Patients with drug-refractory atrioventricular nodal reentrant tachycardia: Clinical features, electrophysiological characteristics, and predictors of medication failure

AbstractBackground and purposeDrug responses vary markedly from patient to patient in atrioventricular nodal reentrant tachycardia (AVNRT), the most common form of paroxysmal regular supraventricular tachycardia in adults. However, clinical and electrophysiological (EP) characteristics of patients with AVNRT whose tachycardia attacks could not be adequately controlled by antiarrhythmic agents have not been studied in a large patient cohort. We aimed to define the clinical and EP features of patients with drug-refractory AVNRT.Methods and resultsA total of 266 consecutive patients with AVNRT undergoing catheter ablation after a period of medical treatment were analyzed: 144 patients with drug-refractory AVNRT (Group 1) and 122 patients with drug-responsive AVNRT (Group 2). Age was significantly higher (p=0.027) and the presence of hypertension (p=0.030), diabetes mellitus (p=0.047), and valvular heart diseases (p=0.008) was more frequent in Group 1 compared to Group 2. Among the EP features, atrial-His jump (81% vs 69%, p=0.028) and atrial vulnerability (26% vs 14%, p=0.018) were significantly higher, echo zone was significantly more long-lasting (44±24ms vs 38±22ms, p=0.018), and tachycardia cycle length (TCL) was significantly longer (348±41ms vs 329±38ms, p=0.000) in Group 1 than in Group 2. Multivariate analysis showed that hypertension (p=0.036), valvular heart disease (p=0.014), atrial vulnerability (p=0.037), TCL (p=0.003), and wide echo zone (p=0.028) were independent predictors for drug-refractory AVNRT.ConclusionIn the presence of hypertension, valvular heart disease, atrial vulnerability, long-lasting echo zone, and relatively slow AVNRT, medical treatment is less likely to prevent the tachycardia episodes