Electrophysiologic Mechanisms of Polymorphic Ventricular Tachycardia/Torsade de Pointes in the Presence of Normal or Long QT

2000 ◽  
pp. 276-284
Author(s):  
G. Turitto ◽  
N. El-Sherif
Author(s):  
Raphael Rosso ◽  
Aviram Hochstadt ◽  
Dana Viskin ◽  
Ehud Chorin ◽  
Arie Lorin Schwartz ◽  
...  

Abstract Aims Distinctive types of polymorphic ventricular tachycardia (VT) respond differently to different forms of therapy. We therefore performed the present study to define the electrocardiographic characteristics of different forms of polymorphic VT. Methods and results We studied 190 patients for whom the onset of 305 polymorphic VT events was available. The study group included 87 patients with coronary artery disease who had spontaneous polymorphic VT triggered by short-coupled extrasystoles in the absence of myocardial ischaemia. This group included 32 patients who had a long QT interval but nevertheless had their polymorphic VT triggered by ectopic beats with short coupling interval, a subcategory termed ‘pseudo-torsade de pointes] (TdP). For comparison, we included 50 patients who had ventricular fibrillation (VF) during acute myocardial infarction (‘ischaemic VF’ group) and 53 patients with drug-induced TdP (‘true TdP’ group). The QT of patients with pseudo-TdP was (by definition) longer than that of patients with polymorphic VT and normal QT (QTc 491.4 ± 25.2 ms vs. 447.3 ± 55.6 ms, P < 0.001). However, their QT was significantly shorter than that of patients with true TdP (QTc 564.6 ± 75.6 ms, P < 0.001). Importantly, the coupling interval of the ectopic beat triggering the arrhythmia was just as short during pseudo-TdP as during polymorphic VT with normal QT (359.1 ± 38.1 ms vs. 356.6 ± 39.4 ms, P = 0.467) but was much shorter than during true TdP (581.2 ± 95.3 ms, P < 0.001). Conclusions The coupling interval helps discriminate between polymorphic VT that occurs despite a long QT interval (pseudo-TdP) and polymorphic arrhythmias striking because of a long QT (true TdP).


2018 ◽  
Vol 1 (46) ◽  
pp. 28-30
Author(s):  
Agnieszka Wojdyła-Hordyńska ◽  
Grzegorz Hordyński ◽  
Patrycja Pruszkowska-Skrzep ◽  
Oskar Kowalski

Implantable cardioverter-defibrillator (ICD) is an indicated therapy for Long QT (LQT) patients after syncope or cardiac arrest survival. Premature ventricular contractions (PVCs) triggers ablation is also a known, yet, still rare, method aiming at ventricular tachycardia or torsade de pointes treatment in LQT syndrome. We present a 21-year-old female with no previous medical history admitted after syncope during cycling. Family history revealed sudden cardiac death in a 36-year-old father of the patient. Genetic test presented a puntiform mutation of KCNH2 gene. Beta-blocker and life vest therapy were introduced. Three months later the patient was admitted due to presyncopy and documented polymorphic ventricular tachycardia initiated by premature ventricular contractions. The clinical PVC triggers ablation was performed and cardioverter-defibrillator implanted. The PVC in the left aortic cusp was successfully ablated, and an ICD was implanted to utilise an atrial pacing. During the next 12-months follow up no VTs were recorded.


2021 ◽  
Author(s):  
Sharen Lee ◽  
Jiandong Zhou ◽  
Kamalan Jeevaratnam ◽  
Wing Tak Wong ◽  
Ian Chi Kei Wong ◽  
...  

AbstractIntroductionLong QT syndrome (LQTS) and catecholaminergic ventricular tachycardia (CPVT) are less prevalent cardiac ion channelopathies than Brugada syndrome in Asia. The present study compared paediatric/young and adult patients with these conditions.MethodsThis was a territory-wide retrospective cohort study of consecutive patients diagnosed with LQTS and CPVT attending public hospitals in Hong Kong. The primary outcome was spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF).ResultsA total of 142 LQTS (mean onset age= 27±23 years old) and 16 CPVT (mean presentation age=11±4 years old) patients were included. For LQTS, arrhythmias other than VT/VF (HR=4.67, 95% confidence interval=[1.53-14.3], p=0.007), initial VT/VF (HR=3.25 [1.29-8.16], p=0.012) and Schwartz score (HR=1.90 [1.11-3.26], p=0.020) were predictive of the primary outcome for the overall cohort, whilst arrhythmias other than VT/VF (HR=5.41 [1.36-21.4], p=0.016) and Schwartz score (HR=4.67 [1.48-14.7], p=0.009) were predictive for the adult subgroup (>25 years old; n=58). All CPVT patients presented before the age of 25 but no significant predictors of VT/VF were identified. A random survival forest model identified initial VT/VF, Schwartz score, initial QTc interval, family history of LQTS, initially asymptomatic, and arrhythmias other than VT/VF as the most important variables for risk prediction in LQTS, and initial VT/VF/sudden cardiac death, palpitations, QTc, initially symptomatic and heart rate in CPVT.ConclusionClinical and ECG presentation vary between the pediatric/young and adult LQTS population. All CPVT patients presented before the age of 25. Machine learning models achieved more accurate VT/VF prediction.


2009 ◽  
Vol 39 (9) ◽  
pp. 386 ◽  
Author(s):  
Jae Hee Kim ◽  
Sun Hee Park ◽  
Kyun Hee Kim ◽  
Won Suk Choi ◽  
Jung Kyu Kang ◽  
...  

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