Left Atrium Research Articles

Atrial fibrillation and prediabetes: Interplay between left atrium and systemic diseases

Atrial fibrillation (AF) is associated with multiple other comorbidities, i.e. multimorbidity. Prediabetes is one of the multiple comorbidities observed in patients with AF, whereby these two disease entities share the same pathophysiological mechanisms, namely oxidative stress and inflammation. Although prediabetes is reported to have a negative impact on major adverse cardiac or cerebrovascular events in hospitalized AF patients, information about the interactions between prediabetes and AF remains inconsistent. A more in-depth exploration of pathophysiology and more comprehensive prospective clinical studies of AF and diabetes would provide a thorough understanding of the timing of events and further treatment strategies. Deeper investigations are needed to clarify the interactions and causal relationships between AF and prediabetes.

Cardiac remodeling in elite young Asian female soccer players

IntroductionAn athlete's heart (AH) varies depending on race, sex, age, and the type and intensity of training. Given that soccer is a common sport, evaluation of cardiac function in soccer players is important; however, few studies have analyzed adolescent soccer players. Therefore, this study, aimed to identify early changes in AH in soccer players by evaluating the echocardiographic findings of adolescent Asian female soccer players for whom existing data are scarce.MethodsWe evaluated 20 Korean female under-20 national soccer team players and 42 age-matched healthy females. Participants provided physical examination data such as height, weight, blood pressure, and pulse, along with echocardiographic results. On echocardiography, parameters related to the morphology of the left atrium (LA) and left ventricle (LV) and those related to the systolic and diastolic function of the LV were measured.ResultsThe athlete group had a lower blood pressure and pulse rate than the control group. Echocardiography indicated that both the LA volume index and LV volume in the athlete group were large by approximately 1.5 times compared with those in the control group. The LV wall thickness and mass index were also significantly large in the athlete group. For LV diastolic function, parameters indicating early diastolic filling were substantially higher in the athlete group than in the control group.ConclusionsAdolescent female soccer players exhibited differences in cardiac morphology and an enhanced diastolic function. Therefore, this study suggests that AH begins in adolescence, with changes in both morphology and function.

Insulin mitigates acute ischemia induced atrial fibrillation and sinoatrial node dysfunction ex vivo.

Acute atrial ischemia is a well-known cause of postoperative atrial fibrillation (POAF). However, mechanisms through which ischemia contributes to the development of POAF are not well understood. In this study, ex vivo Langendorff perfusion was used to induce acute ischemia and reperfusion in the heart in order to mimic POAF. Inducibility of atrial fibrillation (AF) was evaluated using programmed electrical stimulation and confirmed with open-atrium optical mapping. Compared to the control group without ischemia, 25 minutes of ischemia substantially increased the incidence of AF. The right atrium was more susceptible to AF than the left atrium. Administering insulin for 30 minutes before ischemia and during reperfusion with 25 minutes of ischemia greatly reduced the vulnerability to AF. However, insulin treatment during reperfusion only did not show substantial benefits against AF. Optical mapping studies showed that insulin mitigates ischemia-induced abnormal electrophysiology, including shortened action potential duration and effective refractory period, slowed conduction velocity, increased conduction heterogeneity, and altered calcium transients. In conclusion, insulin reduced the risk of acute ischemia/reperfusion-induced AF via improving the electrophysiology and calcium handling of atrial cardiomyocytes, which provides a potential therapy for POAF.

