Atrial Shunt Research Articles

Effects of biventricular shunt on pump characteristics in a maglev total artificial heart.

Severe left ventricular failure can progress to right ventricular failure, necessitating alternatives to heart transplantation, such as total artificial heart (TAH) treatment. Conventional TAHs encounter challenges associated with miniaturization and hemocompatibility owing to their reliance on mechanical valves and bearings. A magnetically levitated TAH (IB-Heart) was developed, utilizing a magnetic bearing. The IB-Heart features a distinctive biventricular shunt channel situated between the flow paths of the left and right centrifugal blood pumps, simplifying and miniaturizing its control system. However, the impact of these shunt channels remains underexplored. This study aimed to investigate the effects of shunt flow on pump characteristics and assess the IB-Heart's potential to regulate flow balance between systemic and pulmonary circulation. At a rotational speed of 2000 rpm and flow rate range of 0-10 L/min, shunt flow exhibited a minor impact, with a 1.4 mmHg (1.3%) effect on pump characteristics. Shunt flow variation of about 0.13 L/min correlated with a 10 mmHg pressure difference between the pumps' afterload and preload conditions. This variance was linked to changes in the inlet flow rates of the left and right pumps, signifying the ventricular shunt structure's capacity to mirror the function of an atrial shunt in alleviating pulmonary congestion. The IB-Heart's ventricular shunt structure enables passive regulation of left-right flow balance. The findings establish a fundamental technical groundwork for the development of IB-Hearts and TAHs with similar shunt structures. The innovative coupling of centrifugal pumps and the resultant effects on flow dynamics contribute to the advancement of TAH technology.

Anomalous hepatic drainage and platypnea-orthodeoxia in cyanotic children.

The aetiology of cyanosis could be unclear in children, even for specialised paediatricians. Two cases were reported: first, a 6-year-old child with features of left isomerism and Fallot was fortuitously diagnosed with anomalous hepatic venous drainage before complete repair. Second, a newborn with an antenatal diagnosis of ductus venosus agenesis had an isolated intermittent right-to-left atrial shunt when upright, with favourable outcome, in contrast to the association with significant heart malformations including inferior caval vein interruption. Multimodality imaging and 3D printing helped to rule out extracardiac causes of persistent cyanosis and plan surgical repair.

Feasibility of Catheter Ablation for Biatrial Tachycardia Using Multiple Catheters via an Atrial Shunt Device.

Feasibility of Catheter Ablation for Biatrial Tachycardia Using Multiple Catheters via an Atrial Shunt Device.

Utility of Follow-Up Echocardiograms in Uncomplicated Surgical Secundum Atrial Septal Defect Closures: Preliminary Analysis.

Though less common in the current era, surgical closure of secundum atrial septal defects (ASD2) is still performed in certain clinical situations. Guidelines currently recommend lifelong follow-up with transthoracic echocardiograms (TTE) for patients who have undergone a surgical ASD2 closure. The goal of this study was to determine the utility of follow-up TTE in patients who underwent an uncomplicated ASD2 closure. Chart review was performed on patients who had a surgical ASD2 closure between April 1, 1996, and August 30, 2021. Patients were excluded if they had other congenital heart disease, had a diagnosis of a residual ASD2, atrial/ventricular arrhythmias, pulmonary hypertension, heart failure, or did not have a follow-up TTE > 6months after the procedure. The most recent TTEs and clinic notes were evaluated. A total of 30 patients met the criteria. The median age at ASD2 surgery was 4.0years (IQ; 1.9-10.5). ASD2 was closed via patch repair in 16 patients and primarily closed in 14 patients. The most recent TTE was performed a median of 9.5years (IQ; 4.0, 14.7) after ASD2 closure. Two patients had mild right atrial and ventricular dilation, one patient had mild right atrial dilation, and one patient had mild right ventricular dilation. All other patients had qualitatively normal right-sided chamber sizes. All patients had normal biventricular function (left ventricular fractional shortening (median 36% (IQ; 33, 42)), no evidence of residual atrial shunts, and no evidence of pulmonary hypertension. No patient was on any cardiac medications at last clinic visit. Four patients were discharged from cardiology clinic and 10 patients were lost to follow-up. There were no deaths. Twenty-four patients had 46 repeat echocardiograms > 1year after ASD2 with no change in clinical management. In patients who underwent an uncomplicated ASD2 closure, there were no significant abnormalities noted on follow-up TTEs. The need for repeat lifetime TTEs and their frequency, in this uncomplicated population, should be reassessed if larger studies with longer follow-up confirm these initial findings.

