Generating and influencing Torsades de Pointes - like polymorphic ventricular tachycardia in isolated guinea pig hearts

1998 ◽  
Vol 93 (4) ◽  
pp. 285-294 ◽  
Author(s):  
A. Gerhardy ◽  
G. Scholtysik ◽  
A. Schaad ◽  
R. Haltiner ◽  
T. Hess
Keyword(s):  
Ventricular Tachycardia ◽  
Guinea Pig ◽  
Torsades De Pointes ◽  
Polymorphic Ventricular Tachycardia

Portable Monitor and Defibrillators (DRAFT)

2018 ◽  
Author(s):  
Robert Bauer ◽  
Raghavan Murugan
Keyword(s):  
Ventricular Tachycardia ◽  
Patient Outcomes ◽  
Torsades De Pointes ◽  
Polymorphic Ventricular Tachycardia ◽  
Rapid Response Teams ◽  
Portable Monitor ◽  
Care Facilities ◽  
Transcutaneous Pacing ◽  
Portable Monitors ◽  
Acute Care Facilities

Portable monitors with the capability of defibrillation, synchronized cardioversion, and transcutaneous pacing are frequently used by the rapid response teams (RRTs) in several acute care facilities to provide quick information and to treat lethal arrhythmias in critically ill and unstable patients. Portable monitors are used on lethal arrhythmias such as ventricular fibrillation (VF), monomorphic ventricular tachycardia (VT), or polymorphic ventricular tachycardia, also known as Torsades de pointes (TdP). Properly identifying lethal arrhythmias and knowing how to use the portable monitor/defibrillator is essential to positive patient outcomes. In this chapter, we review the use of portable monitors for monitoring and detection of cardiac arrhythmias as well as outline the procedure for defibrillation, synchronized cardioversion, and transcutaneous pacing in the setting of RRT activation.

scholarly journals Tetrodotoxin-sensitive Navs contribute to early and delayed afterdepolarizations in long QT arrhythmia models

2018 ◽  
Vol 150 (7) ◽  
pp. 991-1002 ◽  
Author(s):  
Megan Koleske ◽  
Ingrid Bonilla ◽  
Justin Thomas ◽  
Naveed Zaman ◽  
Stephen Baine ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Action Potential ◽  
Qt Interval ◽  
Torsades De Pointes ◽  
Cellular Level ◽  
Polymorphic Ventricular Tachycardia ◽  
Wild Type ◽  
Long Qt ◽  
Delayed Afterdepolarizations

Recent evidence suggests that neuronal Na+ channels (nNavs) contribute to catecholamine-promoted delayed afterdepolarizations (DADs) and catecholaminergic polymorphic ventricular tachycardia (CPVT). The newly identified overlap between CPVT and long QT (LQT) phenotypes has stoked interest in the cross-talk between aberrant Na+ and Ca2+ handling and its contribution to early afterdepolarizations (EADs) and DADs. Here, we used Ca2+ imaging and electrophysiology to investigate the role of Na+ and Ca2+ handling in DADs and EADs in wild-type and cardiac calsequestrin (CASQ2)-null mice. In experiments, repolarization was impaired using 4-aminopyridine (4AP), whereas the L-type Ca2+ and late Na+ currents were augmented using Bay K 8644 (BayK) and anemone toxin II (ATX-II), respectively. The combination of 4AP and isoproterenol prolonged action potential duration (APD) and promoted aberrant Ca2+ release, EADs, and DADs in wild-type cardiomyocytes. Similarly, BayK in the absence of isoproterenol induced the same effects in CASQ2-null cardiomyocytes. In vivo, it prolonged the QT interval and, upon catecholamine challenge, precipitated wide QRS polymorphic ventricular tachycardia that resembled human torsades de pointes. Treatment with ATX-II produced similar effects at both the cellular level and in vivo. Importantly, nNav inhibition with riluzole or 4,9-anhydro-tetrodotoxin reduced the incidence of ATX-II–, BayK-, or 4AP-induced EADs, DADs, aberrant Ca2+ release, and VT despite only modestly mitigating APD prolongation. These data reveal the contribution of nNaVs to triggered arrhythmias in murine models of LQT and CPVT-LQT overlap phenotypes. We also demonstrate the antiarrhythmic impact of nNaV inhibition, independent of action potential and QT interval duration, and provide a basis for a mechanistically driven antiarrhythmic strategy.

scholarly journals Role of electrocardiogram in diagnosis of inherited arrhythmia syndromes

2020 ◽  
Vol 71 (2) ◽  
pp. 1-7
Author(s):  
Ružica Jurčević ◽  
Lazar Angelkov ◽  
Dejan Vukajlović ◽  
Velibor Ristić ◽  
Dejan Kojić ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Torsades De Pointes ◽  
Pathogenic Mutation ◽  
Polymorphic Ventricular Tachycardia ◽  
Early Repolarization ◽  
St Segment Elevation ◽  
St Segment ◽  
Qt Syndrome ◽  
The Right

The aim of this paper is to define the role of electrocardiogram (ECG) in diagnosis, prognosis and treatment of inherited arrhythmias syndromes. Brugada Syndrome diagnosis is established in presence of coved type ST-segment elevation (type 1) ≥ 2mm in ≥ 1 of the right precordial leads V1 to V2. Long QT Syndrome is diagnosed when one of factors is present: QTc ≥ 480 ms, QTc ≥ 460 ms in patients with unexplained syncope, pathogenic mutation or risk score > 3. Polymorphic ventricular tachycardia (VT) Torsades de Pointes have specific presentation in ECG with characteristic illusion of the QRS complex twisting around the isoelectric baseline. The early repolarization pattern in patients resuscitated from otherwise unexplained ventricular fibrillation (VF)/polymorphic VT or in a sudden cardiac death (SCD) victims makes diagnosis of Early Repolarization Syndrome. Short QT Syndrome is diagnosed in the presence of a QTc ≤ 340 ms or QTc < 360 ms with one or more of the following factors: a pathogenic mutation, survival of a VT/VF episodes, family history of this disease and SCD in family at age ≤ 40. Catecholaminergic Polymorphic Ventricular Tachycardia has ECG appearance of bidirectional VT or polymorphic ventricular premature beats or VT induced by exercise or catecholamine.

scholarly journals Short-Coupled Variant of "Torsades de Pointes" and Polymorphic Ventricular Tachycardia

2014 ◽  
Author(s):  
Muhieddine Omar Chokr ◽  
Francisco Carlos da Costa Darrieux ◽  
Carina Abigail Hardy ◽  
Denise Tessariol Hachul ◽  
Allisson Valadão de Oliveira Britto ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Torsades De Pointes ◽  
Polymorphic Ventricular Tachycardia

PP-310 POLYMORPHIC VENTRICULAR TACHYCARDIA (TORSADES DE POINTES) DUE TO LICORICE ROOT TEA

2012 ◽  
Vol 155 ◽  
pp. S201-S202
Author(s):  
S. Öztürk ◽  
K. Karaman ◽  
M. Çetin ◽  
C. Zencir ◽  
E. Yildiz ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Torsades De Pointes ◽  
Licorice Root ◽  
Polymorphic Ventricular Tachycardia
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