Atrial septal defect (ASD), trans-catheter closure – case report

Atrial septal defect (ASD) is one of the most common types of congenital heart defects, occurring in about 25% of children. An atrial septal defect occurs when there is a failure to close the communication between the right and left atria. It encompasses defects involving both the true septal membrane and other defects that allow for communication between both atria. There are five types of atrial septal defects ranging from most frequent to least: patent foramen ovale, ostium secundum defect, ostium primum defect, sinus venosus defect, and coronary sinus defect. Small atrial septal defects usually spontaneously close in childhood. Large defects that do not close spontaneously may require percutaneous or surgical intervention to prevent further complications such as stroke, dysrhythmias, and pulmonary hypertension. This activity describes the evaluation, diagnosis, and management of atrial septal defect and highlights the role of team-based interprofessional care for affected patients. Atrial septal defects are frequently asymptomatic. The characteristic murmur is a soft, systolic ejection murmur over the pulmonic area (second intercostal space) combined with a wide, fixed splitting of S2. Many ASDs go undiagnosed until adulthood; therefore, treatment, especially of large defects, is often delayed. Untreated large defects can cause exercise intolerance, cardiac dysrhythmias, palpitations, increased incidence of pneumonia, pulmonary hypertension and increased mortality.

Abstract 4122350: Most Diabetes Mellitus Patients Had Right Lower Pulmonary Vein Thrombi; Additionally, Many Patients Had Extended Large Rod-Like Thrombi in the Left Atrium

Background: Retrieved thrombus studies have shown that retrieved thrombi have calcifications, indicating that the thrombi are old. Left atrium diverticula (LADs) are common; however, the mechanisms of LAD formation are poorly understood. Pulmonary vein thrombi (PVTs) are common and are underestimated. In 2022, we reported that 98.6% of senior patients with age-related diseases such as hypertension, dyslipidemia and atrial fibrillation had PVTs, as estimated by cardiac computed tomography (CT) and transesophageal echocardiography (TEE). Additionally, we reported a case in which a malignant lymphoma patient had ATs in the right lower pulmonary vein, in which extended large rod-like thrombi in the left atrium (LA) were found, as determined by TEE. Patients with type 2 diabetes mellitus (T2DM) must have PVTs. The characteristics of extended LA thrombi in patients with T2DM are unclear. Methods: Thirty-one patients with T2DM (73.5 +/- 8.9 y.o., from 50 y.o. to 88 y.o.; male, 24) were examined for PVTs, as estimated via TEE and cardiac CT. Results: Thirty (97%) patients with T2DM had PVTs in the right lower pulmonary vein (RLPV) and connected LA thrombi, as estimated using TEE. Among them, 27 (87%) patients had large white rod-like LA thrombi extending from RLPV thrombi, and the diameter of the thin part of the rod-like LA thrombi was approximately 5 mm. The end of the LA thrombi was mainly attached to the left side of the anterior wall or the posterior side of left side wall of the LA. Additionally, there were left atrium diverticula (LADs) around the attachment regions. Three patients had RLPV thrombi and connected shorter LA thrombi. A 79-year-old male patient did not have detectable PVTs. The patient had taken apixaban (2.5 mg, twice daily) for six years due to atrial fibrillation and stroke. Conclusions: Most (97%) elderly T2DM patients had RLPV thrombi. Additionally, many (87%) patients had extended large rod-like thrombi in the LA. The diameter of the thin part of the large rod-like LA thrombi was approximately 5 mm. There were LADs around the attachment regions where the ends of the LA thrombi from the RLPV thrombi were attached.

Abstract 4124323: Extensive atrial cardiomyopathy indicated by left atrial low-voltage areas predicts subsequent stroke after atrial fibrillation ablation