Clinical outcomes of the cuff wrapping technique in the modified Bentall procedure: a propensity score-matched study.

This study was designed to evaluate the clinical outcomes of our modified cuff wrapping Bentall (M-Bentall) procedure, which uses a cuff wrapping technique with remnant aortic root tissue. From July 2017 to December 2021, a total of 136 patients met the inclusion criteria for this study. Among them, patients who underwent the modified Bentall procedure using the cuff wrapping technique were included in the M-Bentall group (n=46), while patients who underwent the classic Bentall (C-Bentall) procedure were categorized into the C-Bentall group (n=90). To reduce baseline differences between the two groups, 1:1 nearest-neighbor propensity score matching (PSM) was performed. Demographic and perioperative data were documented and compared between the two groups. Ninety patients were successfully matched (45 pairs). In-hospital mortality was not significantly different between the two groups after PSM (P=1). No differences were found in serious adverse events. The cardiopulmonary bypass (CPB) time was longer in the M-Bentall group than in the C-Bentall group (154 vs. 126 min, P=0.018). The same was also observed for the aortic cross-clamp time (113 vs. 92 min, P=0.009). Postoperatively, the peak value of D-dimer showed a significant difference, with higher values in the C-Bentall group (4.73 vs. 2.89 mg/L, P=0.019). The incidence of postoperative contrast extravasation at the aortic root (P=0.030) was higher in the C-Bentall group. The incidence of persistent aortic-right atrial shunts showed an increased tendency in the C-Bentall group (8.89% vs. 0%, P=0.117). The cuff wrapping technique is a safe and effective method to facilitate hemostasis of the aortic root in the modified Bentall procedure.

Atrial Fibrillation Burden and Atrial Shunt Therapy in Heart Failure With Preserved Ejection Fraction

BackgroundAtrial fibrillation (AF) is a common comorbidity in patients with heart failure with preserved ejection fraction (HFpEF) and in heart failure with mildly reduced ejection fraction (HFmrEF). ObjectivesThis study sought to describe AF burden and its clinical impact among individuals with HFpEF and HFmrEF who participated in a randomized clinical trial of atrial shunt therapy (REDUCE LAP-HF II [A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients with Heart Failure]) and to evaluate the effect of atrial shunt therapy on AF burden. MethodsStudy investigators characterized AF burden among patients in the REDUCE LAP-HF II trial by using ambulatory cardiac patch monitoring at baseline (median patch wear time, 6 days) and over a 12-month follow-up (median patch wear time, 125 days). The investigators determined the association of baseline AF burden with long-term clinical events and examined the effect of atrial shunt therapy on AF burden over time. ResultsAmong 367 patients with cardiac monitoring data at baseline and follow-up, 194 (53%) had a history of AF or atrial flutter (AFL), and median baseline AF burden was 0.012% (IQR: 0%-1.3%). After multivariable adjustment, baseline AF burden ≥0.012% was significantly associated with heart failure (HF) events (HR: 2.00; 95% CI: 1.17-3.44; P = 0.01) both with and without a history of AF or AFL (P for interaction = 0.68). Adjustment for left atrial reservoir strain attenuated the baseline AF burden-HF event association (HR: 1.71; 95% CI: 0.93-3.14; P = 0.08). Of the 367 patients, 141 (38%) had patch-detected AF during follow-up without a history of AF or AFL. Atrial shunt therapy did not change AF incidence or burden during follow-up. ConclusionsIn HFpEF and HFmrEF, nearly 40% of patients have subclinical AF by 1 year. Baseline AF burden, even at low levels, is associated with HF events. Atrial shunt therapy does not affect AF incidence or burden. (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients with Heart Failure [REDUCE LAP-HF II]; NCT03088033)

