Intracardiac Shunts Research Articles

Paradoxical Hypoxemia Following Positive Pressure Ventilation: Exploring the Pathophysiology.

Positive pressure ventilation can trigger paradoxical hypoxemia through a right-to-left shunt in patients with patent foramen ovale.Unexplained hypoxemia after initiating positive pressure ventilation warrants investigating intracardiac shunts with a saline contrast echocardiogram.Adjusting bilevel positive airway pressure settings based on individual haemodynamics is essential for improving oxygenation.

Prevalence, determinants, and impact of significant shunt after percutaneous patent foramen ovale closure

Abstract Introduction Percutaneous closure of patent foramen ovale closure is increasingly performed for secondary prevention of PFO-related arterial embolic event. The clinical significance of postclosure residual right-to-left significant shunt remains unclear. Purpose To describe the prevalence, determinants, and clinical impact of a significant post-closure. Methods The AIR-FORCE is an ongoing prospective international registry of patients undergoing PFO closure from 19 centers in France, Canada and Italy. Only patients undergoing PFO for secondary prevention of an arterial embolic event with at least one available post-closure contrast transthoracic echocardiography (TTE) with agitated saline injection and Valsalva maneuvers were analyzed. Residual shunt was categorized according to the number of bubbles in the left atrial within 3 cardiac cycles at the first available contrast TTE as small (<10), moderate (10-20) or severe (> 20). Determinants of the presence of moderate or severe shunt were evaluated with multivariate logistic regression and its impact on the primary outcome (stroke, transient ischemic attack or peripheral arterial emboly) was evaluated with Cox model adjusted on age and sex. Results A total of 2413 patients, with a median age of 49.3 [40.4-57.4] years, 56% male, undergoing PFO closure between 2001 and 2023 were included. The first contrast TTE, which was performed after a median delay of 3.4 [0.9-5.8] months, reported the presence of moderate or severe residual shunt in 214 (8.9% 95%CI 7.8-10.1) patients. Determinants of the presence of moderate or severe residual shunt at the first contrast TTE were decreased body mass index (per 1kg/m², aOR 0.96 95%CI 0.93-0.99), severe shunt prior to PFO closure (aOR 3.54 95%CI 2.25-5.55) and increased device left disc diameter (per 1mm, aOR 1.08 95%CI 1.05-1.12). With a median follow-up of 2.2 [0.9-4.9] years, a total of 60 events were reported and the presence of moderate or severe residual shunt was associated with an increased risk of the primary outcome (aHR 2.46 95%CI 1.15-5.24) (Figure 1). Conclusions A moderate to severe residual right-to-left intracardiac shunt is not uncommon after PFO percutaneous closure and seems to be associated with an increased risk of arterial emboly recurrence.

A patient with unexplained hypoxemia after a fall diagnosed with platypnea orthodeoxia syndrome: approaches to resolving discrepancies between level of hypoxemia and clinical presentation.

Platypnea orthodeoxia syndrome (POS) is a rare cause of hypoxemia. Diagnosis of POS is challenging, requiring a high index of clinical suspicion, special investigations, and collaboration with multiple specialists. We describe an 86-yr-old male who presented to the emergency department with hip pain after a witnessed fall. He was noted to be hypoxemic at presentation with a peripheral oxygen saturation (SpO2) of 84% on room air, with an inadequate increase in oxygenation after administration of a fractional concentration of inspired oxygen (FIO2) of 1.00. A chest radiograph, computed tomography pulmonary angiogram, and Doppler ultrasound of the liver were unremarkable. In the supine position with an FIO2 of 0.65, his SpO2 and arterial partial pressure of oxygen (PaO2) (96% and 74mm Hg, respectively) increased significantly relative to the seated position (84% and 50mm Hg, respectively). Contrast transthoracic echocardiography (TTE) showed a large patent foramen ovale (PFO) with right-to-left shunt. Transthoracic echocardiography showed rotation of the patient's heart, enabling direct alignment of the inferior vena cava with the PFO, creating a large anatomical right-to-left shunt in the seated position. Right heart catheterization confirmed a large PFO with normal right-sided heart pressures. He was treated with a septal occlusion and his SpO2 in the seated position improved immediately. The patient was discharged home without requiring supplemental oxygen. Platypnea orthodeoxia syndrome is a rare presentation of hypoxemia. Positional changes in oxygenation are the cardinal feature of POS. Discordance between lung imaging and the severity of hypoxemia should prompt investigation for an intracardiac shunt, which can occur in POS even in the absence of increased right-sided heart pressures. Either contrast TTE or transesophageal echocardiography is necessary to make this diagnosis.

