Potential Diagnostic and Prognostic Values of Left Atrial Strain in Valvular Heart Disease.

There has been increasing evidence supporting the importance of left atrial (LA) functional analysis and measurement in various physiologic and pathologic cardiovascular conditions due to its high diagnostic and prognostic values. Assessment of LA strain (LAS) has emerged as an early marker of subclinical LA dysfunction. Using speckle-tracking echocardiography, LAS can be measured in all phases of LA function (reservoir, conduit, and booster pump). In valvular heart disease (VHD), surgical and nonsurgical interventions should be performed before irreversible left ventricular (LV) and/or LA myocardial dysfunction. The current guidelines recommended using LV strain as a parameter for early detection and timely intervention. Currently, many published data have shown the diagnostic and prognostic values of LAS in VHD, which is encouraging to integrate LAS during echo assessment. In this review, we aim to collect the current data about the clinical utility of LAS changes in risk stratification, predicting outcome, and guiding the time of intervention in VHD. The review summarized these data according to the type of valve pathologies.

Steerable Delivery Sheath for Left Atrial Appendage Closure in Patients With Severely Enlarged Left Atria.

Background: Enlarged left atrium (LA) is frequently identified in patients who undergo left atrial appendage closure (LAAC) and negatively affects the device's final position and intervention results. Steerable delivery sheath (SDS) could represent an option to overcome these difficulties. We aimed to assess the feasibility of SDS-assisted procedures and compare their efficacy to the standard sheath strategy. Methods: This study analyzed patients from our institution's LAAC registry who had severe LA enlargement on CT scan (index LA volume >90 mL/m2) and underwent AMULET device implantation between January 2019 and March 2023. The patients underwent postprocedural CT scan to assess the device's position, residual LAA filling, and peridevice leaks. Results: A total of 195 consecutive patients were screened and 47 (24%) met the inclusion criteria (n = 22 SDS group; n = 25 standard group). There was no difference in baseline clinical, anatomical, or procedural characteristics. The procedural technical success (96%) and complication rates (9% vs 4%; P = .59) were comparable in both groups. Post-LAAC CT scans were obtained in 19 SDS group and 22 standard group patients. We observed significantly lower incidences of residual patent LAA (26% vs 72%; P = .005), peridevice leaks (16% vs 64%; P = .004), and off-axis device position (0% vs 27%; P = .02) in SDS compared to the standard group, suggesting a better LAA sealing. Conclusions: Severe LA enlargement was frequent among LAAC candidates. In this situation, the use of SDS appears feasible and safe, leading to more efficient closures on follow-up imaging without a higher risk of periprocedural complications.

Giant right and left atrium: spectrum of rheumatic triple valve disease (double hit with double impact): a case report and review of the literature.

BACKGROUND: Rheumatic heart disease (RHD) continues to pose a significant burden on global health, particularly in socioeconomically disadvantaged populations. We present the case of a 38-year-old woman with severe multivalvular RHD and giant atria, highlighting the challenges and complexities of managing this condition. CASE PRESENTATION: The patient presented with progressively worsening dyspnoea, signs of right heart failure, and severe valvular abnormalities. Diagnostic evaluations revealed severe mixed mitral valve disease in the form of mitral stenosis and regurgitation, along with involvement of the aortic and tricuspid valves, leading to significant enlargement of both atria. Despite facing socioeconomic constraints and poor adherence to treatment, the patient underwent successful surgical intervention, resulting in remarkable symptomatic improvement. CONCLUSIONS: Through this case, we emphasise the importance of early detection, comprehensive management strategies, and multidisciplinary care in addressing the complexities of RHD. Despite the challenges posed by socioeconomic disparities, positive outcomes can be achieved with timely diagnosis and appropriate intervention. This case underscores the need for targeted efforts to improve access to healthcare resources and reduce the global burden of RHD.

Left atrial strain by cardiac MRI feature tracking in mitral stenosis before and after balloon valvuloplasty.

