Right Ventricle-dependent Coronary Circulation Research Articles

Fetal pulmonary valvuloplasty for pulmonary atresia with intact ventricular septum: a single-center clinical experience.

Fetal pulmonary valvuloplasty for pulmonary atresia with intact ventricular septum: a single-center clinical experience.

Computed Tomographic Angiography Provides Reliable Coronary Artery Evaluation in Infants With Pulmonary Atresia Intact Ventricular Septum

Evaluate the use of coronary CTA as an initial assessment for determining Right Ventricle Dependent Coronary Circulation (RVDCC) in neonates with Pulmonary Atresia with Intact Ventricular Septum (PA IVS). Retrospective review of cases with coronary CTA and compare with available catheter angiography, pathology, surgical reports, and outcomes from Mar 2015 to May 2022. In our cohort of 16 patients, 3 were positive for RVDCC, confirmed by pathologic evaluation, and there was concordance for presence or absence of RVDCC with catheter angiography in 5 patients (4 negatives for RVDCC, 1 positive). Clinical follow up for the 8 patients that underwent RV decompression had no clinical evidence of myocardial ischemia. Our findings suggest that coronary CTA is reliable as first-line imaging for determination of RVDCC in neonates with PA IVS. These findings, if supported by further prospective study, may reserve invasive coronary angiography for cases with diagnostic uncertainty or at the time of necessary transcatheter interventions.

Duct Stenting vs. Modified Blalock-Taussig Shunt: New Insights Learned From High-Risk Patients With Duct-Dependent Pulmonary Circulation.

BackgroundAs no data were available on the comparison of outcomes between modified Blalock-Taussig shunts (MBTs) vs. duct-stenting (DS) in patients with pulmonary atresia (PA) and an increased ductal tortuosity and in patients with pulmonary atresia and intact septum (PA-IVS) with right ventricle-dependent coronary circulation (RVDCC), we aimed to perform a single-center retrospective evaluation.MethodsBetween 2010 and 2019, 127 patients with duct-dependent pulmonary circulation (DDPC) underwent either MBTs (without additional repairs) (n = 56) or DS (n = 71). The primary endpoint was defined as arriving at the next planned surgery (Glenn or biventricular repair) avoiding one of the following: (1) unplanned surgery or unplanned perforation of the pulmonary valve (PVP) with a stent, (2) procedure-related permanent complications, and (3) death. Two subgroups were considered: (1) patients who had a ductal curvature index (DCI) >0.45 (n = 32) and (2) patients with PA-IVS and RVDCC (n = 13). Ductal curvature index (DCI) was measured in all the patients to assess the tortuosity of the ducts. Patients with DCI >0.45 were considered as being in a high-risk group for the duct-stenting; a previous study showed that the patients with a DCI < 0.45 had a better outcome when compared with those with a DCI> 0.45.ResultsThe primary outcome was achieved equally in the two groups (77.5% in DS, 75% in MBTs). Hospital deaths, need for ECMO, and the occurrence of major complications was more frequent in the group with MBTs with an Odds Ratio (OR) of 5, 0.8, and 4, respectively, and a 95% Confidence Interval (CI) 1.1–22.6, 0.7–0.9, and 1.6–10.3, respectively, and a P-value < 0.05. For the two subgroups, the primary outcome was achieved in 64% of patients with a DCI >0.45 who received MBTs compared to 20% in those with DS (OR 3.5, 95% CI 1.2–10, P 0.005). While 74.1% of the patients with PA-IVS and RVDCC after DS had achieved the primary outcome, all patients with MBTs had an impaired outcome (OR 3.5, 95%CI 1–11.2, P 0.004).ConclusionMBTs showed a better outcome in patients with tortuous ducts compared to DS. DS seems to be superior in patients with DDPC with DCI <0.45 and patients with PA-IVS with RVDCC.

