DOES RADIOFREQUENCY CATHETER ABLATION INDUCE A DETERIORATION IN SYMPATHETIC INNERVATION - A POSITRON-EMISSION-TOMOGRAPHY STUDY

Radiofrequency catheter ablation (RFCA) is an effective treatment for the interruption of accessory bypass tracts in WPW syndrome or the mod ification of the AV-nodal conduction system in patients with AV-nodal tachycardias. However RFCA may also damage cardiac innervation. The pu rpose of this pilot study was to assess possible changes in sympatheti c innervation after RFCA as evaluated by the cathecholamine analog car bone-11-hydoxyephedrine (HED) positron emission tomography (PET) which allows the visualisation of sympathetic nerve terminals. We investiga ted nine patients with supraventricular tachycardias before and two to six weeks after RFCA. Myocardial perfusion was depicted by n-13-ammon ia-PET. In addition to visual analysis, HED retention was quantified i n the myocardial quandrant distal to the location of intervention; the se results were compared with values in remote areas. Before RFCA, myo cardial perfusion showed homogenous distribution in 8 of 9 patients. O ne patient showed a perfusion defect in the posterior wail HED retenti on matched perfusion distribution in all patients. After RFCA there wa s no significant change observed either in ammonia or in HED distribut ion. quantitative HED retention data showed no significant change befo re versus after RFCA. Thus, HED-PET does not demonstrate any abnormali ties of tracer uptake indicating integrity of sympathetic nerve termin als after radiofrequency ablation therapy.