P256 AN UNUSUAL CASE OF PACEMAKER MALFUNCTION WITH NON COMMON ELCTROCARDIOGRAPHIC PRESENTATION AND UNEXPECTED ECHOCARDIOGRAPHIC FINDING

Abstract This clinical case shows the diagnostic challenge and the management of a 79 y–o male with recent hospitalization for infero–lateral STEMI undergoing primary PCI of Right Coronary Artery with 2 DES and following DDDR MRI PM (pacemaker) implantation due to the development of persistent 2:1 Atrio–Ventricular Block. One month later, admission at Emergency Department for syncope. Normal parameters were found at laboratory analyses. The electro–stimulator activity evaluation showed a PM malfunction with ventricular capture failure. Thus, the increase of PM output up to electric ventricular capture (8 Volt/120 msec) was performed, but the following Electrocardiogram showed a PM–induced rhythm with RBBB–morphology. Then, the bedside Echocardiogram showed an apparent presence of a linear hyper–echogenic image into left ventricle with no inter–ventricular septal defect neither inter–ventricular shunt, inter–atrial septal hypermobility with no evident inter–atrial shunt at rest; while a chest Radiography identified the atrial and ventricular leads with no accurate individuation of their position. The patient was admitted in Intensive Cardiac Care Unit with confirmation of intermittent failure to ventricular capture and RBBB–morphology during PM–induced rhythm at telemetry monitoring. Due to Electrocardiographic and Echocardiographic findings, a strong suspect of abnormal position of the ventricular lead into left ventricle through a possible PFO has been raised. A chest Computed Tomography was performed confirming the anomalous position of the ventricular lead: it reached the left atrium through an inter–atrial defect/patent foramen ovale (PFO), then crossing the mitral valve up to left ventricle. The PM–lead repositioning was scheduled two days after. After positioning of temporary stimulator lead in right ventricle, the ventricular lead has been withdrawn from left–side chambers and positioned into septal–apical right ventricle; furthermore, the position of right atrial lead has been optimized (because of frequent spontaneous passage to the left atrium through the PFO, during manual maneuvers) thus obtaining good stability of the device. During the following days, the telemetry monitoring showed a PM–induced rhythm, without capture nor sensing failure. The chest Radiography confirmed the correct position of leads and the pre–discharge Echocardiography showed a LVEF 57% with no valvular pathology and with atrial and ventricular leads into right–side chambers.

PO-04-028 INTERATRIAL SHUNT LEADING TO SEVERE HYPOXEMIA: A RARE COMPLICATION OF PACEMAKER-ASSOCIATED INFECTIVE ENDOCARDITIS