Right Ventricle-Dependent Coronary Circulation: Location of Obstruction Is Associated With Survival

Pulmonary atresia with intact ventricular septum (PAIVS) with right ventricle-dependent coronary circulation (RVDCC) carries suboptimal outcomes primarily due to cardiac ischemia. We hypothesize clinical outcomes are affected by the level of coronary obstruction, a surrogate for vulnerable myocardium. We conducted a single-institution retrospective analysis of all neonates with PAIVS with RVDCC from 1995 to 2017. RVDCC was defined as the presence of any coronary-cameral fistula with coronary obstruction proximal to the fistula and angiographic evidence of RV perfusion of the myocardium through the fistulous communication. Location of coronary obstruction was categorized as either proximal or distal segments, using the SYNTAX score criteria. Transplant-free survival was compared between patients with proximal and distal obstruction, then these groups were compared with patients without RVDCC. Of 103 neonates with PAIVS, 28 (27%) had RVDCC: 18 proximal (64%), 10 distal (36%). Median age at last follow-up for patients with RVDCC was 1.8 years (interquartile range, 0.3-8.1 years). All deaths (10 of 28, 36%) occurred at 6 months old or earlier. Proximal coronary artery obstruction was associated with decreased transplant-free survival relative to distal obstruction (hazard ratio= 3.63; 95% confidence interval, 1.01-13.00; P= .048). Transplant-free survival at 1 year was 33% and 70% in the proximal and distal obstruction groups, respectively. Compared with patients without RVDCC, patients with proximal obstruction had significantly lower transplant-free survival (P < .001), whereas patients with distal obstruction did not (P= .217). The location of coronary artery obstruction affects clinical outcome and may represent a potential branch point in the management for PAIVS with RVDCC.

Prediction of biventricular repair by echocardiography in borderline ventricle

Objective:In recent years, attempting the biventricular pathway or biventricular conversions in patients with borderline ventricle has become a hot topic. However, inappropriate pursuit of biventricular repair in borderline candidates will lead to adverse clinical outcomes. Therefore, it is important to accurately assess the degree of ventricular development before operation and whether it can tolerate biventricular repair. This review evaluated ventricular development using echocardiography for a better prediction of biventricular repair in borderline ventricle.Data sources:Articles from January 1, 1990 to April 1, 2019 on biventricular repair in borderline ventricle were accessed from PubMed, using keywords including “borderline ventricle,” “congenital heart disease,” “CHD,” “echocardiography,” and “biventricular repair.”Study selection:Original articles and critical reviews relevant to the review's theme were selected.Results:Borderline left ventricle (LV): (1) Critical aortic stenosis: the Rhodes score, Congenital Heart Surgeons Society regression equation and another new scoring system was proposed to predict the feasibility of biventricular repair. (2) Aortic arch hypoplasia: the LV size and the diameter of aortic and mitral valve (MV) annulus should be taken into considerations for biventricular repair. (3) Right-dominant unbalanced atrioventricular septal defect (AVSD): atrioventricular valve index (AVVI), left ventricular inflow index (LVII), and right ventricle (RV)/LV inflow angle were the echocardiographic indices for biventricular repair. Borderline RV: (1) pulmonary atresia/intact ventricular septum (PA/IVS): the diameter z-score of tricuspid valve (TV) annulus, ratio of TV to MV diameter, RV inlet length z-score, RV area z-score, RV development index, and RV-TV index, etc. Less objective but more practical description is to classify the RV as tripartite, bipartite, and unipartite. The presence or absence of RV sinusoids, RV dependent coronary circulation, and the degree of tricuspid regurgitation should also be noted. (2) Left-dominant unbalanced AVSD: AVVI, LV, and RV volumes, whether apex forming ventricles were the echocardiographic indices for biventricular repair.Conclusions:Although the evaluation of echocardiography cannot guarantee the success of biventricular repair surgery, echocardiography can still provide relatively valuable basis for surgical decision making.

Myocardial strain abnormalities in fetuses with pulmonary atresia and intact ventricular septum.

