This study to investigate the effects of RF ablation on left atrial systolic function in patients with atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular tachycardia (AVRT).

A total of 100 patients with persistent，in whom successful RF ablation of slow pathway or accessory pathway was performed. Patients with atrial fibrillation, structural heart disease, ventricular arrhythmias, impaired left ventricular systolic function or on antiarrhythmics were excluded. All the patients had echocardiographic study before ablation 、1 day and 1 months after ablation. Left atrial systolic function was assessed using atrial ejection force (AEF) according to Manning's formula (AEF = 0.5 x ρ x MA x A(2), r: blood density = 1.06 g/cm(3), MA: mitral orifice area [cm(2)], A: A wave velocity). The following left atrial dimensions were assessed: antero-posterior (LA-AP), infero-superior (LA-IS, long axis), medio-lateral (LA-ML, short axis). The correlations between AEF and electrophysiological parameters were analysed (VA - ventriculo-atrial conduction, VA/CL - tachycardia cycle length).

Inclusion Criteria:

Patients with paroxysmal supraventricular tachycardia,includes atrioventricular reentrant tachycardia and atrioventricular nodal reentrant tachycardia， Age is >14 years

Exclusion Criteria:

Atrial fibrillation, Atrial tachycardia， Structural heart disease, Ventricular arrhythmias, Patients with impaired left ventricular systolic function or on antiarrhythmics