Application Of Multislice Spiral CT In Atrial Fibrillation Before Radio Frequency Cather Ablation: Clinical Study

Background Atrial fibrillation is the most common clinical atrial arrhythmia. Over theage of65in the crowd，incidence of atrial fibrillation is about6%,while over85the rate isabout10%.In recent years, with the deepening of the research of atrialfibrillational.Pulmonary vein in atrial fibrillation triggered and drive plays an importantroles,most of the paroxysmal atrial fibrillation originated in the pulmonary vein.The openposition of pulmonary vein is the muscle connection parts of the left atrium-pulmonaryvein.Foundation is there is "muscle sleeve" in anatomical.Pulmonary vein has to releasethe ability of electrical activity.Therefore, radio frequency ablation atrial fibrillation wayis mainly directed against the pulmonary vein open near the left atrium inablation.Through radio frequency ablation technology directly removes excited stove orelectrical isolation of the vein and atrial electric connection can make the atrial fibrillationdisappear, so as to achieve the purpose of treatment.The effects of the treatment dependon pulmonary vein ectopic excitement the correct orientation and complete isolation.Toevaluate pulmonary vein anatomy details before radio frequency ablation is veryimportant.With multilayer spiral CT technology rapid development.Its rapid volumescanning, and has strong3d reconstruction function and image post-processing ability.Byplanar reorganization (MPR), maximum density projection (MIP),volume representation(VR) and simulation endoscopy (VE) to evaluation pulmonary vein and left atriumconnection imaging.This study through analysis of pulmonary vein MSCT imagingevaluation, analysis of pulmonary vein parting, further clear pulmonary vein variationtypes.At the same time to study the diameters of the pulmonary vein ostia.It willcontribute to the smooth progress of atrial fibrillation radio frequency ablation, shortenthe X-ray exposure time, reduce complications. Thrombosis especially, the left atrial thrombosis is the most commoncomplications.When the atrial fibrillation attack,atrial lose effective contraction diastolicfunction, blood can’t normal filling and emptying, lead to local blood flow clogged, is thefoundation of thrombosis.With atrial fibrillation catheter ablation technology development,whether there is the atrial thrombus is one of the important target needs to be judgedbefore catheter ablation,and left atrium thrombus, resulting in the presence ofintraoperative and postoperative stroke risk is higher, it is the absolute contraindicationsof radio frequency ablation.Therefore, left atrial thrombosis were detected for the choiceof treatment and the prognosis of patients have important significance.Trans esophagealechocardiography is the common clinical detection in patients with atrial fibrillation leftatrial thrombus the most accurate method.But the inspection belongs to the minimallyinvasive examination, inspection process, patients must endure the pain, and at the sametime, older or cardiac insufficiency patients can’t tolerate this inspection.With thedevelopment of CT, the test noninvasive and fast volume scanning characteristics makes itmore and more applied in left atrial thrombus inspection and selection. Through theanalysis of patients with atrial fibrillation MSCT and transesophageal echocardiographycontrast study of MSCT evaluation in patients with atrial fibrillation left atrium thrombusvalue.Part one Multislice CT evaluation of pulmonary vein in patients with atrialfibrillation Objective To explore the value of the multislice computed tomography onpulmonary vein and left atrium anatomic connection mode and pulmonary vein diameterbefore atrial fibrillation radio frequency ablation. Methods The experimental group:Weevaluated120subjects with atrial fibrillation. The control group：Randomly selected fromAugust to December2011with normal chest enhanced scans.Based on the CTimages.MPR, MIP, CPR,VE and VR etc. Reconstruction way were used.Observe thepulmonary vein anatomy variation.In atrial fibrillation group and normal group pulmonary vein variation on statistical analysis of the distribution of gender and left andright side.Measuring atrial fibrillation group and normal group standard pulmonary veinorifice diameter, and carries on the statistical analysis.Results The pulmonary vein can bedivided into five types, the most common, standard group, a total of75cases of atrialfibrillation, accounting for62.5%in the atrial fibrillation group (75/120); the normalgroup, a total of65cases, accounting for65%in the normal group (65/100); Commontrunk of left pulmonary veins is the most common type of mutation atrial fibrillationgroup, accounting for18.3%in the atrial fibrillation group.Single branch of the rightpulmonary veins is the most common type of mutation in the normal group, accounting for13%; In atrial fibrillation group, the occurrence of pulmonary vein variation in gender andleft/right side has no statistical significance. Normal group of pulmonary vein variation nostatistical differences in the gender, the right side of the mutation rate is higher than theleft. Atrial fibrillation group and normal group the occurrence of pulmonary vein variationin gender and left and right side has no statistical significance.75cases of atrialfibrillation group and65cases of normal standard set of four pulmonary veins in patientswith atrial fibrillation two upper pulmonary vein thick, two inferior pulmonary vein issmaller, statistically between the long and short diameters of the atrial fibrillation groupand the normal group pulmonary vein differences in the atrial fibrillation group lowerright pulmonary vein round.Right superior pulmonary vein ostium have the most roundupper right pulmonary vein orifice of the normal control group. The atrial fibrillationgroup comparison of the pulmonary vein with the normal group, the P values were lessthan0.05, the proof of atrial fibrillation group than in the normal group two on thepulmonary vein and the two inferior pulmonary vein mouth diameter and short diameterincreases.Conclusion Multislice CT can accurately display anatomical variations of thepulmonary veins and left atrium and study the diameters of the pulmonary vein ostia. Itwill contribute to the smooth progress of atrial fibrillation radio frequency ablation. Part two The clinical research of MSCT and the transesophageal echocardiography(TEE) applied in the detection of left atrial thrombusObjective Investigate the clinical value of multislice spiral CT imaging evaluation ofatrial fibrillation in patients with left atrial thrombus. Methods We evaluated120subjectswith atrial fibrillation. Each patient received MSCT scan and a trans esophagealechocardiography (TEE) at the same time during be in hospital.The results of the MSCTwere compared with esophageal echocardiography as the gold standard. Results On thebasis of echocardiography. Multislice CT and the ultrasonic testing of the coincidence ratewas89.2%, specificity was92.7%, the diagnostic sensitivity to54.5%, positive predictivevalue42.9%, negative predictive value was95.3%, positive likelihood ratio7.48;Negative likelihood ratio of0.49. After four pairs in the table chi-square, chi-square=0.31, P>0.05). That multislice CT scan and TEE left atrium thrombus no statisticallysignificant results. Conclusion: MSCT can be left as a clinical diagnosis of thrombosis ofa screening method, and can be a important supplementary classics esophagusechocardiography noninvasive detection method.