Global and regional myocardial deformation have not been well described in fetuses with pulmonary atresia and intact ventricular septum (PA/IVS). Speckle-tracking echocardiography (STE), an angle-independent technique for assessing global and regional strain, may be a more sensitive way of determining ventricular systolic dysfunction compared with traditional 2D echocardiography. The aim of this study was to assess myocardial deformation in fetuses with PA/IVS compared with control fetuses and to determine if, in fetuses with PA/IVS, strain differs between those with and those without right ventricle-dependent coronary circulation (RVDCC). This was a retrospective analysis of fetuses with PA/IVS examined at two medical centers between June 2005 and October 2017. Left ventricular (LV) and right ventricular (RV) regional and global longitudinal strain (GLS) and strain rate were obtained using STE, and comparisons were made between fetuses with PA/IVS and gestational age (GA)-matched controls. Postnatal outcome was assessed, including the presence of RVDCC. Fifty-seven fetuses with PA/IVS and 57 controls were analyzed at a mean GA of 26.5 ± 5 weeks. LV-GLS was significantly decreased in fetuses with PA/IVS compared with controls (-17.4 ± 1.7% vs -23.7 ± 2.0%, P < 0.001). LV strain rate was also significantly decreased (-1.01 ± 0.21/s vs -1.42 ± 0.20/s, P < 0.001). Fetuses with PA/IVS had decreased strain in all segments. Similarly, RV strain was significantly decreased in fetuses with PA/IVS (-11.6 ± 3.8% vs -24.6 ± 2.5%, P < 0.0001). Thirty-six patients had postnatal cardiac catheterization performed to define coronary anatomy; 10 fetuses had RVDCC. Fetuses with RVDCC had decreased LV strain compared with those without (-15.8 ± 1.2% vs -17.9 ± 1.7%, P = 0.009). RV strain was also decreased in fetuses with RVDCC vs those without (-7.0 ± 2.9% vs -12.1 ± 3.2%, P = 0.0004). Fetuses with PA/IVS have decreased global and regional LV and RV strain compared with controls. The finding of decreased LV strain may be due to altered ventricular mechanics in the context of a hypertensive right ventricle and/or abnormal coronary perfusion. Moreover, fetuses that were found to have RVDCC postnatally had decreased LV and RV strain compared with those that did not. These results encourage further investigation to assess whether fetal ventricular strain could be a prenatal predictor of RVDCC. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Long-term outcomes of single-ventricle palliation for pulmonary atresia with intact ventricular septum: Fontan survivors remain at risk of late myocardial ischaemia and death.

The specific outcomes of patients with pulmonary atresia with intact ventricular septum late after Fontan palliation are unknown. Patients with smaller right ventricles and myocardial sinusoids are known to have worse survival in the first years of life. Whether the potential for coronary ischaemia affects the long-term outcomes of these patients after Fontan palliation is still unknown. All patients with pulmonary atresia with intact ventricular septum who underwent the Fontan procedure from 1984 to 2016 in Australia and New Zealand were identified, and preoperative, perioperative and follow-up data were collected. Late follow-up data were available for 120 patients. The median length of follow-up after the Fontan procedure was 9.1 years (interquartile range 4.2-15.4 years). Late death occurred in 9% of patients (11/120). Six were sudden, unexpected deaths; 4 of those occurred in patients known to have right ventricle-dependent coronary circulation (RVDCC). Those with RVDCC had a higher incidence of sudden death (4/20 vs 2/100; P = 0.007). RVDCC was associated with late death (P = 0.01) and the development of myocardial ischaemia after Fontan completion (P < 0.001). The 10-year survival rate was 77% (95% confidence interval 56-100%) for patients with RVDCC vs 96% (95% confidence interval 92-100%) for patients without RVDCC. Long-term survival of patients with pulmonary atresia with intact ventricular septum after the Fontan procedure is excellent, but patients with RVDCC remain susceptible to coronary ischaemia and sudden death. Closer surveillance and investigation for exercise-induced ischaemia may be necessary.

