The Sinus Venosus Veno-Venous Bridge: Not a septal defect

This review provides an update on the morphology of the sinus venosus defect. It was earlier believed that a 'common wall' separated the right pulmonary veins from the superior caval vein. In the sinus venosus defects, this wall was absent. Current evidence shows that the superior rim of the oval fossa, rather than forming a second septum or representing a common wall, is an infolding between the walls of the caval veins and the right pulmonary veins. The sinus venosus defect is caused by the anomalous connection of one or more pulmonary veins to a systemic vein. However, the pulmonary vein(s) retain their left atrial connections, leading to a veno-venous bridge that allows interatrial shunting outside the oval fossa. True atrial septal defects are located within the oval fossa or in the anteo-inferior buttress, while sinus venosus defects, ostium defects and coronary sinus defects are morphologically distinct from them.

The correlation between epicardial fat thickness and longitudinal left atrial reservoir strain in patients with type 2 diabetes mellitus and controls

BACKGROUND

Diabetes mellitus (DM) has been documented among the strongest risk factors for developing heart failure with preserved ejection fraction (HFpEF). The earliest imaging changes in patients with DM are the left atrial (LA) functional and volumetric changes. The aim of this study was to determine the correlation between epicardial fat thickness (EFT) and longitudinal LA reservoir strain (LARS) in patients with type 2 DM (T2DM), as compared with non-diabetic controls.

RESULTS

The study samples in this case-control study comprised of consecutive patients with T2DM (n=64) and matched non-diabetic controls (n=30). An echocardiography was performed on all patients and EFT, volumetric and longitudinal LARS, left ventricular (LV) global longitudinal strain (LVGLS), pulsed-wave Doppler-derived transmitral early (E wave) and late (A wave) diastolic velocities, and tissue-Doppler-derived mitral annular early diastolic (e') and peak systolic (s') velocities were obtained. The study results demonstrated that the patients with T2DM had thicker EFT (5.96±2.13 vs. 4.10±3.11 mm) and increased LA volume index (LAVI) (43.05± 44.40 vs. 29.10±11.34 ml/m2) in comparison with the non-diabetic ones (p-value: 0.005 and 0.022, respectively). On the other hand, a direct association was observed between EFT and the E/e' ratio, and an inverse correlation was established between EFT and LARS in patients with T2DM (r=0.299, p-value=0.020 and r=- 0.256, p-value=0.043, respectively). However, regression analysis showed only LV mass index (LVMI) (β=0.012, 95% CI 0.006-0.019, p-value<0.001), LAVI (β=- 0.034, 95% CI - 0.05-0.017, p-value<0.001), and EFT (β=- 0.143, 95% CI - 0.264-- 0.021, p-value=0.021) were independently correlated with LARS.

CONCLUSIONS

LARS is considered as an important early marker of subclinical cardiac dysfunction. Thickened epicardial fat may be an independent risk factor for decreased LA reservoir strain. Diabetics are especially considered as a high risk group due to having an increased epicardial adipose tissue thickness.

Spontaneously disappearing right atrial mass in a preterm infant: a case report

Background

There is currently a lack of evidence-based guidelines regarding ideal management of a neonate, specifically a preterm, with thrombo-embolus. There are no clear guidelines as to the time-frame of spontaneous resolution of a thrombo-embolus.

Case summary

A large pedunculated right atrial mass was identified on a clinician-performed cardiac ultrasound in a preterm neonate. The mass was smaller than half of the atrial size and was not causing obstruction. The mass disappeared spontaneously within 6 days and was retrospectively presumed to have been a thrombus. The neonate remained asymptomatic with no signs suggesting that the mass may have embolized.

Discussion

In this case of an incidentally identified asymptomatic intracardiac mass in a preterm infant, presumed to be a thrombus, our conservative 'wait and watch' approach was not associated with any adverse pulmonary or systemic effects.

An Unusual Presentation of Right Atrial Myxoma: A Case Report

A right atrial myxoma extending to the inferior vena cava with associated right-to-left shunting leading to systemic desaturation is an exceedingly rare clinical entity. The number of cases reported in the literature to date is not more than five. This case study presents a 45-year-old female who was referred to our center with symptoms of breathlessness, easy fatigability, generalized weakness, and central cyanosis. On routine blood investigation, polycythemia was detected. On preoperative 2D-transthoracic echocardiography, the diagnosis of right atrial mass was confirmed but the reason for cyanosis was not revealed. A tumor thrombus in a branch of the right lower pulmonary artery with a small locoregional pulmonary infarct along with right atrial myxoma was reported in computed tomography angiography of the heart and great vessels. On-table transesophageal echocardiography showed patent foramen ovale (PFO) with right-to-left shunting because of raised right atrial pressure and dynamic obstruction of the tricuspid valve by the mass. The myxoma was resected completely via right atrial approach along with primary closure of PFO. Postoperative period was uneventful, and the patient was discharged on day seven. At three-month follow-up, the patient was doing well.

Novel Cause of Late Atrial Septal Defect Devices Embolization

Transcatheter closure of septal defects using specialized devices is a common procedure that has a high success rate. Embolization of Atrial septal defect devices is a known complication seen at a rate of 0.5%. We report a case of late ASD device occluder embolization immediately after brain MRI with clinical consequences and intraoperative evidence of right atrial wall thermal injury. To our knowledge Atrial septal occluder (ASO) device embolization post magnetic resonance imaging (MRI) was not reported before, although theoretically possible and that's why six to eight weeks post device implantation MRI is prohibited even with current MRI compatible devices.

Developing a random forest algorithm to identify patent foramen ovale and atrial septal defects in Ontario administrative databases

Purpose

Routinely collected administrative data is widely used for population-based research. However, although clinically very different, atrial septal defects (ASD) and patent foramen ovale (PFO) share a single diagnostic code (ICD-9: 745.5, ICD-10: Q21.1). Using machine-learning based approaches, we developed and validated an algorithm to differentiate between PFO and ASD patient populations within healthcare administrative data.

