Conventional fluroscopically guided mapping using multiple endocardial catheters allowed successful ablation of simple forms of tachyarrhythmias. Recently, the introduction of advanced mapping techniques had revolutionized the mapping of complex cardiac arrhythmias. In order to evaluate this new electroratomic (EA) mapping technique we studied 105 pts with supraventricular tachyarrhythmia (SVT). Fifty five of them were subjected to EA mapping compared to 52 subjected to conventional mapping. Our study proved that EA system markedly reduced fluoroscopic exposure for all patients, and achieved a markedly higher success rate in cases of focal atiral tachycardial and persistent forms of atrial fibrillation and those with left atrial dilatation compared to the conventional method.