Echocardiography to predict left ventricular filling pressure for long-term paediatric heart transplant patients.

OBJECTIVES: Left ventricular diastolic dysfunction is a recognised sequela following transplantation in paediatric heart transplant patients. Traditional echocardiographic indices do not correlate well with left ventricular filling pressure immediately after transplantation. This study aimed to assess whether these indices have any long-term correlation after transplantation in paediatric patients. METHODS: A retrospective chart review of 41 patients who had a heart transplant before the age of 24 years was performed. The median time since the transplantation was 11 years. Data obtained from surveillance cardiac catheterisation and echocardiographic examination were reviewed. Traditional echocardiographic indices of diastolic function were compared with the pulmonary capillary wedge pressure and left ventricular end-diastolic pressure obtained from cardiac catheterisation. RESULTS: The median age at transplant was 12.1 years, and the median time since transplant was 11 years. Eighteen patients (43%) had a history of at least one rejection episode and 12 patients (29%) had a history of cardiac allograft vasculopathy. There was no correlation between mitral inflow E velocity, mitral E/A ratio, tissue Doppler velocities, mitral E/e' (mitral inflow E velocity to mitral annular velocity), and elevated pulmonary capillary wedge pressure or elevated left ventricular end-diastolic pressure. There was no correlation between mitral valve deceleration time or isovolumetric relaxation time with elevated pulmonary capillary wedge pressure or elevated left ventricular end-diastolic pressure. CONCLUSION: Our findings suggest that traditional echocardiographic indices of diastolic function do not correlate well with elevated invasive pulmonary capillary wedge pressure or elevated left ventricular end-diastolic pressure in paediatric heart transplant patients' long-term post-transplantation.

Safe closure of percutaneous ventricular access site for interventions in structural heart disease.

Percutaneous transapical ventricular access for transcatheter procedures in structural heart disease is associated with an increased risk of bleeding from the access site. There are currently numerous suture and sutureless closure devices that are being investigated to close the transapical access site safely and effectively. Meticulous preprocedural planning with advanced imaging techniques is recommended to lay out the access path and closure of the transapical access site.

Postinfarction ventricular septal rupture: Transcatheter intervention or surgical repair?

Postinfarction ventricular septal rupture is an infrequent but potentially fatal complication of acute myocardial infarction. The 30-day mortality rate with the transcatheter approach when performed in the acute phase (<2 weeks) was 25.3% compared to 50% when surgery is performed in the acute phase (within 3 weeks). There is no correlation between defect size and mortality. New York Heart Association class IV and time to ventricular septal defect closure are risk predictors for transcatheter closure for a 30-day mortality rate of 31.5%.

A randomized controlled laboratory study on the long-term effects of methylphenidate on cardiovascular function and structure in rhesus monkeys.

BACKGROUND: Whether long-term methylphenidate (MPH) results in any changes in cardiovascular function or structure can only be properly addressed through a randomized trial using an animal model which permits elevated dosing over an extended period of time. METHODS: We studied 28 male rhesus monkeys (Macaca mulatta) approximately 7 years of age that had been randomly assigned to one of three MPH dosages: vehicle control (0 mg/kg, b.i.d., n = 9), low dose (2.5 mg/kg, b.i.d., n = 9), or high dose (12.5 mg/kg, b.i.d., n = 10). Dosage groups were compared on serum cardiovascular and inflammatory biomarkers, electrocardiograms (ECGs), echocardiograms, myocardial biopsies, and clinical pathology parameters following 5 years of uninterrupted dosing. RESULTS: With the exception of serum myoglobin, there were no statistical differences or apparent dose-response trends in clinical pathology, cardiac inflammatory biomarkers, ECGs, echocardiograms, or myocardial biopsies. The high-dose MPH group had a lower serum myoglobin concentration (979 ng/mL) than either the low-dose group (1882 ng/mL) or the control group (2182 ng/mL). The dose response was inversely proportional to dosage (P = .0006). CONCLUSIONS: Although the findings cannot be directly generalized to humans, chronic MPH exposure is unlikely to be associated with increased cardiovascular risk in healthy children.

Transcatheter Intervention for Treatment of Coronary Stenosis After Unroofing of the Anomalous Left Coronary Artery.

