Electrophysiology
Catheter Ablation for Ventricular Tachycardia in Patients with Structural Heart Disease Timothy M Markman, MD 1,2, Daniel A McBride, MD 1, and Jackson J Liang, DO 1,2 1. Department of Medicine; 2. Cardiovascular Division, Electrophysiology Section, Hospital of the University of Pennsylvania, University of Pennsylvania, Philadelphia, PA
Abstract Ventricular tachycardia is a potentially fatal arrhythmia that occurs most frequently in patients with structural heart disease. Acute and longterm management can be complex, requiring an integrated approach with multiple therapeutic modalities including antiarrhythmic drugs, implantable cardioverter defibrillators, and catheter ablation. Each of these options has a role in management of ventricular tachycardia and are generally used in combination. It is essential to be aware that each approach has potential deleterious consequences that must be balanced while establishing a treatment strategy. Catheter ablation for ventricular tachycardia is performed with increasing frequency with rapidly evolving techniques. In this review, we discuss the acute and long-term management of ventricular tachycardia with a focus on techniques and evidence for catheter ablation.
Keywords Ventricular tachycardia, arrhythmias, structural heart disease, catheter ablation, radiofrequency ablation, antiarrhythmic drugs Disclosure: The authors have no conflicts of interest to declare. Received: 9 November 17 Accepted: 20 December 17 Citation: US Cardiology Review, 2018;12(1):51–6. DOI: 10.15420/usc.2017:28:3 Correspondence: Jackson J Liang, DO, Electrophysiology Section, Division of Cardiology Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19103. E: Jackson.liang@uphs.upenn.edu
Ventricular tachycardia (VT) occurs most frequently in patients with structural heart disease. Management of VT in these patients can be complex, requiring an integrated approach with multiple therapeutic modalities. Antiarrhythmic drugs (AADs) can be effective in the management of VT and implantable cardioverter defibrillators (ICDs) have been shown to effectively prevent sudden cardiac death due to ventricular arrhythmias.1–3 Unfortunately, ICDs do not prevent the recurrence of episodes of VT and appropriate ICD shocks are associated with significant morbidity and increased rates of mortality.4,5 AADs can be used to minimize the frequency of ICD shocks, but long-term use may be required to achieve continued VT suppression and these medications can have substantial side effects. Radiofrequency catheter ablation of VT is an effective treatment method for patients with VT in the setting of structural heart disease.6,7 Although there is limited evidence that catheter ablation improves overall mortality,8 catheter ablation is clearly effective in reducing VT burden and decreasing the number of appropriate ICD therapies. As technology and procedural techniques have improved over time, catheter ablation for VT has become an increasingly utilized treatment strategy. While optimal timing of VT ablation remains debated, it is often considered only late in the course of progressive structural heart disease, especially at institutions with less experience in the procedure.9,10 In this review, we discuss the management of VT with a focus on patients with underlying structural heart disease, including the use of AADs and ICDs. We also
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review the basics of VT ablation, the evidence behind the procedure, and future directions in the field.
Initial Management of Ventricular Tachycardia Once a diagnosis of VT is made, acute management is initially focused on achieving hemodynamic stability. If the VT causes hemodynamic instability – a function of both characteristics of the arrhythmia (especially rate) and the patient’s underlying cardiac function – electrical cardioversion can successfully restore sinus rhythm, at least temporarily. Patients who are hemodynamically unstable during VT or those with major comorbidities should be admitted to an intensive care unit where metabolic, respiratory, or other circulatory derangements should be immediately identified and corrected. Further acute management generally focuses on AADs, reprogramming of ICDs to decrease the frequency of recurrent shocks, and termination of clinically significant arrhythmias with anti-tachycardia pacing, and occasionally catheter ablation (Table 1 and Figure 1).11,12 The use of ICDs has been shown to substantially improve mortality and decrease the risk of sudden cardiac death in patients with VT both for primary and secondary prevention.1,2,5 Even with ICDs in place, AADs are also generally required both in the acute and long-term management of VT to decrease the rate of recurrent arrhythmias. AADs can reduce the incidence of both appropriate and inappropriate ICD shocks. However, all AADs may cause side effects and proarrhythmic effects have been reported in nearly 10 % of patients treated with AADs for ventricular arrhythmias.13,14
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