Cardiac catheter intervention complexity and safety outcomes in adult congenital heart disease

OBJECTIVE

To describe the intervention spectrum, complexity, and safety outcomes of catheter-based interventions in a contemporary adult congenital heart disease (ACHD) tertiary cohort.

METHODS

All patients over 16 years who underwent a catheter-based intervention for ACHD in our centre between 2000 and 2016 were included. Baseline demographics, clinical characteristics, indications for and complexity of intervention, procedural complications and early and mid-term mortality were analysed.

RESULTS

Overall, 1644 catheter-based interventions were performed. Intervention complexity ranged from simple (67.5%) to intermediate (26.4%) and to high (6.1%). Commonly performed procedures were atrial septal defect (33.4%) and patent foramen ovale closure (26.1%) followed by coarctation of the aorta (11.1%) and pulmonary artery interventions (7.0%). Age at index intervention was 40±16 years, 758 (46.1%) patients were male, 73.2% in New York Heart Association (NYHA) class I, 20.2% in NYHA class II, whereas 6.6% in NYHA class III/IV. In-hospital mortality was 0.7%. Median postinterventional length of stay was 1 day. Complications occurred in 129 (7.9%) with major adverse events in 21 (1.3%). One-year postintervention survival rates were 98.7% (95% CI 98.2 to 99.2). Over the study period, there was a notable shift in intervention complexity, with a predominance of simple procedures performed in early years and more complex procedures in later years. Furthermore, the case mix during the study broadened (p<0.001) with new catheter-based interventions and a more individualised approach to therapy.

CONCLUSION

This study shows an increasing complexity and expanding variability of ACHD catheter-based interventions, associated with low major complications, short hospital stays and low early and mid-term mortality. Ongoing investment in ACHD catheter interventions is warranted.

Symptomatic partial and transitional atrioventricular septal defect repaired in infancy

Objectives

Infants with symptomatic partial and transitional atrioventricular septal defect undergoing early surgical repair are thought to be at greater risk. However, the outcome and risk profile of this cohort of patients are poorly defined. The aim of this study was to investigate the outcome of symptomatic infants undergoing early repair and to identify risk factors which may predict mortality and reoperation.

Methods

This multicentre study recruited 51 patients (24 female) in three tertiary centres between 2000 and 2015. The inclusion criteria were as follows: (1) partial and transitional atrioventricular septal defect, (2) heart failure unresponsive to treatment, (3) biventricular repair during the first year of life.

Results

Median age at definitive surgery was 179 (range 0–357) days. Sixteen patients (31%) had unfavourable anatomy of the left atrioventricular valve: dysplastic (n=7), double orifice (n=3), severely deficient valve leaflets (n=1), hypoplastic left atrioventricular orifice and/or mural leaflet (n=3), short/poorly defined chords (n=2). There were three inhospital deaths (5.9%) after primary repair. Eleven patients (22%) were reoperated at a median interval of 40 days (4 days to 5.1 years) for severe left atrioventricular valve regurgitation and/or stenosis. One patient required mechanical replacement of the left atrioventricular valve. After median follow-up of 3.8 years (0.1–11.4 years), all patients were in New York Heart Association (NYHA) class I. In multivariable analysis, unfavourable anatomy of the left atrioventricular valve was the only risk factor associated with left atrioventricular valve reoperation.

Conclusions

Although surgical repair is successful in the majority of the cases, patients with partial and transitional atrioventricular septal defect undergoing surgical repair during infancy experience significant morbidity and mortality. The reoperation rate is high with unfavourable left atrioventricular valve anatomy.

Best practice critical cardiac care in the neonatal unit

Major congenital or acquired heart disease in neonates presents with cyanosis, hypoxia, acute circulatory failure or cardiogenic shock. Antenatal diagnosis is made in up to 50% but heart disease is unanticipated in the remainder. The presence of significant heart disease in premature infants is also frequently not suspected at first; in general, whatever the underling cardiac anomaly, the clinical condition is worse, deteriorates more quickly and carries a poorer prognosis in premature and low birth weight infants. Although congenital cardiac malformations are the most likely, other important cardiac disorders are encountered. In general initial treatment options, often without a precise diagnosis, include diuretics, prostin, catecholamines, phosphodiesterase inhibitors, ventilation and occasionally ECMO but the key to successful treatment remains the correct diagnosis. Many conditions will only show significant improvement with treatment by the interventional cardiologist or cardiac surgeon.

