What to Do When Clinical Arrhythmia Is Uninducible?: Stepwise Approach
Catheter ablation has been established as a versatile modality to treat a wide range of tachyarrhythmias. Cost-effectiveness studies have generally favored catheter ablation over medical treatment because of its potential curative effect. In the electrophysiology (EP) laboratory, induction and maintenance of clinical arrhythmias is the cornerstone of diagnosis and treatment, especially in cases where the clinical arrhythmia is not documented on baseline electrocardiogram. Ventricular tachycardia ablation is performed after mapping during sinus rhythm or during tachycardia. Activation mapping during VT is felt to be the most reliable method for the identification of the ablation target but, likewise, requires the VT to be inducible. During VT, a three-dimensional mapping system permits the reconstruction of the reentry circuit, allowing subsequent RF application at the level of reentry isthmus. However, VT induction is not always possible in the basal state. With this, a various number of medications were started to be used as a means to facilitate arrhythmia induction, including isoprenaline, adrenaline, and atropine.