Left Atrium Research Articles

HeartMate 3 for Heart Failure with Preserved Ejection Fraction: In Vitro Hemodynamic Evaluation and Anatomical Fitting.

Heart failure with preserved ejection fraction (HFpEF) constitutes approximately 50% of heart failure (HF) cases, and encompasses different phenotypes. Among these, most patients with HFpEF exhibit structural heart changes, often with smaller left ventricular cavities, which pose challenges for utilizing ventricular assist devices (VADs). A left atrial to aortic (LA-Ao) VAD configuration could address these challenges, potentially enhancing patient quality of life by lowering elevated mean left atrial pressure (MLAP). This study assessed the anatomical compatibility and left atrial unloading capacity using a simulated VAD-supported HFpEF patient. A HeartMate3-supported HFpEF patient in an LA-Ao configuration was simulated using a cardiovascular simulator. Hemodynamic parameters were recorded during rest and exercise at seven pump flow rates. Computed tomography scans of 14 HFpEF (NYHA II-III) and six heart failure with reduced ejection fraction patients were analysed for anatomical comparisons. HFpEF models were independently assessed for virtual anatomical fit with the HM3 in the LA-Ao configuration. Baseline MLAP was reduced from 15 to 11mmHg with the addition of 1L/min HM3 support in the rest condition. In an exercise simulation, 6L/min of HM3 support was required to reduce the MLAP from 29 to 16mmHg. The HM3 successfully accommodated six HFpEF patients without causing interference with other cardiac structures, whereas it caused impingement ranging from 4 to 14mm in the remaining patients. This study demonstrated that the HM3 in an LA-Ao configuration may be suitable for unloading the left atrium and relieving pulmonary congestion in some HFpEF patients where size-related limitations can be addressed through pre-surgical anatomical fit analysis.

Observational study on the identification of left atrial tachycardia circuits using Local Activation Time Histogram.

Mapping of atypical atrial arrythmias arising in the left atrium is often challenging. The Local Activation Time (LAT) Histogram, a new function of the 3D color mapping system CARTO version 7, may help improve identification of atrial tachycardia circuits. We aimed to assess the effectiveness of the LAT Histogram for identification of left atrial tachycardia circuits. This retrospective study compared 25 consecutive cases of left atrial tachycardia that were treated before use of LAT Histogram (unused group) and 25consecutive cases that were treated after introduction of LAT Histogram (used group) at Nagano Chuo Hospital. We evaluated whether we could identify the circuit of left atrial tachycardia from the electrophysiology lab data during ablation and the CARTO system data and whether we could perform effective ablation. Door-to-door time, skin-to-skin time, and fluoroscopy time (p≤.011) were all shorter in the LAT Histogram used group versus unused group, while mapping analysis times were longer in the used group (p ≤.019). A significantly greater number of cases in the LAT Histogram used compared with the unused group had ablation for entrance or exit points (19vs. 10 cases; p=.001 for first map). Ablation resulted in a return to sinus rhythm and changed cycle length at the first mapping in 20 cases (80%) in the LAT Histogram unused group and in 24 cases (96%) in the used group. LAT Histogram may provide a simple and effective method to identify entrance and exit locations in left atrial tachycardia.

Left atrial and ventricular longitudinal strain by cardiac magnetic resonance feature tracking improves prognostic stratification of patients with ST-segment elevation myocardial infarction.

We aimed to investigate the predictive value of left atrium (LA) and left ventricle (LV) longitudinal strain derived by CMR-FT early after ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). Patients with STEMI who received pPCI and completed CMR within the following week were enrolled. LA and LV longitudinal strain parameters were derived from cine CMR by FT; conventional CMR indexes were also performed. The primary endpoint was the occurrence of major cardiovascular adverse events (MACE), defined as a composite of death, reinfarction, and congestive heart failure (HF). 276 participants (median age, 57 years, IQR, 48-66 years; 85% men) were included in this study. CMR was usually completed on the 5 (IQR,4-7) days after pPCI. During a median follow-up of 16 months, MACE occurred in 35 (12.7%) participants. Multivariable Cox regression analysis showed that LA conduit strain (HR 0.91, 95%CI: 0.84, 0.98, p = 0.013) and LV global longitudinal strain (HR 1.17, 95%CI: 1.03, 1.34, p = 0.016) remained independently associated with MACE. Participants with impaired LA conduit strain (≤ 12.8%) and LV global longitudinal strain (> -13.1%) had a higher risk of MACE than those with preserved. Longitudinal strain of LA and LV could provide independent prognostic information in STEMI patients, and comprehensive assessment of Left atrial and ventricular longitudinal strain significantly improved the prognosis.