Pacemaker-lead-associated infective endocarditis is a serious complication with high morbidity and mortality. We present a case of persistent hypoxemia from significant right to left atrial shunting across the patent foramen ovale (PFO) as a result of pacemaker-lead-associated infective endocarditis with large vegetations. N/A A 56-year-old female with stroke, sleep apnea, diabetes mellitus, hypertension, and sick sinus syndrome with dual chamber pacemaker implantation, was admitted with acute hypoxic respiratory failure requiring high flow nasal cannula. A chest x-ray did not show any obvious etiology of hypoxemic respiratory failure. Arterial blood gas showed no hypercapnia ruling out hypoventilation as the cause of hypoxemia. A very high A-a gradient was noted, raising suspicion for shunting. Blood cultures were positive for staphylococcus capitis bacteremia. A transesophageal echocardiogram (TEE) showed several large vegetations (Image A) attached to the atrial and ventricular lead, tricuspid valve with associated severe tricuspid regurgitation, and a PFO (Image B) with a large right to left shunt as a result of large right-sided vegetations (Image C). A pacemaker extraction procedure was planned; however, there was a concern for paradoxical septic embolism across the PFO. As such, an ASD occluder device was temporarily placed across the PFO during the procedure to prevent right-to-left embolization. PFO occlusion dramatically improved hypoxemia during the procedure. The infected pacemaker system was then successfully extracted. The PFO occluder device was subsequently removed at the end of the case, given ongoing bacteremia and the risk of device seeding. The patient recovered well with the resolution of hypoxemia and was discharged however presented again one month later with a stroke. TEE exam showed a large echo-dense lesion straddling the atrial septum through the PFO, likely vegetation that embolized to the left circulation causing the stroke (Image D). The patient is currently awaiting cardiac surgery for definitive treatment once medically stable. Pacemaker-associated infective endocarditis can lead to mechanical complications, including tricuspid regurgitation and rarely shunting across the atria, causing severe hypoxemia as in our patient. There are no clear guidelines regarding the management of such atrial defects with shunting peri-device extraction to prevent systemic embolization of vegetations.

Unrecognized Patent Foramen Ovale in Patient With Sinus Venosus-Type Atrial Septal Defect With Partial Anomalous Pulmonary Venous Return.

Unrecognized Patent Foramen Ovale in Patient With Sinus Venosus-Type Atrial Septal Defect With Partial Anomalous Pulmonary Venous Return.

Percutaneous atrial shunt closure and the risk of recurrent ischemic stroke: A register-based, nationwide cohort study

ObjectivesWe aimed to investigate the risk of recurrent stroke in patients with transcatheter closure of an atrial shunt (ASCIos), compared to patients with an atrial shunt and cerebrovascular event (CVE) but only medical treated (ASMed), and to age- and sex-matched control individuals without a previous CVE. MethodsIn total, 663 ASCIos patients were identified in the Swedish National Patient Register from 1997 to 2016 and matched by using propensity score with 663 ASMed patients. Nine age- and sex-matched controls to ASCIos patients (n = 6,302) without a diagnosis of atrial shunt or history of CVE were randomly selected from the general population. ResultsAt a mean follow-up of 6.5 years, the incidence rate of recurrent stroke in the ASCIos group vs ASMed group was 0.9 vs 0.7 per 100 patient-years. The hazard ratio of recurrent stroke in the ASCIos group compared with index stroke in the control group was 9.9 (95% confidence interval, 5.5–17.9). The incidence of atrial fibrillation was similar in the ASCIos and the ASMed group, however four times higher in the ASCIos than in the control group. ConclusionsOur large nationwide, register-based cohort study showed that, unexpectedly, the risk of recurrent stroke in the ASCos group was as high as in the ASMed group and almost ten times higher than the risk of an index stroke in matched controls without previous stroke.

Exercise-Induced Left Atrial Hypertension in Heart Failure With Preserved Ejection Fraction