The aim was to investigate LA strain by feature tracking cardiac MRI in mitral stenosis (MS) patients before and after percutaneous balloon mitral valvuloplasty (PBMV). Patients underwent cardiac MRI before and after successful PBMV (n = 18). Mitral valve area, transmitral velocity and gradients, LA volumes and ejection fraction (LAEF) were measured. LA strain feature tracking analysis was used to calculate LA reservoir, conduit, and booster strain. LA strain, LA volumes, LAEF and mitral valve severity indices were compared before and after PBMV. Correlations between LA strain and other cardiac MRI parameters were assessed. After PBMV, mitral valve area increased from 1.18 ± 0.25 cm2 to 2.26 ± 0.27 cm2, p < 0.001. Transmitral peak velocity decreased from 1.7 ± 0.37 m/s to 1.3 ± 0.27 m/s, p < 0.001. Transmitral peak gradient decreased from 12.4 ± 4.8 mmHg to 6.8 ± 2.9 mmHg, p < 0.001, and mean gradient decreased from 6.9 ± 3.8 mmHg to 2.9 ± 1.4 mmHg, p < 0.001. Maximal LA volume decreased from 73.1 ± 14.2 ml/m2 to 62.7 ± 16.3 ml/m2, p = 0.018; corrected p value = 0.054. LAEF increased from 36.3 ± 8.7% to 44.4 ± 9.5%, p = 0.010. Reservoir strain increased from 11.7 ± 3.1% to 14.9 ± 3.6% after PBMV, p = 0.009, and conduit strain from 3.8 ± 2% to 6 ± 2.3%, p = 0.005. Booster strain insignificantly increased after PBMV. Cardiac MRI feature tracking provides information on the 3 LA functional phases. Significant improvement was observed in reservoir and conduit functions after successful PBMV.

Anomalies Unveiled: A Fascinating Case Study of Type I Pulmonary Artery-to-Left Atrium Fistula.

The pulmonary artery-to-left atrium (LA) fistula is one of the rare and unique structural causes of silent cyanosis. This correctable abnormality can be identified by having a high index of clinical suspicion and appropriate investigations using echocardiography and cardiac computed tomography (CT). We report an eight-year-old child who had worsening exertional dyspnea, long-standing central cyanosis, and recurrent infections. A large-sized fistula connecting the right pulmonary artery (RPA) to the LA with all the right- and left-sided pulmonary veins showed normal drainage into the LA, suggesting a type I RPA-to-LA fistula, which was diagnosed on cardiac CT. Percutaneous closure using the occluder device is planned as further management for the patient.

Transesophageal echocardiography diagnosis of abnormal left atrium to inferior vena cava communication: A case report.

Abnormal traffic between the left atrium (LA) and inferior vena cava (IVC) in the database is currently rare. Herein, we present a unique case of abnormal traffic between the LA and the IVC, which was diagnosed using transesophageal echocardiography and confirmed by computed tomography angiography. This case substantiates the superiority of transesophageal echocardiography over transthoracic echocardiography in detecting specific site lesions.

Correlation of left atrial strain with invasively measured left ventricular end-diastolic pressure; determining LA strain cut-off value.