Background: Atrial fibrillation (AF) is a leading cause of stroke. However, predictors of stroke after AF ablation have not been well clarified, therefore, evidences of anticoagulation therapy after the procedure have been limited. Although left atrial low-voltage areas (LVAs) reflects atrial cardiomyopathy, which is a potential cause of thromboembolism, there are few reports of an association between LVAs and stroke. The purpose of this study was to investigate the association between atrial cardiomyopathy assessed by LVAs and stroke in patients undergoing AF ablation. Methods: The study design was a single center, retrospective observational study. This study included 1,486 (age, 68 ± 10 years; female, 501 [34%]; persistent AF, 905 [61%]) consecutive patients who underwent initial AF ablation from December 2014 to March 2022. The definition of LVAs were areas with a bipolar voltage of <0.5 mV in the left atrium. The area of LVAs in the whole left atrium was divided into 3 groups, namely <5cm 2 , 5-20 cm 2 and ≥20 cm 2 . Stroke after AF ablation was followed for 60 months. Results: Of 1,486 patients, LVAs were found in 352 (24%) patients, and 25 (1.7%) patients developed stroke (hemorrhagic stroke, 4 [16%] patients; ischemic stroke 21 [84%] patients). Freedom from stroke was significantly lower in patients with LVAs than in those without (<5cm 2 : 98.3%, 5-20 cm 2 : 95.4%, ≥20 cm 2 : 88.8%, p<0.001). Additionally, LVAs ≥20 cm 2 was an independent predictor of the development of stroke after AF ablation (hazard ratio 4.9, 95% confidence interval: 2.0-12; p=0.001, adjusted by estimated glomerular filtration rate and AF recurrence after ablation). Conclusion: In patients with initial AF ablation, freedom from stroke after AF ablation was significantly lower in patients with LVAs ≥20 cm 2 than in patients with LVAs 5-20 cm 2 and in patients with LVAs <5cm 2 . Particularly, LVAs ≥20 cm 2 was an independent predictor of the development of stroke after AF ablation.

Robot-Assisted Atrial Septal Defect Closure Via the Left Atrium: Dual Case Reports.

Robot-Assisted Atrial Septal Defect Closure Via the Left Atrium: Dual Case Reports.

Abstract 4118882: Decompensated Heart Failure Secondary to a Non-Coronary Sinus of Valsalva to Right Atrium Fistula: A Case Report

Introduction: Sinus of Valsalva aneurysm (SVA) accounts for 3.5% of all congenital cardiac anomalies. Rupture occurs in 35% of cases and can lead to life-threatening fistulas, predominantly involving the right ventricle or right atrium. Description of Case: 62-year-old female with hypertension and hypothyroidism presented to the ER with progressively worsening dyspnea over the past week. She also reported worsening lower extremity edema, orthopnea, and paroxysmal nocturnal dyspnea. Chest X-ray showed large pleural effusions. Her ejection fraction was 66% ejection fraction with a fistula between the right sinus of Valsalva and the right atrium on transthoracic echocardiogram (TTE) which was also seen on transesophageal echocardiogram (TEE). Her heart failure was due to the fistula as she had no coronary artery disease on coronary angiogram. She had cardiothoracic surgery for fistula repair. Postoperatively, she developed complete heart block requiring a permanent pacemaker. She had no further complications and was discharged home in good condition. Discussion: SVA affects the right sinus (94%), with the non-coronary (5%) and left sinus (1%) being less commonly involved. Aneurysm rupture typically forms a fistula into the right ventricle (60%), right atrium (29%), left atrium (6%), or left ventricle (4%), and rarely into the pericardial cavity (1%). Symptoms vary by rupture size and location. TTE is the initial diagnostic tool but has limited sensitivity (50%) for detecting fistulas, whereas TEE has a 90% sensitivity. Cardiac MRI and CT can further refine diagnoses, and cardiac catheterization assesses coronary arteries preoperatively. Surgical closure with a patch is the primary treatment for ruptured SVA, significantly improving survival rates compared to non-surgical management.

Abstract 4129839: Successful Left Atrial Appendage Occlusion (LAAO) with WATCHMAN FLX via Transhepatic Approach