BackgroundMany patients with heart failure and preserved ejection fraction have no overt volume overload and normal resting left atrial (LA) pressure. ObjectivesThis study sought to characterize patients with normal resting LA pressure (pulmonary capillary wedge pressure [PCWP] <15 mm Hg) but exercise-induced left atrial hypertension (EILAH). MethodsThe REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc. IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure) trial randomized 626 patients with ejection fraction ≥40% and exercise PCWP ≥25 mm Hg to atrial shunt or sham procedure. The primary trial outcome, a hierarchical composite of death, heart failure hospitalization, intensification of diuretics, and change in health status was compared between patients with EILAH and those with heart failure and resting left atrial hypertension (RELAH). ResultsPatients with EILAH (29%) had similar symptom severity, but lower natriuretic peptide levels, higher 6-minute walk distance, less atrial fibrillation, lower left ventricular mass, smaller LA volumes, lower E/e′, and better LA strain. PCWP was lower at rest, but had a larger increase with exercise in EILAH. Neither group as a whole had a significant effect from shunt therapy vs sham. Patients with EILAH were more likely to have characteristics associated with atrial shunt responsiveness (peak exercise pulmonary vascular resistance <1.74 WU) and no pacemaker (63% vs 46%; P < 0.001). The win ratio for the primary outcome was 1.56 (P = 0.08) in patients with EILAH and 1.51 (P = 0.04) in those with RELAH when responder characteristics were present. ConclusionsPatients with EILAH had similar symptom severity but less advanced myocardial and pulmonary vascular disease. This important subgroup may be difficult to diagnose without invasive exercise hemodynamics, but it has characteristics associated with favorable response to atrial shunt therapy. (A Study to Evaluate the Corvia Medical, Inc. IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure [REDUCE LAP-HF TRIAL II]; NCT03088033)

Neurological, Extracardiac, and Cardiac Manifestations of Ebstein's Anomaly Along With its Genetics, Diagnostic Techniques, Treatment Updates, and the Future Ahead.

Ebstein's anomaly is a congenital heart defect characterized by the displacement of the tricuspid valve, and its leaflets to be malformed. Due to the defect involving the tricuspid valve, there is a reverse flow of blood into the right-sided atrium, which may lead to cardiac hypertrophy and edema of the lower extremities. There is a decreased flow of blood out of the right heart due to reduced right ventricular contractility and tricuspid regurgitation. Children afflicted with thisanomaly usually suffer from atrial septal defect and this is usually diagnosed before birth on a routine ultrasound scan. In neonates, cyanosis can be seen due to right-to-left atrial shunting or as a result of severe congestive heart failure. If the infant has pulmonary hypertension, cyanosis is markedly increased as there will be a limitation in pulmonary blood flow. In adults, arrhythmias, cyanosis, and heart failure are seen. The bundle of Kent leads to the formation of an electrical conduction abnormality between the right ventricle and atrium. This leads to a condition commonly known as Wolff- Parkinson-White syndrome in patients. An enlarged spherical heart is usually present on a chest X-ray. ECG changes of Ebstein's anomaly show taller than usual P waves, PR prolongation, and right bundle branch block. There can be certain neurological and extracardiac manifestations too such as hemiplegia, stroke, dysarthria, etc. During fetal life, specifically at 16 and 20 weeks of gestation, the anomaly can be diagnosed via echocardiography. Prostaglandin infusion (PGE1) is given to maintain pulmonary circulation in neonates if cyanosis is seen. In children and adults with congestive cardiac failure due to this anomaly, medical management includes digoxin, beta-blockers, diuretics, and angiotensin converting enzyme (ACE) inhibitors to improve heart failure. Surgical treatment includes valve reconstruction. In this article, we review the pathophysiology, genetics, diagnosis, management, and prognosis of Ebstein's Anomaly along with a comprehensive discussion on its genetics, neurological manifestations, extracardiac features, and current advancements in treatment.

Long-term outcome after closure of an atrial shunt in patients aged 60 years or older with ischemic stroke: A nationwide, registry-based, case-control study

