The Role of KCNQ1 Mutations and Maternal Beta Blocker Use During Pregnancy in the Growth of Children With Long QT Syndrome

Impact of Beta-Blocker Therapy on Pregnant Women With Long QT Syndrome: A Systematic Review

Long QT syndrome (LQTS) presents significant challenges for pregnant women due to the elevated risk of arrhythmic events. Beta-blocker therapy is a cornerstone of treatment in managing LQTS, but its use during pregnancy introduces potential fetal risks. This systematic review synthesizes the evidence on the efficacy and safety of beta-blocker therapy in pregnant women with LQTS. A systematic review was conducted to assess studies on beta-blocker use in pregnant women diagnosed with LQTS. We reviewed observational studies and case reports to evaluate maternal cardiac outcomes, fetal safety, and the need for postpartum management. Studies were selected based on inclusion criteria focused on LQTS, beta-blocker therapy during pregnancy, and associated maternal and fetal outcomes. Our review showed that beta-blocker therapy significantly reduced arrhythmic events in pregnant women with LQTS, particularly in symptomatic carriers. Multiple studies demonstrated that the continuation of beta-blocker therapy throughout pregnancy and the postpartum period minimized maternal cardiac risks. However, beta-blocker use was associated with fetal risks such as intrauterine growth restriction (IUGR), lower birth weight, and, in some cases, bradycardia. Atenolol, in particular, was linked to significant fetal growth restrictions, while other beta-blockers, such as propranolol and metoprolol, showed more variable effects on fetal outcomes. Despite these concerns, some studies reported favorable postnatal growth recovery in infants exposed to beta-blockers in utero. Beta-blocker use must be carefully managed due to potential fetal risks. Regular monitoring, individualized treatment plans, and appropriate selection of beta-blocker type are essential to optimizing both maternal and fetal outcomes. Further research is necessary to refine treatment protocols and reduce fetal risks associated with beta-blocker therapy during pregnancy.

Eosinophilic Infiltration of the Sino-Atrial Node in Sudden Cardiac Death Caused by Long QT Syndrome

Sudden death is defined as the unexpected death of a healthy person that occurs within the first hour of the onset of symptoms or within 24 h of the victim being last seen alive. In some of these cases, rare deleterious variants of genes associated with inherited cardiac disorders can provide a highly probable explanation for the fatal event. We report the case of a 21-year-old obese woman who lost consciousness suddenly in a public place and was pronounced dead after hospital admission. Clinical autopsy showed an inconclusive gross examination, while in the histopathological analysis an eosinophilic inflammatory focus and interstitial fibrosis in the sino-atrial node were found. Molecular autopsy revealed an intronic variant in the KCNQ1 gene (c.683 + 5G > A), classified as likely pathogenic for long QT syndrome according to the guidelines provided by the American College of Medical Genetics and Genomics. Therefore, there were many anomalies that could have played a role in the causation of the sudden death, such as the extreme obesity, the cardiac anomalies and the KNCQ1 variant. This case depicts the difficult interpretation of rare cardiac structural abnormalities in subjects carrying rare variants responsible for inherited arrhythmic disorders and the challenge for the forensic pathologist to make causal inferences in the determinism of the unexpected decease.