Gender and age differences in candidates for radiofrequency catheter ablation of idiopathic ventricular arrhythmias.

BACKGROUND The prevalence, gender- and age-related differences, ablation success rate and inter-relationship between the origins of the idiopathic ventricular arrhythmias (I-VA) have not been clarified. METHODS AND RESULTS A total of 625 consecutive patients with symptomatic, drug resistant I-VA (315 males and 310 females; mean age, 54 ± 17 years; 218 ventricular tachycardias, 407 premature ventricular contractions) who underwent catheter ablation were studied. The patients were divided into 5 groups based on the VA origin: (1) outflow tract (OT)-VA, consisting of right ventricular (RV) OT-VA and left ventricular (LV) OT-VA; (2) inflow tract (IT)-VA, consisting of tricuspid annulus (TA)-free wall (FW)-VA, IT-septum-VA, and mitral (MA)-FW-VA; (3) LV-inferoseptum-VA; (4) LV-other-VA; and (5) RV-other-VA. RVOT-VA in women were 1.5 times more frequent than in men, while LVOT-VA were more frequent in men. The prevalence of LVOT origin I-VA increased with age compared to that for the RVOT. The mean age of MA-FW-VA patients (62 ± 14 years) was higher than that of TA-FW-VA patients (51 ± 18 years; P = 0.03). The ablation success rate for RVOT-VA (88%) was higher than that for LVOT-VA (58%; P<0.0001). A multivariate analysis revealed that the patient age was one of the valuable predictors of a successful ablation (odds ratio=0.97; 95% confidence interval: 0.95-0.99; P=0.007). CONCLUSIONS Distinct gender and age differences were found in the incidence of I-VA according to their site of origin.