Methods

Using data housed at ICES, we identified patients who underwent transcatheter closure in Ontario between October 2002 and December 2017 using a Canadian Classification of Interventions code (1HN80GPFL, N = 4680). A novel random forest model was developed using demographic and clinical information to differentiate those who underwent transcatheter closure for PFO or ASD. Those patients who had undergone transcatheter closure and had records in the CorHealth Ontario cardiac procedure registry (N = 1482) were used as the reference standard. Several algorithms were tested and evaluated for accuracy, sensitivity, and specificity. Variable importance was examined via mean decrease in Gini index.

Results

We tested 7 models in total. The final model included 24 variables, including demographic, comorbidity, and procedural information. After hyperparameter tuning, the final model achieved 0.76 accuracy, 0.76 sensitivity, and 0.75 specificity. Patient age group had the greatest influence on node impurity, and thus ranked highest in variable importance.

Conclusions

Our random forest classification method achieved reasonable accuracy in identifying PFO and ASD closure in administrative data. The algorithm can now be applied to evaluate long term PFO and ASD closure outcomes in Ontario, pending future external validation studies to further test the algorithm.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-022-01837-2.

Actual management costs of patients with non-valvular atrial fibrillation treated with percutaneous left atrial appendage closure or oral anticoagulation

AIMS

Comparing actual management costs in patients with non-valvular atrial fibrillation (AF) treated with percutaneous left atrial appendage closure (LAAC) or OAC only.

METHODS AND RESULTS

Patients undergoing percutaneous LAAC and AF patients treated with OAC only were matched for gender, age, and diagnosis related groups (DRG) clinical complexity level (CCL). Costs for cardiovascular outpatient clinic visits and hospitalizations were derived from the actual reimbursement records. Between 1/2012 and 12/2016, 8478 patients were referred: 7801 (92%) managed with OAC and 677 (8%) with percutaneous LAAC. Matching resulted in 558 patients (279 per group) for final analysis. Age was 74.9 ± 7.5 years, 244 were female (43.7%), and DRG CCL was 1.8 ± 1.1. Annualized management cost before percutaneous LAAC was € 3110 (IQR: € 1281-8127). After 4.5 ± 1.4 years follow-up, annualized management cost was € 1297 (IQR: € 607-2735) in OAC patients and € 1013 (IQR: € 0-4770) in patients after percutaneous LAAC (p = 0.003). Percutaneous LAAC was the strongest independent determinant to reduce follow-up costs (B = -0.8; CI: -1.09 ̶̶̶̶̶ -0.6; p < 0.0001). Estimated 3-year survival was 92% in percutaneous LAAC and 90% in OAC patients (p = 0.7).

CONCLUSION

Percutaneous LAAC significantly reduces management costs. Management costs are significantly higher for patients treated with only OAC compared to patients after percutaneous LAAC. In spite of their complex comorbid profile, percutaneous LAAC patients show a follow-up survival rate similar to patients solely treated with OAC. Future studies are necessary to investigate the potential net economic and clinical benefit of percutaneous LAAC in patients treated with OAC only.

Left atrial appendage closure with the watchman device reduces atrial fibrillation management costs

AIMS

To report hospitalization costs of patients with non-valvular atrial fibrillation (AF) submitted to percutaneous left atrial appendage closure (LAAC) with the Watchman device.

METHODS

Pre- and post-procedural hospitalization AF-related costs were calculated using the DRG system (diagnosis-related groups) and compared.

RESULTS

Between 2012 and 2016, 677 non-valvular AF patients underwent LAAC. Median time from first cardiac hospitalization to LAAC was 5.9 years (IQR 1.6-9.1) and median follow-up after LAAC was 4.8 years (IQR 3.6-5.6). LAAC mortality was 1.3% and follow-up mortality 16.9%. Median pre-LAAC hospitalization cost was € 17,867 (IQR € 7512-35,08) and post-LAAC € 8772 (IQR € 1183-25,159) (p < 0.0001). Annualized cost pre-LAAC was 3773 € (IQR € 1644-8,493) and post-LAAC 2,001 € (IQR € 260-6913) (p < 0.0001). Follow-up survivors had significantly lower post-LAAC costs (p < 0.0001) and after a survival cut-off time of 4.6 years LAAC procedural and post-procedural hospitalization costs achieved parity with pre-LACC costs (AUC 0.64; p = 0.02). CHA2DS2-VASc score (B = 0.04; p = 0.02; 95% CI 0.006-0.08), and HAS-BLED score (B = 0.08; p = 0.004; 95% CI 0.02-0.14) were independent determinants for annualized hospitalization costs post-LAAC. At Cox-regression analysis the DRG mean clinical complexity level (CCL) was the only independent determinant for follow-up mortality (OR = 2.2; p < 0.0001; 95% CI 1.6-2.8) with a cut-off value of 2.25 to predict follow-up mortality (AUC 0.72; p < 0.0001; Spec. 70%; Sens. 70%).

CONCLUSION

Hospitalization costs pre-LAAC are consistent, and after LAAC, they are significantly reduced. Costs seem related to the patient's risk profile at the time of the procedure. With the increase in post-LAAC survival time, the procedure becomes economically more profitable.

Effects of genetic background, sex, and age on murine atrial electrophysiology

AIMS

Genetically altered mice are powerful models to investigate mechanisms of atrial arrhythmias, but normal ranges for murine atrial electrophysiology have not been robustly characterized.

METHODS AND RESULTS

We analyzed results from 221 electrophysiological (EP) studies in isolated, Langendorff-perfused hearts of wildtype mice (114 female, 107 male) from 2.5 to 17.7 months (mean 7 months) with different genetic backgrounds (C57BL/6, FVB/N, MF1, 129/Sv, Swiss agouti). Left atrial monophasic action potential duration (LA-APD), interatrial activation time (IA-AT), and atrial effective refractory period (ERP) were summarized at different pacing cycle lengths (PCLs). Factors influencing atrial electrophysiology including genetic background, sex, and age were determined. LA-APD70 was 18 ± 0.5 ms, atrial ERP was 27 ± 0.8 ms, and IA-AT was 17 ± 0.5 ms at 100 ms PCL. LA-APD was longer with longer PCL (+17% from 80 to 120 ms PCL for APD70), while IA-AT decreased (-7% from 80 to 120 ms PCL). Female sex was associated with longer ERP (+14% vs. males). Genetic background influenced atrial electrophysiology: LA-APD70 (-20% vs. average) and atrial ERP (-25% vs. average) were shorter in Swiss agouti background compared to others. LA-APD70 (+25% vs. average) and IA-AT (+44% vs. average) were longer in 129/Sv mice. Atrial ERP was longer in FVB/N (+34% vs. average) and in younger experimental groups below 6 months of age.