Left atrium longitudinal strain (LAS) with speckle tracking method has been proposed as a non-invasive method for the assessment of left ventricular filling pressure and diastolic dysfunction. This study aimed to investigate left atrial strain compared to invasively measured left ventricular filling pressure. All Patients candidates for coronary angiography were consecutively recruited. LAS measured by transthoracic echocardiography. Left ventricular end-diastolic pressure (LVEDP) pressure was invasively measured. Current echocardiographic modalities for diastolic function evaluated. A total of 125 people were included. 45 patients had preserved ejection fraction (EF ≥ 50%) and 85 patients had reduced EF (EF < 50%) and compared two groups. LVEDP was significantly higher in reduced EF compared to preserved EF (p-value < 0.001). LA-reservoir and LA-booster strains were significantly lower in patients with reduced EF compared to preserved EF (p-value = 0.008, mean Reservoir = 16.4% ± 6.4, mean Reservoir = 19.5% ± 5.6, respectively) and (p-value = 0.009, mean Booster = 9.09% ± 4.0, mean Booster =11. 9% ± 4.3, respectively). LA 4ch-reservoir strain <14.4%, and LA 2ch-reservoir strain <14.1% were related to LVEDP≥20 mmHg (sensitivity 63.5% and specificity 75%) (sensitivity 77.9% and specificity of 60%) respectively. LAS is significantly lower in patients with elevated LVEDP (≥ 20mmHg). LAS is significantly lower in patients with reduced EF. Both LA-reservoir and LA-booster strains have a significant relation to predicting LVFP but LA-reservoir strain is more accurate. The mean LA-reservoir strain less than 12.4% is associated with LVEDP ≥ 20mmHg.

Simulating left atrial arrhythmias with an interactive N-body model.

BACKGROUND: Heart disease and strokes are leading global killers. While atrial arrhythmias are not deadly by themselves, they can disrupt blood flow in the heart, causing blood clots. These clots can travel to the brain, causing strokes, or to the coronary arteries, causing heart attacks. Additionally, prolonged periods of elevated heart rates can lead to structural and functional changes in the heart, ultimately leading to heart failure if untreated. The left atrium, with its more complex topology, is the primary site for complex arrhythmias. Much remains unknown about the causes of these arrhythmias, and computer modeling is employed to study them. METHODS: We use N-body modeling techniques and parallel computing to build an interactive model of the left atrium. Through user input, individual muscle attributes can be adjusted, and ectopic events can be placed to induce arrhythmias in the model. Users can test ablation scenarios to determine the most effective way to eliminate these arrhythmias. RESULTS: We set up muscle conditions that either spontaneously generate common arrhythmias or, with a properly timed and located ectopic event, induce an arrhythmia. These arrhythmias were successfully eliminated with simulated ablation. CONCLUSIONS: We believe the model could be useful to doctors, researchers, and medical students studying left atrial arrhythmias.

Assessment of left atrial function provides incremental value: the left atrial volumetric/mechanical coupling index in patients with chronic kidney disease.

Background: Heart failure is a common cause of adverse cardiovascular outcomes in patients with chronic kidney disease (CKD). Left atrial (LA) characteristics are thought to be involved in the development of heart failure. However, LA assessment is complex. Though a variety of parameters have been defined, there is no single parameter that best defines LA function. Pilot data indicate that left atrial volumetric/mechanical coupling index (LACI) may be useful, but data with CKD are lacking. Aim: The objective of this study was to define LACI in a cohort of patients with CKD and to assess its value in evaluating LA function and predicting heart failure. Methods: A cohort of patients with CKD was enrolled at our hospital between 2021 and 2023. Follow-up was performed for heart failure. LACI is a volumetric to mechanical coupling index, calculated as the ratio of the LA volume index to the tissue-Doppler myocardial velocity at atrial contraction. Spearman's rank correlation or Pearson's correlation was used to calculate the correlation between LACI and echocardiographic/hemodynamic variables. Receiver operating characteristic curve (ROC) analysis was utilised to derive the area under the curve (AUC) for LACI, LVGLS, LASr, LASct and LASI for the detection of heart failure. Kaplan-Meier survival curves were employed to compare clinical outcomes based on LACI thresholds. A multivariable logistic regression analysis was employed to assess the relationship between risk factors and elevated LACI. Cox proportional hazards regression was used to identify risk factors for heart failure. Results: LACI showed a positive correlation with NT-proBNP, CK-MB, LAVI, E/e' and LASI (r = 0.504, 0.536, 0.856, 0.541 and 0.509, p < 0.001); and a negative correlation with LASr (r = -0.509, p < 0.001). On the ROC analysis for the determination of heart failure, the AUC of LACI was comparable to those of LVGLS (0.588 vs. 509, p = 0.464), LASr (0.588 vs. 0.448, p = 0.132), LASct (0.588 vs. 0.566, p = 0.971) and LASI (0.588 vs. 0.570, p = 0.874). The cardiovascular risk factors increased by LACI were age, BMI, diabetes, triglycerides, LA size, LASr, LASI, E/A, E/e' and EF (p < 0.05). During a median follow-up of 16 months (range, 6-28 months), the event-free survival curves demonstrated a higher risk of heart failure in the group with LACI > 5.0 (log-rank test: P < 0.001). LACI > 5.0 was an independent predictor of heart failure [OR: 0.121, 95% CI (0.020-0.740), p = 0.022]. Conclusion: LACI may prove to be a valuable tool for assessing LA function in patients with CKD, and could be integrated into the routine assessment of LA for the purpose of prognostic assessment and clinical decision-making in patients with CKD.