Left atrial and ventricular longitudinal strain by cardiac magnetic resonance feature tracking improves prognostic stratification of patients with ST-segment elevation myocardial infarction.

We aimed to investigate the predictive value of left atrium (LA) and left ventricle (LV) longitudinal strain derived by CMR-FT early after ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). Patients with STEMI who received pPCI and completed CMR within the following week were enrolled. LA and LV longitudinal strain parameters were derived from cine CMR by FT; conventional CMR indexes were also performed. The primary endpoint was the occurrence of major cardiovascular adverse events (MACE), defined as a composite of death, reinfarction, and congestive heart failure (HF). 276 participants (median age, 57 years, IQR, 48-66 years; 85% men) were included in this study. CMR was usually completed on the 5 (IQR,4-7) days after pPCI. During a median follow-up of 16 months, MACE occurred in 35 (12.7%) participants. Multivariable Cox regression analysis showed that LA conduit strain (HR 0.91, 95%CI: 0.84, 0.98, p = 0.013) and LV global longitudinal strain (HR 1.17, 95%CI: 1.03, 1.34, p = 0.016) remained independently associated with MACE. Participants with impaired LA conduit strain (≤ 12.8%) and LV global longitudinal strain (> -13.1%) had a higher risk of MACE than those with preserved. Longitudinal strain of LA and LV could provide independent prognostic information in STEMI patients, and comprehensive assessment of Left atrial and ventricular longitudinal strain significantly improved the prognosis.

The Impact of Close Proximity of Left Atrium to Descending Aorta on Left Inferior Pulmonary Vein Triggers or Drivers of Atrial Fibrillation: A Risk Score Model

BackgroundPrior studies have investigated cardiac anatomy and clinical parameters as predictors for pulmonary vein and non-pulmonary vein triggers. ObjectivesTo assess the link between the descending aorta to left inferior pulmonary vein (Dao-LIPV) distance and the occurrence of triggers and drivers in atrial fibrillation (AF) ablation procedures. MethodsDrug-refractory AF patients who underwent first-time index catheter ablation from January 2010 to December 2019 were retrospectively assembled. The Dao-LIPV distance was measured from pre-ablation pulmonary vein computed tomography. Patients were categorized based on the presence of LIPV triggers and/or drivers. Multivariate logistic regression was used to identify risk factors. ResultsA total of 886 consecutive patients with drug-refractory AF were studied, and 63 (7.1%) patients were identified to have LIPV triggers and/or drivers. The Dao-LIPV distance had a better predictive performance (AUC: 0.70) compared to persistent AF (AUC: 0.57). Multivariate logistic regression analysis showed that Dao-LIPV distance ≤ 2.5 mm (Odds ratio [OR] 3.96 [95% CI 2.15-7.29], p <0.001) and persistent AF (OR 1.73 [95% CI 1.02-2.94], p=0.044) were independent predictors for the presence of LIPV triggers and/or drivers. A risk score model was established to predict the probability of LIPV triggers or drivers with persistent AF (10.2%), Dao-LIPV distance ≤ 2.5mm (11.4%), and both (15.0%). ConclusionsThe close proximity of the Dao-LIPV was correlated to the presence of LIPV triggers or drivers. We developed a risk score model indicating that persistent AF and Dao-LIPV distances ≤ 2.5mm significantly increase the risk of LIPV triggers/drivers, aiding electrophysiologists in preparing for and performing catheter ablation more effectively.

Comparative Analysis of Treatment Strategies for Postoperative Pulmonary Hypertensive Crisis in Congenital Heart Disease

Background: Pulmonary hypertensive crisis (PHC) is a serious life-threatening complication in children with congenital heart disease (CHD) after surgery, with acute onset and high mortality. However, there is still no effective means to deal with this complication. Therefore, our department developed the left atrium and right ventricle duct bridging technique to treat children with PHC, and compare its effects with conventional methods of treatment to determine the best solution for dealing with this complication. Methods: A retrospective analysis of 41 children with CHD surgery and postoperative PHC in our hospital from January 2015 to December 2022 was performed. According to the rescue method, the group with conventional therapy combined with left atrium to right ventricle duct bridging treatment vs. simple conventional therapy were defined as group A and group B respectively, with 13 cases and 28 cases in each group. The success rate of rescue, the complication rate, the length of intensive care unit stay, the delayed chest closure duration, the duration of PHC, the ratio of pulmonary circulation/systemic circulation pressure, the oxygenation index and the cardiac index at 30 min, 1 h, 2 h, 4 h and 6 h after rescue were compared between the two groups. Results: There was a higher success rate of rescue (84.62% vs. 68.86%; p &gt; 0.05), lower complication rate (15.38% vs. 21.43%; p &gt; 0.05), shorter duration of PHC (6.77 ± 2.13 min vs. 13.07 ± 4.05 min; p = 0.000), shorter duration of delayed sternal closure (32.23 ± 5.46 h vs. 38.14 ± 8.61 h; p = 0.029) and shorter length of ICU stay (81.69 ± 8.31 h vs. 93.57 ± 16.84 h; p = 0.021) in group A; After the rescue, the pulmonary artery pressure and cardiopulmonary function recovery rate in group A were faster than those in group B. Conclusions: In conclusion, left atrial to right ventricular duct bridging therapy is more effective in the treatment of PHC after surgery for CHD.

