Spectrum Analysis In Atrial Fibrillation

Objects:The purpose of this study was to determine the role of dominant frequency (DF) and organized index (OI) in outcomes of pulmonary vein (PV) isolation for paroxysmal atrial fibrillation (AF) and persistent AF.Methods:01and DF of electrograms in coronary vein sinus (CS) during AF were obtained by frequency spectra analysis in60patients with paroxysmal AF and27persistent AF who underwent PV isolation. Based on the results of12months follow up, patients with recurrent AF were included in group recurrence and those with sinus rhythm were included in group sinus rhythm.Results:In patients with paroxysmal AF, there was no significant difference of DF at baseline between group recurrence and group sinus rhythm (6.2±1.4Hz vs.6.5±1.0Hz, p=0.513). After PV isolation, DF decreased to4.9±1.3Hz in group recurrence (p=0.001), while DF decreased to4.0±1.0Hz in group sinus rhythm (p<0.001). A significant difference was found in DF after PV isolation between group recurrence and group sinus rhythm (p=0.006) and the changes of DF was significantly different between group recurrence and group sinus rhythm (1.3±1.2vs.2.4±1.3, p=0.006). Specifically, DF was reduced by PV isolation in all patients in group recurrence; in group sinus rhythm, DF was reduced by PV isolation in34patients, while in the other two patients, DF increased after PV isolation.OI was calculated at baseline and after PV isolation.01in group recurrence before PV isolation was64±15%, and was73±8%after PV isolation (p=0.01). Specifically,01increased after PV isolation in nine patients; in another three patients,OI did not increase after PV isolation. In group sinus rhythm,OI was72±14%before PV isolation and was90±4%after PV isolation (p<0.001). Specifically,OI decreased in three patients after ablation in group sinus rhythm; in the other33patients,OI increased after PV isolation. There was no significant difference in OI between group recurrence and group sinus rhythm at baseline (p=0.095); the increment of OI after PV isolation in group recurrence was significantly lower than group sinus rhythm (8.7±10%vs.18±15%, p=0.034). After PV isolation,OI was significantly higher in group sinus rhythm than in group recurrence (p <0.001). In addition, patients in both groups whose OI decreased after ablation were not those patients whose DF increased after ablation.In patients with persistent AF, there was no significant difference between DF in group recurrence and group sinus rhythm (1.0±1.1vs.0.4±1.0Hz, P=0.158). Conclusions:A decrease in DF and an increase in OI after PV isolation may suggest a better clinical outcome in patients with paroxysmal AF but not in patients with persistent AF. Analysis of the frequency gradient in different models of AF and using the gradient to predict the outcome of the atrial fibrillation ablationObjects:The aim of the experimental study was to investigate the frequency gradient in different models of AF; the aim of the clinic study was to investigate if the frequency gradient can indicate the mechanisms of the atrial fibrillation (AF) and suggest the outcome of the ablation of the atrial fibrillation.Methods:In experimental study,15dogs were divided into the following three groups:group1included sustained atrial tachypacing for4-hours;100mM acetylcholine (Ach) was applied to the left atrial appendage (LAA) in group2; and group three contained the application of a500mM Ach. Next, we introduced electric stimulations to induce AF, and five sites from the left atrium were used as recording sites. Domain frequency (DF) analysis was performed at every site and the effective refractory periods (ERPs) and AF inducibility index were obtained.In clinic study, the consecutive patients with AF who will undergo the pulmonary vein isolation were included in the study. Before ablation, type of AF (paroxysmal or persistent AF) was diagnosed by doctor who would not know the ablation and results of the frequency analysis. The frequency analysis was performed on the sites of the pulmonary vein and orifice of the coronary sinus. Based on the frequency gradient presence or not, the patients were divided into two groups:the frequency gradient presence group and the no the frequency gradient presence group. After ablation, the frequency analysis was performed on the site of the orifice of the coronary sinus again. The patients were followed up in the next2years. Results In experimental study, Compared to baseline (108±18vs.138±12ms, P<0.001), group1ERPs were significantly decreased. There was no difference in decrements of ERPs at each site following pacing (P=0.646). Similar to group1ERPs, group2also showed a significant decrease (114±19vs.138±16ms, P<0.001ms, P<0.001), however, significance was further found in decrements of ERPs when comparing each site (P=0.017). All sites in group3were decreased significantly (114±28vs.142±15ms, P<0.001), and significance was also found in the decrements of ERPs at each site following Ach application (P<0.001). There was no significance in DF at each site in group1, however groups2and3were significantly different.In clinic study, there was no significant difference in baseline between the frequency gradient presence group and the no frequency gradient presence group. In the former group, recurred AF presented in7patients while30patients remain sinus rhythm; in the latter group, recurred AF presented in13patients while4patients remain sinus rhythm. The patients with or without the frequency gradient presence didn’t related to the patients with types of AF. The mechanisms of AF in1patient with multiply sources can be accurately deduced by the characteristics of the frequency gradient.Conclusion:We identified that different properties of the frequency gradient exist in different experimental models of AF. And the frequency gradient can indicate the mechanisms of the atrial fibrillation and suggest the outcome of the ablation of the atrial fibrillation Objects:This study aims to investigate if the frequency spectral components reflect the drivers of the paroxysmal atrial fibrillationMethods：Two simple signals were constructed and integrated to one. The spectral analysis was performed on these three signals in the pilot study.60patients with paroxysmal AF were included in the clinic study. Spectral analysis was performed before and after Pulmonary vein (PV) isolation. During ablation, drivers of the AF were identified. The dominant frequency (DF) of the coronary sinus (CS) ostium and PVs, and the fixed frequency spectral components of the CS ostium were identified. Changes of the DF and fixed frequency spectral components before and after PV isolation were studied. The distance from the recording site to the PV was measured in each patient.Results:The spectra of the integrated signal has two components, each reflect previous simple signal. In clinic study, fixed frequency spectral components were identified in30patients. The distance from the recording site to the PV in these patients were significantly different than other patients (to the right PV:48±9mm vs.64±8mm, P<0.05; to the left PV:51±9mm vs.65±8mm, P<0.05). The frequency of the fixed frequency spectral components was equal to (or within0.1HZ) the DF of the driving PV. The fixed frequency spectral component whose frequency equal to the DF of the driving PV decreased or disappeared accordingly after the driving PV isolation.Conclusion:The fixed frequency spectral components may reflect the drivers of the paroxysmal AF.