CONCLUSION

This work defines normal ranges for murine atrial EP parameters. Genetic background has a profound effect on these parameters, at least of the magnitude as those of sex and age. These results can inform the experimental design and interpretation of murine atrial electrophysiology.

Atrial Septal Aneurysm and Atrial Septal Defect Association - an Uncommon But Well- Recognized Association

Atrial septal aneurysm (ASA) is an uncommon but wellrecognized cardiac abnormality. This educational text reviews the case of a 54-year-old female presenting an ASA related to a small ostium secundum atrial septal defect. The considerable signs and symptoms, interestingly, have not been justified by the clinical and hemodynamic investigations. So, we opted for a better imaging investigation with cardiac catheterization and transesophageal echocardiography. The surgical process was earlier indicated and performed with aid of cardiopulmonary bypass.

Long-term evaluation of sensing variability of a floating atrial dipole in a single‑lead defibrillator: The mechanistic basis of long-term stability of amplified atrial electrogram

BACKGROUND

A single‑lead implantable cardioverter-defibrillator (ICD) with a floating atrial dipole has been developed to enhance the diagnostic capability of atrial arrhythmias and to facilitate adjudication of arrhythmic events without the additional effort required for atrial lead insertion. However, there have been concerns about the long-term reliability of atrial sensing.

METHODS

We enrolled patients with the single-chamber ICD with atrial-sensing electrodes from 4 tertiary university hospitals in Korea. Minimal, maximal, and mean P wave amplitudes were collected at 3-6 months, 6-12 months, and 12-24 months after implantation. The difference between the minimal and maximal sensing amplitudes was calculated as an indicator of the variability of atrial sensing, while the atrial sensing stability was assessed using the mean amplitude.

RESULTS

A total of 86 patients were included for analysis. The variability of atrial sensing amplitudes significantly decreased at 12-24 months compared to 3-6 months (p = 0.01), while mean atrial amplitudes were stable throughout the mean follow-up duration of 17.4 months. Nine patients (10.5%) experienced inappropriate ICD therapy mostly due to misclassification of supraventricular tachycardia.

CONCLUSIONS

Under the hypothesis that sensing stability can be guaranteed as the variability decreases with time, we suggest that the concern about long-term sensing stability of a floating dipole can be abated with an ICD that has been implanted for over 2 years.

Exercise blood pressure and cardiac structure: A systematic review and meta-analysis of cross-sectional studies

OBJECTIVES

A hypertensive response to exercise (HRE) is associated with cardiovascular disease and high blood pressure (BP). Sub-clinical changes to cardiac structure may underlie these associations, although this has not been systematically determined. Via systematic review and meta-analysis, we aimed to (1) assess the relationship between exercise BP and cardiac structure, and (2) determine if cardiac structure is altered in those with an HRE, across various study populations (including those with/without high BP at rest).

DESIGN AND METHODS

Three online databases were searched for cross-sectional studies reporting exercise BP, HRE and cardiac structural variables. Random-effects meta-analyses and meta-regressions were used to calculate pooled correlations between exercise BP and cardiac structure, and pooled mean differences and relative risk between those with/without an HRE.

RESULTS

Forty-nine studies, (n=23,707 total; aged 44±4 years; 63% male) were included. Exercise systolic BP was associated with increased left ventricular (LV) mass, LV mass index, relative wall thickness, posterior wall thickness and interventricular septal thickness (p<0.05 all). Those with an HRE had higher risk of LV hypertrophy (relative risk: 2.6 [1.85-3.70]), increased LV mass (47±7g), LV mass index (7±2g/m²), relative wall thickness (0.02±0.005), posterior wall thickness (0.78±0.20mm), interventricular septal thickness (0.78±0.17mm) and left atrial diameter (2±0.52mm) vs. those without an HRE (p<0.05 all). Results were broadly similar between studies with different population characteristics.

CONCLUSIONS

Exercise systolic BP is associated with cardiac structure, and those with an HRE show evidence towards adverse remodelling. Results were similar across different study populations, highlighting the hypertension-related cardiovascular risk associated with an HRE.

Exercise Program Improves Functional Capacity and Quality of Life in Uncorrected Atrial Septal Defect-Associated Pulmonary Arterial Hypertension: A Randomized-Control Pilot Study

OBJECTIVE

To assess the effect of combined hospital and home-based exercise programs on functional capacity and quality of life (QoL) among uncorrected atrial septal defect-associated pulmonary arterial hypertension (ASD-PAH) patients.

METHODS

This study was a randomized controlled trial with uncorrected ASD-PAH patients as the subjects. They were allocated randomly into control and exercise groups. Exercise group subjects performed hospital and home-based exercise programs, completing baseline 6-minute walking test (6MWT) and EQ-5D-3L QoL test (Utility Index and EQ-VAS scores), and were followed up for 12 weeks. The primary outcomes were 6MWT distance and EQ-5D-3L score at week 12. The N-terminal pro B-type natriuretic peptide (NT-proBNP) level was also assessed. A repeated-measure ANOVA was performed to detect endpoint differences over time.

RESULTS

The exercise group contained 20 subjects and control group contained 19. In total, 19 exercise group subjects and 16 control group subjects completed the protocol. The 6MWT distance, Utility Index score, and EQ-VAS score incrementally improved significantly in the exercise group from baseline until week 12, with mean differences of 76.7 m (p<0.001), 0.137 (p<0.001) and 15.5 (p<0.001), respectively. Compared with the control group, the exercise group had significantly increased 6MWT distance and utility index score at week 12. The EQ-VAS score increased in the exercise group at week 12. The NT-proBNP level decreased at week 12 in the exercise group.

CONCLUSION

Combined hospital and home-based exercise program added to PAH-targeted therapy, improving functional capacity and QoL in uncorrected ASD-PAH patients.