The influence of transcatheter aortic valve replacement on left atrial mechanics: a systematic review and meta-analysis.

Aims: The morphology and function of the left atrium (LA) are intimately tied to left ventricular loading conditions. Data pertaining to the effect of transcatheter aortic valve replacement (TAVR) on LA function and geometry are scarce. The aim of the study was to quantify associations between TAVR and LA remodelling by pooling available data from published observational studies. Methods and results: A systematic review and meta-analysis were performed. Studies reporting serial LA speckle-tracking echocardiographic (STE) data, before and after TAVR, were included. Other outcome data included LA area and indexed volume (LAVi) and standard chamber measurements. Outcomes were stratified by timing of follow-up echocardiography: early (<6 months) or late (≥6 months). Twelve studies were included, comprising 1066 patients. The mean reduction in LAVi was 2.72 mL/m2 [95% confidence interval (CI) 1.37-4.06, P < 0.01]. LA reservoir function improved overall by a mean difference (MD) of 3.71% (95% CI 1.82-5.6, P < 0.01), although there was significant heterogeneity within the pooled studies (I 2 = 87.3%). Significant improvement in reservoir strain was seen in both early follow-up (MD 3.1%, P < 0.01) and late follow-up studies (MD 4.48%, P = 0.03), but heterogeneity remained high (I 2 = 65.23 and 94.4%, respectively). Six studies reported a change in LA contractile function, which recovered in the early follow-up studies (MD 2.26, P < 0.01), but not in the late group (MD 1.41, P = 0.05). Pooled improvement in LA booster function was 1.96% (95% CI 1.11-2.8, P < 0.01). Conclusion: TAVR is associated with significant negative LA remodelling, and an improvement in LA mechanics, quantified by STE. The prognostic implications of these findings require further study.

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 Atrioventricular Coupling Index: A Novel Diastolic Parameter to Refine Prognosis in Heart Failure.

BACKGROUND: Left atrioventricular coupling index (LACI), an index coupling left atrial to left ventricular (LV) volume at end-diastole, has been shown to be associated with prognosis in different clinical settings. However, the relation between LACI and LV diastolic dysfunction (DD) remains to be established. The aims of the present study were to investigate the association between LACI and LV DD and to assess its prognostic value in patients with heart failure (HF). METHODS: A total of 1,158 patients with HF in stable condition, on optimal medical therapy, were retrospectively analyzed (derivation cohort). Clinical and echocardiographic features were characterized across LACI tertiles. The independent prognostic value of LACI (end point: all-cause death or HF hospitalization) was assessed using Cox regression. Results were validated in an external cohort of 242 patients with HF. RESULTS: In the derivation cohort, the median LACI value was 0.29 (interquartile range, 0.19-0.42). Patients in the third tertile (LACI > 0.36) were older and presented with more advanced HF symptoms. Although the prevalence of grade 1 DD (American Society of Echocardiography/European Association of Cardiovascular Imaging classification) progressively decreased across LACI tertiles, the prevalence of grade 3 DD significantly increased (8%, 23%, and 46%, respectively; P < .0001). A cutoff value of ≥0.26 identified moderate to severe DD with an area under the curve of 0.75. During follow-up (median, 28 months; interquartile range, 11-53 months), 407 patients (35%) reached the end point. On multivariable analysis, LACI was independently associated with outcomes (hazard ratio for a 1-SD increase, 1.16; 95% CI, 1.06-1.28; P = .002), showing incremental predictive value over the DD grading system (net reclassification improvement = 0.150, P < .0001). The prognostic value of LACI was consistent in the external validation cohort. CONCLUSIONS: LACI is associated with DD severity and is an independent predictor of outcomes in patients with HF.