Left atrial appendage occlusion (LAAO) with the WATCHMAN FLX (Boston Scientific) has been proven to reduce stroke risk in patients with paroxysmal atrial fibrillation (PAF). Certain circumstances may preclude LAAO1. In this case, transhepatic vein access was used to successfully deploy a WATCHMAN FLX in a 72 year old male with PAF not on anticoagulation due to recent subdural hemorrhage and recurrent bilateral lower extremity deep venous thrombosis (DVT) post IVC filter placement. Recent attempt at LAAO was unsuccessful due to total occlusion of bilateral femoral veins (Figure 1 A-B) and inability to cross the IVC. Access to the inferior branch of the right hepatic vein was achieved by micropuncture technique at the right mid-axillary line at the level of the 12th rib, which was confirmed by venogram (Figure 2A). The 4F microsheath was upsized to 16F. Intraoperative TEE was used for device sizing and delivery (Figure 3A). The transseptal sheath and dilator were positioned in the right atrium at the level of the fossa ovalis (Figure 3B) before successfully crossing into the left atrium (Figure 2B). After confirming placement (Figure 3C), a pigtail catheter was positioned within the LAA (Figure 3D) and an angiogram was performed (Figure 2C). A 24 mm WATCHMAN FLX was partially unsheathed and positioned (Figure 3E). Repeat LAA angiogram was performed through the WATCHMAN delivery sheath (Figure 2D). A Tug test was performed. The device was released (Figure 3F). Repeat venogram was performed to confirm location (Figure 2E) of the access site, and coil embolization closure of the venotomy access site was performed (Figure 2F). The patient was discharged the following day on dual antiplatelet (aspirin, clopidogrel) without complication. Venous access via right hepatic vein is a viable option for LAAO using the WATCHMAN FLX device.

Abstract 4138733: Predictive Value of Serum Vasoactive Intestinal Peptide for Low-Voltage Areas in Atrial Fibrillation

Introduction: Identifying low-voltage areas (LVAs) within left atrium (LA) is crucial for predicting atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). Animal studies have shown that the parasympathetic neurotransmitter vasoactive intestinal peptide (VIP) affects atrial electrophysiological remodeling. Hypothesis: Thus, we hypothesized that elevated serum VIP levels might contribute to the development of LVAs and that serum VIP concentrations could serve as a biomarker for LVA presence in AF patients. Aims: The aim of this study is to investigate the relationship between the blood levels of VIP and the presence of LVAs in AF patients with electroanatomical mapping (EAM). Methods: We conducted an observational, prospective cross-sectional study on AF patients undergoing PVI between 2021 and 2023. Blood samples for VIP were collected before atrial septal puncture, and EAM was performed using CARTO 3® before PVI. VIP concentrations were measured using an enzyme-linked immunosorbent assay kit. Patients were divided into two groups based on LVA presence (≥5% or <5%) as determined by EAM. Results: Among the 108 patients, 51 (47%) had LVA. VIP levels were significantly higher in patients with LVA compared to those without (median [interquartile range]: 335.1 [274.1-456.5] pg/mL vs. 247.7 [196.1-294.0] pg/mL, p<0.001). No difference was observed in VIP levels by LVA sites. Multivariate logistic regression identified VIP and sex as independent predictors of LVA (per 50 pg/mL, odds ratio [OR]: 1.44, 95% confidence interval [CI]: 1.13-1.83, p<0.001, OR: 4.67, 95% CI: 1.69-12.89, p=0.002, respectively). Females with high VIP had lower conduction velocity compared to other groups. (low VIP male: 0.9 [0.6-1.0] m/s, high VIP male: 0.9 [0.7-1.1] m/s, low VIP female: 0.8 [0.7-1.0] m/s, high VIP female: 0.7 [0.3-0.8] m/s, p=0.013). Incorporating VIP levels (≥288 pg/mL) into an existing predictive score (age ≥65 years, female, and LA volume index ≥57 mL/m 2 ) significantly improved LVA detection (area under the curve: 0.784 vs. 0.707, p<0.001). Conclusions: Serum VIP levels are higher in patients with LVAs, and VIP is a reliable predictor of LVA presence. Incorporating VIP levels into existing predictive models enhances the power for identifying LVAs in AF patients. Serum VIP measurement could be valuable for detecting LVAs, improving risk stratification, and tailoring strategies in AF management.

