{"title":"Roles of Atrial Arrhythmias in Triggering Torsade de Pointes in Patients With Acquired Long QT Syndrome.","authors":"Nobuhiro Takasugi, Susumu Endo, Mieko Takasugi, Ryota Tochibora, Akihiro Yoshida, Takatomo Watanabe, Tomonori Kawaguchi, Yoshihisa Yamada, Hiromitsu Kanamori, Hiroaki Ushikoshi, Hiroyuki Okura","doi":"10.1161/CIRCEP.123.012675","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>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.</p><p><strong>Methods: </strong>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 <i>U</i> test or Fisher exact test.</p><p><strong>Results: </strong>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, <i>P</i>=0.008). AAs-induced group exhibited macroscopic T-wave alternans more frequently than non-AAs-induced group (6 versus 0 event, <i>P</i>=0.02).</p><p><strong>Conclusions: </strong>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.</p>","PeriodicalId":10319,"journal":{"name":"Circulation. Arrhythmia and electrophysiology","volume":" ","pages":"e012675"},"PeriodicalIF":9.1000,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Circulation. Arrhythmia and electrophysiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1161/CIRCEP.123.012675","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/9/5 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"CARDIAC & CARDIOVASCULAR SYSTEMS","Score":null,"Total":0}
引用次数: 0
Abstract
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 U 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, P=0.008). AAs-induced group exhibited macroscopic T-wave alternans more frequently than non-AAs-induced group (6 versus 0 event, P=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.
期刊介绍:
Circulation: Arrhythmia and Electrophysiology is a journal dedicated to the study and application of clinical cardiac electrophysiology. It covers a wide range of topics including the diagnosis and treatment of cardiac arrhythmias, as well as research in this field. The journal accepts various types of studies, including observational research, clinical trials, epidemiological studies, and advancements in translational research.