L. Comparative study between original and traditional method in establishing a chronic sinus node damage model in rabbit. J Appl Physiol 113: 1802-1808, 2012. First published August 16, 2012 doi:10.1152/japplphysiol.00480.2012.-Sick Sinus Syndrome is a common and refractory arrhythmia, needing further study in which setting up a credible sinus node damage model is important. To explore the feasibility and superiority of an original formaldehyde pinpoint pressing permeation (FPPP) method for building a chronic sinus node damage (CSND) model, 5 rabbits were chosen from 35 as a sham-operation group, and the remaining were randomly divided into two groups: the formaldehyde wet compressing (FWC) group, in which models were established by applying a cotton bud dipped in 20% formaldehyde onto the sinus node (SN) area, and the FPPP group, in which models were established by injecting formaldehyde into the SN area through a self-made pinpointing and injecting electrode. We found that in both groups, the HR at 2 h, 24 h, 1 wk, and 2 wk after modeling decreased compared with premodeling; sinoatrial conduction time, sinus node recovery time, and corrected sinus node recovery time were prolonged compared with premodeling. The indexes mentioned shortened by 2 wk after modeling compared with 2 h in the FWC group, whereas they were stable after modeling in the FPPP group. The modeling achievement ratio in the FPPP group was higher and the death rate was lower. Under light microscope, paraffin sections of the SN tissue and cells showed severe injury in both groups. The results indicate that the CSND models in rabbits can be successfully established by the FPPP method, with higher achievement ratio, lower death rate, better stabilization effect, and less damaging comparing with the traditional method. chronic sinus node damage; model establishing; novel method; electrophysiology THE SICK SINUS SYNDROME (SSS) is a clinically common and refractory arrhythmia, whose precise pathogenesis has not yet been clearly elucidated. Clinical and experimental studies have shown that the cardiac pacing and conducting dysfunction resulting from the damage of sinus node (SN) cells may be the direct pathological mechanism (1). Therefore, the setting up of a credible and stable sinus node damage model is most important in the experimental study of SSS. Various methods are used to establish animal sinus node damage models. Most researchers utilize the method of applying a cotton bud dipped in 20% formaldehyde onto the sinus node area (6). Other methods include ligating the artery supplying the sinus node with blood (10), cryocoagulation of the sinus node area (4), and radiofrequency catheter ablation of the sinus node area (6). Most of these methods have difficulties pinpointing the sinus node area, require large incisal openings, and have a low survival rate. Moreover, they are only used to establish acute models rather than chronic ones. We therefore created a more refined approach, the formaldehyde pinpoint pressuring permeation (FPPP) method, f...