Stradivari harp tree-ring data.

Three tree ring sequences were collected on the soundboard of the Stradivari harp. Due to the presence of the strings in the centre of the harp soundboard, the sampling of the tree ring widths was focused separately on the right side (RX), the central (CX) and the left side (LX). Tree ring measurements were carried out by using the Video Time Table (VTT), an instrument that combines a portable measuring device and a digital, high-resolution video camera. The VTT allowed non-invasive measurements of the tree rings to be made in situ and to immediately verify the quality of the sampling. The growth rings of the central portion were sampled using a high-resolution camera, which made it possible to bypass the barrier formed by the neck and strings. The consequent parallax and focus problems were overcome by taking many photographs from different angles. The measurements on the photographs were made with the CooRecorder program. The dendrochronological data were acquired with the PAST4 program and graphically processed and analysed with the PAST4 and 5 programs.

"Near-zero" fluoroscopic exposure in supraventricular arrhythmia ablation using the EnSite NavX™ mapping system: personal experience and review of the literature.

PURPOSE: Radiofrequency catheter ablation (RFCA) of supraventricular tachyarrhythmias carries a small but non-negligible radiation risk. Studies in children already showed the feasibility of using three-dimensional mapping systems as the primary guide for catheter visualization and positioning in these RFCAs. We aim to demonstrate the feasibility and safety of such an approach in young and middle-aged patients. METHODS: Fifty patients (age 34 ± 12) with supraventricular tachyarrhythmias underwent electrophysiological study; of these, 47 patients proceeded to RFCA guided by the EnSite NavX(TM) system (23 with atrioventricular nodal reentry tachycardia, 16 with an accessory pathway, six with typical atrial flutter, and two with right atrial tachycardia). RESULTS: In 38/50 cases (76%), electroanatomical mapping avoided fluoroscopy entirely, including four cases requiring access to the left heart chambers by a retrograde approach. In the remaining 12/50 cases (24%), fluoroscopy use was limited to 122 ± 80 s, with a correspondingly low radiation exposure (dose area product 1.3 ± 1.1 mGy × m(2)). All procedures were acutely successful, with a procedural time of 113 ± 37 minutes, and without incurring in any major complication. Over a mean follow-up of 12 ± 3 months, we observed one recurrence of pre-excitation and one relapse of atrial flutter. CONCLUSIONS: Our study shows that non-fluoroscopic RFCA of supraventricular tachyarrhythmias using the EnSite NavX(TM) system is feasible, safe, and effective in a population of relatively young adults. Our experience of a non-fluoroscopic approach in these procedures deserves consideration, particularly in the young or in other patients at higher radiation risk.