Background: Little is known about the role of atrial arrhythmias (AAs) in triggering Torsade de Pointes (TdP) in patients with long QT syndrome (LQTS). The aim of this study was to examine the contribution of AAs to the development of TdP in acquired LQTS patients.
Methods: The initiation patterns of 81 episodes of TdP obtained from 34 consecutive acute acquired LQTS patients (14 men, median age, 69 years; median QTc, 645.5 ms) with documented TdP were analyzed. The initiation mode of TdP was divided into 3 categories: (1) preceding short-long sequence (SLS); (2) sudden R-on-T phenomenon without preceding SLS; and (3) increased atrial rate. The patients were divided into 2 groups based on the presence or absence of AAs-induced TdP; AAs-induced (n=18) and non-AAs-induced (n=16) groups. The association of clinical/ECG characteristics and TdP frequency after initiating conventional therapy with AAs-induced TdP was evaluated. The groups were compared using the Mann-Whitney test or Fisher exact test.
Results: AAs-induced group comprised 52.9% (18/34) of the patients studied. TdP was preceded by AAs-initiated SLSs in 41.2% (14/34) of the patients and was directly induced by R-on-T AAs (AAs coincidentally encountered a vulnerable repolarizing region during the T wave) in 23.5% (8/34). AAs triggered 48 (59.3%) of the 81 TdP episodes. AAs initiated SLSs in 67.8% (40/59) of the SLS-induced TdP episodes. R-on-T AAs accounted for 23.5% (19/81) of the TdP episodes. AAs-induced group experienced TdP after initiating therapy more frequently than non-AAs-induced group (2.5 versus 1 event, =0.008). AAs-induced group exhibited macroscopic T-wave alternans more frequently than non-AAs-induced group (6 versus 0 event, =0.02).
Conclusions: AAs play a key role in triggering TdP in more than half of patients with acute acquired LQTS and can increase TdP frequency after initiating therapy. Thus, AAs are not benign but rather can be life-threatening in patients with acute acquired LQTS.
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http://dx.doi.org/10.1161/CIRCEP.123.012675 | DOI Listing |
J Cell Mol Med
September 2024
Department of Pharmacology (National Key Laboratory of Frigid Zone Cardiovascular Diseases, the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, China.
Cancer is the leading public health problem worldwide. However, the side effects accompanying anti-cancer therapies, particularly those pertaining to cardiotoxicity and adverse cardiac events, have been the hindrances to treatment progress. Long QT syndrome (LQTS) is one of the major clinic manifestations of the anti-cancer drug associated cardiac dysfunction.
View Article and Find Full Text PDFHeart Rhythm O2
August 2024
Department of Pediatric Cardiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China.
Background: Long QT syndrome (LQTS) is a rare cardiac disorder characterized by prolonged ventricular repolarization and increased risk of ventricular arrhythmias. This review summarizes current knowledge of LQTS pathogenesis and treatment strategies.
Objectives: The purpose of this study was to provide an in-depth understanding of LQTS genetic and molecular mechanisms, discuss clinical presentation and diagnosis, evaluate treatment options, and highlight future research directions.
Int J Cancer
January 2025
Faculty of Medicine, School of Kinesiology and Physical Activity Sciences, University of Montreal, Montreal, Quebec, Canada.
An example of chemotherapy-induced cardiotoxicity in cancer survivors is acquired long QT syndrome (aLQTS), which may cause serious yet preventable life-threatening consequences. Our objective was to identify and characterize childhood acute lymphoblastic leukemia (ALL) survivors with possible aLQTS using maximal exercise testing. In this cross-sectional study with exploratory analysis, a total of 250 childhood ALL survivors were evaluated for abnormal QT interval prolongation using the McMaster cycle exercise test.
View Article and Find Full Text PDFCirc Arrhythm Electrophysiol
October 2024
Gifu University Hospital (N.T., S.E., R.T., A.Y., T.W., T.K., Y.Y., H.K., H.U., H.O.).
Background: Little is known about the role of atrial arrhythmias (AAs) in triggering Torsade de Pointes (TdP) in patients with long QT syndrome (LQTS). The aim of this study was to examine the contribution of AAs to the development of TdP in acquired LQTS patients.
Methods: The initiation patterns of 81 episodes of TdP obtained from 34 consecutive acute acquired LQTS patients (14 men, median age, 69 years; median QTc, 645.
Cureus
July 2024
General Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA.
Long QT syndrome (LQTS) is a severe cardiac disorder characterized by an abnormally prolonged QTc interval on an electrocardiogram (ECG), which can result in life-threatening irregular heart rhythms. The use of certain medications, particularly anti-arrhythmic drugs such as quinidine, sotalol, and amiodarone, can lead to acquired LQTS by prolonging the QT interval through the inhibition of specific ion channels responsible for heart repolarization, which may present symptoms like fainting, seizures, and sudden cardiac arrest. This systematic review, conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, focused on analyzing the association between Long QT syndrome and drugs utilized for managing arrhythmias, involving a thorough examination of six selected studies from an initial pool of 68 articles.
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