Transcatheter closure of the Gerbode type ventricular septal defect after redo mitral valve replacement

Gerbode defect is an uncommon ventricular septal defect (VSD) resulting in a left ventricle to right atrium shunt. Although typically congenital, acquired defects have been reported following infective endocarditis, cardiac surgery, trauma, or acute myocardial infarction. This condition causes left-to-right intracardiac shunt and potential hemodynamic instability. This complex anatomy poses therapeutic challenges, and optimal management is often unclear. We present a case of acquired Gerbode defect following a redo mitral valve replacement surgery in a 71-year-old man who developed severe dyspnea and pulmonary hypertension. Treatment was successfully performed with percutaneous transcatheter VSD closure using an Amplatzer device. This case highlights the importance of considering Gerbode defects in postoperative patients and demonstrates the efficacy of transcatheter closure in reducing symptoms and avoiding high-risk redo cardiac surgery. Transcatheter repair offers shorter recovery times, reduces pain, and avoids repeat sternotomy, making it a valuable and minimally invasive alternative for patients with acquired Gerbode defects. Keywords: Gerbode defect, left ventricle to right atrium shunt, redo mitral valve replacement, transcatheter closure

Mitral valve infective endocarditis as a manifestation of disseminatedCryptococcus neoformans infection: a case report

Infective endocarditis is a disease that affects mainly the endocardial surface of the heart and cardiac valves (native or prosthetic). The main risk factors for developing infective endocarditis are male sex, older age, intracardiac shunts, prosthetic valves, rheumatic, and congenital heart disease, intracardiac devices, intravenous drugs use, immunosuppression, and hemodialysis. Streptococci and Staphylococci spp. have been the most frequent isolated organisms. On the other hand, the most common fungal organism in infective endocarditis is Candida albicans (24-46%), followed by Aspergillus spp. (25%), and a few cases by Cryptococcus neoformans, which are associated with higher rate of mortality. This case provides an interesting case of Cryptococcus neoformans native valve infective endocarditis in a young woman with stage IV chronic kidney disease and severe malnutrition.

Evaluation of mid-term outcomes of partial and intermediate atrioventricular canal defect surgery.

The risk factors for reoperation and mortality after partial and intermediate atrioventricular canal defect repair are unclear. This study assessed the mid-term outcomes and risk factors for reoperation and mortality after partial and intermediate atrioventricular canal defect surgery. Ninety-seven patients who underwent primary repair of intermediate (n = 45) or partial (n = 52) atrioventricular canal defect between 2005 and 2019 were included in this single-centre study. The median age was 5 years (2.7-8.9 years). The median follow-up time was 32 months (1.6-90.8 months). The estimated freedom from reoperation at 1, 5, and 10 years was 97%, 91%, and 73%, respectively.In multivariable analyses, post-operative left atrioventricular valve regurgitation of grade II or higher (odds ratio [OR]: 5.3, 95% confidence interval [CI]: 1.8-15.5, p = 0.01) and post-operative residual intracardiac shunt (OR: 11.6, 95% CI: 1.6-85.8, p = 0.02) were risk factors for reoperation.In multivariable analyses, perioperative reoperation (OR: 93.4, 95% CI: 3.9-218.7, p = 0.01) and the need for right atrioventricular valve repair (OR: 11.2, 95% CI: 1.0 - 123.3, p = 0.04) were risk factors for mortality. Mortality was higher in patients under 2.6 years of age. For patients undergoing repair of partial or intermediate atrioventricular canal defect, those with post-operative left atrioventricular valve regurgitation of grade II or higher and post-operative residual intracardiac shunt have an increased reoperation risk. Higher mortality can be expected after a perioperative reoperation, and in patients requiring right atrioventricular valve repair during the index procedure.

