Correlation Between P-wave Terminal Force And F-wave Amplitude In Lead V1 On Electrocardiogram With Left Atrial Appendage Flow Velocity In Patients With Non-valvular Atrial Fibrillation

Objective:The purpose of this study was to analyze the correlation between P-wave terminal force in lead V1（Ptf V₁）during sinus rhythm and f-wave amplitude in lead V1at the onset of atrial fibrillation with left atrial appendage flow velocity in patients with non-valvular atrial fibrillation（AF for short）,and to explore the relevant factors affecting left atrial appendage flow velocity in conjunction with other clinical data and cardiac ultrasound indices.Methods:This study was a retrospective study.A total of 168 consecutive patients with atrial fibrillation who met the inclusion and exclusion criteria of this study were admitted to the Department of Cardiology of the Second Hospital of Dalian Medical University between March 1,2021 and August 31,2022,with a mean age of 60.1±9.4years and 105 males（62.5%）.Clinical data were collected,including gender,age,history of smoking,history of alcohol consumption,history of stroke,history of hypertension,history of diabetes mellitus,history of coronary artery disease,type of atrial fibrillation（paroxysmal AF or persistent AF）,CHA₂DS₂-VASc score,and transesophageal echocardiography（TEE）and transthoracic cardiac ultrasound.The parameters included left atrial appendage velocity（LAAV）,left atrial diameter（LAD）,left ventricular end-diastolic diameter（LVEDD）,left ventricular ejection fraction（LVEF）,oval orifice non-closure,mitral regurgitation,mitral orifice flow velocity（E）,etc.The ECG parameters included Ptf V₁ in sinus rhythm and V1 lead f-wave amplitude in atrial fibrillation.The data of the blood tests included D-dimer,platelets,creatinine,B-type brain natriuretic peptide（BNP）,and the rhythm at the time of TEE was recorded.According to the LAAV suggested by TEE,LAAV≤40 cm/s was defined as reduced flow velocity,and 168 patients were divided into normal LAAV group and reduced LAAV group.Statistical methods:Normally distributed measures were expressed as X±S,and two independent samples t-test was used to compare the two groups;skewed measures were expressed as median M（P25,P75）,and rank sum test was used to compare the two groups;count data were expressed as percentages,and chi-square test was used to compare the two groups.Correlations between general clinical data,AF rhythm,type of AF,cardiac ultrasound indices,and ECG indices and reduced LAAV were analyzed by univariate and multifactorial logistic regression.Before logistic regression,covariates were screened for covariates,and the VIF of all covariates did not exceed 5.Adjusting factors were also selected according to the covariate screening principle:confounders were correlated with reduced LAAV（≤40 cm/s）or the change in P value was greater than 10%before and after comparing confounders into the regression model.The data were analyzed using the R language package（http://www.r-project.org;version3.4.3）,Empower Stats（http://www.empowerstats.com）.The predictive value of the above independent correlates of reduced LAAV was assessed using receiver operating characteristic（ROC）curves,and the area under the curve,cut-off value,sensitivity and specificity were calculated.P<0.05 indicates that the results were statistically significant.Results:Among 168 patients,71 patients（mean age 60.1±9.4,male 46）were in the group with normal LAAV;97 patients（mean age 62.6±9.6,male 59）were in the group with reduced LAAV;（1）There were no statistically significant differences between the two groups in age,sex,history of hypertension,diabetes mellitus,coronary artery disease,stroke,smoking,alcohol consumption,oval foramen unclosed,mitral regurgitation,creatinine,D-dimer,platelets,and left ventricular end-diastolic internal diameter were not statistically significant（P>0.05）.Compared with the group with normal LAAV,the group with reduced LAAV had higher CHA₂DS₂-VASc score,higher BNP level,larger LAD,larger E value,reduced LVEF（<50%）,persistent atrial fibrillation,and a higher proportion of AF rhythm during TEE examination,and the differences were statistically significant（P<0.05）.（2）Multifactor logistic regression analysis showed that AF rhythm at TEE was an independent correlate of reduced LAAV（OR=5.7,95%CI 2.3-14.1,P<0.001）and the type of persistent AF was an independent correlate of reduced LAAV（OR=8.4,95%CI 3.3-21.5,P<0.001）;（3）Further analysis of the data of patients with complete data of ECG index Ptf V₁ and f-wave amplitude in168 patients and reperformed multifactorial logistic regression analysis,the results suggested that in paroxysmal AF,Ptf V₁ increase in sinus rhythm was an independent correlate of reduced LAAV（OR=8.7,95%CI 1.7 to 44.3,P=0.009）;in patients with paroxysmal AF,increased f-wave amplitude was an independent correlate of reduced LAAV（OR=7.8,95%CI 1.5 to 40.0,P=0.014）,and in patients with persistent AF,there was no statistically significant correlation between increased f-wave amplitude and reduced LAAV（OR=0.9,95%CI 0.2 to 4.9,P=0.911）,with statistically significant differences in the results across AF types and a p-value equal to 0.0164 for the analysis of the interaction test.Conclusions:In non-valvular patients with paroxysmal AF,increased ECG Ptf V1 in sinus rhythm and coarse fibrillation f-wave at fibrillating rhythm were independent correlates of reduced LAAV and were predictive of reduced LAAV.Higher CHA₂DS₂-VASc scores,increased BNP levels,increased LAD,reduced LVEF,and persistent AF were more likely to result in reduced LAAV.