The following are key points to remember from the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias (VAs) from the Heart Rhythm Society and other societies worldwide, with collaboration from the American College of Cardiology and others:

1. Re-entry is by far the most common mechanism of ventricular tachycardia (VT) in patients with structural heart disease. In structurally normal hearts, triggered activity is the most common mechanism; it is caused by intracellular calcium overload causing oscillations in the membrane potential and delayed afterdepolarizations.
2. Transient myocardial ischemia is a known cause of polymorphic rather than monomorphic sustained VT. Monomorphic VT in the setting of prior myocardial infarction is typically due to scar-related re-entry and not due to acute ischemia. Revascularization alone is unlikely to reduce the recurrence of monomorphic VT.
3. Advanced cardiac imaging, such as computed tomography (CT), cardiac magnetic resonance imaging (CMR), and fluorodeoxyglucose positron emission tomography are useful for the evaluation in patients with VAs, especially if structural heart disease is suspected following an echocardiogram.
4. CMR and programmed ventricular stimulation can be useful for risk stratification for sudden cardiac death in patients with frequent premature ventricular contractions (PVCs). Periodic measurement of left ventricular ejection fraction (LVEF) and LV end-diastolic dimensions, along with quantification of PVC burden, may be useful for patients with a high PVC burden (approximately 10% or higher) to identify deteriorating LV function before symptoms of heart failure appear.
5. Right and left outflow tracts are the most common sites of origin for idiopathic VAs in patients without structural heart disease. In patients with frequent and symptomatic PVCs originating from the right ventricular outflow tract in an otherwise normal heart, catheter ablation is recommended in preference to metoprolol or propafenone.
6. For patients with recurrent ventricular fibrillation (VF) refractory to antiarrhythmic medications and triggered by PVCs from a potentially identifiable site, successful ablation of the PVC can lead to VF suppression. The triggering PVC is often located in the Purkinje system and can exhibit slight variations in morphology. For patients who are clinical nonresponders to cardiac resynchronization therapy, with limited biventricular pacing due to frequent PVCs, successful PVC ablation is associated with improvement in heart failure class and a modest improvement in LVEF.
7. In patients with ischemic heart disease who experience recurrent monomorphic VT despite chronic amiodarone therapy, or when antiarrhythmic therapy is not tolerated or contraindicated, catheter ablation is recommended in preference to escalating antiarrhythmic drug therapy. In patients with nonischemic and recurrent sustained monomorphic VT for whom antiarrhythmic medications are ineffective, contraindicated, or not tolerated, catheter ablation is useful for reducing recurrent VT and implantable cardioverter-defibrillator shocks.
8. The PAAINESD risk score is helpful to identify patients undergoing scar-related VT ablation who are at increased periprocedural risk. PAAINESD risk score includes the following: chronic obstructive pulmonary disease [5 points], age >60 years [3 points], general anesthesia [4 points], ischemic cardiomyopathy [6 points], New York Heart Association class III or IV [6 points], EF <25% [3 points], presentation with VT storm [5 points], diabetes mellitus [3 points].
9. Advanced preprocedural imaging with CT and CMR helps with procedural planning. Ultrasound-guided femoral arterial and venous access is recommended to reduce the incidence of vascular access complications during VA ablation. For intraprocedural imaging during ablation of VAs, fluoroscopy (including coronary angiography) and especially intracardiac echocardiography are useful.
10. In addition to the traditional unipolar radiofrequency catheter ablation, innovation and new modalities of tissue destruction may help to improve outcomes of VA ablation. Contact force sensing, hypotonic external irrigation, simultaneous unipolar or simultaneous bipolar radiofrequency delivery, needle ablation, cryoablation, transvascular ethanol ablation, and stereotactic radiofrequency offer specific advantages in appropriate clinical scenarios and may improve outcomes of the ablation procedures.

Editor's Note: This clinical document is intended to supplement the 2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death and the 2015 ESC Guidelines for the Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death.

Keywords: Amiodarone, Anti-Arrhythmia Agents, Arrhythmias, Cardiac, Cardiac Resynchronization Therapy, Cardiomyopathies, Catheter Ablation, Coronary Angiography, Cryosurgery, Death, Sudden, Cardiac, Defibrillators, Implantable, Diabetes Mellitus, Fluoroscopy, Heart Failure, Magnetic Resonance Imaging, Metoprolol, Myocardial Infarction, Myocardial Ischemia, Positron-Emission Tomography, Propafenone, Pulmonary Disease, Chronic Obstructive, Stroke Volume, Tachycardia, Ventricular, Tomography, X-Ray Computed, Ventricular Fibrillation, Ventricular Premature Complexes

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