Oral Enoximone as an Alternative to Protracted Intravenous Medication in Severe Pediatric Myocardial Failure

Phosphodiesterase 3 inhibitors have been used successfully in pediatric patients with acute or chronic myocardial dysfunction over the last two decades. Their protracted continuous intravenous administration is associated with risk of infectious and thromboembolic complications. Weaning intravenous medication and starting oral angiotensin-converting enzyme (ACE) inhibitors and/or beta-blockers can be challenging. We reviewed retrospectively hospital records of 48 patients receiving oral enoximone treatment in a single tertiary pediatric cardiac center between November 2005 and April 2014. Failure to wean from intravenous milrinone infusion and/or intolerance of ACE inhibitors and/or beta-blockers was indications for oral enoximone treatment. Age of the patients ranged between 0.5 and 191 months (median 7.5 months) at the time of starting enoximone treatment. There were 14 patients (29 %) with left ventricular dysfunction due to myocarditis or dilated cardiomyopathy and 34 patients (71 %) with myocardial dysfunction complicating congenital heart disease. Fifteen (44 %) of these 34 patients had left ventricular dysfunction, 13 (38 %) right ventricular dysfunction, and in 6 (18 %) both ventricles were failing. Duration of oral enoximone treatment was between 3 days and 34 months (median of 2.3 months). Myocardial functional recovery allowed for weaning of enoximone treatment in 15 patients (31 %) after 6 days-15 months (median 5 months). No adverse hemodynamic effects were noted. Blood stained gastric aspirates encountered in two patients resolved with concomitant milk administration. Based on our limited experience, oral enoximone is a well-tolerated and promising alternative to intravenous medication and/or other commonly used oral medications in selected pediatric patients with chronic heart failure.

Low-bandwidth teleconsultations for patients with complex congenital heart diseases

We have reviewed our experience with a low-bandwidth paediatric telecardiology link (using ISDN at 128 kbit/s) between a tertiary centre in Belgrade and a tertiary centre in London. Over a two-year period, 12 videoconferences were held, during which 40 case histories of 38 patients were presented from Belgrade. The patients were aged 7 days to 20 years, and most of them had complex congenital heart defects. Changes in diagnosis and/or therapy occurred in 21 cases. Clinically relevant changes in diagnosis occurred in 2/40 cases (5%). In 12 cases, there were slight differences in opinion which resulted in minor changes in therapy for 9 of the patients. In another 9 patients, major changes in therapy occurred. There were no major problems with the quality of image and sound in any of the videoconferences. Our experience suggests that when there are experienced paediatric cardiologists at both ends of the connection, transmission via a single ISDN line is safe and accurate.

Uncommon variants of the scimitar syndrome in two siblings

The Scimitar syndrome is a complex association of cardiovascular and bronchopulmonary abnormalities, with the main feature a partial or total anomalous right pulmonary venous drainage to the inferior vena cava. A number of cases that lack of all the features of the typical syndrome have been described as Scimitar variant, but the incidence is rare. Familial occurrence is exceptional and limited to few cases in literature. We report two sibling diagnosed with an uncommon variant of the Scimitar syndrome.

Magnetic navigation in adults with atrial isomerism (heterotaxy syndrome) and supraventricular arrhythmias

AIMS

We analysed the type and mechanism of supraventricular arrhythmias encountered in a series of symptomatic adults with atrial isomerism undergoing catheter ablation procedures.

METHODS AND RESULTS

The study population included consecutive adults with atrial isomerism who had previously undergone surgical repair or palliation of the associated anomalies. Patients underwent electrophysiological study for symptomatic arrhythmia in our institution between 2010 and 2012 using magnetic navigation in conjunction with CARTO RMT and three-dimensional (3D) image integration. Eight patients (five females) with a median age of 33 years [interquartile range (IQR) 24-39] were studied. Access to the cardiac chambers of interest was obtained retrogradely via the aorta using remotely navigated magnetic catheters in six patients. Radiofrequency ablation successfully targeted twin atrioventricular (AV) nodal reentrant tachycardia in two patients, atrial fibrillation (AF) in three, focal atrial tachycardia (AT) mainly originating in the left-sided atrium in four patients, and macro-reentrant AT dependent on a right-sided inferior isthmus in three patients. The median fluoroscopy time was 3.0 min (IQR 2-11). After a median follow-up of 10 months (IQR 6-21), five of the ablated patients are free from arrhythmia; two patients experienced episodes of self-terminated AF and AT, respectively, within one month post-ablation; the remaining patient had only non-sustained AT during the electrophysiological study and was managed medically.

