Double tachycardia. One heart with two arrhythmias. Difficulties in diagnosis and treatment with radiofrequency ablation--case report

Double tachycardia (DT) is a coincidence of two arrhythmias. We described the coincidence of frequent and symptomatic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) and atrioventricular nodal reentrant tachycardia (AVNRT). 54-years-old woman had no organic heart disease and 24 hours ECG Holter monitoring showed paroxysm of tachycardia and more than five thousands of PVCs. The patient was selected to invasive electrophysiology study (EPS) and radiofrequency (RF) ablation. The EPS confirmed induction of AVNRT and the presence of PVCs originating from RVOT The modification of slow pathway of AVNRT using RF ablation was performed. The ablation of PVCs was unsuccessful. After the ablation, ventricular arrhythmia remained symptomatic and patient underwent second session of RF ablation. With applications of RF current in RVOT only the reduction of PVCs was obtained but after 24 hours PVCs disappeared. During 12-month follow-up the patient remained free of any arrhythmias and palpitations.