Abstract 4138281: Relationship of Collagen Metabolism Biomarkers, Left Atrial Fibrosis and Ablation Outcome in Atrial Fibrillation

Introduction: Inflammation and fibrinogenesis in the left atrium are hypothesized to play a major role in the development of atrial fibrillation (AF). We previously showed that collagen metabolism biomarkers (CMB) are significantly elevated in patients with AF compared to healthy controls. Objective: We sought to investigate the relationship between CMB, Left Atrial Fibrosis (LAF) and AF recurrence after ablation. Methods: Patients with AF undergoing ablation evaluation (N= 96) were prospectively enrolled between 2015 – 2020. Plasma samples were collected prior to ablation and analyzed for CMB using commercially available ELISA kits. Sixty-four patients underwent AF ablation and were followed for 6 months for AF recurrence. CMR was performed in 48 patients using cine and 3D high resolution, late gadolinium enhancement imaging on 3T MRI to measure LAF. Patients were classified into 2 groups dichotomized by the median LAF value. Results: Mean age was 60.3 ± 10.3 years, mean BMI 29.7 ± 4.9 kg/m2, mean CHA2DS2-VASc score 1.9 ± 1.4 and 27% were women. Paroxysmal AF was present in 52.5%. The median LAF score was 13.6% (IQR 9.8 – 21.7). High PINP, high CITP and low TIMP-2 were associated with high LAF score (Table 1). High CITP was also associated with recurrence of AF after ablation {4.26 ng/ml (IQR 3.22 - 4.65) vs 3.26 ng/ml (IQR1.92 - 4.25), P = 0.02}. Conclusion: Higher levels of PINP and CITP were significantly associated with higher LAF score in AF patients. TIMP-2 was associated with low LAF. Higher CITP was also associated with AF recurrence after ablation. Further larger studies are needed to better understand the relationship between collagen biomarkers, LA fibrosis and their clinical impact on rhythm control in AF.

Abstract 4147632: Unusually Expeditious Expansion of an Atrial Myxoma

Description of the Case Report: A 44-year-old female with a past medical history of unspecified skin cancer presented with exertional dyspnea for 1 day before admission and syncope 7 months before admission. Physical exam was noted for soft low low-pitched diastolic murmur at the cardiac apex, not appreciated on prior exam. Echocardiography revealed a 3.3x4.7 cm pedunculated, homogenous mass in the left atrium obstructing the mitral valve. Serum BNP was measured as 326. An echocardiogram from less than 29 months prior was reviewed and showed no mass in the left atrium. The patient underwent successful surgical resection of the mass. The mass measured approximately 7x6x2 cm. Histologic analysis reported a proliferation of myxoid stroma with cytologically bland spindle cells positive for calretinin, compatible with cardiac myxoma. Following the surgery, the patient experienced resolution of symptoms. Discussion: Atrial myxomas are the most common primary cardiac tumors. They present as mitral valve obstruction, mitral valve regurgitation, arrhythmias, or systemic thromboembolism. They are exceedingly rare with an incidence of 0.5 to 1 case per million individuals annually and typically resected immediately. Therefore, instances with well-documented growth rates are uncommon. In this case, we present an unusually fast-growing myxoma in a woman with shortness of breath and syncope. The reported growth rate of atrial myxomas ranges from 1.3 to 6.9 mm a month. Our patient had a negative echocardiogram less than 2.5 years before her presentation, followed by the development of a 7 x 6 x 2 cm mass. Since the onset is unknown, the precise growth rate of our patient's tumor is unknown but was at least 24 mm/month. It is important to consider myxoma in the differential diagnosis of a woman with new onset murmur and syncopal episode. Furthermore, recognizing the potential for rapid expansion is crucial to assessing the risks versus benefits of myxoma section.

Abstract 4120434: A Rare Case Of Localized Ventricular Tachycardia Due To Mitral Annular Disjunction And a Subvalvular Aneurysm