PERFORATING THE ATRETIC PULMONARY VALVE IN NEONATES USING CORONARY TOTAL OCCLUSION HARDWARE

Interventional therapy is possible in selected patients with of pulmonary atresia with intact ventricular septum (PA- IVS). Among the various interventional options available, radiofrequency and laser assisted perforation may be more successful, but have substantial cost and expertise involved. On the other hand coronary hardware used to cross totally occluded coronary arteries is often readily available in catheterization labs and interventional cardiologists are familiar with their use. We describe the technique of mechanical catheter pulmonary valve (PV) perforation using currently available coronary hardware meant for coronary chronic total occlusion. Eight neonates diagnosed to have PA- IVS underwent PV perforation using the coronary hardware. All these babies had a well formed right ventricle (RV) with no evidence of RV dependent coronary circulation. After complete echocardiographic evaluation and an informed parental consent, patients were electively intubated, mechanically ventilated, adequately heparinized and were put on intravenous prostaglandin infusion. Basic steps involved localizing the atretic segment and coaxial alignment of catheters using biplane fluoroscopy, crossing the atretic segment with soft end of perforating guide wire, stabilizing the assembly, followed by graded balloon dilatation never exceeding 130% of pulmonary annulus. The PV was crossed retrogradely in one patient when antegrade approach was not possible. Procedure was successful in 7 / 8 cases (89.5%). Valve opening was achieved in all patients with immediate fall in RV systolic pressures. One neonate died following surgery after catheter induced RV perforation. All surviving cases were discharged from hospital in good general condition with no evidence of heart failure and room air saturation of > 85 %. No patient required an additional procedure over a short follow up period. With appropriate patient and hardware selection, PV perforation using readily available coronary hardware is feasible in PA-IVS.

Pulmonary Atresia/Intact Ventricular Septum: Influence of Coronary Anatomy on Single-Ventricle Outcome

We investigated the influence of coronary artery abnormalities on outcome in patients with pulmonary atresia/intact ventricular septum (PA-IVS) for planned single-ventricle palliation. Catheterization and medical records were reviewed in patients with PA-IVS for planned single-ventricle palliation at our institution between 2000 and 2012. Primary outcome was death or transplantation. Patients with confirmed or strong suspicion of stenosis in 2 or more main coronary arteries or coronary ostial atresia were defined as having right ventricle-dependent coronary circulation (RVDCC); those with stenosis of 1 main vessel or normal anatomy were defined as having non-RVDCC. Of 58 patients with PA-IVS, 17 (30%) underwent single-ventricle palliation. Ten (59%) had RVDCC (3with ostial atresia) and 7 (41%) had non-RVDCC. Median follow-up time was 8.2 years (0 months-11.3 years), with 1 patient in each group lost to follow-up. Five patients with RVDCC died, including the 3 patients with ostial atresia, and 1 underwent transplantation at 6 months of life. No deaths occurred after second-stage palliation. Three of the 4 surviving patients with RVDCC completed a Fontan operation, and 2 of these patients had evidence of cardiac ischemia on follow-up. No deaths occurred among patients with non-RVDCC. Kaplan-Meier analysis demonstrated significantly better survival in patients with non-RVDCC (100%) than in patients with RVDCC (40%) (p= 0.026). In patients with PA-IVS undergoing single-ventricle palliation, RVDCC is associated with high early mortality, especially with coronary ostial atresia. There should be early consideration of transplantation inneonates with RVDCC. Patients with non-RVDCC undergoing single-ventricle palliation have excellent long-term outcomes, with no mortality seen in this series.

Individualized surgical management of pulmonary atresia with intact ventricular septum

To delineate individualized surgical management strategy for the optimal management of pulmonary atresia with intact ventricular septum (PA/IVS). Between 1997 to 2005, 52 consecutive patients with PA/IVS, 31 male and 21 female, aged 2-9, divided into 2 groups according if right ventricle-dependent coronary circulation (RVDCC) existed, underwent individualized surgical treatment. The patients in Group I (with: RVDCC, n = 6) underwent single ventricle repair. Forty-six patients were in Group II (without RVDCC), 13 of which with severe right ventricular hypoplasia (tricuspid valve Z value < -4)underwent single ventricle repair and 33 of which were with mild to moderate right ventricular hypoplasia (Z value > -4). One critical neonate underwent systemic- pulmonary artery shunt. The other 32 of the 33 patients received right ventricular decompression procedures firstly, and 6 of them presented optimal hemodynamics and oxygenation and achieved biventricular repair. If the patients presented unstable hemodynamics or hypoxemia after right ventricular decompression procedure, an additional shunt was added. 13 young infants (0-2 months) underwent additional systemic-pulmonary artery shunt, and 13 patients (> 3 months-old) underwent additional bidirectional cavopulmonary shunt (1.5 ventricular repair)The patients were followed up for 1-10 years. There were 1 early death in Group I and 7 early deaths in Group II. The total early mortality was 15%. A successful definitive repair was achieved in 26 cases (50%). Follow-up reported 3 late deaths. Individualized surgical management based on the presence of RVDCC, right ventricular hypoplasia grading, right ventricular growth potential, hemodynamic situation, and oxygen saturation after the decompression procedure is helpful to improve the surgical results of PA/IVS