Unveiling a Rare Complication: Arterial Air Embolism during Hemodialysis without Intracardiac Shunt

Unveiling a Rare Complication: Arterial Air Embolism during Hemodialysis without Intracardiac Shunt

Omic-signature of bronchopulmonary dysplasia associated pulmonary hypertension in

PDA and ASD are common intracardiac shunts noted in prematurely born infants. While there is evidence of persistent PDA and ASD associated with a higher risk for developing bronchopulmonary dysplasia (ICS-BPD) and pulmonary hypertension (ICS-BPD-PH), the underlying pathogenesis is poorly understood and hence challenging to identify at-risk infants. Our study goal was to evaluate transcriptomic expression and associated pathways in tracheal aspirates (TAs) of low-birth-weight infants with hemodynamically significant cardiac shunt (ICS) that develop bronchopulmonary dysplasia (ICS-BPD) and pulmonary hypertension (ICS-BPD-PH). TAs were collected from preterm infants with ICS and a diagnosis of BPD or BPD-PH from a single center. 36 TA samples including 19 ICS-BPD and 17 ICS-BPD-PH were analyzed. MiRNA expression was determined via PCR arrays, and mRNA expression via RNA seq. Data were analyzed using limma. 11 miRNAs and 10 mRNAs were differentially expressed (adjusted p < 0.05) in ICS-BPD-PH group when compared to ICS-BPD. Ingenuity Pathway Analysis identified associations with cellular growth, proliferation, death, and cell function pathways. TAs from preterm infants show differentially expressed miRNAs and mRNAs in ICS-BPD-PH when compared to ICS-BPD, an in-silico model identified target molecules that could be playing a role in BPD-PH pathogenesis in low-birth-weight infants with ICS. Pulmonary hypertension associated with severe BPD (BPD-PH) is a distinct disease in preterm infants with severe BPD and the role of intracardiac shunt (ICS) in its development is controversial and often challenging for clinical management. Our pilot study, researching specific endotyping of infants with pulmonary hypertension associated with BPD using multiomics approach has identified molecular markers and potential underlying pathways associated with this condition. These markers could aid in stratifying high risk infants with ICS that are at risk for developing BPD-PH and aid clinical management.

Thrombus entrapped in patent foramen ovale and its unique treatment with low molecular weighted heparin

Patent foramen ovale (PFO) is a congenital heart defect that affects %25-30 population. PFO can be cathegorized as most common site for intra-cardiac shunting. But thrombus in PFO is extremely rare. There is no consensus of treatment of this situation. We present a case of thrombus in PFO which is standing in both sides of interatrial septum and unique treatment of this thrombus with low molecular weighted heparin.

Aorto-pulmonary artery fistula with Laubry-Pezzi syndrome: A diagnostic enigma

Usually diagnosed post-mortem, aortopulmonary artery fistula is an exceptionally rare and often highly lethal condition. Here, we present a unique case of a 29-year-old woman with no history of aortic aneurysm or previous aortic surgery, referred for surgical management of Laubry-Pezzi syndrome in whom an aorto-pulmonary artery fistula bridging the ascending aorta and the main pulmonary artery was discovered intra operatively. The patient was successfully managed with an uneventful postoperative recovery. Our case outlines the inaugural reported occurrence of an aortopulmonary artery fistula coinciding with Laubry-Pezzi syndrome. Unique features include subtle onset of heart failure over months due to occult left ventricular volume overload, challenging diagnosis alongside known intracardiac shunts, emphasizing the need for vigilance, and demonstration of successful surgical outcomes despite high morbidity and mortality.

Differential Stroke Volume between Left and Right Ventricles as a Predictor of Clinical Outcomes: The MESA Study.