Introduction: Mitral annular disjunction (MAD) is an abnormality of the mitral valve where a portion of the mitral annulus and valve leaflets insert into the left atrium away from the fibrous annulus. Since its identification in 1981 its diagnosis has increased due to the advancements in cardiac imaging. It’s association with ventricular arrythmia (VA) and sudden cardiac death (SCD) underscores the importance of its identification. We present a case of ventricular tachycardia (VT) that is attributed to MAD with associated sub-mitral valve left ventricular aneurysm (SMA) formation. Case: A 51-year-old African American male with history of posterior papillary muscle premature ventricular contractions (PVC), PVC induced cardiomyopathy, and family history of sudden cardiac death in his mother who presented to the emergency department due to palpitations. Electrocardiogram (ECG) showed sustained monomorphic VT at a rate of 160 bpm. This converted to normal sinus rhythm with intravenous amiodarone and metoprolol. Further work up included cardiac magnetic resonance which identified a 4 x 1.8 x 1.4 cm SMA on the basal inferior and inferolateral walls. There was near transmural late gadolinium enhancement (LGE) of the aneurysm and an associated 7 mm of MAD with posterior mitral valve prolapse (MVP). He underwent left heart catheterization which was normal. ECG showed a superior right axis with associated right bundle branch block which correlated to a basal inferolateral exit and to the location of the SMA. Ultimately the patient underwent implantation of secondary prevention implantable cardioverter-defibrillator and initiation of sotalol. Discussion: The prevalence of MAD is approximately 30% in those with MVP and 8% in the general population. Those patients with MAD and MVP appear to be at higher risk for VA and SCD. The most likely mechanism for this association is the fibrotic changes that occur in the basal inferolateral left ventricle because of mechanical stretch on the papillary muscles by the prolapsing leaflets. The scar and aneurysm that develop can serve as substrate for reentrant VA. Treatment for this involves surgical repair of the mitral valve annulus and correction of the MAD distance which has been shown to improve arrythmia. Conclusion: This case illustrates an important but poorly understood arrhythmogenic entity that will increase in incidence as cardiac imaging advances. Its implications in VA and SCD warrant further research.

Abstract 4138622: Cardiac Rhabdomyosarcoma: An Updated Review of the English Literature From 1980 Through 2023

Cardiac Rhabdomyosarcoma (CR) is a rare malignant neoplasm of the heart occurring in all age groups and genders. It can arise anywhere in the heart with varied clinical presentation. Available data on CR are mainly from case reports and series that are limited by small sizes. The purpose of this study was to characterize the epidemiology, presentation, management, hospital course, and outcomes of CR published in the English literature from 1980-2023. Methods: We reviewed and included all published case reports with a diagnosis of CR in adult patients (age >18 years) on PubMed and Google Scholar using the keywords “primary cardiac tumor” and “cardiac rhabdomyosarcoma”. Data was extracted onto an Excel spreadsheet for analysis and the outcomes of interest were demographics, clinical presentation, diagnostic modalities, management, complications, and outcomes. We used descriptive statistics to analyze the data. Results: Among a total of 97 patients from 19 countries included in this study, 54% were males and the median age was 49 years (range 18-80). The main symptoms were dyspnea (37.1%), palpitations (23.7%), chest pains (16.5%) and syncope (6.5%). Hypotension or heart failure and arrhythmias were present in 10.3% and 9.3%, respectively and 5.2% had pericardial effusion. In addition to those with metastatic tumors, 22.7% had chronic co-morbidities. The majority of the cases were primary tumors (85.6%), and the remainder were (14.4%). All patients had at least one imaging modality including echocardiography (89%) and CT/MRI (84%). The commonest sites of cardiac involvement were the left atrium (35%), right atrium (33%), right ventricle (20%), and left ventricle (12%). Approximately 68% involved a single cardiac site while 32% involved multiple sites. Among the patients, 96% underwent surgery while 33% and 25% had chemotherapy and 25% radiotherapy, respectively. The median length of hospital stay was 11 days (range, 2-68 days), and mortality was recorded in 79.3% (77/97) of the patients. The median survival time was reported in 42 patients, and it was 6 months (range, 0-36 months). Conclusion: Cardiac rhabdomyosarcoma is a rare and aggressive malignant neoplasm. Most cases are primary tumors with poor outcomes such as a very short median survival time and a very high mortality rate despite the combination of surgery, chemotherapy, and radiotherapy. This calls for further research into the early diagnosis and optimal management strategies to improve outcomes.

Abstract 4115846: Early Right and Left Ventricular Echocardiographic Parameters Improvement in Obese Patients After Bariatric Surgery.