BackgroundAccording to the current guidelines, evidence of the effects of transcatheter closure in patients aged ≥60 years with an atrial shunt and cryptogenic stroke is still limited. MethodsUsing Swedish health registries, patients aged ≥60 years who had previously developed a cryptogenic cerebrovascular event and undergone transcatheter closure were identified. Patients with atrial fibrillation were excluded, and the remaining patients were propensity score-matched with patients of the same age and risk profile who had only undergone medical treatment and with controls from the general population. They were then followed up until 2017 (mean period of 7.1 ± 3.9 years). ResultsIn total, 100 patients of the intervention group were matched with 100 patients of the medical treatment group and with 100 controls and followed up. The hazard ratio for a recurrent ischemic stroke in the intervention group compared with the medical treatment group was 0.8 (95% confidence interval, 0.3–2.1), and that compared with the controls was 2.3 (95% confidence interval, 0.6–8.9). Atrial fibrillation occurred at the same rate in the two treatment groups (odds ratio, 0.8; 95% confidence interval, 0.4–1.7). However, patients in the intervention group developed vascular disease at a lower rate (odds ratio, 0.5; 95% confidence interval, 0.25–0.85). ConclusionsPatients aged ≥60 years with cryptogenic stroke may undergo transcatheter closure of an atrial shunt after thorough screening for other potential causes of stroke. The incidence of vascular disease seems to be mitigated in these patients relative to medically treated patients.

The Role of the Anesthesiologist and the Modern Intraoperative Echography in Ventriculoatrial Shunt for Hydrocephalus: From Hakim to Nowadays.

The introduction of US-guided venipuncture in clinical practice has greatly facilitated the surgical approach to patients with hydrocephalus. Especially in infants and children, where it results in a lower technical failure rate, less time and fewer complications than the traditional referral method, this technique has become a clinical protocol. This dynamic or "real time" technique has become one of the anesthetist's tools. This allowed the anesthesiologists to be part of the surgical team, so they not only dedicate themselves to inducing and maintaining general anesthesia but also to performing venipuncture of the central vein of the neck and to locating the tip of the catheter.The anesthetist's tools have made it possible to perform a simple and safe method, and the anesthesiologists have become an active part of the surgical team, charged with a specific role during the positioning of the ventricular atrial shunt.

Biventricular longitudinal strain as a predictor of functional improvement after D-shant device implantation in patients with heart failure.

The creation of an atrial shunt is a novel approach for the management of heart failure (HF), and there is a need for advanced methods for detection of cardiac function response to an interatrial shunt device. Ventricular longitudinal strain is a more sensitive marker of cardiac function than conventional echocardiographic parameters, but data on the value of longitudinal strain as a predictor of improvement in cardiac function after implantation of an interatrial shunt device are scarce. We aimed to investigate the exploratory efficacy of the D-Shant device for interatrial shunting in treating heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF), and to explore the predictive value of biventricular longitudinal strain for functional improvement in such patients. A total of 34 patients were enrolled (25 with HFrEF and 9 with HFpEF). All patients underwent conventional echocardiography and two-dimensional speckle tracking echocardiogram (2D-STE) at baseline and 6 months after implantation of a D-Shant device (WeiKe Medical Inc., WuHan, CN). Left ventricular global longitudinal strain (LVGLS) and right ventricular free wall longitudinal strain (RVFWLS) were evaluated by 2D-STE. The D-Shant device was successfully implanted in all cases without periprocedural mortality. At 6-month follow-up, an improvement in New York Heart Association (NYHA) functional class was observed in 20 of 28 patients with HF. Compared with baseline, patients with HFrEF showed significant reduced left atrial volume index (LAVI) and increased right atrial (RA) dimensions, as well as improved LVGLS and RVFWLS, at 6-month follow-up. Despite reduction in LAVI and increase in RA dimensions, improvements in biventricular longitudinal strain did not occur in HFpEF patients. Multivariate logistic regression demonstrated that LVGLS [odds ratio (OR): 5.930; 95% CI: 1.463-24.038; P = 0.013] and RVFWLS (OR: 4.852; 95% CI: 1.372-17.159; P = 0.014) were predictive of improvement in NYHA functional class after D-Shant device implantation. Improvements in clinical and functional status are observed in patients with HF 6 months after implantation of a D-Shant device. Preoperative biventricular longitudinal strain is predictive of improvement in NYHA functional class and may be helpful to identify patients who will experience better outcomes following implantation of an interatrial shunt device.