Background Valvular heart disease and intracardiac shunts can disrupt the balance between left ventricular (LV) and right ventricular (RV) stroke volumes. However, the prognostic value of such imbalances has not been established among asymptomatic individuals. Purpose To assess the association between differential ventricular stroke volumes quantified using cardiac MRI and clinical outcomes in individuals without cardiovascular disease. Materials and Methods This secondary analysis of a prospective study included participants without cardiovascular disease at enrollment (July 2000 to July 2002) who underwent cardiac MRI. Differences in stroke volume were calculated as LV stroke volume minus RV stroke volume, and participants were categorized as having balanced (greater than or equal to -30 mL to ≤30 mL), negative (less than -30 mL), or positive (>30 mL) differential stroke volumes. Multivariable Cox proportional hazard regression models were used to test the association between differences in stroke volume and adverse outcomes. Results A cohort of 4058 participants (mean age, 61.4 years ± 10 [SD]; 2120 female) were included and followed up for a median of 18.4 years (IQR, 18.3-18.5 years). During follow-up, 1006 participants died, 235 participants developed heart failure, and 764 participants developed atrial fibrillation. Compared with participants who had a balanced differential stroke volume, those with an increased differential stroke volume showed a higher risk of mortality (hazard ratio [HR], 1.73 [95% CI: 1.12, 2.67]; P = .01), heart failure (HR, 2.40 [95% CI: 1.11, 5.20]; P = .03), and atrial fibrillation (HR, 1.89 [95% CI: 1.16, 3.08]; P = .01) in adjusted models. Participants in the negative group, with a decreased differential stroke volume, showed an increased risk of heart failure compared with those in the balanced group (HR, 2.09 [95% CI: 1.09, 3.99]; P = .03); however, this was no longer observed after adjusting for baseline LV function (P = .34). Conclusion Participants without cardiovascular disease at the time of study enrollment who had an LV stroke volume exceeding the RV stroke volume by greater than 30 mL had an increased risk of mortality, heart failure, and atrial fibrillation compared with those with balanced stroke volumes. ClinicalTrials.gov Identifier: NCT00005487 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Almeida in this issue.

Cardiac Development and Related Clinical Considerations

The anatomy, physiology, and hemodynamics of the premature heart vary along the range of gestational ages cared for in neonatal intensive care units, from 22 weeks to term gestation. Clinical management of the preterm neonate should account for this heterogenous development. This requires an understanding of the impact of ex utero stressors on immature and disorganized cardiac tissue, the different state of hemodynamics across intracardiac shunts impacting the natural transition from fetal to neonatal life, and the effects of intensive pharmacologic and non-pharmacologic interventions that have systemic consequences influencing cardiac function. This article provides a review of the increasing but still limited body of literature on the anatomy, hemodynamics, and electrophysiology of the preterm heart with relevant clinical considerations.

Follow-Up of Secundum ASD, Muscular VSD, or PDA Diagnosed During Neonatal Hospitalization.

The ideal follow-up of neonates who have a secundum atrial septal defect (ASD), muscular ventricular septal defect (VSD), or patent ductus arteriosus (PDA) remains uncertain. Newborns with findings limited to a secundum ASD, muscular VSD, and/or PDA on their neonatal hospitalization discharge echocardiogram and at least one outpatient follow-up echocardiogram performed between 9-1-17 and 9-1-21 were evaluated and patient follow-up assessed through 9-1-23. 95 infants met inclusion criteria. 43 infants had a secundum ASD, 41 had a muscular VSD, and 54 had a PDA at newborn hospital discharge. 39/95 had more than one intracardiac shunt. 56 were discharged from care, 26 were still in follow-up and 13 were lost to recommended follow-up. No patients received intervention during the follow-up period of 2 to 6years. Of the 43 infants with a secundum ASD, 16 (37.2%) had demonstrated closure of the ASD, and 13 (30.2%) were discharged from care with an ASD < 3.5mm in diameter. 3/43 infants with secundum ASD had a defect with a diameter of more than 5mm at their last echocardiogram. No infant discharged from their neonatal hospitalization with a secundum ASD, muscular VSD, or PDA needed any intervention from 2 to 6years of follow-up. Ongoing follow-up with echocardiography of those infants with a secundum ASD is of greater value than of those with muscular VSD or PDA.