Anomalous origin of left coronary artery (LCA) from the right coronary cusp with an intramural course is usually managed with unroofing of the intramural segment. Available literature demonstrates an uneventful course following surgery in most patients. Coronary stenosis following the unroofing procedure treated with percutaneous coronary intervention has not been described in the past. We describe a case where an 11-year-old girl with anomalous origin of the LCA from the right coronary cusp presented with near syncope. Surgical unroofing of the intramural segment was done without any post-operative complications and the patient remained asymptomatic for 9 months. She then presented with chest pain, abnormal troponin levels, and ST-T wave changes on EKG. A CT angiogram done revealed short segment narrowing of the LCA near its origin. Cardiac catheterization with coronary angiography demonstrated short segment narrowing of the LCA just distal to origin. Stenting of the left main coronary artery was done with a drug eluting stent. She underwent the procedure without complications. The patient continued to be asymptomatic 16 months after placement of the stent and there was no residual stenosis seen on a repeat CT angiogram at 3 months after the procedure.

Prestenting for prevention of melody valve stent fractures: A systematic review and meta-analysis.

INTRODUCTION: The role of right ventricular outflow tract (RVOT) prestenting in the prevention of Melody valve stent fractures (SFs) is not well defined. We aimed to perform a systematic review and meta-analysis comparing the incidence of SF in Melody valve transcatheter pulmonary implants with and without prestenting. METHODS: PubMed, EMBASE, and Cochrane Central were searched for studies that reported the incidence of SF in Melody valve transcatheter pulmonary implants stratified by the presence or absence of RVOT prestenting. Subgroup analyses were performed for (1) SF associated with a loss of stent integrity and (2) SF requiring reintervention. RESULTS: Five studies and 360 patients were included, of whom 207 (57.5%) received prestenting. Follow-up ranged from 15 to 30 months. SF were significantly reduced in the prestenting group (16.7%) when compared to no prestenting (33.5%) (odds-ratio [OR] 0.39; 95%CI 0.22-0.69). Patients who received prestenting also had a lower incidence of (1) SF associated with loss of stent integrity (OR 0.16; 95%CI 0.05-0.48) and (2) SF requiring reintervention (OR 0.15; 95%CI 0.02-0.91). CONCLUSION: Our findings suggest that stenting of the RVOT prior to Melody valve implantation is associated with a reduction in the incidence of SF and fracture-related reinterventions.

Incidence and factors influencing the spontaneous closure of Fontan fenestration.

INTRODUCTION: The Fontan operation is the final stage of single ventricle palliation in patients with complex congenital heart disease. Fenestration in the Fontan conduit, providing an atrial level right to left shunt, has been shown to reduce early postoperative morbidity. However, there is limited data on the long-term fate of this fenestration. The aim of this study is to define the rate of spontaneous closure of the fenestration in the Fontan conduit and factors predictive of the fate of the fenestration. METHODS: This was a retrospective study reviewing the medical records of the patients who underwent fenestrated Fontan operation at our center. Preoperative, intraoperative and postoperative variables including the status of the Fontan fenestration were extracted and analyzed. RESULTS: Of 67 patients included in the study, 15 (22%) had spontaneous closure of the fenestration. Of the remaining 52 patients, 11 (20%) had procedural closure of this fenestration (10 via cardiac catheterization and 1 via surgery) at a median duration of 3 months after the Fontan operation. Patients with higher preoperative pulmonary vascular resistance and a history of postoperative systemic venous thromboembolism had higher likelihood of having persistence of the fenestration with P value of .045 and .037, respectively. CONCLUSIONS: The rate of spontaneous closure of the Fontan fenestration was 22% in our study. Elevated preoperative pulmonary vascular resistance and history of systemic venous thromboembolism are predictive of persistent Fontan fenestration.

Percutaneous Pulmonary Valve Implantation: Present Status and Evolving Future.

Due to recurrent right ventricular outflow tract (RVOT) dysfunction, patients with complex congenital heart disease of the RVOT traditionally require multiple surgical interventions during their lifetimes. Percutaneous pulmonary valve implantation (PPVI) has been developed as a nonsurgical alternative for the treatment of right ventricular to pulmonary artery stenosis or pulmonary regurgitation. PPVI has been shown to be a safe and effective procedure in patients with dysfunctional surgical RVOT conduits. In this population, PPVI has the potential to improve symptoms, functional capacity, and biventricular hemodynamics. However, limitations to the anatomical substrate and size of the RVOT currently restrict PPVI eligibility to less than one-quarter of patients with RVOT dysfunction. The current review discusses contemporary practices in PPVI, evidence supporting the procedure, and future technologies and developments in the field.