Cardiac effect induced by Crotalus durissus cascavella venom: Morphofunctional evidence and mechanism of action

Envenoming, resulting from snake bites, is a global public health problem. The present study was undertaken to investigate the influence of Crotalus durissus cascavella (Cdcas) venom on cardiac activity and the mechanisms of action underlying its effect. To investigate the inotropic and chronotropic effects induced by Cdcas, studies were performed on the left and right atria. A series of tests were conducted to investigate whether the negative inotropic effect, induced by Cdcas, was related to cardiac damage. Cdcas venom (0.1-30 μg/mL) elicited a significant negative inotropic effect. The addition of Cdcas crude venom (7.5, 15 and 30 μg/mL) did not induce significant alterations in cell proliferation, nor in the enzymatic activity of total-CK and CKMB. Ultrastructural evaluation demonstrated that cardiac cells from isoproterenol and Cdcas groups revealed discreet swelling and displaced intermyofibrillar mitochondria with disorganization of the cristae. No change was observed in cardiac electrical activity in perfused isolated rat hearts with Cdcas. In addition, Cdcas reduced contractility in isolated cardiomyocytes from the rat left ventricle. The negative inotropic effect of Cdcas was reduced by l-NAME (100 μM), PTIO (100 μM), ODQ (10 μM) and KT5823 (1 μM), suggesting the participation of NO/cGMP/PKG pathway due to Cdcas. In non-anesthetized rats, Cdcas induced hypotension followed by bradycardia, the latter was also observed by ECG (anesthetized animals). Our results suggest that the negative inotropic effect induced by Cdcas venom is unrelated to cardiac toxicity, at least, at the concentrations tested; and occurs through of NO/cGMP/PKG pathway, likely leading to hypotension and bradycardia when administered in vivo.

Atrial tachyarrhythmias and heart failure events in patients with arrhythmogenic right ventricular cardiomyopathy

Background

Atrial tachyarrhythmias (ATAs) are associated with an increased risk of incident heart failure (HF). The aim of this study was to evaluate the incidence of ATAs and time of ATA development during disease progression as well as the influence of ATAs on HF-related events in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).

Methods

We retrospectively studied 90 ARVC patients who met the definitive diagnosis of the 2010 Task Force Criteria and were diagnosed with ARVC at our institutions between 1974 and 2012. The main outcomes were death due to HF and hospitalization due to worsening HF.

Results

Eleven patients had a history of ATAs at the time of ARVC diagnosis. Of 79 patients without a prediagnosis history of ATAs, 21 (27%) newly experienced ATAs during a median follow-up period of 11.4 (range, 0.1–29.6) years. Among them, 15 patients experienced their first hospitalization due to worsening HF a median of 1.7 (range, 0.0–9.8) years after the occurrence of ATAs. Patients with ATAs were more likely to experience death due to HF and hospitalization due to worsening HF than patients without ATAs (odds ratio 19.2, 95% confidence interval 2.0–92.3, P < 0.01 and odds ratio 29.7, 95% confidence interval 8.4–104.8, P < 0.01, respectively). Multivariable analysis revealed that ATAs were associated with an increased risk of hospitalization due to worsening HF (hazard ratio 15.55, 95% confidence interval 4.82–50.17, P < 0.01).

Conclusions

Our study suggests that the occurrence of ATAs is associated with an increased risk of HF-related events and worsens the prognosis of ARVC patients.

Routine Transesophageal Echocardiography in Atrial Fibrillation Before Electrical Cardioversion to Detect Left Atrial Thrombosis and Echocontrast

BACKGROUND

Transesophageal echocardiography (TEE) before electrical cardioversion (ECV) in atrial fibrillation (AF) is not routinely performed in anticoagulated patients.

METHODS

Starting from TEE findings of anticoagulated and non-anticoagulated patients referred for ECV, we investigated the rate of spontaneous echo-contrast (SEC) and left atrial thrombus (LAT) and identified their independent predictors.

RESULTS

A total of 403 patients were included: 262 (65%) had no anticoagulation, 47 (11.7%) were onnovel oral anticoagulant (rivaroxaban), 74 (18.4%) on warfarin INR>2, and 20 (5.0%) on warfarin INR<2.In 41 (10.1%) there was LAT and in 154 (38.2%) SEC. Patients with LAT had a significantly lower left ventricular ejection fraction (LVEF%) (p=0.001). Patients with SEC were significantly older (p=0.04), had lower LVEF% (p<0.0001),higher CHADSVASC score (p<0.0001), and higher rate of coronary artery disease (CAD) (p=0.03). In 56.8% of warfarin patients (INR>2) there was SEC (p=0.002). At multivariate analysis therapeutic anticoagulation with warfarin (p=0.003; OR:2.2; CI: 1.3-3.7),CHADSVASC score (p<0.0001; OR=1.2; CI: 1.1-1.4), and LVEF% (p<0.0001; OR:0.95; CI: 0.93-0.97; inverse relationship) were SEC predictors. A 3.5 CHADSVASC score cut-off was predictor of SEC (AUC: 0.7; p<0.0001). LVEF% was the only predictor of LAT (p=0.02; OR=0.96; CI: 0.93-0.99; inverse relationship).

CONCLUSIONS

Echocardiography before ECV identifies clear LAT/SEC in more than a third of AF patients, independently by their anticoagulation regimen. LAT/SEC rates increasewith decrement of LVEF%. Increment of CHADSVASC score increases SEC risk. In anticoagulated patients SEC rate remains higher than expected. Therapeutic anticoagulation with Warfarin appears positively and independently correlated to SEC occurrence.

Comparison of Postoperative Changes in Inflammatory Marker Levels Between Transthoracic and Transcatheter Device Closures of Atrial Septal Defects in Children

Objective

To explore the postoperative changes in inflammatory markers in children who underwent device closure of an atrial septal defect (ASD) via a transthoracic or transcatheter approach.

Methods

The experimental and clinical data were retrospectively collected and analyzed for a total of 53 pediatric patients between September 2018 and December 2018. According to the different treatments, 19 patients who underwent transthoracic device closure were assigned to group A, and the remaining 34 patients who underwent a transcatheter approach were assigned to group B.

Results

All patients were successfully occluded without any device-related severe complication. Compared with the preoperative levels, the postoperative levels of most inflammatory cytokines in both groups were significantly increased and reached a peak on the first day after the procedure. The level of postoperative inflammatory cytokines was significantly lower in group B than in group A. In addition, there was no significant difference in procalcitonin before and after the transcatheter approach.