Elevated pulmonary capillary wedge pressure, higher blood pressure, and lower cardiac index in infants with bronchopulmonary dysplasia

BackgroundLeft ventricular diastolic dysfunction indicated by elevated pulmonary capillary wedge pressure (ePCWP) may worsen cardiorespiratory status in bronchopulmonary dysplasia (BPD), but the scope of ePCWP by cardiac catheterization is not well described. MethodsThis single-center retrospective cohort study included infants with BPD without congenital heart disease, significant intracardiac shunts, or pulmonary vein stenosis who underwent cardiac catheterization from 2010 to 2021. ePCWP was defined as >10 mmHg. Quantitative measures of ventricular systolic and diastolic function were performed on existing echocardiograms. Patients with and without ePCWP were compared using the Chi-squared or Wilcoxon rank-sum tests. Associations between catheterization hemodynamics and echocardiographic parameters were assessed by simple linear regression. ResultsSeventy-one infants (93% Grade 2 or 3 BPD) met inclusion criteria, and 30 (42%) had ePCWP. Patients with ePCWP were older at catheterization (6.7 vs. 4.5 months, p < 0.001), more commonly underwent tracheostomy (66.7% vs. 29.3%, p = 0.003), and had higher mean systemic blood pressure [64.5 (56.0, 75.0) vs. 47.0 (43.0, 55.0) mm Hg, p < 0.001], higher systemic vascular resistance [11.9 (10.4, 15.6) vs. 8.7 (6.7, 11.2) WU*m2, p < 0.001), and lower cardiac index [3.9 (3.8, 4.9) vs. 4.7 (4.0, 6.3) L/min/m2, p = 0.03] at catheterization. Mean pulmonary artery pressure, pulmonary vascular resistance, and mortality were similar between the groups. Echocardiographic indices of left ventricular diastolic dysfunction did not correlate with PCWP. ConclusionsePCWP was common in infants with severe BPD who underwent cardiac catheterization in this cohort. The association between ePCWP and higher systemic blood pressure supports further study of afterload reduction in this population.

Transcatheter balloon angioplasty of internal pulmonary artery bands to improve pulmonary blood flow: a case series.

Pulmonary artery banding (PAB) is used to restrict pulmonary blood flow in select patients with large left-to-right intracardiac shunts or unrestrictive pulmonary blood flow prior to eventual surgical repair or palliation. More recently, surgical placement of an internal or intraluminal PAB (IPAB) has been used to restrict pulmonary circulation. Here we present two patients who underwent balloon angioplasty of the IPAB to treat cyanosis and improve pulmonary blood flow.

Comparison of post-operative transesophageal and transthoracic echocardiogram findings following atrioventricular septal defect repair.

Success of atrioventricular septal defect repair is defined by post-operative atrioventricular valve function and presence of residual intracardiac shunting. We evaluated differences in interpretation of atrioventricular valve function and residual defects between transesophageal and transthoracic echocardiography in a contemporary cohort of infants undergoing atrioventricular septal defect repair. Among 106 patients, we identified an increase in left and right atrioventricular valve regurgitation, right atrioventricular valve inflow gradient, and increased detection rate of residual intracardiac shunting on transthoracic compared to transesophageal echocardiograms, although residual shunts identified only on transthoracic echocardiogram were not haemodynamically significant. Findings may help inform expectation of post-operative transthoracic echocardiogram findings based on intraoperative assessment.

Improvement in Echocardiographic and Diagnostic Biomarkers after Systemic Glucocorticoid Therapy in Infants with Pulmonary Hypertension

To assess the effect of treating pulmonary hypertension (PH) in infants less than 1 year of age with systemic glucocorticoids while using echocardiographic and diagnostic biomarkers as measures of efficacy. A retrospective chart review was performed on 17 hospitalized infants less than one year of age at St. Louis Children's Hospital who received a five- to seven-day course of systemic glucocorticoid treatment followed by a three-week taper with no significant intracardiac shunts from January 1, 2017, to December 31, 2021. Quantitative echocardiographic indices for PH, N-terminal pro b-type natriuretic peptide (NT-proBNP) and/or b-type natriuretic peptide (BNP) levels were collected pre-glucocorticoid treatment, after the glucocorticoid burst, and following the 21-day taper. Mean (+/- SD) gestational age was 32.1 (+/-5.8) weeks, 5 infants were (29%) concomitantly treated with sildenafil, and 8 were male. Twelve were classified as World Health Organization (WHO) group 3 PH (71%), and 5 WHO group 1 PH. There were significant improvements 30 days post-glucocorticoid initiation in BNP levels (p=0.008), partial pressure of carbon dioxide (p=0.03), eccentricity index (p=0.005), RV ejection time (p=0.04), pulmonary artery acceleration time (PAAT) (p=0.002), and PAAT to right ventricular ejection time ratio (PAAT/RVET) (p=0.02). Tricuspid regurgitation velocity was not able to be assessed. There were no mortalities during the study timeline. In our retrospective study, systemic glucocorticoid therapy was well tolerated and appeared to be associated with significant improvement in cardio-pulmonary function in infants with PH. Further prospective study in a larger sample is warranted.