Effects of controlled antegrade pulmonary blood flow on cardiac function after bidirectional cavopulmonary anastomosis.

BACKGROUND: Bidirectional cavopulmonary anastomosis (BCPA) has been used as an intermediate stage in the treatment of patients with single-ventricle physiology. Leaving additional antegrade pulmonary blood flow has been shown to improve postoperative arterial blood oxygen saturations; however, controversy continues over whether the potential increase in systemic venous pressure is detrimental. We studied the effects of controlled antegrade pulmonary blood flow on cardiac function in patients after BCPA. METHODS: From January 1993 to July 2000, 128 patients underwent BCPA. Mean age at operation was 6.2 +/- 4 months (range 2 to 36 months). In group 1 (n = 72), restricted antegrade pulmonary blood flow was maintained through a native narrowed pulmonary valve or by adjustment of previously placed pulmonary artery band with the goal of maintaining the mean pulmonary artery pressure less than 16 mm Hg. In group 2 (n = 56), BCPA was the only source of pulmonary blood flow. RESULTS: One hospital death (0.8%) occurred. The mean pulmonary artery pressure at the end of the operation was 13 +/- 2 mm Hg in group 1 compared with 12 +/- 2 mm Hg in group 2, a difference that was not significant. Patients in group 1 had higher arterial oxygen saturations (84% +/- 3% compared with 74% +/- 3% in group 2, p < 0.05), and shorter mean hospital stay (9 +/- 3 days compared with 15 +/- 2 days, p < 0.05). Persistent pleural effusion (> 10 days) or late chylothorax occurred in 4 patients from group 1 and 3 from group 2, a difference that was not significant. During a mean follow-up of 36 +/- 10 months no late deaths occurred. The mean oxygen saturation remained higher in group 1, 80% +/- 3% compared with 74% +/- 4% in group 2, and the hematocrit was lower, at 38% +/- 3% compared with 46% +/- 4% (p < 0.05 for both comparisons). Cardiac catheterizations were performed in 68 patients before completion Fontan. Total pulmonary artery (Nakata) index was 263 +/- 34 mm(2)/m(2) in group 1 (n = 40) and 188 +/- 13 mm(2)/m(2) in group 2 (n = 28) (p < 0.05). The mean pulmonary artery pressure and mean ventricular end-diastolic pressure were similar. CONCLUSIONS: Controlled antegrade pulmonary blood flow may have favorable effects on cardiac function for a selected group of patients and does not appear to have adverse effects on subsequent suitability for completion Fontan.

The amplatzer [corrected] septal occluder as a standard for therapy of secundum-type [corrected] atrial septal defect.

Atrial septal defect (ASD) accounts for 5-10% of congenital heart malformations. An uncorrected ASD may lead to congestive heart failure, severe pulmonary hypertension, or paradoxical arterial embolism with stroke. Transthoracic echocardiography is often diagnostic in the pediatric population, but transesophageal echocardiography may be required in adults. Closure of an ASD traditionally has been performed surgically, but the most common type (secundum ASD) can now be closed with a percutaneously deployed device. We briefly describe the types of ASDs and their diagnosis. Results of percutaneous closure in 74 children and adults are then presented.

Transmyocardial migration of a temporary epicardial pacing wire: a pediatric case report.

Transmyocardial migration of a retained temporary epicardial pacing wire has been rarely reported in adult patients after heart surgery. We present the case of a child in whom a temporary epicardial pacing wire was discovered incidentally in the right ventricular outflow tract one year after surgical repair of congenital heart disease. The pacing wire was subsequently extracted using the snare method during cardiac catheterization. Clinicians caring for patients after congenital heart surgery should be aware of this uncommon though potentially life-threatening complication.

Pediatric cardiomyopathies: causes, epidemiology, clinical course, preventive strategies and therapies.