Abstract 14957: Validation of Echocardiography Color Doppler Velocity Reconstruction Against 4d Flow Mri in Assessment of Right Ventricular Intracardiac Flow

Introduction: Intracardiac flow imaging of the right ventricle [RV] may improve the management of congenital heart disease like repaired Tetralogy of Fallot [rTOF] or atrial shunts that cause RV dilation [RVD]. However, this is mostly performed via 4D flow magnetic resonance imaging [MRI], which has limited availability and is resource intensive. We propose the use of conventional echocardiography as a viable alternative to assess RV intracardiac flow. Hypothesis: We hypothesize that a velocity reconstruction algorithm implemented for conventional color Doppler echocardiography can resolve flow quantities with good agreement to 4D flow MRI. Methods: We retrospectively collected echos for children with rTOF/RVD and age-matched controls. Color Doppler echos of the RV were evaluated using an in-house algorithm called Doppler Velocity Reconstruction [DoVeR]. Measurements from 4D flow MRI and DoVeR were post-processed to collect hemodynamics parameters for relative pressure difference , vortex strength , total kinetic energy , and viscous energy loss . Agreement between modalities was performed by cross-correlation and L2-norm difference between indexed chamber-average timeseries measurements. Results: 10 rTOF subjects, 3 RVD, and 7 age-matched controls were identified. There was qualitative agreement in spatial and time series measurements between DoVeR and 4D flow MRI (Figure 1). For timeseries measurements, there was strong correlation (median R &gt; 0.85) with low differences (median L2 &lt; 15%) between DoVer and 4D flow MRI. Conclusions: A color Doppler reconstruction method, DoVeR, can effectively measure hemodyanmics parameters using conventional color Doppler echocardiography, with strong agreement against 4D flow MRI. Figure 1: Left – Flow field overlaid onto pressure reconstruction and pressure difference estimates between DoVeR and 4D flow modalities. Right – Correlation coefficient and difference between modality timeseries measurements.

Abstract 14460: Aortic Valve Infective Endocarditis Complicated by Complete Heart Block and Gerbode’s Defect

Introduction: Aortic root abscess with complete heart block is a rare complication of infective endocarditis (IE). Early diagnosis and prompt surgical management are necessary to prevent fatal outcomes. Case Presentation: A 45-year-old male with past medical history of uncontrolled diabetes mellitus was referred to our cardiac intensive care unit for management of complete heart block. His symptoms including exertional dyspnea, hiccups, and dry cough started two weeks prior to presentation. The patient was bradycardic, hypoxic, and hypotensive on examination. Labs were significant for marked leukocytosis 21,000/ul with a neutrophilic predominance. Blood cultures were obtained, and the patient was started on empiric antibiotics vancomycin and piperacillin-tazobactam. Electrocardiogram (ECG) showed evidence of complete heart block and a temporary transvenous pacemaker was placed. A transthoracic echocardiogram was obtained that showed evidence of severe aortic regurgitation and aortic valve vegetations. Due to high clinical suspicion, a transesophageal echocardiogram was immediately performed that revealed aortic root abscess. Patient underwent successful debridement of aortic valve vegetations and aortic valve replacement. Intraoperative findings also included a subaortic left ventricular to right atrial (LV-RA) shunt also known as Gerbode’s defect that was repaired with pericardial patch. Blood cultures and intraoperative tissue cultures confirmed a Staphylococcus lugdunensis infection. He received six weeks of intravenous antibiotics. At 2-month follow-up, the patient reported doing well. Conclusion: New complete heart block may be a manifestation of aortic root abscess. This case illustrates the need to maintain a high level of suspicion for complicated infective endocarditis in patients with sepsis and complete heart block. Timely diagnosis with imaging and early surgical repair results in favorable outcomes.

Machine Learning Model for Predicting Risk of In-Hospital Mortality after Surgery in Congenital Heart Disease Patients.

