His bundle pacing versus left bundle branch pacing on ventricular function in atrial fibrillation patients referred for pacing: a prospective crossover comparison.

BACKGROUND: His bundle pacing (HBP) and left bundle branch pacing (LBBP) both provide physiologic pacing which maintain left ventricular synchrony. They both improve heart failure (HF) symptoms in atrial fibrillation (AF) patients. We aimed to assess the intra-patient comparison of ventricular function and remodeling as well as leads parameters corresponding to two pacing modalities in AF patients referred for pacing in intermediate term. METHODS: Uncontrolled tachycardia AF patients with both leads implantation successfully were randomized to either modality. Echocardiographic measurements, New York Heart Association (NYHA) classification, quality-of-life assessments and leads parameters were obtained at baseline and at each 6-month follow up. Left ventricular function including the left ventricular endo-systolic volume (LVESV), left ventricular ejection fraction (LVEF) and right ventricular (RV) function quantified by tricuspid annular plane systolic excursion (TAPSE) were all assessed. RESULTS: Consecutively twenty-eight patients implanted with both HBP and LBBP leads successfully were enrolled (69.1 ± 8.1 years, 53.6% male, LVEF 59.2% ± 13.7%). The LVESV was improved by both pacing modalities in all patients (n = 23) and the LVEF was improved in patients with baseline LVEF at less than 50% (n = 6). The TAPSE was improved by HBP but not LBBP (n = 23). CONCLUSION: In this crossover comparison between HBP and LBBP, LBBP was found to have an equivalent effect on LV function and remodeling but better and more stable parameters in AF patients with uncontrolled ventricular rates referred for atrioventricular node (AVN) ablation. HBP could be preferred in patients with reduced TAPSE at baseline rather than LBBP.

Three-dimensional echocardiographic assessment of left ventricular volume in different heart diseases using a fully automated quantification software.

BACKGROUND: HeartModel (HM) is a fully automated adaptive quantification software that can quickly quantify left heart volume and left ventricular function. This study used HM to quantify the left ventricular end-diastolic (LVEDV) and end-systolic volumes (LVESV) of patients with dilated cardiomyopathy (DCM), coronary artery heart disease with segmental wall motion abnormality, and hypertrophic cardiomyopathy (HCM) to determine whether there were differences in the feasibility, accuracy, and repeatability of measuring the LVEDV, LVESV, LV ejection fraction (LVEF) and left atrial end-systolic volume (LAESV) and to compare these measurements with those obtained with traditional two-dimensional (2D) and three-dimensional (3D) methods. AIM: To evaluate the application value of HM in quantifying left heart chamber volume and LVEF in clinical patients. METHODS: A total of 150 subjects who underwent 2D and 3D echocardiography were divided into 4 groups: (1) 42 patients with normal heart shape and function (control group, Group A); (2) 35 patients with DCM (Group B); (3) 41 patients with LV remodeling after acute myocardial infarction (Group C); and (4) 32 patients with HCM (Group D). The LVEDV, LVESV, LVEF and LAESV obtained by HM with (HM-RE) and without regional endocardial border editing (HM-NE) were compared with those measured by traditional 2D/3D echocardiographic methods to assess the correlation, consistency, and repeatability of all methods. RESULTS: (1) The parameters measured by HM were significantly different among the groups (P < 0.05 for all). Compared with Groups A, C, and D, Group B had higher LVEDV and LVESV (P < 0.05 for all) and lower LVEF (P < 0.05 for all); (2) HM-NE overestimated LVEDV, LVESV, and LAESV with wide biases and underestimated LVEF with a small bias; contour adjustment reduced the biases and limits of agreement (bias: LVEDV, 28.17 mL, LVESV, 14.92 mL, LAESV, 8.18 mL, LVEF, -0.04%). The correlations between HM-RE and advanced cardiac 3D quantification (3DQA) (r s = 0.91-0.95, P < 0.05 for all) were higher than those between HM-NE (r s = 0.85-0.93, P < 0.05 for all) and the traditional 2D methods. The correlations between HM-RE and 3DQA were good for Groups A, B, and C but remained weak for Group D (LVEDV and LVESV, r s = 0.48-0.54, P < 0.05 for all); and (3) The intraobserver and interobserver variability for the HM-RE measurements were low. CONCLUSION: HM can be used to quantify the LV volume and LVEF in patients with common heart diseases and sufficient image quality. HM with contour editing is highly reproducible and accurate and may be recommended for clinical practice.