Conclusion

Systemic inflammatory reactions occurred after transthoracic or transcatheter device closure of ASDs in pediatric patients. However, these inflammatory reactions were more significant in patients who underwent a transthoracic approach than in patients who underwent a transcatheter approach.

Towards chamber specific heart-on-a-chip for drug testing applications

Modeling of human organs has long been a task for scientists in order to lower the costs of therapeutic development and understand the pathological onset of human disease. For decades, despite marked differences in genetics and etiology, animal models remained the norm for drug discovery and disease modeling. Innovative biofabrication techniques have facilitated the development of organ-on-a-chip technology that has great potential to complement conventional animal models. However, human organ as a whole, more specifically the human heart, is difficult to regenerate in vitro, in terms of its chamber specific orientation and its electrical functional complexity. Recent progress with the development of induced pluripotent stem cell differentiation protocols, made recapitulating the complexity of the human heart possible through the generation of cells representative of atrial & ventricular tissue, the sinoatrial node, atrioventricular node and Purkinje fibers. Current heart-on-a-chip approaches incorporate biological, electrical, mechanical, and topographical cues to facilitate tissue maturation, therefore improving the predictive power for the chamber-specific therapeutic effects targeting adult human. In this review, we will give a summary of current advances in heart-on-a-chip technology and provide a comprehensive outlook on the challenges involved in the development of human physiologically relevant heart-on-a-chip.

Intimal sarcoma of the left atrium presenting with transient ischaemic attack - A case report and review of the literature

A 31-year-old female with a history of polycystic ovary syndrome and two recent miscarriages presented with symptoms of a transient ischemic attack. Echocardiography to assess for possible embolic source identified a 4.8 cm left atrial mass, presumed to be an atrial myxoma. At surgery the tumor was suspicious of malignancy. Histopathology revealed a heterogeneous hyper- and hypo-cellular spindle cell tumor showing mild atypia. Atrial myxoma markers were negative. The Ki67 proliferation factor was 30% and fluorescence in situ hybridization (FISH) analysis showed MDM2 amplification. Expert review confirmed the morphological, immunohistochemical, and FISH features to be of a cardiac intimal sarcoma. Recent improvements in imaging, surgery, and molecular testing have increased diagnoses of primary cardiac intimal sarcomas. Here we discuss the pathological and clinical implications of these rare atrial myxoma mimics. <Learning objective: Intimal sarcomas are rare, aggressive tumors typically associated with great vessels, however, molecular diagnoses of cardiac intimal sarcomas are increasing. Presentation is varied. Cardiac symptoms and emboli in young patients should prompt investigation with high levels of suspicion. Intimal sarcomas show MDM2 amplification with genetic aberration. Careful pre-operative planning to achieve clear surgical margins almost doubles life expectancy. Chemoradiotherapy may be beneficial. MDM2 and PDGFRa inhibitors are in development.>.

Electrocardiographic evidence of abnormal atrial phenotype in Brugada syndrome

BACKGROUND

Brugada syndrome (BrS) is an inherited ion channelopathy that may predispose affected individuals to atrial cardiomyopathy. We tested the hypothesis that BrS patients have higher degrees of atrial electrophysiological abnormalities compared to controls, and these can be reflected by changes in P-wave parameters determined on the electrocardiogram (ECG).

METHODS

This was a single-center retrospective study comparing BrS patients to age- and gender-matched control subjects. Mean P-wave duration (PWD_mean), maximum PWD (PWD_max) and minimum PWD (PWD_min), P-wave dispersion (PWD_max - PWD_min), and P-wave terminal force in V1 (PTFV1) were measured. PWD_max ≥ 120 ms, in the presence and absence of biphasic P-waves in the inferior leads, were termed advanced and partial inter-atrial block (IAB), respectively.

RESULTS

The proportion of IAB was significantly higher in BrS patients (28/51; 55%) than in control subjects (14/51; 27%; Fisher's Exact test; P < 0.01). Advanced IAB was observed in two BrS patients but none of the control subjects (P = 0.50). Compared to controls, BrS patients showed higher PWD_mean (107 [98-113] vs. 97 [90-108] ms; KWANOVA, P < 0.01), PWD_max (123 [110-132] vs. 113 [107-121] ms; P < 0.001) but statistically indistinguishable PWD_min (82 [72-92] vs. 77 [69-85]; P = 0.09), and P-wave dispersion (38 [26-52] vs. 37 [23-45] ms; P = 0.14). PTFV1 was significantly higher in BrS patients than in control subjects (24 [0-40] vs. 0 [0-27] mm.ms; P < 0.05).

CONCLUSION

Atrial conduction abnormalities are frequently observed in BrS. These patients may require monitoring for future development of atrial fibrillation and stroke.

Embolization of high-output idiopathic renal arteriovenous fistula primarily using an atrial septal defect occluder via venous access: a case report

Background

The case report is to evaluate the efficacy and safety of embolization of a high-output idiopathic renal arteriovenous fistula (IRAVF) with an atrial septal defect occluder (ASDO) via venous access.

Case presentation

A 57-year-old male diagnosed with high-output IRAVF received embolization with an ASDO via renal venous access and compact occlusion with 3 vascular plugs and a detachable elastic coil. The IRAVF was successfully occluded. After a follow-up of 2 months, renal arterial computed tomography angiography (CTA) showed the precise location of the ASDO. No complications were observed after 2 years’ follow-up.

Conclusions

Based on present results, embolization of a high-output IRAVF with an ASDO via venous access might be an efficient and safe method.

Evaluating the effect of magnesium supplementation and cardiac arrhythmias after acute coronary syndrome: a systematic review and meta-analysis

BACKGROUND

Atrial and ventricular cardiac arrhythmias are one of the most common early complications after cardiac surgery and these serve as a major cause of mortality and morbidity after cardiac revascularization. We want to evaluate the effect of magnesium sulfate administration on the incidence of cardiac arrhythmias after cardiac revascularization by doing this systematic review and meta-analysis.

METHODS

The search performed in several databases (SID, Magiran, IranDoc, IranMedex, MedLib, PubMed, EmBase, Web of Science, Scopus, the Cochrane Library and Google Scholar) for published Randomized controlled trials before December 2017 that have reported the association between Magnesium consumption and the incidence of cardiac arrhythmias. This relationship measured using odds ratios (ORs) with a confidence interval of 95% (CIs). Funnel plots and Egger test used to examine publication bias. STATA (version 11.1) used for all analyses.

