Exploring The Correlation Between NT-proBNP Value In Plasma And The Low Voltage And Scar Area Ratio Of Left Atrial In Patients With Atrial Fibrillation

Background:Atrial fibrillation is one of the common heart diseases and the prevalence rate increased as the increasing of age.Atrial fibrosis is one of significance influence factors which lead to recurrence of AF after RFCA.So it is important to evaluate the atrial muscle fibers before ablation and and it can guide doctors to choose the treatment strategy.At present we mainly depend on high density voltage measurement which base on electrophysiological examination to evaluate left atrial atrial fibrosis.But still lack of effective and noninvasive means to assessment of atrial fibrosis.As a biochemical marker,BNP not only plays an important role in the diagnosis and prognosis of heart failure.But also play an important role in the pathogenesis of atrial fibrillation.Our previous studies have found that the plasma NT- pro BNP level can be used as a predictor factor in the recurrence of AF after RFCA.This may be related to atrial fibrosis degree.So we speculate that the NT-pro BNP value in plasma can reflect the degree of atrial fibrosis indirectly.Purpose of Research:To explore the correlation between NT-pro BNP value in plasma and the low voltage and scar area ratio of left atrial in patients with atrial fibrillation.We will comprehensive analysis the clinical data.Expecting to found a convenient,noninvasive and cheap way to assess atrial fibrosis in AF patients.Research method:The AF patients from the first affiliated hospital of Nanchang university who initially accepted RFCA guiding by Ensite Navx were selected.The NT-pro BNP value in plasma was tested before RFCA.We divided the patients into A group(NT-pro BNP?200pg/ml,n=19) and B group(NT-pro BNP>200pg/ml,n=24)base on the NT-pro BNP is greater than 200 pg/ml or not.The basic clinical data were recorded.The patient's age was divided into two groups(A group?60y,n=19;B group>60y,n=24).Divided into group A(?35mm,n=17)and group B(>35mm,n=26)based on left atrial diameter.Paroxysmal AF group(n=29) and persistent AF group(n=14).We mapped the voltage of left atrial under the sinus rhythm during the operation.the low voltage(bipolar voltag 0.05-0.5mv) and scar area(bipolar voltag<0.05mv) ratio of left atrial was computed.independent t-test analysis statisticallydifference between the groups.Using Multiple Linear Regression to evaluate the predictive value of Plasma NT-pro BNP value and other clinical dates on the left atrial low voltage and scar area ratio.Results: 1.The mean value of the low voltage and scar area ratio of left atrial in these 43 patients was 8.45±4.02%.Paroxysmal AF group was higher than persistent AF group[(10.40 ± 3.82)%vs.(6.58 ± 3.31)%](P < 0.05).Merge hypertension group was higher than no hypertension group[(10.40±3.82)%vs.(6.58±3.31)%](P<0.05);Merge carotid atheromatous plaque was higher than no carotid atheromatous plaque[(11.23±3.14)%vs.(7.60±3.91)%](P<0.05);NT-pro BNP>200pg/ml group was higher than NT-pro BNP?200pg/ml group[(11.04±2.90)% vs.(5.17±2.60)%](P< 0.001);A group of left atrial diameter was lower than B group [(5.04 ± 2.78)%vs.(10.67±3.04)% ](P<0.001);B group of age was higher than A group[(9.91±4.13)%vs.(6.59±3.08)%](P=0.006)?2.Multivariate Linear Regression analysis showed that NT-pro BNP can be used as independent effecting factor for left atrial low voltage and area ratio( ?=0.002,P=0.001).we also found that age and diameter of left atrial are independent effecting factors(P<0.05).Conclusion:AF patients' plasma NT-pro BNP value can be used as independent effecting factors for left atrial low voltage and scar area ratio.It may used for assessing myocardial fibrosis degree of left atrial.The left atrial diameter and age can be used as independent effecting factors for left atrial low voltage and area ratio.