In situ ascending aortic thrombus in a patient with metastatic lung adenocarcinoma and no aortic atherosclerosis or cisplatin exposure: a case report

BackgroundAn ascending aortic thrombus is exceedingly rare. Two instances have been reported in the setting of lung cancer, but only after cisplatin use, which is associated with hypercoagulability. We present the first case of a patient with lung cancer who developed an ascending aortic thrombus without structural risk factors or chemotherapy use.CaseA 60-year-old white female with significant smoking history presented with several weeks of malaise. A chest computed tomography scan revealed a 2.2-cm right upper lobe mass. As an outpatient, right hilar lymph node immunohistochemistry (IHC) samples via endobronchial ultrasound confirmed thyroid transcription factor-1 adenocarcinoma. After the procedure, the patient endorsed dyspnea and was advised to go to the emergency department. A chest computed tomography angiography identified a new 2.4 × 1.1 × 1.1 cm thrombus within the proximal aortic arch. No pulmonary emboli or intrapulmonary shunts were identified. A hypercoagulable workup was negative. Transthoracic echocardiogram was without left ventricular thrombus, akinesis or hypokinesis, left atrial dilation, or intracardiac shunts. A lower extremity ultrasound was negative for deep vein thrombosis. Given the procedural risk, thrombectomy was deferred. The patient was transitioned to enoxaparin, and a repeat computed tomography for resolution is in process.ConclusionTo our knowledge, this is the only case detailing an in situ ascending aortic thrombus in the setting of lung cancer, without structural risk factors, chemotherapy use, or other hypercoagulable comorbidities. Optimal management for an aortic thrombus and malignant disease is less clear. Clinicians should be vigilant for unusual arterial thromboses in patients with high metastatic burden.

Cyanotic Severe Pulmonary Stenosis with an Intracardiac Shunt: A Case Report and Literature Review

Pulmonary stenosis is a congenital defect, with isolated severe cases rarely associated with cyanosis. We report a 10-year-old girl diagnosed with severe pulmonary stenosis (peak gradient 111 mmHg), presented with worsening cyanosis, chest discomfort, and exercise intolerance. We were perplexed by the presence of cyanosis in her current condition. The answer emerged during a right heart catheterization, revealing a previously undetected patent foramen ovale with eluded identification through a non-invasive trans-thoracic echocardiography.

Delayed Diagnosis of Right Heart Failure Due to Sinus Venosus Atrial Septal Defect, Persistent Left Superior Vena Cava and Partial Anomalous Pulmonary Venous Return

Sinus venosus atrial septal defects (SVASD) are uncommon and often underdiagnosed as they are visualised poorly on transthoracic echocardiography (TTE). A 59-year-old man was referred following worsening dyspnoea. A TTE demonstrated dilated right chambers, with torrential tricuspid regurgitation and a dilated coronary sinus. Agitated saline test raised the suspicion of both persistent left superior vena cava (PLSVC) and an intracardiac shunt, despite interrogation of the interatrial septum not demonstrating any defects. CT imaging of the thorax was performed revealing a superior SVASD alongside a PLSVC, and partial anomalous pulmonary venous return. SVASD are considerably uncommon, compared to other types of atrial septal defects (ASD). TTE has poor sensitivity in diagnosing SVASD, highlighting the importance of multimodality imaging in such cases. The purpose of this case report is to highlight unique features demonstrated on TTE, especially during the agitated saline study, which showcased the presence of a PLSVC alongside an intracardiac shunt that was undetected through conventional TTE alone.