Estimate of the hydraulic force in the aging heart: a cardiovascular magnetic resonance imaging study

BackgroundCoupling between left ventricle (LV) and left atrium (LA) plays a central role in the process of cardiac remodeling during aging and development of cardiac disease. The hydraulic force (HyF) is related to variation in size between LV and LA. The objectives of this study were to: (1) derive an estimate of left atrioventricular HyF using cine- Magnetic Resonance Imaging (MRI) in healthy subjects with a wide age range, and (2) study its relationship with age and conventional diastolic function parameters, as estimated by reference echocardiography.MethodsWe studied 119 healthy volunteers (mean age 44 ± 17 years, 58 women) who underwent Doppler echocardiography and MRI on the same day. Conventional transmitral flow early (E) and late (A) LV filling peak velocities as well as mitral annulus diastolic longitudinal peak velocity (E’) were derived from echocardiography. MRI cine SSFP images in longitudinal two and four chamber views were acquired, and analyzed using feature tracking (FT) software. In addition to conventional LV and LA strain measurements, FT-derived LV and LA contours were further used to calculate chamber cross-sectional areas. HyF was approximated as the difference between the LV and LA maximal cross-sectional areas in the diastasis phase corresponding to the lowest LV-LA pressure gradient. Univariate and multivariate analyses while adjusting for appropriate variables were used to study the associations between HyF and age as well as diastolic function and strain indices.ResultsHyF decreased significantly with age (R²=0.34, p < 0.0001). In addition, HyF was significantly associated with conventional indices of diastolic function and LA strain: E/A: R²=0.24, p < 0.0001; E’: R²=0.24, p < 0.0001; E/E’: R²=0.12, p = 0.0004; LA conduit longitudinal strain: R²=0.27, p < 0.0001. In multivariate analysis, associations with E/A (R2 = 0.39, p = 0.03) and LA conduit strain (R2 = 0.37, p = 0.02) remained significant after adjustment for age, sex, and body mass index.ConclusionsHyF, estimated using FT contours, which are primarily used to quantify LV/LA strain on standard cardiac cine MRI, varied significantly with age in association with subclinical changes in ventricular filling. Its usefulness in cohorts of patients with left heart disease to detect LV-LA uncoupling remains to be evaluated.

Estimate of the hydraulic force in the aging heart: a cardiovascular magnetic resonance imaging study

BackgroundCoupling between left ventricle (LV) and left atrium (LA) plays a central role in the process of cardiac remodeling during aging and development of cardiac disease. The hydraulic force (HyF) is related to variation in size between LV and LA. The objectives of this study were to: (1) derive an estimate of left atrioventricular HyF using cine- Magnetic Resonance Imaging (MRI) in healthy subjects with a wide age range, and (2) study its relationship with age and conventional diastolic function parameters, as estimated by reference echocardiography.MethodsWe studied 119 healthy volunteers (mean age 44 ± 17 years, 58 women) who underwent Doppler echocardiography and MRI on the same day. Conventional transmitral flow early (E) and late (A) LV filling peak velocities as well as mitral annulus diastolic longitudinal peak velocity (E’) were derived from echocardiography. MRI cine SSFP images in longitudinal two and four chamber views were acquired, and analyzed using feature tracking (FT) software. In addition to conventional LV and LA strain measurements, FT-derived LV and LA contours were further used to calculate chamber cross-sectional areas. HyF was approximated as the difference between the LV and LA maximal cross-sectional areas in the diastasis phase corresponding to the lowest LV-LA pressure gradient. Univariate and multivariate analyses while adjusting for appropriate variables were used to study the associations between HyF and age as well as diastolic function and strain indices.ResultsHyF decreased significantly with age (R²=0.34, p < 0.0001). In addition, HyF was significantly associated with conventional indices of diastolic function and LA strain: E/A: R²=0.24, p < 0.0001; E’: R²=0.24, p < 0.0001; E/E’: R²=0.12, p = 0.0004; LA conduit longitudinal strain: R²=0.27, p < 0.0001. In multivariate analysis, associations with E/A (R2 = 0.39, p = 0.03) and LA conduit strain (R2 = 0.37, p = 0.02) remained significant after adjustment for age, sex, and body mass index.ConclusionsHyF, estimated using FT contours, which are primarily used to quantify LV/LA strain on standard cardiac cine MRI, varied significantly with age in association with subclinical changes in ventricular filling. Its usefulness in cohorts of patients with left heart disease to detect LV-LA uncoupling remains to be evaluated.