Background: Severe obesity causes hemodynamic changes in the circulatory system, which leads to the development of heart failure with either preserved or reduced ejection fraction. Weight loss achieved through bariatric surgery is likely to possibly reverse many of hemodynamic and structural abnormalities caused by obesity. Hypothesis: Right and left ventricular parameters of heart failure and function improve as soon as 3 months after surgery. Methods: Detailed echocardiographic parameters assessing left and right ventricular function in severely obese patients undergoing bariatric surgery were analyzed. The following parameters of left and right ventricular function were compared in the examinations performed before, 3 and 6 months after surgery: left ventricular ejection fraction (LVEF), LV and RV global longitudinal strain (GLS), peak early (e’) and late (a’) diastolic annular velocities (lateral and septal) with calculation of E/e’ ratios, left atrium volume index ( LAVI), TRV (tricuspid regurgitation velocity), tricuspid annular plane systolic excursion (TAPSE), maximum systolic velocity of the lateral part of the tricuspid annulus-s’ and accelerated pulmonary time (AcT). Results: Forty obese patients (76% women) with mean BMI 40.3 (SD 5.6) and mean age of 42.4 (SD 11.9) years were enrolled. BMI as 6 months was 31.2 (SD 5.1). Baseline and follow-up results of echocardiography are presented for both left and right ventricular parameters in Table 1 and Table 2. Conclusions: Only GLS for right and left ventricle, FWS and TRV improve siginicantly within 6 months from bariatric surgery. On the other hand, these changes are significant as early as 3 months after bariatric surgery.

Abstract 4136863: Diffuse Functional and Structural Abnormalities in Fibrosis: Potential Structural Basis for Sustaining Atrial Fibrillation

Background: Structural remodeling is associated with atrial fibrillation (AF), but detailed structural and functional characteristics is not well defined. Goal: Using a novel transgenic goat model with cardiac-specific overexpression of TGF-β1 leading to increased cardiac fibrosis, we evaluated detailed structural and functional differences between fibrotic and healthy regions of the atria. Methods: Ex-vivo MRI and histology were used to evaluate fibrosis, fiber disarray, and structural anisotropy. Ex-vivo MRI intensity values were scaled to standard deviations around the mean. The functional analysis examined conduction speeds and direction heterogeneity. Conduction anisotropy was measured along the fiber direction obtained with diffusion tensor imaging. Results: The transgenic goats (n=12) had, on average, 21% of the left atria labeled as fibrotic determined from ex-vivo MRI. The histology samples taken from the labeled fibrotic regions had an increase in fibrosis percentage compared to labeled healthy regions (7.78±3.76% vs 2.80±1.86%, p<0.01). The structural anisotropy was lower in fibrotic regions (0.196±0.002 vs 0.244±0.002, p<0.01). Fiber disarray was greater in the fibrotic regions (20.3±0.2° vs 19.2±0.1°, p<0.01). The fibrotic regions had slower conduction speeds (0.78±0.02 m/s vs 1.12±0.02 m/s, p<0.01) and more aligned conduction directions (30.5±0.2° vs 31.6±0.1°, p<0.01), potentially developing unidirectional conduction block. Conduction anisotropy, measured on the fiber directions, was found to be lower in the fibrotic regions (1.86±0.05 vs 2.10±0.02, p=0.04). As scaled MRI intensity increased, the conduction speed, heterogeneity, and anisotropy all decreased. Conclusions: Functional and structural differences exist between fibrotic and healthy regions of the atria. Though statistically significant, the changes are not discrete. The correlation showed gradual functional abnormalities with MRI intensities. Fibrotic regions tended to have increased fiber disarray, slower conduction, and more unidirectional propagation with lower conduction and structural anisotropy. Diffuse functional and structural abnormalities may allow fibrotic regions to serve as a substrate to sustain AF.