Pediatric cardiomyopathies, which are rare but serious disorders of the muscles of the heart, affect at least one in every 100,000 children in the USA. Approximately 40% of children with symptomatic cardiomyopathy undergo heart transplantation or die from cardiac complications within 2 years. However, a significant number of children suffering from cardiomyopathy are surviving into adulthood, making it an important chronic illness for both pediatric and adult clinicians to understand. The natural history, risk factors, prevalence and incidence of this pediatric condition were not fully understood before the 1990s. Questions regarding optimal diagnostic, prognostic and treatment methods remain. Children require long-term follow-up into adulthood in order to identify the factors associated with best clinical practice including diagnostic approaches, as well as optimal treatment approaches. In this article, we comprehensively review current research on various presentations of this disease, along with current knowledge about their causes, treatments and clinical outcomes.

Role of transcatheter therapy in the treatment of coarctation of the aorta.

Coarctation of the aorta is one of the most common congenital heart defects. Transcatheter therapy for treatment of coarctation is effective, with low morbidity and mortality rates. The current trend is toward primary stent implantation for treatment, however, the results of balloon angioplasty in children and young adults are equivalent to the results following primary stent placement. Judicious use of stents is recommended in infants and children.

Procedural results and acute complications in stenting native and recurrent coarctation of the aorta in patients over 4 years of age: a multi-institutional study.

BACKGROUND: We report a multi-institutional experience with intravascular stenting (IS) for treatment of coarctation of the aorta. METHODS AND RESULTS: Data was collected retrospectively by review of medical records from 17 institutions. The data was broken down to prior to 2002 and after 2002 for further analysis. A total of 565 procedures were performed with a median age of 15 years (mean=18.1 years). Successful reduction in the post stent gradient (<20 mm Hg) or increase in post stent coarctation to descending aorta (DAo) ratio of >0.8 was achieved in 97.9% of procedures. There was significant improvement (P<0.01) in pre versus post stent coarctation dimensions (7.4 mm+/-3.0 mm vs. 14.3+/-3.2 mm), systolic gradient (31.6 mm Hg+/-16.0 mm Hg vs. 2.7 mm Hg+/-4.2 mm Hg) and ratio of the coarctation segment to the DAo (0.43+/-0.17 vs. 0.85+/-0.15). Acute complications were encountered in 81/565 (14.3%) procedures. There were two procedure related deaths. Aortic wall complications included: aneurysm formation (n=6), intimal tears (n=8), and dissections (n=9). The risk of aortic dissection increased significantly in patients over the age of 40 years. Technical complications included stent migration (n=28), and balloon rupture (n=13). Peripheral vascular complications included cerebral vascular accidents (CVA) (n=4), peripheral emboli (n=1), and significant access arterial injury (n=13). Older age was significantly associated with occurrence of CVAs. A significant decrease in the technical complication rate from 16.3% to 6.1% (P<0.001) was observed in procedures performed after January 2002. CONCLUSIONS: Stent placement for coarctation of aorta is an effective treatment option, though it remains a technically challenging procedure. Technical and aortic complications have decreased over the past 3 years due to, in part, improvement in balloon and stent design. Improvement in our ability to assess aortic wall compliance is essential prior to placement of ISs in older patients with coarctation of the aorta.

Intermediate follow-up following intravascular stenting for treatment of coarctation of the aorta.

BACKGROUND: We report a multiinstitutional study on intermediate-term outcome of intravascular stenting for treatment of coarctation of the aorta using integrated arch imaging (IAI) techniques. METHODS AND RESULTS: Medical records of 578 patients from 17 institutions were reviewed. A total of 588 procedures were performed between May 1989 and Aug 2005. About 27% (160/588) procedures were followed up by further IAI of their aorta (MRI/CT/repeat cardiac catheterization) after initial stent procedures. Abnormal imaging studies included: the presence of dissection or aneurysm formation, stent fracture, or the presence of reobstruction within the stent (instent restenosis or significant intimal build-up within the stent). Forty-one abnormal imaging studies were reported in the intermediate follow-up at median 12 months (0.5-92 months). Smaller postintervention of the aorta (CoA) diameter and an increased persistent systolic pressure gradient were associated with encountering abnormal follow-up imaging studies. Aortic wall abnormalities included dissections (n = 5) and aneurysm (n = 13). The risk of encountering aortic wall abnormalities increased with larger percent increase in CoA diameter poststent implant, increasing balloon/coarc ratio, and performing prestent angioplasty. Stent restenosis was observed in 5/6 parts encountering stent fracture and neointimal buildup (n = 16). Small CoA diameter poststent implant and increased poststent residual pressure gradient increased the likelihood of encountering instent restenosis at intermediate follow-up. CONCLUSIONS: Abnormalities were observed at intermediate follow-up following IS placement for treatment of native and recurrent coarctation of the aorta. Not exceeding a balloon:coarctation ratio of 3.5 and avoidance of prestent angioplasty decreased the likelihood of encountering an abnormal follow-up imaging study in patients undergoing intravascular stent placement for the treatment of coarctation of the aorta. We recommend IAI for all patients undergoing IS placement for treatment of CoA.