CONCLUSION

Various supraventricular tachycardia mechanisms are possible in adults with heterotaxy syndrome, all potentially amenable to radiofrequency ablation. The use of remote magnetic navigation along with 3D mapping facilitated the procedures and resulted in a short radiation time.

Total Anomalous Pulmonary Venous Connection

Background—

Late mortality after repair of total anomalous pulmonary venous connection is frequently associated with pulmonary venous obstruction (PVO). We aimed to describe the morphological spectrum of total anomalous pulmonary venous connection and identify risk factors for death and postoperative PVO.

Methods and Results—

We conducted a retrospective, international, collaborative, population-based study involving all 19 pediatric cardiac centers in the United Kingdom, Ireland, and Sweden. All infants with total anomalous pulmonary venous connection born between 1998 and 2004 were identified. Cases with functionally univentricular circulations or atrial isomerism were excluded. All available data and imaging were reviewed. Of 422 live-born cases, 205 (48.6%) had supracardiac, 110 (26.1%) had infracardiac, 67 (15.9%) had cardiac, and 37 (8.8%) had mixed connections. There were 2 cases (0.5%) of common pulmonary vein atresia. Some patients had extremely hypoplastic veins or, rarely, discrete stenosis of the individual veins. Sixty (14.2%) had associated cardiac anomalies. Sixteen died before intervention. Three-year survival for surgically treated patients was 85.2% (95% confidence interval 81.3% to 88.4%). Risk factors for death in multivariable analysis comprised earlier age at surgery, hypoplastic/stenotic pulmonary veins, associated complex cardiac lesions, postoperative pulmonary hypertension, and postoperative PVO. Sixty (14.8%) of the 406 patients undergoing total anomalous pulmonary venous connection repair had postoperative PVO that required reintervention. Three-year survival after initial surgery for patients with postoperative PVO was 58.7% (95% confidence interval 46.2% to 69.2%). Risk factors for postoperative PVO comprised preoperative hypoplastic/stenotic pulmonary veins and absence of a common confluence.

Conclusions—

Preoperative clinical and morphological features are important risk factors for postoperative PVO and survival.

Hypoplastic Circumflex Retroesophageal Right-Sided Cervical Aortic Arch With Unusual Vascular Arrangement and Severe Coarctation

We report the case of a 12-year-old boy with a hypoplastic retroesophageal circumflex right-sided cervical aortic arch and coarctation. After the incidental finding of a heart murmur when the boy was 9 years old, cardiac magnetic resonance showed a right-sided cervical aortic arch, hypoplastic transverse arch, and separate origin of the left common carotid, right common carotid, right vertebral, and right subclavian arteries. The left subclavian artery arose from the proximal descending aorta next to the coarctation. An extra-anatomical ascending to descending aorta tube graft was inserted through a right lateral thoracotomy with good results.

Closure of a large patent ductus arteriosus in adults: first do no harm

See article on page 514

Transcatheter closure of perimembranous ventricular septal defects in infants and children using the Amplatzer perimembranous ventricular septal defect occluder

There are very few published reports of the transcatheter closure of perimembranous ventricular septal defects (PMVSDs) using the Amplatzer PMVSD occluder with encouraging initial results. This report presents initial and 1-year results from 54 patients with PMVSDs who underwent transcatheter closure at 5 different institutions with the Amplatzer PMVSD occluder. Sixty-five patients with PMVSDs were enrolled at 5 European centers. Eleven of the 65 patients did not fulfill the patient selection criteria at the initial echocardiographic evaluation or at cardiac catheterization. As a result, a total of 54 patients underwent attempted transcatheter closure using the Amplatzer PMVSD occluder. The median age of the patients was 5.1+/-3.6 years (range 0.3 to 13), and the median weight 18.5+/-10.3 kg (range 5 to 45). Devices were permanently implanted in 49 of 54 patients. Complete occlusion of the communication at 1-year follow-up was observed in 46 of 49 patients (94%). Main early procedural complications included (1) device embolization (2 patients), (2) severe bradycardia with hemodynamic compromise (2 patients), and (3) Mobitz II (2:1) heart block (1 patient). Late procedural complications included complete heart block (1 patient). No other complications were observed during follow-up. In conclusion, the Amplatzer PMVSD occluder is promising device that can be used for transcatheter closure in selected patients with PMVSDs. Further studies and long-term follow-up are required before this technique enters routine clinical practice.