Cyanotic heart disease due to a hypoplastic right ventricle with pulmonary valve atresia, an intact ventricular septum, with atrial level shunting in a day‐old Arabian foal

AbstractAn 8‐h‐old Arabian foal was presented for evaluation of progressive weakness since birth. The foal presented laterally recumbent with pale and muddy mucous membranes, a grade III/VI left basilar murmur, and an irregularly, irregular rhythm. Transthoracic echocardiogram along with an electrocardiogram (EKG) was performed. Atrial fibrillation was recorded throughout the examination. The left and right atria were both significantly enlarged. A right to left shunt across the atrial septum was confirmed via an intravenous injection of agitated saline. The tricuspid valve was rudimentary without apparent atrioventricular flow and no ventricular septal defect was appreciated. The animal was euthanased, and necropsy found dysplasia of the tricuspid valve, a hypoplastic right ventricle with pulmonary valve atresia, and an intact ventricular septum. This condition is similar, both haemodynamically and in terms of prognosis, to tricuspid atresia, which has been described previously in Arabian foals, with the exception that there is the complete absence of connection between the atrium and ventricle in the case of tricuspid atresia. Of 14 previously reported cases of tricuspid atresia in neonatal foals, nine were Arabian foals. Further investigation into the possibility of hypoplastic right ventricle as a familial condition in the Arabian breed should be considered.

Cyanotic heart disease due to a hypoplastic right ventricle with pulmonary valve atresia, an intact ventricular septum, with atrial level shunting in a day‐old Arabian foal

AbstractAn 8‐h‐old Arabian foal was presented for evaluation of progressive weakness since birth. The foal presented laterally recumbent with pale and muddy mucous membranes, a grade III/VI left basilar murmur, and an irregularly, irregular rhythm. Transthoracic echocardiogram along with an electrocardiogram (EKG) was performed. Atrial fibrillation was recorded throughout the examination. The left and right atria were both significantly enlarged. A right to left shunt across the atrial septum was confirmed via an intravenous injection of agitated saline. The tricuspid valve was rudimentary without apparent atrioventricular flow and no ventricular septal defect was appreciated. The animal was euthanased, and necropsy found dysplasia of the tricuspid valve, a hypoplastic right ventricle with pulmonary valve atresia, and an intact ventricular septum. This condition is similar, both haemodynamically and in terms of prognosis, to tricuspid atresia, which has been described previously in Arabian foals, with the exception that there is the complete absence of connection between the atrium and ventricle in the case of tricuspid atresia. Of 14 previously reported cases of tricuspid atresia in neonatal foals, nine were Arabian foals. Further investigation into the possibility of hypoplastic right ventricle as a familial condition in the Arabian breed should be considered.

Exploratory analysis of predictors of ventricular aneurysm in a cohort of 291 patients with acute myocardial infarction

