Intracardiac CrYoablation for AtrioVentricular Nodal Reentrant Tachycardia

Pre-Electrophysiology Study Inclusion Criteria: * Supraventricular tachycardia (SVT) compatible with atrioventricular nodal reentrant tachycardia (AVNRT), documented by ECG, TTM, Holter or event monitor Pre-Electrophysiology Study Exclusion Criteria: * History of sustained (≥30 seconds) of ventricular tachycardia * Atrial tachycardia or other arrhythmia that could be confused with AVNRT * Reversible cause of SVT * History of previous AVNRT ablation * Therapy with amiodarone within last 90 days * Unstable angina/myocardial infarction/open heart surgery in past 60 days * New York Heart Association (NYHA) Classification III or IV currently or within the past 90 days * Implantable cardiac rhythm device * Atrioventricular block (first degree (PR interval ≥ 220ms), second degree, or third degree) or left bundle branch block * Stroke or transient ischemic attack within the past 180 days * Life expectancy less than 12 months * Female known to be pregnant * Unable/unwilling to give informed consent * Unable/unwilling to comply with follow-up visits and study requirements * Less than 18 years of age * Active systemic infection * Cryoglobulinemia * Other conditions where the manipulation of the catheter would be unsafe (for example, intracardiac mural thrombus) * Participating in a concurrent clinical study that may confound the results of this study Post-Electrophysiology Study Inclusion Criteria: * Subject must have one electrophysiology study documented inducible sustained (grea…