Evaluation Of Right Ventricular Function In Patients With Atrial Fibrillation By Echocardiography

PART 1 Relationship between echocardiographic and magnetic resonance derived measures of right cardiac size and function in patients with atrial fibrillationObjective1. To explore whether systolic functional markers in ASE 2009 guidelines for echocardiographic assessment of the right heart is suitable to patients with atrial fibrillation (AF).2. Using CMR as a gold standard, we detected the sensitivity, specificity and threshold of echocardiographic right ventricular markers in AF patients.MethodsProspective test.16 patients with AF were enrolled in PUMCH from Sep.2014 to Dec. 2014. Collecting their clinical datas, echocardiographic and CMR values. Storing 2D movie images from apical four-chamber view, then using EchoPac system to draw time-strain curves of the endocrine, middle-layer and epicardial layers.Results1. There were significant positive correlations of left and right atrial diameters between echocardiography and CMR.2. Both right ventricular end diastolic area and right ventricular end systolic area were related to MRI right ventricular volumes.3. Binary logistic regression showed that CMR right ventricular ejection factor (CMR-RVEF) was linearly dependent with right ventricular middle-layer peak longitudinal systolic strain (RV-PLSS-MID), tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular systolic peak speed (S’).4. In ROC analysis, RV-PLSS-MID got the largest Area under curve (0.836) among all the right ventricular functional markers.-17% could be regarded as a threshold of right ventricular dysfunction (0.909 of sensitivity and 0.800 of spectivity).5. In Bland-Altman analysis,2.5 multiply RV-PLSS-MID was consistent with MRI-RVEF.6. AF patients with RVEF< 48% had lower RV-PLSS-ENDO than RVEF≥48% subgroup (-18.4% vs.-23.9%,p=0.011).Conclusion1. S’and TAPSE, which were recommended by ASE guidelines, could also be applied to AF patients, while RV-PLSS-MID had better sensitivity and specificity to identify right ventricular systolic dysfunction.2.2.5 multiply RV-PLSS-MID could help evaluate RVEF.3. We propose a combination of TAPSE, S’and PLSS to detect right ventricular systolic dysfunction in AF patients.PART 2 Structure and pressure modifications of right heart in patients with atrial fibrillationObjective1. To explore the possible risk factors of right ventricular pressure modification in patients with AF.2. To study the structure and pressure datas of right heart in patients with AF.Methods Case control study, recording the clinical and echocardiographic datas.Results Patients with definite diagnosis of AF were involved from May 2011 to May 2013 in PUMC hospital, with left ventricular ejection factor> 45%. The prevalences of diabetic mellitus and hypertension were higher in AF patients with right ventricular systolic pressure (RVSP)≥30mmHg than<30mmHg (p< 0.05). EHRA score> I, left atrial enlargement were correlated positively with RVSP≥30mmHg in AF patients (p< 0.05). There were significant differences on tricuspid regurgitation (TR), inferior vena cava diameter, left atrial diameter, right ventricular diameter, resting heart rate, CHAD-S2 scores, CHADS2-VASc scores and percentage of EHRA score> I between AF patients with enlarged right atrium and normal size. AF patients with right ventricular enlargement had elevating inferior vena cava diameter, left atrial diameter, percentage of hypertension significantly; and have decreased left ventricular ejection factor obviously. Left atrial diameter was correlated positively with TR, right ventricular systolic pressure, right ventricular diameter, and right atrial diameter.Conclusion1. When accompanying with hypertention, diabetic mellitus, EHRA score> I, larger volume of the systemic circulation and chronic history (occurrence of left atrial enlargement), AF patients are more prone to suffer from elevating right ventricular systolic pressure and right ventricular enlargement.2. Left atrial enlargement might be a strong evidence of right ventricular dysfunction in AF patients.PART 3 Echocardiographic evaluation of right ventricular systolic function in Atrial fibrillationObjective1. To explore the incidence and risk factors of right ventricular dysfunction in AF patients.2. To compare right ventricular structural and functional parameters in patients with paroxysmal and persistent AF.3. To compare right ventricular structures and functions in AF patients with different durations.4. To observe the accuracy of single beat method in evaluating right ventricular function of AF patients.Methods Case control study.55 AF patients in cardiology department of PUMCH from Jan 2013 to Jan 2015 were involved. Collecting their clinical datas and echocardiographic markers. Storing their 2D gray scale echocardiography images from 4-chamber view. Using EchoPac software system to generate right ventricular time-strain curves of each layers. An index beat is defined as the beat after the nearly equal preceding and pre-preceding intervals.Results1. Comparing with paroxysmal AF group, persistent AF group is manifestated as decreasing RVEF (58.1±12.9% vs.47.8±14.9%), TAPSE (18.4±4.1% vs.15.3±3.3%) and higher left atrium inner diameters.2. Comparing with paroxysmal AF group, the RV-PLSS-T (20.2±4.4% vs.14.7±4.1%), RV-PLSS-ENDO (23.0±5.0% vs.16.2±5.4%), RV-PLSS-MID (19.9±4.4% vs. 14.8±4.1%), RV-PLSS-EPI (17.6±4.5% vs.13.0±3.5%) and LV-PLSS-T (18.3±4.1% vs.14.6±3.6%) decrease significantly in persistent AF group (p<0.01).3. All the RV longitudinal strain markers (RV-PLSS-T, RV-PLSS-ENDO, RV-PLSS-MID and RV-PLSS-EPI) decrease in keeping with the prolonged course of AF. If AF patients are grouped according to the durations of disease (<1 year,1-5 years,>5 years), the RV-PLSS-EPI (19.1 ±5.1% vs.17.6±3.7% vs.14.2±4.4%) and RV-PLSS-T (21.2±4.4% vs.19.7±4.5% vs.16.6±4.9%) present obvious differences in ANOVA analyses (p<0.05).4. If right ventricular dysfunction is defined as TAPSE<16mm, AF patients with decreasing TAPSE are presented with larger left atriums, lower percentage of LVEF and LV-PLSS-T. If right ventricular dysfunction is defined as RVEF<44%, AF patients with decreasing RVEF are presented with larger right atriums, prolonged durations of AF, and lower percentage of LV-PLSS-T(p<0.05 respectively).5. If dividing AF patients into two groups according to the RV-PLSS-T and RV-PLSS-MID (<17% vs≥17%), the AF patients with decreasing strains have longer course, higher percentages of persistent AF, faster heart rates and larger left atriums relatively. Although there is no difference in LVEF between two groups, LV-PLSS-T decreased significantly in AF patients with lower right ventricular strains(p<0.05 respectively).6. There are significant positive correlations between index beat method and average method in traditional right ventricular function markers such as TAPSE, RVEF, S’ and FAC, and in right ventricular longitudinal systolic markers including RV-PLSS-T, RV-PLSS-ENDO, RV-PLSS-MID and RV-PLSS-EPI (r> 0.85, p< 0.001, respectively). Taking average values of ten beats as gold standard, Bland-Altman analyses showing significant consistency between gold standard and method of single beat values.ConclusionThe possible risk factors of right ventricular dysfunction in AF patients include prolonged course of AF, fast heart beats, persistent AF, enlarged left atriums and decreasing LV-PLSS-T. Right ventricular function and longitudinal strains are more prone to suffer from persistent AF comparing with paroxysmal AF. In right ventricular functional evaluation of AF patients, the index beat is a good alternative which could be used to measure TAPSE, RVEF, S’, FAC, LV and RV longitudinal systolic strains, and is as accurate as the time-consuming method of averaging multiple cardiac cycles.PART 4 The values of ventricular systolic longitudinal functional assessment in patients with atrial fibrillation before and after ablationObjective1. To explore the influence of radiofrequency ablation on right and left ventricular function in patients with atrial fibrillation.2. To investigate prognostic values of right ventricular functional parameters in predicting AF recurrence after ablation.Methods Perspective cohort study.55 patients with AF in cardiology department of PUMCH from Jan 2013 to Jan 2015 were involved. Echocardiography were practiced before, and at 1-3 days,3-6 months intervals after the radiofrequency ablation surgery. Storing their 2D gray scale echocardiography images from 4-chamber view. Using EchoPac software system to generate right and left ventricular time-strain curves. We also visited the involved patients every 6 months, recording their medical therapy, endpoint events, to compare prognoses in AF patients with normal and decreasing right ventricular function.Results1. AF patients with early recurrence after the ablation are manifested as significant decreased TAPSE and RV-PLSS of globe and each layers. The percentage of early recurrence is obvious elevated in AF patients with RV longitudinal dysfunction (defined as S’<10cm/s, or RV-PLSS<17%) and with left ventricular longitudinal dysfunction (defined as LV-PLSS<19%)(p<0.05 respectively).2. Early recurrence of AF are significantly positively correlated with durations of AF, TAPSE, RV-PLSS-T, RV-PLSS-ENDO, RV-PLSS-MID and RV-PLSS-EPI (OR=1.039,0.852,0.813,0.872,0.824,0.771, p<0.05, respectively). However, after adjusting in binary logistic model, only course of AF (OR=1.050) and RV-PLSS-T (OR=0.770) are independent risk factors of early recurrence of AF after ablation (p<0.05 respectively).3. RV longitudinal strains (including RV-PLSS-T, RV-PLSS-ENDO, RV-PLSS-MID and RV-PLSS-EPI) are significantly negatively correlated with endpoint events (including recurrence of AF, readmission of cardiovascular events and arrhythmia related symptoms). AF patients with decreased RV longitudinal strains show elevating percentages of endpoint events and shortening event-free survival.4. After the ablation of AF, S’,TAPSE, RV-PLSS-T, RV-PLSS-ENDO, RV-PLSS-MID and RV-PLSS-EPI improve significantly and quickly, the obvious differences still persist after 3-6 months of ablation.Conclusion1. Radiofrequency ablation surgery could improve RV longitudinal function rapidly, which might be attributed to correction of atrial tachycardia.2. LV-PLSS-T is more sensetive than LVEF to evaluate left ventricular longitudinal systolic function.3. AF patients with worse RV longitudinal systolic function are more prone to suffer from early recurrence after ablation. Decreasing RV strains might help predict endpoint events including AF recurrence, cardiovascular readmission and arrhythmic symptoms.