Exclusion of the non-functioning right ventricle in children with pulmonary atresia and intact ventricular septum☆

A group of patients with pulmonary atresia and intact ventricular septum (PAIVS) have to undergo single ventricle repair. In these patients, the presence of the non-functioning right ventricle (RV) may lead to the aggravation of RV to coronary connections and left ventricular (LV) dysfunction. To prevent these deleterious effects, the RV was excluded surgically. Between December 2000 and February 2006, 10 patients with PAIVS underwent RV exclusion in conjunction with cavo-pulmonary anastomosis (n=6) or systemic-to-pulmonary artery shunt (n=4). Median age at surgery was 5 months (range, 0.2-13.8). Median z-value of the tricuspid valve was -4.0 (range, -6.5 to -1.3). None had RV dependent coronary circulation. The tricuspid valve was closed directly or using a patch. Thrombotic materials were inserted into the RV cavity in eight patients. There was no mortality. Follow-up was completed in all patients for up to 79.1 months (median, 30.3). Seven patients underwent a Fontan procedure and the other three are waiting. Eight patients showed completely obliterated RV after exclusion. One of the two patients who had residual RV cavity underwent re-exclusion after a Fontan operation. Postoperative echocardiography revealed that LV end-diastolic dimension increased with borderline significance (p=0.050), whereas LV end-systolic dimension showed no significant changes. During follow-up, LV showed no evidence of regional ischemia or global dysfunction, and fractional shortening significantly increased compared with the pre-exclusion value (p=0.017). This study demonstrates that RV exclusion may be performed safely in a selected group of patients with PAIVS. This procedure may have beneficial effects on LV systolic function, by preventing possible ischemia, and on LV diastolic function, by obliterating the non-functioning cavity and improving the geometry of the ventricular septum.

Pulmonary Atresia With Intact Ventricular Septum: Limitations of Catheter-Based Intervention

Pulmonary atresia with intact ventricular septum (PAIVS) has a wide spectrum of anatomic heterogeneity and invokes a wide variety of treatment strategies. We reviewed the outcome of our patients with PAIVS in order to delineate strategies for the optimal management of PAIVS. In particular, the possibility of avoiding neonatal surgical intervention with catheter-based technology was assessed. The study cohort was composed of all patients presented with PAIVS from January 1999 through December 2005. Demographic and anatomic variables were analyzed to determine association with in-hospital mortality. Forty-four infants with PAIVS underwent catheter valvuloplasty (n = 17) and (or) surgical intervention (n = 42). The mean age and weight of the infants was six days and 3.1 kg, and the average follow-up was 40 +/- 29.5 months. Five (11%) had right ventricle dependent coronary circulation (RVDCC) and six (14%) had Ebstein's anomaly. Five (11%) patients died. Of those who underwent catheter valvotomy, three (18%) underwent shunt placement, 12 (71%) underwent right ventricular outflow tract reconstruction with shunt placement, and only two (12%) did not require a further surgical intervention in the newborn period. Multivariable analyses demonstrated RVDCC (odds ratio 21.3, p = 0.025) and Ebstein's anomaly (odds ratio 16.0, p = 0.038) to be risk factors for in-hospital mortality. Of those patients with Ebstein's anomaly, a single ventricle approach had a better outcome. We demonstrated excellent recent outcomes for patients with PAIVS. Catheter-based interventions rarely avoid surgical repair. The RVDCC and Ebstein's anomaly were associated with high mortality. In patients with Ebstein's anomaly, single ventricular pathway may be the better strategy for this specific patient population.