Prognostic value of left atrial size and function by cardiac magnetic resonance in non-ischemic cardiomyopathy.

To evaluate left atrial (LA) function and strain parameters by cardiac magnetic resonance imaging (CMR) in patients with non-ischemic cardiomyopathy (NICM) and evaluate the association of these parameters with long-term clinical outcomes. We retrospectively included 92 patients with NICM and 50 subjects with no significant cardiovascular disease (control group). We calculated LA volumes using the Simpson area-length method to derive LA ejection fraction and expansion index. LA reservoir (ƐR), conduit (ƐCD), and contractile strain (ƐCT) were measured using dedicated CMR software (cvi42, Circle Cardiovascular Imaging Inc., version 5.14). An adjusted multivariate regression analysis was performed to determine the association of LA parameters with death and heart failure hospitalization (HFH). NICM patients were older with male preponderance. The mean age for NICM patients was 59.6 ± 15.9 years, 64% males, and 73% whites versus 52.2 ± 12.4 years, 34% male and 64% white for controls. LA strain patterns were significantly lower in NICM patients when compared to controls. During a median follow-up of 58.9 months, 12 patients (13%) died and 33(35.9%) had a HFH. None of the clinical or CMR factors were significantly associated with death. On multivariate analysis, after adjusting for age and significant univariate variables, ƐR was the only variable significantly associated with the HFH (OR 0.98, CI 0.96-1.0). Unadjusted and adjusted Cox proportional hazard models divided by the median ƐR (~ 18%) showed a significant difference in HFH over time (χ2 statistic = 21.1; P value = 0.03). In NICM patients, all LA strain components were reduced. ƐR was found to be significantly associated with HFH.

Echocardiographic evaluation of left atrial volume and comparative analysis to left atrial to aortic root ratio in premature neonates and infants with patent ductus arteriosus.

PURPOSE: Left atrium to aortic root ratio (LA/Ao) is an echocardiographic marker of hemodynamically significant patent ductus arteriosus (PDA). Since 2-dimensional measurement of the ratio is geometrically limited, left atrial volume (LAV) which has 3-dimensional characteristics was investigated. The aim of this study was to determine a correlation between LA/Ao ratio and LAV as well as holodiastolic flow reversal in preterm neonates with and without a PDA. METHODS: A retrospective evaluation of neonates with and without PDA was performed. Targeted neonatal echocardiography evaluation of LA/Ao and LAV was measured from parasternal long-axis view and the apical 4 and 2-chamber views, respectively. Univariate and linear regression analysis were performed. RESULTS: 200 patients were included of whom 158 (79.0%) had a PDA shunt. The median gestational age at the time of echo was 27.4 weeks (IQR: 25.7-29.4 weeks). The median LA/Ao ratio was 1.51 (IQR: 1.26-1.83) and median LAV indexed to weight was  .91 mL/kg (IQR: .65-1.18 mL/kg). There was a significant correlation between LA/Ao and LAV indexed to weight in the PDA group (r2 = .080, p = .0003). LA/Ao ratio and LAV indexed to weight differed significantly between those with diastolic flow reversal versus no-flow reversal (LA/Ao, p = .003; LAV, p = .001). CONCLUSIONS: This study demonstrated a significant correlation between LA/Ao and LAV in preterm infants with PDA, with greater magnitude of discordance for LAV. The power of LAV versus LA/Ao in monitoring hemodynamically significant PDA requires prospective evaluation.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

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

BACKGROUND: Coupling 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. METHODS: We 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. RESULTS: HyF 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. CONCLUSIONS: HyF, 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.