ObjectiveIn this study, we explored the determinants of ventricular aneurysm development following acute myocardial infarction (AMI), thereby prompting timely interventions to enhance patient prognosis.MethodsIn this retrospective cohort analysis, we evaluated 297 AMI patients admitted to the First People’s Hospital of Changzhou. The study was structured as follows. Comprehensive baseline data collection included hematological evaluations, ECG, echocardiography, and coronary angiography upon admission. Within 3 months post-AMI, cardiac ultrasounds were administered to detect ventricular aneurysm development. Univariate and multivariate logistic regression analysis were employed to pinpoint the determinants of ventricular aneurysm formation. Subsequently, a predictive model was formulated for ventricular aneurysm post-AMI. Moreover, the diagnostic efficacy of this model was appraised using the ROC curves.ResultsIn our analysis of 291 AMI patients, spanning an age range of 32–91 years, 247 were male (84.9%). At the conclusion of a 3-month observational period, the cohort bifurcated into two subsets: 278 patients without ventricular aneurysm and 13 with evident ventricular aneurysm. Distinguishing features of the ventricular aneurysm subgroup were markedly higher values for age, B-type natriuretic peptide(BNP), Left atrium(LA), Left ventricular end-diastolic dimension (LEVDD), left ventricular end systolic diameter (LVEWD), E-wave velocity (E), Left atrial volume (LAV), E/A ratio (E/A), E/e ratio (E/e), ECG with elevated adjacent four leads(4 ST-Elevation), and anterior wall myocardial infarction(AWMI) compared to their counterparts (p < 0.05). Among the singular predictive factors, total cholesterol (TC) emerged as the most significant predictor for ventricular aneurysm development, exhibiting an AUC of 0.704. However, upon crafting a multifactorial model that incorporated gender, TC, an elevated ST-segment in adjacent four leads, and anterior wall infarction, its diagnostic capability: notably surpassed that of the standalone TC, yielding an AUC of 0.883 (z = -9.405, p = 0.000) as opposed to 0.704. Multivariate predictive model included gender, total cholesterol, ST elevation in 4 adjacent leads, anterior myocardial infarction, the multivariate predictive model showed better diagnostic efficacy than single factor index TC (AUC: 0. 883 vs. 0.704,z =-9.405, p = 0.000), it also improved predictive power for correctly reclassifying ventricular aneurysm occurrence in patients with AMI, NRI = 28.42% (95% CI: 6.29-50.55%; p = 0.012). Decision curve analysis showed that the use of combination model had a positive net benefit.ConclusionLipid combined with ECG model after myocardial infarction could be used to predict the formation of ventricular aneurysm and aimed to optimize and adjust treatment strategies.

Long-term outcomes of phenoclusters in preclinical heart failure with preserved and mildly reduced ejection fraction.

The identification of subjects at higher risk for incident heart failure (HF) with preserved ejection fraction (EF) suitable for more intensive preventive programmes remains challenging. We applied phenomapping to the DAVID-Berg population, comprising subjects with preclinical HF, aiming to refine HF risk stratification. The DAVID-Berg study prospectively enrolled 596 asymptomatic outpatients with EF>40% with hypertension, diabetes mellitus or known cardiovascular disease. In this cohort, we performed an unsupervised cluster analysis on 591 patients, including clinical, laboratory, electrocardiographic and echocardiographic parameters. We tested the association between each cluster and a composite outcome of HF/death. The median age was 70years, 55.5% were males and the median EF was 61.0%. Phenomapping provided three different clusters. Subjects in Cluster 3 were the oldest and had the highest prevalence of atrial fibrillation, the lowest estimated glomerular filtration rate (eGFR), the highest N-terminal pro-brain natriuretic peptide (NT-proBNP) and the largest left atrium. During a median follow-up of 5.7years, 13.4% of subjects experienced HF/death events (N=79). Compared with Clusters 1 and 2, Cluster 3 had the worst prognosis (log-rank test: Cluster 3 vs. 1 P<0.001; Cluster 3 vs. 2 P=0.008). Cluster 3 was associated with a risk of HF/death 2.5 times higher than Cluster 1 [adjusted hazard ratio (HR)=2.46, 95% confidence interval (CI) 1.24-4.90]. Based on phenomapping, older patients with lower kidney function and worse diastolic function might represent a subset of preclinical HF with EF>40% who deserve more efforts to prevent clinical HF.

Cardiac Mechanics and the Risk of Atrial Fibrillation in a Community-Based Cohort of Older Adults.

Assessment of cardiac structure and function improves risk prediction of new-onset atrial fibrillation (AF) in different populations. We aimed to comprehensively compare standard and newer measures of cardiac structure and function in improving prediction of AF in a cohort of older adults without history of AF and stroke. We included 5050 participants without prevalent AF and stroke (mean age 75 ± 5 years, 59% women and 22% Black) from the Atherosclerosis Risk in Communities (ARIC) study who underwent complete 2-dimensional echocardiography, including speckle-tracking analysis of the left ventricle (LV) and left atrium (LA). We assessed the association of cardiac measures with incident AF (including atrial flutter) and quantified the extent to which these measures improved model discrimination and risk classification of AF compared with the CHARGE-AF score. Over a median follow-up time of 7 years, 676 participants developed AF (incidence rate, 2.13 per 100 person-years). LV mass index and wall thickness, E/e' and measures of LA structure and function, but not LV systolic function, were associated with incident AF, after accounting for confounders. Above all, LA reservoir strain, contraction strain, and LA minimal volume index (C-statistics [95%Confidence interval]: 0.73 [0.70,0.75], 0.72 [0.70,0.75] and 0.72 [0.69,0.75], respectively) significantly improved the risk discrimination of the CHARGE-AF score (baseline C-statistic: 0.68 [0.65,0.70]) and achieved the highest category-based net reclassification improvement (29%, 24% and 20%, respectively). In a large cohort of older adults without prevalent AF and stroke, measures of LA function improved the prediction of AF more than other conventional cardiac measures.

