Tag: ventricular tachycardia

Current Management of Ventricular Tachycardia: Approaches and Timing

Current Management of Ventricular Tachycardia: Approaches and Timing

Authors: John, Roy M.; Stevenson, William

Ventricular tachycardia (VT) in the presence of structural heart disease is associated with sudden cardiac death and warrants prompt attention. Implantable cardioverter defibrillators (ICDs) while highly effective in terminating sustained ventricular arrhythmias and reducing mortality, have no effect on the arrhythmia substrate and recurrent shocks for VT termination occur in approximately 20% of patients. Shocks worsen quality of life and are associated with progression of heart failure and increased mortality. Antiarrhythmic drugs, mainly in the form of beta-blockers or amiodarone, are moderately effective in reducing ICD therapies but drug intolerance and serious toxicities of amiodarone necessitate drug cessation in a quarter of patients. Catheter ablation has emerged as an effective treatment for control of frequent VT episodes and can be life saving in cases of incessant VT or VT storm. As experience increases, it is being used increasingly earlier, rather than a last resort therapy. Efficacy varies with the nature of the underlying heart disease. Intramural arrhythmia substrate and failure to create permanent ablation lesions remain challenges and repeat procedures are necessary in a third to a half of patients. For idiopathic VTs or PVCs that are symptomatic or worsen LV function, catheter ablation is often an effective therapy.

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Changing the Way We “See” Scar: How Multimodality Imaging Fits in the Electrophysiology Laboratory

Changing the Way We “See” Scar: How Multimodality Imaging Fits in the Electrophysiology Laboratory

Author: Wokhlu, Anita

Substrate characterization is the mainstay of ablation for ventricular tachycardia (VT). Although the use of electroanatomic voltage mapping (EAVM) in the electrophysiology (EP) laboratory has enabled real-time approximation of myocardial scar, it has limitations. This is related to the subjective and tedious nature of voltage mapping and the challenges of defining the transmurality of scar. Various noninvasive methods of scar assessment have emerged, with magnetic resonance imaging (MRI) being the most accurate. Integrated MRI and electroanatomic voltage mapping studies demonstrate good correlation. Nonetheless, MRI has advantages. These include (1) preprocedure identification of epicardial and intramural scar, (2) assessment of ablative lesion formation after unsuccessful ablations, (3) identification of heterogeneous regions of scar, where critical conducting channels are likely to occur, and (4) predictive value in the assessment of sudden cardiac death (SCD). Integration of scar imaging in ventricular tachycardia ablation and risk stratification has great potential to advance the practice of arrhythmia management.

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