Reference ranges and Z-scores of atrioventricular and ventriculoatrial time intervals in normal fetuses.

OBJECTIVE: To establish a reference range and compare differences among three methods, and then to construct Z-score reference ranges in normal fetuses from the three methods to provide an extra tool for fetal conduction time assessment. METHODS: A total of 227 echocardiographic examinations were finally included. Fetal atrioventricular (AV) time and ventriculoatrial (VA) time intervals were measured by three methods: superior vena cava/ascending aorta (SVC/AAO), pulmonary artery/pulmonary vein (PA/PV) and tissue Doppler imaging (TDI). Regression analysis of the mean and standard deviation was performed to establish Z-scores. RESULTS: With the three methods, positive correlations of intervals with gestational age (GA) and fetal heart rate (FHA) were observed, while intervals were negatively correlated with fetal heart rate (FHR). Correlations between VA/AV and GA, FHA and FHR were weak. The general trend of all intervals was towards an increase. In AV intervals, PA/PV revealed the longest mean AV time interval and SVC/AAO showed the shortest interval. In addition, PA/PV revealed the shortest VA interval. CONCLUSION: This study presents not only the reference range of AV and VA intervals with the three methods but also the Z-score reference ranges for these indices against GA and FHA in normal fetuses. Each method has a different reference range, and appropriate application can facilitate diagnosis and treatment.

Numerical prediction of thrombosis risk in left atrium under atrial fibrillation.

The remodeling of the left atrial morphology and function caused by atrial fibrillation (AF) can exacerbate thrombosis in the left atrium (LA) even spike up the risk of stroke within AF patients. This study explored the effect of the AF on hemodynamic and thrombosis in LA. We reconstructed the patient-specific anatomical shape of the LA and considered the non-Newtonian property of the blood. The thrombus model was applied in the LA models to simulate thrombosis. Our results indicate that AF can aggravate thrombosis which mainly occurs in the left atrial appendage (LAA). Thrombosis first forms on the LAA wall then expands toward the internal LAA. The proposed computational model also shows the potential application of numerical analyses to help assess the risk of thrombosis in AF patients.

Z-score reference ranges for pulsed-wave Doppler indices of the cardiac outflow tracts in normal fetuses.

To determine Z-score equations and reference ranges for Doppler flow velocity indices of cardiac outflow tracts in normal fetuses. A prospective cross-sectional echocardiographic study was performed in 506 normal singleton fetuses from 18 to 40 weeks. Twelve pulsed-wave Doppler (PWD) measurements were derived from fetal echocardiography. The regression analysis of the mean and the standard deviation (SD) for each parameter were performed against estimated fetal weight (EFW) and gestational age (GA), in order to construct Z-score models. The correlation between these variables and fetal heart rate were also investigated. Strong positive correlations were found between the twelve PWD indices and the independent variables. A linear-quadratic regression model was the best description of the mean and SD of most parameters, with the exception of the velocity time interval (VTI) of ascending aorta against EFW, which was best fitted by a fractional polynomial. Z-score equations and reference values for PWD indices of fetal cardiac outflow tracts were proposed against GA and EFW, which may be useful for quantitative assessment of potential hemodynamic alternations, particularly in cases of intrauterine growth retardation and structural cardiac defects.

Z-Score Reference Ranges for the Offset of the Tricuspid Septal Leaflet in Normal Fetuses.

