in patients with cirrhosis and affect their treatment outcomes. Propranolol is often used to prevent gastroesophageal...
BACKGROUND
Prolonged QT intervals are extremely common in patients with cirrhosis and affect their treatment outcomes. Propranolol is often used to prevent gastroesophageal variceal hemorrhage in patients with cirrhosis; however, it is uncertain whether propranolol exerts a corrective effect on QT interval prolongation in patients with cirrhosis.
AIM
The study aimed to investigate the therapeutic effects of propranolol on patients with cirrhosis and prolonged QT intervals.
METHODS
A retrospective cohort study approach was adopted. Patients with cirrhosis complicated by moderate-to-severe gastroesophageal varices, who were hospitalized at the Affiliated Hospital of Guangdong Medical University between 1 December 2020 and 31 November 2022, were included in the study. The patients were divided into the propranolol and control groups based on whether they had received propranolol. Upon admission, the patients underwent tests on liver and kidney functions, electrolytes, and coagulation function, as well as abdominal ultrasonography and electrocardiography. In addition to conventional treatment, the patients were followed up after the use or non-use of propranolol for treatment and subsequently underwent reexamination of the aforementioned tests.
RESULTS
The propranolol group (26 patients) had an average baseline corrected QT (QTc) interval of 450.23 ± 37.18 ms, of which 14 patients (53.8%) exhibited QTc interval prolongation. Follow-up was continued for a median duration of 7.00 days after the administration of propranolol and conventional treatment. Electrocardiographic reexamination revealed a decrease in the QTc interval to 431.04 ± 34.64 ms ( = 0.014), and the number of patients with QTc interval prolongation decreased to five (19.2%; < 0.001). After treatment with propranolol and multimodal therapy, QTc interval normalization occurred in nine patients with QTc interval prolongation, leading to a normalization rate of 64.3% (9/14). The control group (n = 58) had an average baseline QTc interval of 453.74 ± 30.03 ms, of which 33 patients (56.9%) exhibited QTc interval prolongation. After follow-up for a median duration of 7.50 days, the QTc interval was 451.79 ± 34.56 ms ( = 0.482), and the number of patients with QTc interval prolongation decreased to 30 (51.7%; = 0.457). The QTc interval normalization rate of patients in the control group with QTc interval prolongation was merely 10.0% (3/33), which was significantly lower than that in the propranolol group ( < 0.001).
CONCLUSION
In patients with cirrhosis complicated by QT interval prolongation, the short-term use of propranolol aids in correction of a long QT interval and provides positive therapeutic value for cirrhotic cardiomyopathy.
PubMed: 38738176
DOI: 10.3389/fphar.2024.1370261 -
Journal of Clinical Medicine Apr 2024Pediatric patients who undergo implant insertion into the chest wall face a high risk of implant exposure to the external environment. Five months after an 8-year-old...
Pediatric patients who undergo implant insertion into the chest wall face a high risk of implant exposure to the external environment. Five months after an 8-year-old boy underwent implantable cardioverter-defibrillator (ICD) implantation in a subcutaneous pocket in the left anterolateral chest wall to manage long QT syndrome, ICD replacement became necessary owing to exposure risk from distal and lateral thinning of the ICD pocket. Pocket rupture and exposure would increase the risk of infection; therefore, we performed ICD removal and primary pocket closure. Two weeks later, a new suprafascial pocket was created, an acellular dermal matrix (ADM) was attached to the inner wall to prevent ICD protrusion, and a new ICD was inserted. One year postoperatively, the ADM was engrafted, and no complications were observed. A thin subcutaneous layer increases the risk of ICD implantation complications. Inner wall strengthening with an ADM can help prevent pocket rupture.
PubMed: 38731143
DOI: 10.3390/jcm13092614 -
BMC Medical Genomics May 2024Long QT syndrome (LQTS) is a cardiac channelopathy characterized by impaired myocardial repolarization that predisposes to life-threatening arrhythmias. This study aimed...
BACKGROUND
Long QT syndrome (LQTS) is a cardiac channelopathy characterized by impaired myocardial repolarization that predisposes to life-threatening arrhythmias. This study aimed to elucidate the genetic basis of LQTS in an affected Iranian family using whole exome sequencing (WES).
METHODS
A 37-year-old woman with a personal and family history of sudden cardiac arrest and LQTS was referred for genetic study after losing her teenage daughter due to sudden cardiac death (SCD). WES was performed and variants were filtered and prioritized based on quality, allele frequency, pathogenicity predictions, and conservation scores. Sanger sequencing confirmed segregation in the family.
RESULTS
WES identified a novel heterozygous frameshift variant (NM_000238.4:c.3257_3258insG; pGly1087Trpfs*32) in the KCNH2 encoding the α-subunit of the rapid delayed rectifier potassium channel responsible for cardiac repolarization. This variant, predicted to cause a truncated protein, is located in the C-terminal region of the channel and was classified as likely pathogenic based on ACMG guidelines. The variant was absent in population databases and unaffected family members.
CONCLUSION
This study reports a novel KCNH2 frameshift variant in an Iranian family with LQTS, expanding the spectrum of disease-causing variants in this gene. Our findings highlight the importance of the C-terminal region in KCNH2 for proper channel function and the utility of WES in identifying rare variants in genetically heterogeneous disorders like LQTS. Functional characterization of this variant is warranted to fully elucidate its pathogenic mechanisms and inform personalized management strategies.
Topics: Humans; Long QT Syndrome; ERG1 Potassium Channel; Female; Exome Sequencing; Adult; Pedigree; Frameshift Mutation
PubMed: 38715010
DOI: 10.1186/s12920-024-01900-z