Natural History of Pulmonary Atresia With Intact Ventricular Septum and Right-Ventricle–Dependent Coronary Circulation Managed by the Single-Ventricle Approach

Natural History of Pulmonary Atresia With Intact Ventricular Septum and Right-Ventricle–Dependent Coronary Circulation Managed by the Single-Ventricle Approach

Unifocalization of Major Aortopulmonary Collaterals in Single-Ventricle Patients

Unifocalization of major aortopulmonary collateral arteries (MAPCAs) in pulmonary atresia with ventricular septal defect and intracardiac repair has become the standard of care. However, there are no reports addressing unifocalization of MAPCAs in single-ventricle patients. It is unknown whether their pulmonary vascular bed can be reconstructed and low enough pulmonary vascular resistance achieved to allow for superior or total cavopulmonary connections. We reviewed data on all patients with functional single ventricles and unifocalization procedures of MAPCAs. From 1997 to 2005, 14 consecutive children with various single-ventricle anatomies were operated on. Patients had a median of three surgical procedures (range, 1 to 5). Two patients had absent, all others diminutive central pulmonary arteries, with an average of 3.5 +/- 1.2 MAPCAs. Seven patients (50%) had bidirectional Glenn procedures, and 3 of these had Fontan procedures. Median postoperative pulmonary artery pressures measured 12.5 mm Hg (Glenn) and 14 mm Hg (Fontan), respectively. Six patients are alive today (46%), with 1 patient lost to follow-up. Three patients died early and 3 late after initial unifocalization to shunts. One other patient survived unifocalization, but was not considered a candidate for a Glenn procedure and died after high-risk two-ventricle repair. Another patient with right-ventricle-dependent coronary circulation died of sepsis late after Glenn. In selected patients with functional single ventricles and MAPCAs, the pulmonary vascular bed can be reconstructed sufficiently to allow for cavopulmonary connections. Venous flow to the pulmonary vasculature decreases cardiac volume load and is likely to increase life expectancy and quality of life for these patients.

Natural History of Pulmonary Atresia With Intact Ventricular Septum and Right-Ventricle–Dependent Coronary Circulation Managed by the Single-Ventricle Approach

Long-term outcome of patients with pulmonary valvar atresia and intact ventricular septum with right-ventricle-dependent coronary circulation (PA/IVS-RVDCC) managed by staged palliation directed toward Fontan circulation is unknown, but should serve as a basis for comparison with management protocols that include initial systemic-to-pulmonary artery shunting followed by listing for cardiac transplantation. Retrospective review of patients admitted to our institution with the diagnosis of PA/IVS-RVDCC from 1989 to 2004. All angiographic imaging studies, operative reports, and follow-up information were reviewed. Right-ventricle-dependent coronary circulation was defined as situations in which ventriculocoronary fistulae with proximal coronary stenosis or atresia were present, putting significant left ventricle myocardium at risk for ischemia with right ventricle decompression. Thirty-two patients were identified with PA/IVS-RVDCC. All underwent initial palliation with modified Blalock-Taussig shunt (BTS). Median tricuspid valve z-score was -3.62 (-2.42 to -5.15), and all had moderate (n = 13) or severe (n = 19) right ventricular hypoplasia. Median follow-up was 5.1 years (9 months to 14.8 years). Overall mortality was 18.8% (6 of 32), with all deaths occurring within 3 months of BTS. Aortocoronary atresia was associated with 100% mortality (3 of 3). Of the survivors (n = 26), 19 have undergone Fontan operation whereas 7, having undergone bidirectional Glenn shunt, currently await Fontan. Actuarial survival by the Kaplan-Meier method for all patients was 81.3% at 5, 10, and 15 years, whereas mean survival was 12.1 years (95% confidence interval: 10.04 to 14.05). No late mortality occurred among those surviving beyond 3 months of age. In patients with PA/IVS-RVDCC, early mortality appears related to coronary ischemia at the time of BTS. Single-ventricle palliation yields excellent long-term survival and should be the preferred management strategy for these patients. Those with aortocoronary atresia have a particularly poor prognosis and should undergo cardiac transplantation.

Catheterization in neonates with pulmonary atresia with intact ventricular septum

Cardiac catheterization is infrequently required in babies with pulmonary atresia with intact ventricular septum. The main indications are to decide on the best form of treatment, the options being determined by the right ventricular as well as infundibular morphology and the presence of right-ventricle dependent coronary circulation. In most cases, an interventional approach is appropriate. This can consist of radiofrequency or laser perforation of the atretic pulmonary valve, combined with balloon dilation. In some patients, additional stenting of the arterial duct may be needed.