Abstract 4119267: Diagnosing An Uncommon Presentation of Cardiac Sarcoidosis with Isolated Bi-Atrial Involvement: A Case Report

Background: Sarcoidosis, a systemic granulomatous inflammatory disorder can involve various organs, including the heart but isolated bi-atrial cardiac involvement is rare. Advanced cardiac imaging especially in atypical presentations, can aid in early diagnosis. Case: A 59 year-old man with history of biopsy-proven pulmonary sarcoidosis presented with non exertional chest pain for 2 months. EKG, cardiac enzymes, and Initial echocardiogram(TTE) was unremarkable. Stress echocardiogram ruled out myocardial ischemia. CT scan noted mediastinal lymphadenopathy consistent with known sarcidosis. In absence of other explainable etiolgies for chest pain, Cardiac MRI was done and showed preserved biventricular function, subepicardial enhancement in the basal inferior, inferolateral, and anterolateral walls. The enhancement raised suspicion for CS. However, symptoms resolved spontaneously, cardiac workup paused and he was monitored conservatively with serial Echocardiogram(TTE) until onset of dyspnea 3 years later. Repeat TTE and EKG then noted newly enlarged left atrium and atrial tachycardia. Further testing with Cardiac positron emission tomographic imaging with F-18 fluorodeoxyglucose (FDG-PET CT) showed abnormal myocardial uptake in both atrial posterior walls but no ventricular involvement, indicative of isolated bi-atrial inflammation in CS. He was treated with prednisone and methotrexate. Successful symptom and inflammation resolution on FDG-PET CT occurred in 3 months Discussion: CS is rare and seen clinically in about 5% and diagnosed postmortem in 25% of sarcoidosis cases. Symptoms vary widely, with potential for severe heart complications. Left ventricle and interventricular septum are commonly involved, but isolated bi-atrial involvement is rare. Early diagnosis aided by Cardiac MRI and FDG-PET CT is crucial. Prednisone is mainstay of treatment, often combined with methotrexate. Cases of concurrent atrial CS involvement and bi-atrial fibrosis with Left ventricular hyperenhancement are documented, but this is the first known report of isolated bi-atrial hyperenhancement on FDG-PET CT for CS. This case highlights the need for symptom correlation with clinical and imaging follow-up, especially in atypical presentations.

Pediatric 3D transesophageal echocardiography reveals prolapse of accessory mitral valve tissues into the left atrium in a neonate.

Pediatric 3D transesophageal echocardiography reveals prolapse of accessory mitral valve tissues into the left atrium in a neonate.

Rare case of aorto-left atrial tunnel with associated bicuspid aortic valve, large patent ductus arteriosus, and atrial septal defects.

Aorto-cardiac tunnels represent uncommon cardiovascular anomalies connecting the ascending aorta to cardiac chambers and are typically characterized by extra-cardiac tubular channels. Among these, the involvement of the left atrium is exceptionally rare, with only a few cases reported in literature. Here, we describe a case of an aorto-left atrial tunnel in a 6-year-old boy with an associated bicuspid aortic valve, a large patent ductus arteriosus, and atrial septal defects. This case highlights the significance of multimodal imaging in the accurate identification and characterization of rare cardiovascular anomalies.

Detection of a Gossypiboma as a Retrocardiac Mass in a Female Patient with a History of Coronary Artery Bypass Graft

Introduction: "Gossypiboma," also known as "textiloma," refers to retained surgical items left in the body after an operation. These retained items can lead to a range of issues, from asymptomatic cases to life-threatening complications. Diagnostically challenging, gossypibomas can mimic malignant masses, making it essential to consider them in the differential diagnosis of postoperative patients with unexplained symptoms. Imaging is crucial for detection and management. Case Presentation: A 69-year-old female with a history of coronary artery bypass graft (CABG) surgery presented with exertional shortness of breath. Imaging revealed a large mass near the left atrium. Initially suspected to be a tumor, further investigation identified it as retained surgical gauze from her surgery ten years prior. Despite the mass, the patient exhibited only mild symptoms, and given her stable condition, regular follow-ups were recommended. Conclusions: Gossypibomas are rare but serious complications that may surface years after surgery. This case highlights the importance of meticulous surgical practices and careful postoperative monitoring. It underscores the need for accurate gauze counting and effective communication in the operating room to prevent errors that can lead to health risks and potential legal issues.