RESULTS

Twenty-two studies selected as eligible for this research and included in the final analysis. The total rate of ventricular arrhythmia was lower in the group receiving magnesium sulfate than placebo (11.88% versus 24.24%). The same trend obtained for the total incidence of supraventricular arrhythmia (10.36% in the magnesium versus 23.91% in the placebo group). In general the present meta-analysis showed that magnesium could decrease ventricular and supraventricular arrhythmias compared with placebo (OR = 0.32, 95% CI 0.16-0.49; p < 0.001 and OR = 0.42, 95% CI 0.22-0.65; p < 0.001, respectively). Subgroup analysis showed that the effect of magnesium on the incidence of cardiac arrhythmias was not affected by clinical settings and dosage of magnesium. Meta-regression analysis also showed that there was no significant association between the reduction of ventricular arrhythmias and sample size.

CONCLUSION

The results of this meta-analysis study suggest that magnesium sulfate can be used safely and effectively and is a cost-effective way in the prevention of many of ventricular and supraventricular arrhythmias.

Clinical Utility of Left Atrial Strain in Children in the Acute Phase of Kawasaki Disease

BACKGROUND

We aimed to evaluate the diagnostic utility of peak left atrial longitudinal strain (PALS) during left ventricular (LV) systole to differentiate children in the acute phase of Kawasaki disease (aKD) from controls. We also aimed to compare the diagnostic utility of PALS with those of conventional echocardiographic indices of diastolic function.

METHODS

Retrospectively measured PALS, LV longitudinal peak systolic strain, and strain rate obtained via velocity vector imaging were compared in a derivation cohort comprising 95 aKD and 67 controls. The utility of PALS in differentiating aKD from controls was compared with those of E/E', E/A, and maximum left atrial volume index (LAVImax). Derived cutoffs from receiver operating characteristic curves were validated in a separate validation cohort comprising 37 aKD and 19 controls.

RESULTS

In the derivation cohort, PALS was significantly decreased in aKD as compared with in controls. For differentiating aKD from controls, PALS outperformed E/E', E/A, and LAVImax. However, cutoffs of PALS (≤40% and ≤39%, before and after adjusting for the presence of significant mitral regurgitation and LV systolic dysfunction, respectively), like those of E/E', E/A, and LAVImax, showed low sensitivity and poor discriminative ability for differentiating aKD from controls. In the validation cohort, for differentiating aKD from controls, both cutoffs of PALS showed low sensitivity, like those of E/E', E/A, and LAVImax.

CONCLUSION

In aKD, impaired left atrial reservoir function could be detected as decreased PALS. For differentiating aKD from controls, PALS outperforms E/E', E/A, and LAVImax. However, like E/E', E/A, and LAVImax, PALS as a single parameter is limited in its clinical utility to differentiate aKD from controls because of its low sensitivity and poor discriminative ability.

Age-dependent atrial arrhythmic phenotype secondary to mitochondrial dysfunction in Pgc-1β deficient murine hearts

INTRODUCTION

Ageing and several age-related chronic conditions including obesity, insulin resistance and hypertension are associated with mitochondrial dysfunction and represent independent risk factors for atrial fibrillation (AF).

MATERIALS AND METHODS

Atrial arrhythmogenesis was investigated in Langendorff-perfused young (3-4 month) and aged (>12 month), wild type (WT) and peroxisome proliferator activated receptor-γ coactivator-1β deficient (Pgc-1β-/-) murine hearts modeling age-dependent chronic mitochondrial dysfunction during regular pacing and programmed electrical stimulation (PES).

RESULTS AND DISCUSSION

The Pgc-1β-/- genotype was associated with a pro-arrhythmic phenotype progressing with age. Young and aged Pgc-1β-/- hearts showed compromised maximum action potential (AP) depolarization rates, (dV/dt)max, prolonged AP latencies reflecting slowed action potential (AP) conduction, similar effective refractory periods and baseline action potential durations (APD90) but shortened APD90 in APs in response to extrasystolic stimuli at short stimulation intervals. Electrical properties of APs triggering arrhythmia were similar in WT and Pgc-1β-/- hearts. Pgc-1β-/- hearts showed accelerated age-dependent fibrotic change relative to WT, with young Pgc-1β-/- hearts displaying similar fibrotic change as aged WT, and aged Pgc-1β-/- hearts the greatest fibrotic change. Mitochondrial deficits thus result in an arrhythmic substrate, through slowed AP conduction and altered repolarisation characteristics, arising from alterations in electrophysiological properties and accelerated structural change.

Development of Tachyarrhythmias Late After the Fontan Procedure: The Role of Ablative Therapy

Patients with a Fontan circulation are at a high risk of developing a variety of cardiac dysrhythmias after cardiac surgery. These dysrhythmias are most often supraventricular tachyarrhythmias (SVT), but ventricular tachyarrhythmias (VT) may also occur. Mechanisms underlying SVT are variable, including both ectopic activity and reentry. Over time, successive SVT may be caused by different mechanisms. The acute success rate of ablative therapy of atrial tachyarrhythmias is considerably high yet during long-term follow-up 'recurrences' frequently occur. It is most likely that these 'recurrences' are caused by a progressive atrial cardiomyopathy instead of arrhythmogeneity of prior ablative lesions.

Worsening Hypoxia Post Lung Transplant: What has Changed?

Platypnoea-orthodeoxia is a rare, but under-diagnosed clinical entity, characterised by postural hypoxia and breathlessness. Underlying pathology is inter-atrial shunt or pulmonary vascular malformation, but what anatomical distortion / physiological alterations initiates right to left shunt, usually against the pressure gradient remains unknown.