Single-ventricle palliation for high-risk neonates: the emergence of an alternative hybrid stage I strategy.

BACKGROUND: Survival after stage I palliation for hypoplastic left heart syndrome or related anomalies remains poor in high-risk neonates. We hypothesized that a less invasive hybrid approach would be beneficial in this patient population. METHODS: The hybrid stage I procedure was performed in the catheterization laboratory. Via a median sternotomy, both branch pulmonary arteries were banded, and a ductal stent was delivered via a main pulmonary artery puncture and positioned under fluoroscopic guidance. RESULTS: Between October 2003 and June 2005, 14 high-risk neonates underwent a hybrid stage I procedure. Eleven of 14 had hypoplastic left heart syndrome. Two also underwent peratrial atrial septal stenting, and 5 required percutaneous atrial stenting later. Two neonates with an intact or highly restrictive atrial septum had emergency percutaneous atrial stent placement. Hospital survival was 11 (78.5%) of 14. One patient required extracorporeal membrane oxygenation support for intraoperative cardiac arrest. He underwent cardiac transplantation but died later of sepsis. One patient died of ductal stent embolization, and a third died of progressive cardiac dysfunction. The first 4 patients required pulmonary artery band revisions. There were none after we modified our technique and added branch pulmonary artery angiograms. There were 2 interstage deaths from atrial stent occlusion and from preductal retrograde coarctation. Eight patients underwent stage II procedures, consisting of aortic arch reconstruction, atrial septectomy, and cavopulmonary shunt. Two patients died after stage II. One patient is awaiting stage II. CONCLUSIONS: The hybrid stage I palliation is a valid option in high-risk neonates. As experience is accrued, it may become the preferred alternative. However, in aortic atresia, the development of preductal retrograde coarctation is a significant problem.

Initial clinical experience with intracardiac echocardiography in guiding transcatheter closure of perimembranous ventricular septal defects: feasibility and comparison with transesophageal echocardiography.

Over the last several years, intracardiac echocardiography (ICE) has been employed successfully in guiding transcatheter device closure of a secundum atrial septal defect (ASD) or patent foramen ovale (PFO). Nothing is known regarding the use of ICE to guide catheter device closure of a perimembranous ventricular septal defect (PMVSD). Twelve patients (seven female/five male) who had a PMVSD (among them, three patients with associated atrial communications: two with an ASD and one with a PFO) underwent attempts at transcatheter device closure using the Amplatzer membranous VSD device of their defects, using sequential transesophageal echocardiography (TEE) and ICE guidance with general endotracheal anesthesia (five patients) and using ICE alone with conscious sedation (seven patients). The mean age of patients was 16.9 +/- 3.7, and their mean weight was 42.4 +/- 6.6. Their mean left ventricular end-diastolic dimension preclosure was 45.7 +/- 2.5. The Qp/Qs ratio ranged from 1.0 to 1.8:1. During the procedure, the ICE catheter was positioned in the right atrium (RA) in all 12 patients and the ICE catheter was advanced to the left atrium to obtain a view of the ventricular septum in 3. Both TEE and ICE provided similar anatomical views of the position of the PMVSD. Furthermore, the relationship of the defect to the aortic valve and tricuspid valves, the measured size of defect, and the guidance of various stages of device deployment were comparable by TEE and ICE. There were no complications encountered during or after closure. We conclude that ICE provides unique images of the PMVSD and measurements similar to those obtained by TEE. ICE potentially could replace TEE in most patients as a guiding imaging tool for PMVSD device closure, thus eliminating the need for general endotracheal anesthesia.