Impact of Chronic Consumption of Herbal Rooibos on Cardiovascular Function in Adults with Cardiovascular Risk.

The prevalence of cardiovascular disease (CVD) has increased in South Africa, emphasizing the importance of prevention strategies. This study used echocardiography to investigate the impact of Rooibos on cardiovascular function in those at risk of CVD. This research aims to contribute to understanding its effects on reducing cardiovascular risk factors. The study design involved a 12-week randomized, parallel, double-blinded, placebo-controlled dietary intervention trial using capsules containing standardized water-soluble extracts of green and traditional fermented Rooibos alongside a placebo control. Echocardiography was incorporated as a diagnostic imaging tool to assess cardiac function in the participant cohort. Aorta (AO) dimensions showed no significant change in any intervention group. Left atrium (LA) reduced in size from 3.832 ± 0.071 cm to 3.675 ± 0.067 cm (P = 0.01). There was no significant change in LA/AO ratio in any intervention group. Interventricular septum diameter in the placebo group decreased from 1.334 ± 0.030 cm to 1.250 ± 0.025 cm (P = 0.002), with no significance in fermented Rooibos, while green Rooibos resulted in a decrease from 1.282 ± 0.036 cm to 1.186 ± 0.029 cm (P = 0.002). Left ventricle posterior wall (LVPW) showed no significant changesin any of the intervention group. The left ventricle mass in the placebo and green Rooibos groups demonstrated no significance changes, while fermented Rooibos caused a decrease from 204.102 ± 7.102 g to 191.394 ± 6.707 g (P = 0.015). The phytochemical bioactive components, such as the polyphenolic antioxidants present in green and fermented Rooibos, improved cardiovascular function. This study confirms the effectiveness of echocardiography as imaging tool for assessing cardiac function in this particular population. Regular Rooibos consumption may offer promising therapeutic benefits for preventing and managing CVD risk.

Potential prognostic indicators in dogs with advanced heart failure secondary to myxomatous mitral valve disease.

Advanced heart failure (AHF) secondary to myxomatous mitral valve disease (MMVD) in dogs has unclear predictive variables and survival time. This retrospective study included 38 dogs with AHF and 38 with stable congestive heart failure (CHF), both due to MMVD. Predictive variables for AHF were analysed, and survival times were calculated using logistic regression and the Kaplan-Meier method. Left atrium to aortic root ratio, normalised left ventricular dimension at the end-diastole and end-systole, isovolumic relaxation time (IVRT) and early transmitral inflow velocity to IVRT ratio were associated with AHF progression. The median survival times were significantly longer in the stable group than in the AHF group. After AHF diagnosis, the median survival times for all-cause and cardiogenic mortality were 194 and 354 days, respectively. This was a single-centre retrospective observational study. The study population was small, with breed bias (overrepresentation of Maltese dogs). Additionally, the treatment plans depended on clinical experience. AHF in dogs with CHF secondary to MMVD is linked to left heart chamber enlargement and increased left ventricular dimensions, significantly reducing survival time to around six months post-diagnosis. Early recognition and appropriate management may improve outcomes, highlighting the importance of advanced treatment strategies.

Long-Term Outcomes of Percutaneous Trans-catheter Device Closure of Atrial Septal Defects During Teenage Life versus Adulthood