Anomalous drainage of inferior vena cava into left atrium associated with ostium secundum atrial septal defect: a case report.

Background: Anomalous drainage of inferior vena cava (IVC) into left atrium (LA) is a rare aetiology of cyanosis in adults. This condition may be associated with atrial septal defects, anomalous pulmonary venous drainage, and pulmonary arteriovenous fistulas. This case report presents an instance of anomalous drainage of IVC into LA, associated with ostium secundum atrial septal defect (ASD). It contributes to the existing literature by highlighting the diagnostic challenges associated with this anomaly, particularly during surgical intervention. Case summary: A 38-year-old male presented with a six-year history of exertional dyspnoea and episodic palpitation. Transthoracic echocardiography revealed a large secundum (ASD), the IVC draining into LA, a left superior vena cava, and mild mitral regurgitation. These findings were further confirmed by right and left heart catheterization and CT angiogram. The patient was referred to CTVS department for surgical correction. The post-operative course was uneventful. At a 1.4-year follow-up, the patient reported significant improvement in symptoms. Discussion: We present a case of anomalous drainage of IVC into LA, associated with ostium secundum ASD. An ASD co-occurs with this condition in ∼70% of the reported cases. This anomaly differs from a low or inferior vena caval secundum ASD, where a prominent Eustachian valve can cause blood shunting from the IVC to LA. If the surgeon is not vigilant, this can be mistaken for the inferior ASD rim, potentially leading to iatrogenic diversion of IVC blood to LA upon ASD closure, resulting in cyanosis. This case underscores the diagnostic and surgical challenges associated with this condition.

Structural, Functional, and Electrical Remodeling of the Atria With Reduced Cardiorespiratory Fitness: Implications for AF.

BACKGROUND: Reduced cardiorespiratory fitness (CRF) is an independent risk factor for the progression of atrial fibrillation (AF). We hypothesized that reduced CRF is associated with structural, functional, and electrical remodeling of the left atrium. OBJECTIVES: This study sought to correlate objectively assessed CRF with functional and electrical left atrial (LA) parameters using invasive and noninvasive assessments. METHODS: Consecutive patients with symptomatic AF undergoing catheter ablation were recruited. CRF was objectively quantified pre-ablation by using cardiopulmonary exercise testing. Using peak oxygen consumption, participants were classified as preserved CRF (>20 mL/kg/min) or reduced CRF (<20 mL/kg/min). LA stiffness was assessed invasively with hemodynamic monitoring and imaging during high-volume LA saline infusion. LA stiffness was calculated as ΔLA diameter/ΔLA pressure over the course of the infusion. LA function was assessed with echocardiographic measures of LA emptying fraction and LA strain. Electrical remodeling was assessed by using high-density electroanatomical maps for LA voltage and conduction. RESULTS: In total, 100 participants were recruited; 43 had reduced CRF and 57 had preserved CRF. Patients with reduced CRF displayed elevated LA stiffness (P = 0.004), reduced LA emptying fraction (P = 0.006), and reduced LA reservoir strain (P < 0.001). Reduced CRF was also associated with reduced LA voltage (P = 0.039) with greater heterogeneity (P = 0.027) and conduction slowing (P = 0.04) with greater conduction heterogeneity (P = 0.02). On multivariable analysis, peak oxygen consumption was independently associated with LA stiffness (P = 0.003) and LA conduction velocities (P = 0.04). CONCLUSIONS: Reduced CRF in patients with AF is independently associated with worse LA disease involving functional and electrical changes. Improving CRF may be a target for restoring LA function in AF.