A machine learning model was developed to estimate the in-hospital mortality risk after congenital heart disease (CHD) surgery in pediatric patient. Patients with CHD who underwent surgery were included in the study. A Extreme Gradient Boosting (XGBoost) model was constructed based onsurgical risk stratification and preoperative variables to predict the risk of in-hospital mortality. We compared the predictive value of the XGBoost model with Risk Adjustment in Congenital Heart Surgery-1 (RACHS-1) and Society of Thoracic Surgery-European Association for Cardiothoracic Surgery (STS-EACTS) categories. A total of 24,685 patients underwent CHD surgery and 595 (2.4%) died in hospital. The area under curve (AUC) of the STS-EACTS and RACHS-1 risk stratification scores were 0.748 [95% Confidence Interval (CI): 0.707-0.789, p 0.001] and 0.677 (95% CI: 0.627-0.728, p 0.001), respectively. Our XGBoost model yielded the best AUC (0.887, 95% CI: 0.866-0.907, p 0.001), and sensitivity and specificity were 0.785 and 0.824, respectively. The top 10 variables that contribute most to the predictive performance of the machine learning model were saturation of pulse oxygen categories, risk categories, age, preoperative mechanical ventilation, atrial shunt, pulmonary insufficiency, ventricular shunt, left atrial dimension, a history of cardiac surgery, numbers of defects. The XGBoost model was more accurate than RACHS-1 and STS-EACTS in predicting in-hospital mortality after CHD surgery in China.

Device Therapy for Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with few options for effective pharmacologic therapies. Numerous device-based approaches to HFpEF therapy have emerged, which aim to treat the clinical and pathophysiologic features common to the varied causes of this syndrome. This review summarizes the current landscape of device therapy in HFpEF with a focus on structural interventions, such as left-to-right atrial shunts; cardiac contractility modulation; autonomic modulation, such as baroreflex activation therapy and splanchnic nerve modulation; and respiratory modulation, such as phrenic nerve stimulation.

Can a simple echocardiographic Doppler VTI based flow comparison between the RVOT and LVOT assist in identifying patients with a significant atrial septal defect?

Abstract Background Detection of haemodynamically significant shunting from atrial septal defect (ASD) can be identified by using the pulmonary-systemic flow ratio (Qp/Qs). However, calculation of Qp/Qs by echocardiography relies on geometric assumptions that outflow tracts are circular, suffers from squared linear measures, and accurate measurement of right ventricular outflow tract (RVOT) diameter is challenging. Whilst adults with ASD should have overt right ventricular dilatation, RV sizing on echocardiography is often subjective and underappreciated. We evaluated whether a dimensionless index of flow (VTI) differences between the RVOT and left ventricular outflow tract (LVOT) could assist in identifying patients with ASD, and compared it with relative atrial index (RAI), a parameter previously assessed in identifying atrial shunting. Methods Data from 64 consecutive patients who underwent ASD closure and had no concomitant lesions, were compared with 63 normal controls. RVOT VTI, LVOT VTI, LVOT diameter, and atrial areas were measured. Results Between controls and ASD patients, there was no difference in LVOT VTI or forward stroke volume, but ASD patients had significantly higher RVOT VTI. The RVOT-LVOT VTI ratio was 1:1 in controls and 1.5:1 in ASD patients. Area under the ROC curve analysis of RVOT-LVOT VTI ratio was 0.83, and a ratio of 1.1:1 predicted patients with ASD with 86% sensitivity and 73% specificity. In comparison, the area under the ROC curve analysis of RAI was 0.70, and an RAI of 1.05:1 predicted patients with ASD with 77% sensitivity and 44% specificity. Conclusion Calculation of the dimensionless RVOT-LVOT VTI ratio is simple, and may be a useful additional semi-quantitative tool to assist cardiologists and sonographers in detecting atrial shunting, particularly in patients with borderline or overt right heart dilatation, and identify who patients should undergo further evaluation. Funding Acknowledgement Type of funding sources: None.