OBJECTIVES: To determine Z-score equations and reference ranges for mitral valve-tricuspid valve distance (MTD) and the MTD index in the fetal heart. METHODS: A prospective cross-sectional study was performed in 899 normal singleton fetuses from 14 to 40 weeks' gestation. The MTD and interventricular septum length (IVSL) were measured offline after electronic cardiac spatiotemporal image correlation volume acquisition. The MTD index was determined as the ratio of MTD to IVSL. Z-score reference ranges of these measurements were determined against gestational age (GA) and estimated fetal weight (EFW), using regression analysis of the mean and standard deviation (SD). RESULTS: Strong positive correlations were found between the MTD and the independent variables. A simple linear regression model was the best description of the mean and SD of MTD based on GA, while a cubic regression best fitted the mean MTD against EFW. In contrast, the MTD index decreased progressively with the independent variables. Fractional polynomials best fitted the MTD index in terms of GA and EFW. CONCLUSION: Normal reference values and Z-scores of fetal MTD and MTD index were provided against GA and EFW, which may be useful tools for quantitative assessment of some cardiac and extracardiac diseases.

Z-scores for fetal left atrial size and left atrium-descending aorta distance in fetuses with isolated total anomalous pulmonary venous connection.

OBJECTIVES: To construct Z-score reference ranges for fetal left atrial (LA) size and left atrium-descending aorta distance (LDD or 'post-LA distance') at 20 to 40 weeks' gestation and to compare these parameters between fetuses with isolated total anomalous pulmonary venous connection (TAPVC) and normal fetuses. METHODS: Three hundred thirty-three normal singleton fetuses from 20 to 40 weeks' gestation were enrolled in a prospective cross-sectional study. Six cardiovascular dimensions were obtained by two-dimensional echocardiography. Z-score reference ranges of these measurements were determined against gestational age (GA) and fetal biometric variables, using regression analysis of the mean and standard deviation. Also, we reviewed fetal echocardiograms from ten fetuses with postnatal diagnosis of isolated TAPVC and made the measurements on archived images. Subsequently, all parameters were compared between the normal and TAPVC groups. RESULTS: A simple linear regression model was the best description of the mean and standard deviation of most variables in normal cases, with the exception of the mean LDD based on GA, which was best fitted by a quadratic regression. Fetuses with TAPVC had significantly lower LA size Z-scores [80% (8/10) of which were under -2] and increased LDD Z-scores [100% (10/10) of which were greater than 2]. Using an LDD Z-score of >2.22 was both highly sensitive (100%) and specific (98.5%) for distinguishing between TAPVC and normal hearts. CONCLUSION: Normal data and Z-scores of fetal LA size and LDD were provided against GA and fetal biometry. This could be useful for quantitative assessment of fetal TAPVC. Increased post-LA distance and decreased LA size may be markers for the prenatal diagnosis of TAPVC. © 2017 John Wiley & Sons, Ltd.

Z-Score Reference Ranges for Angular M-Mode Displacement at 22-40 Weeks' Gestation.

OBJECTIVES: To construct Z-score reference ranges for fetal mitral and tricuspid annular plane systolic excursions (MAPSE and TAPSE), using angular M-mode (AM) and conventional M-mode (CM). METHODS: A prospective cross-sectional investigation was conducted on 261 normal singleton fetuses from 22 to 40 weeks' gestation. TAPSE and MAPSE were measured by AM and CM. Reference ranges of TAPSE and MAPSE derived from AM and CM were determined against gestational age (GA) and heart area (HA), using regression analyses of the mean and standard deviation. RESULTS: TAPSE and MAPSE showed positive correlations with GA and HA. A cubic regression was the best-fitted model for the mean of MAPSE and TAPSE based on HA, while a linear regression model was established for the mean based on GA. Z-scores and 95% reference intervals for predicting MAPSE and TAPSE were established. Strong correlations were found between AM and CM, whereas CM underestimated AM (mean error: MAPSE 0.25 ± 0.18 mm; TAPSE 0.35 ± 0.2 mm). CONCLUSION: Normal data and the Z-scores of fetal MAPSE and TAPSE were provided against GA and HA, which can be useful for quantitative assessment of fetal cardiac dysfunction, particularly in cases of intrauterine growth restriction.