Effect of natriuretic peptides on cerebral artery blood flow in healthy volunteers

The natriuretic peptides (NPs), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP), have vasoactive functions that concern humans and most animals, but their specific effects on cerebral circulation are poorly understood. We therefore examined the responsiveness of cerebral arteries to different doses of the natriuretic peptides in animals and humans. We conducted a dose-response experiment in guinea pigs (in vitro) and a double-blind, three-way cross-over study in healthy volunteers (in vivo). In the animal experiment, we administered cumulative doses of NPs to pre-contracted segments of cerebral arteries. In the main study, six healthy volunteers were randomly allocated to receive two intravenous doses of ANP, BNP or CNP, respectively, over 20 min on three separate study days. We recorded blood flow velocity in the middle cerebral artery (VMCA) by transcranial Doppler. In addition, we measured temporal and radial artery diameters, headache response and plasma concentrations of the NPs. In guinea pigs, ANP and BNP but not CNP showed significant dose-dependent relaxation of cerebral arteries. In healthy humans, NP infusion had no effect on mean VMCA, and we found no difference in hemodynamic responses between the NPs. Furthermore, natriuretic peptides did not affect temporal and radial artery diameters or induce headache. In conclusion, natriuretic peptides in physiological and pharmacological doses do not affect blood flow velocity in the middle cerebral artery or dilate extracerebral arteries in healthy volunteers.

Late endocarditis of Amplatzer atrial septal occluder device in a child

Bacterial endocarditis following atrial septal defect closure using Amplatzer device in a child is extremely rare. We report a 10-year-old girl who developed late bacterial endocarditis, 6 years after placement of an Amplatzer atrial septal occluder device. Successful explantation of the device and repair of the resultant septal defect was carried out using a homograft patch. The rare occurrence of this entity prompted us to highlight the importance of long-term follow up, review the management and explore preventive strategies for similar patients who have multiple co-morbidities and a cardiac device. A high index of suspicion is warranted particularly in pediatric patients.

High atrioventricular phase index on near-field intracardiac electrogram is associated with risk of ventricular arrhythmia

The purposes of this study were to characterize and quantify concordance between consecutive atrial and ventricular activation time points through analysis of phases and to explore its association with outcomes in patients with implantable cardioverter-defibrillator (ICD). Patients with structural heart disease and dual-chamber ICDs underwent 5min baseline right ventricular (V) near-field and atrial (A) electrogram (EGM) recording. The cross-dependencies of phase dynamics of the changes in consecutive A (AA') and V (VV') were quantified and the AV phase dependency index was determined. In Cox regression analysis, a high AV phase index (in the highest quartile, >0.259) was significantly associated with higher risk of ventricular tachyarrhythmias (HR 2.84; 95% CI 1.05-7.67; P=0.04). In conclusion, in ICD patients with structural heart disease, high sinus AV phase dependency index on EGM is associated with the risk of ventricular arrhythmia.

Early recurrence of atrial arrhythmias following pulmonary vein antral isolation: Timing and frequency of early recurrences predicts long-term ablation success

BACKGROUND

Early recurrence of atrial arrhythmia (ERAA) is common after atrial fibrillation (AF) ablation and is associated with long-term recurrence. However, the association between timing or frequency of ERAA and long-term ablation success remains unclear.

OBJECTIVE

We aimed to examine whether timing or frequency of ERAA after pulmonary vein antral isolation (PVAI) affects long-term ablation success.

METHODS

Three hundred AF patients (100 paroxysmal, 100 persistent, 100 long-standing persistent; mean age 59.5 ± 9.6 years, 79% male) undergoing PVAI were included. All patients underwent 30-day monitoring with mobile continuous outpatient telemetry after PVAI and were followed for >1 year. ERAA was defined as AF or organized atrial tachycardia (OAT) in the first 6 weeks, and was categorized as early (weeks 1-2), intermediate (weeks 3-4), or late (weeks 5-6). Long-term ablation success was defined as the absence of AF/OAT lasting >30 seconds off antiarrhythmic drugs 1 year after a single ablation (excluding first 6 weeks).

RESULTS

ERAA occurred in 169 patients (53%); of those, 79 (46.7%) had single ERAA and 90 (53.3%) had multiple ERAAs. ERAA occurred less commonly with paroxysmal versus persistent or long-standing persistent AF (46% vs 57% and 66%; P = .017). ERAA was associated with worse ablation success at 1 year (38.1% vs 79.5% [no ERAA]; P < .001). Multiple (vs single) ERAA more strongly predicted long-term ablation failure (OR: 4.5; 95% CI [2.3-8.8]).

CONCLUSIONS

ERAA after PVAI is associated with decreased long-term ablation success. Patients experiencing multiple ERAA events are at greatest risk for long-term arrhythmia recurrence and represent a subgroup in whom early reablation may be considered.

Echocardiographic Hypertrabeculated/Non-compacted Right Ventricle Accompanied by Atrial Septal Defect and Anomalous Pulmonary Vein Connection

Myocardial noncompaction (NC) is a disorder of the embryonic endomyocardial morphogenesis frequently associated with congenital cardiac abnormalities. NC predominantly affects the left ventricle (LV). Right ventricle (RV) NC may occur in association with LV involvement or in isolation. A 47-year-old woman was admitted for atrial septal defect closure. Transthoracic echocardiography revealed hypertrabeculation of the RV apex, consisting of multiple deep recesses with the entrance of blood flow in color Doppler imaging, suggestive of isolated RV hypertrabeculation/NC. The RV and right atrium (RA) were enlarged, and systolic pulmonary arterial pressure was slightly increased. Our patient's associated abnormalities were atrial septal defect (superior sinus venosus type), anomalous connection of the right upper pulmonary vein to the junction of the superior vena cava and the RA, and large patent foramen ovale. Association between atrial septal defect and partial anomalous pulmonary vein connection and isolated hypertrabeculated/noncompacted RV should be considered by cardiologists.

Intracardiac echocardiography during atrial septal defect and patent foramen ovale device closure in pediatric and adolescent patients

BACKGROUND

Intracardiac echocardiography (ICE) is commonly used during interventional cardiac catheterization in adults, but data regarding the use of ICE in children are limited. There are no data available comparing the effectiveness of preprocedural transthoracic echocardiography (TTE) with that of intraprocedural ICE in predicting atrial septal defect (ASD) size and rim adequacy for percutaneous closure in a pediatric population. The objectives of this study were to describe the investigators' experience using ICE in pediatric and adolescent patients and to compare the effectiveness of preprocedural TTE with that of ICE in predicting ASD size and rim adequacy for percutaneous closure.