Abstract Aim and Objectives To evaluate the long-term follow up outcome of patients who underwent percutaneous trans-catheter closure of atrial septal defects during teenage life versus adulthood. Patients and Methods The study included 100 patients with secundum type ASD were treated by transcatheter closure of their defects. Two year after the procedure patients included in the study were subjected to thorough history taking, physical examination,12 leads surface electrocardiogram and Holter. Full 2D and Doppler echocardiographic study was performed in addition to Tissue Doppler Assessment of left ventricular function. Results At the 2 years follow up of transcatheter ASD closure, the RVEDD had decreased from 22.93±5.889 mm to 18±4.06 mm(P = 0.000). By comparing 2D echocardiographic parameters between teenagers and adults there was a highly significant difference in RV basal diameter (P = 0.004), RV systolic function (P = 0.000), RA area (P = 0.030). Mean PAP decreased from 18.37±4.796 mmHg to 14.77±4.75 mmHg (P = 0.022). RVSP decreased from 28.9±4.425 mmHg to 15.83±4.17 mmHg (P = 0.000). There was statistically significant difference regarding defect size (P = 0.037), device size (P = 0.038) and Holter findings (P = 0.042) while there was no statistically significant difference between both groups regarding mPAP, device type and ECG. Defect size was larger in adult group ranged from 9 to 33 mm with mean ± SD 15.57 ± 6.57 mm than teenagers ranged from 6 to 22 mm with mean ± SD 13.06 ± 5.18 mm. Also, incidence of arrhythmia in adults was higher than teenagers as follows: PACs was in 7 patients (14 %) in adult group while 3 patients (6 %) had PACs in teenagers group and paroxsymal AF was found in 4 patients (8 %) in adult group while no patients in teenagers develop AF. All the patients had normal sinus rhythm before closure and no one developed arrhythmia until 1 year after closure. 50 % of the patients had normal RV size at the 2-year follow up. Regarding Doppler parameters, mitral E/A ratio (P = 0.000) and lateral E/e' ratio (P = 0.041) had significant difference between adults and teenagers as shown in table (8) mostly related to age. Mitral E/A ratio in adults ranged from 0.7 to 1.5 with mean ± SD 1.06 ± 0.20 while in teenagers ranged from 1.1 to 1.8 with mean ± SD 1.45 ± 0.17. Lateral E/e’ ratio in adults ranged from 3 to 7.9 with mean ± SD 5.43 ± 1.24 while in teenagers ranged from 3 to 7 with mean ± SD 4.94 ± 1.13. Conclusion Transcatheter ASD closure leads to a significant improvement in heart cavity dimensions and RV function and reversal of electrical and mechanical changes. Novel parameters for assessment of RV function are promising and appear to be helpful for the assessment of RV function and its response to correction of volume. Key words: Atrial septal defect, arrhythmia, transcatheter closure, adults, teenagers. Abbreviations and Acronyms 2D: Two-Dimensional 3D:Three-dimensional ASD(s): Atrial septal defect(s) BSA: Body surface area CHDs: Congenital heart defects ECG: Electrocardiogram EF: Ejection fraction FAC: Fractional Area Change LA: Left Atrium mPAP: mean Pulmonary Artery Pressure RA: Right Atrium RAA: Right atrial area RBBB: Right Bundle Branch Block RV : Right Ventricle TEE : TransEsophgyeal Echocardiography TTE : TransThoracic Echocardiography

The impact of left atrial morphology on thrombosis risk in atrial fibrillation

Atrial fibrillation (AF) is an arrhythmia disease that can disrupt the movement of the left atrium (LA), which will facilitate thromboembolism in LA and further exacerbate the stroke risk. The left atrial appendage (LAA) is a vital site for thrombus formation. The morphology of the LAA is believed to have a profound effect on thrombosis. However, due to the limitation of observation and monitoring methods, the mechanism of this effect is still unrevealed. Virchow's triad is a theory of thrombogenic mechanisms, stating that endothelial injury, blood hypercoagulability, and blood stasis are the three main factors involved in thrombus formation. In this study, we conducted personalized simulation analyses for 12 AF patients and discussed simulation results from the perspective of Virchow's triad. The simulation results indicate the effectiveness of Virchow's triad in elucidating the thrombosis mechanism within the LAA. The LAA is more prone to thrombosis than the other region of LA, because of the lower blood flow velocity and significantly higher endothelial cell activation potential values there, which indicates a higher risk of blood stasis and endothelial injury, respectively. Furthermore, a comprehensive score is proposed to assess the performance of Virchow's triad in the LAA. The morphology of LA has a significant influence on the performance of the three factors in Virchow's triad. Hence, for a quickly assessment of LAA thrombosis risk in AF patients through the lens of Virchow's triad, we need a more refined shape scoring system that can better reflect patient-specific morphological features of the entire LA.

Optimal Threshold and Interpatient Variability in Left Atrial Ablation Scar Assessment by Dark-Blood LGE CMR.