METHODS

In this retrospective study, all cases in which ICE was used during ASD or patent foramen ovale closure in patients ≤21 years of age at a single institution from January 2002 through October 2013 were reviewed. All studies were performed using the Acuson AcuNav ICE system.

RESULTS

One hundred fifteen patients (65 female; mean age, 12 ± 6 years; range, 10 months to 21 years) were included. All intracardiac echocardiographic studies were performed by the interventional cardiologist performing the catheterization. ICE was used to facilitate ASD closure in 92 patients (81%) and patent foramen ovale closure in 23 (19%). Thirty-eight patients (34%) underwent cardiac catheterization and ICE without general anesthesia. ICE was correlated highly with preprocedural TTE in predicting ASD size (r(2) = 0.76, P < .0001). In nine of 92 patients (9.8%) with ASDs, ICE identified deficient septal rims (n = 8) or complex or multiple ASDs (n = 1) that necessitated surgical closure. There were no major complications.

CONCLUSIONS

ICE can be performed safely and effectively in a large cohort of children and adolescents undergoing percutaneous device closure. ICE may obviate the need for general anesthesia in some patients and is a reasonable alternative to transesophageal echocardiography for this catheter-based procedure in children. ASD measurements with ICE correlate well with preprocedural measurements on TTE; however, ICE more accurately identifies the absence or deficiency of critical septal rims before device closure.

Diastolic function assessed from tagged MRI predicts heart failure and atrial fibrillation over an 8-year follow-up period: the multi-ethnic study of atherosclerosis

OBJECTIVES

The strain relaxation index (SRI), a novel diastolic functional parameter derived from tagged magnetic resonance imaging (MRI), is used to assess myocardial deformation during left ventricular relaxation. We investigated whether diastolic function indexed by SRI predicts heart failure (HF) and atrial fibrillation (AF) over an 8-year follow-up.

METHODS

As a part of the multi-ethnic study of atherosclerosis, 1544 participants free of known cardiovascular disease (CVD) underwent tagged MRI in 2000-02. Harmonic phase analysis was used to compute circumferential strain. Standard parameters, early diastolic strain rate (EDSR) and the peak torsion recoil rate were calculated. An SRI was calculated as difference between post-systolic and systolic times of the strain peaks, divided by the EDSR peak. It was normalized by the total interval of relaxation. Over an 8-year follow-up period, we defined AF (n = 57) or HF (n = 36) as combined (n = 80) end-points. Cox regression assessed the ability of SRI to predict events adjusted for risk factors and markers of subclinical disease. Integrated discrimination index (IDI) and net reclassification index (NRI) of SRI, compared with conventional indices, were also assessed.

RESULTS

The hazard ratio for SRI remained significant for the combined HF and AF end-points as well as for HF alone after adjustment. For the combined end-point, IDI was 1.5% (P < 0.05) and NRI was 11.4% (P < 0.05) for SRI. Finally, SRI was more robust than all other existing cardiovascular magnetic resonance diastolic functional parameters.

CONCLUSION

SRI predicts HF and AF over an 8-year follow-up period in a large population free of known CVD, independent of established risk factors and markers of subclinical CVD.

An inferior sinus venosus interatrial communication associated with a secundum atrial septal defect, clinically presenting in an adult patient: autopsy report

Atrial septal defects (ASD) are the most common congenital cardiac lesion in adults, representing up to 40% of acyanotic shunt lesions in patients older than 40 years. Secundum ASD comprises defects in the area of the oval fossa, and may be associated with other types of interatrial communications. We present a case of a 25 year-old female patient who was asymptomatic until the age 22 when she started presenting exertion dyspnea and lower limbs edema, during her third pregnancy. The patient was admitted in the emergency department because of a febrile respiratory distress syndrome dying in less than 36 hours after her arrival. The autopsy examination revealed pneumonia and a secundum ASD, associated with a rare form of interatrial communication, the inferior sinus venosus defect, which is characterized by an anomalous connection of the right pulmonary veins to the inferior caval vein at its opening in the right atrial cavity, while retaining partially their connection to the left atrium. A dysplastic and thickened mitral valve was also present. Signs of pulmonary hypertension confirm the Eisenmenger syndrome in this adult patient.

Extra Atrial Disease in Patients with "Lone" Atrial Fibrillation

AIMS

Lone atrial fibrillation (LAF) is considered by some to be a primary atrial electrophysiologic disorder. However, we have frequently observed evidence of "extraatrial" diseases - atherosclerosis and associated metabolic disorders - in our LAF patients. We sought to characterize and quantify extraatrial disease burden in LAF patients, and to correlate this burden with features of the arrhythmia including pattern (paroxysmal versus persistent) and response to catheter ablation.

METHODS AND RESULTS

Forty-six consecutive patients with non-familial LAF underwent assessment for evidence of atherosclerosis (computed tomographic vascular calcification and elevated arterial pulse wave velocity) and associated metabolic diseases (dyslipidemia, insulin resistance and inflammation), and then catheter ablation. The cohort had a significant incidence of atherosclerosis (57%) and metabolic (70%) diseases. Patients with persistent AF tended to have a greater extraatrial disease burden than those with paroxysmal AF. A significant inverse relationship between the rate of ablation success and extraatrial disease burden was demonstrated.

CONCLUSIONS

Extraatrial disease was common in this LAF cohort. Correlations between extraatrial disease burden and features of the arrhythmia would, if verified, challenge the notion that LAF is a "primary" electrophysiologic disorder.

Amplatzer device closure of an inferior venosus atrial septal defect after surgical closure of a secundum atrial septal defect

We present a patient who had transcatheter closure of a low atrial septal defect which was overlooked during surgical closure of a secundum atrial septal defect. The residual defect was detected during ablation for atrial flutter, and was closed successfully during the same procedure with an Amplatzer atrial septal occluder (ASO) device.

Delayed Amplatzer device closure of atrial septal defect for persistent cyanosis after surgical correction of severe pulmonary stenosis in early infancy

We present two patients who had delayed transcatheter closure of secundum atrial septal defects for persistent cyanosis after surgical repair of severe pulmonary stenosis. The defects (two in one patient) were closed uneventfully and successfully with Amplatzer ASO devices, with significant improvement in oxygen saturation. The staged approach and the complementary role of surgery and intervention are discussed.