Dark-blood late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) has better correlation with bipolar voltage (BiV) to define ablation scar in the left atrium (LA) compared to conventional bright-blood LGE CMR. This study sought to determine the optimal signal intensity threshold of dark-blood LGE CMR to identify LA ablation scar. In 54 patients scheduled for atrial fibrillation ablation, image intensity ratios (IIRs) were derived from preprocedural dark-blood LGE CMR. In 26 patients without previous ablation, the upper limit of normal was derived from the 95th and 98th percentiles of pooled IIR values. In 28 patients with previous atrial fibrillation ablation, BiV was compared with the corresponding IIR. Receiver-operating characteristics analyses were employed to determine the optimal IIR threshold (ie, the point with the smallest distance to the upper left corner of the receiver-operating characteristics) for LA ablation scar (BiV≤0.15mV). Upper limit of normal corresponded to IIR values 1.16 and 1.21, yielding low sensitivities of 0.32 and 0.09 to detect LA ablation scar. Receiver-operating characteristics analysis of IIR and BiV comparison achieved a median area under the curve of 0.77. Median optimal IIR threshold for LA ablation scar was 1.09, with an average sensitivity of 0.73, specificity of 0.75, and accuracy of 0.71. Median IIR thresholds of 1.00 and 1.10 corresponded to 80% sensitivity and 80% specificity, respectively. There was considerable interpatient variability: optimal IIR thresholds per patient ranged from 1.01 to 1.22. The optimal IIR threshold to identify LA ablation scar by dark-blood LGE CMR is 1.09. Because of interpatient variability, the investigators recommend using a lower (1.00) and upper (1.10) threshold to prevent over- or underestimation of ablation scar.

Cardiovascular Risk Factors and Disparities in Management of Embolic Stroke: A Western Sydney Perspective

Ischaemic stroke remains one of the leading causes of death and disability worldwide. The population of Western Sydney has a unique demographic with lower socioeconomic status and a culturally and linguistically diverse population. This study aims to investigate the demographics and cardiovascular risk factors of patients in Western Sydney, focusing on the prevalence and profile of cardioembolic (CE) strokes and embolic strokes of undetermined source (ESUS). Prospective data were collected in 463 patients with ischaemic stroke presenting to a tertiary centre in Western Sydney, who underwent predischarge transthoracic echocardiography. Patients with haemorrhagic strokes or unclear stroke diagnosis were excluded. Analysis of stroke subtype (CE, ESUS, or non-embolic) and clinical characteristics was performed based on age, gender, and prior atrial fibrillation (AF) prevalence. Of the 463 patients, 147 (32%) had CE strokes, and 147 (32%) had ESUS. Cardioembolic (CE) strokes were associated with older age (≥65 years) and a history of congestive cardiac failure. Older patients had higher rates of hypertension, ischaemic heart disease, AF, and congestive heart failure. History of AF was present in 67 patients (14.5%); however, only 51% received anticoagulation before admission despite a low bleeding risk. The transthoracic echocardiography characteristics of ESUS/non-embolic strokes differed from those of CE strokes; 20% of patients with ESUS had an enlarged left atrium, suggesting a subset of patients with ESUS with a left atrial myopathy. Patients with ischaemic stroke in Western Sydney have a high prevalence of cardiovascular risk factors which were often undertreated. Half of the patients with prior AF did not receive anticoagulation despite low bleeding risk, indicating a gap in optimal stroke prevention. There were distinct echocardiographic characteristics among stroke subtypes. Further analysis of left atrium parameters may provide greater insights into the pathogenesis and prevention of embolic strokes.

ECG and Atrial Appendage Doppler Discordance Is Common in Patients Undergoing Cardiac Surgery: Prospective Study

BackgroundPatients with atrial fibrillation (AF) remain at increased risk of thromboembolism despite apparent maintenance of sinus rhythm with the cause often attributed to periods of asymptomatic AF. Atrial mechanical discordance, with the body of the left atrium (LA) in sinus rhythm and the left atrial appendage (LAA) in AF may also be a contributor. ObjectivesThe purpose of this study was to assess the frequency of electrocardiogram (ECG) rhythm and LAA and/right atrial appendage (RAA) Doppler ejection phenotype (transesophageal echocardiography [TEE]) discordance in patients undergoing cardiac surgery. MethodsOne hundred twenty-four patients undergoing coronary artery bypass graft (CABG), CABG and valve surgery, or isolated valve repair or replacement (valve ± CABG) were prospectively studied. Intraoperative surface ECG rhythm strip and TEE were performed before cardiopulmonary bypass. The ECG and TEE LAA/RAA Doppler spectrum were independently classified as sinus or AF. ResultsOf 107 patients (age 65 ± 12 years; 31% female; 65% CABG, 31% valve ± CABG) without a history of AF, 39 (36%) had ECG and LAA and/or RAA discordance (ECG/LAA Doppler discordance, n = 12 [11%]; ECG/RAA Doppler discordance, n = 35 [33%]). There was no significant difference between concordant and discordant groups with regard to age, gender, history of hypertension, diabetes, heart failure, or stroke (all P > 0.05). ConclusionsA large minority of patients without a history of AF undergoing cardiac surgery have ECG/atrial appendage Doppler discordance, a setting that may promote thromboembolism in non-anticoagulated patients. Clinical parameters do not identify patients at increased risk for discordance.