A retrospective review in 50 patients with subaortic stenosis and intact ventricular septum: 5-year surgical experience

We reviewed the surgical outcomes in adults and children with subaortic stenosis and intact ventricular septum in the current era. The case notes of 50 patients were reviewed for retrospective evaluation of preoperative, intraoperative and postoperative data. Data of primary operations during the period 2000-2005 were compared with data from patients who had re-do surgery during the same period. Thirty-five patients had primary operation and 15 patients had re-do surgery. The median age at primary operation was eight years (range 3 to 44), at second operation was 14 years (range 9 to 26) and at third operation was 15 (range 9 to 47). The entire group had been followed up postoperatively for a median of 2.5 years (range 0 to 5). Pre-operatively, aortic regurgitation was moderate in 13 and severe in three patients. Moderate to severe aortic regurgitation was present in 7 (20%) patients with primary operations and 9 (60%) patients with re-do surgery (P=0.01). Reviewing the first operations of all the re-dos (15 patients) in our series, one patient had myectomy and the rest (14 patients) had isolated resection. Aortic valve regurgitation is more prevalent in patients with recurrent subaortic stenosis. Addition of myectomy is better than shelf resection only.

Pulmonary vein stenosis: initial experience with cutting balloon angioplasty

OBJECTIVE

To determine the safety and effectiveness of cutting balloon angioplasty for pulmonary vein stenosis (PVS).

DESIGN AND SETTING

Retrospective review of case notes and cardiac catheterisation data at the Royal Brompton Hospital.

MAIN OUTCOME MEASURES

Diameter of pulmonary vein, tricuspid regurgitant jet velocity on echocardiogram, and percutaneous oxygen saturation before and after cutting balloon angioplasty.

RESULTS

Three patients had congenital PVS and three had PVS associated with total anomalous pulmonary venous drainage. A total of 27 PVSs were treated during 12 catheterisation procedures. Median patient age at the time of procedure was 12.5 months (range 1.5-36 months) and weight was 7.1 kg (range 2.8-11.1 kg). Minimum pulmonary vein diameter increased significantly on angiography after cutting balloon angioplasty, from mean (SD) 2.3 (0.7) mm to 4.2 (1.9) mm, mean of differences 1.9 mm (95% confidence interval (CI) 0.9 to 2.9 mm, p = 0.0013). Mean (SD) oxygen saturation rose from 79.6 (12.9)% to 83.9 (9.0)%, mean of differences 4.3% (95% CI 0.7% to 8.0%, p = 0.0238). All children's symptoms improved subjectively. Tricuspid regurgitant jet velocity did not change significantly. The longest time interval before repeat intervention was six months. There were no acute deaths; one patient had a small pulmonary haemorrhage and developed a small aneurysm adjacent to the site of angioplasty.

CONCLUSION

Cutting balloon angioplasty is safe in the palliation of PVS in children. It gives some acute relief but often needs to be repeated, as improvement is rarely sustained.

Outcome of transcatheter closure of muscular ventricular septal defects with the Amplatzer ventricular septal defect occluder

OBJECTIVES

To present further experience and intermediate term outcome in 30 patients with single muscular ventricular septal defects (MVSDs) who underwent transcatheter closure with the Amplatzer ventricular septal defect occluder (AVSDO).

PATIENTS AND DESIGN

Thirty patients, aged 4 months to 16 years, with MVSDs underwent transcatheter closure with the AVSDO. The device consists of two low profile disks made of Nitinol wire mesh with a 7 mm connecting waist. The prosthesis size (waist diameter) was selected to be equal to the balloon "stretched" diameter of the defect. A 7-9 French sheath was used to deliver the AVSDO. Fluoroscopy and transoesophageal echocardiography guided the procedure.

RESULTS

The stretched diameter of the defects ranged from 6-14 mm. The communication was completely occluded in 28 of 30 patients (93% closure rate). One patient (a 4 month old infant) with sustained complete left bundle branch block after the procedure went on to develop complete heart block one year later. No other complications were observed during a mean follow up of 2.2 years (range 0.25-4.5 years).

CONCLUSIONS

The AVSDO is an efficient prosthesis that can be safely used in the majority of patients with a single MVSD. Further studies are required to establish long term results in a larger patient population.

Bedside balloon atrial septostomy on neonatal units

Traditionally, neonates with transposition of the great arteries are immediately transferred to a cardiac centre. Travelling to the bedside to perform a balloon atrial septostomy and allowing the child to remain there for a few days before transfer is safe, effective, and a good use of medical resources.

Morphological features pertinent to interventional closure of patent oval foramen

Despite the growing trend of device closure for patent ovale foramens (PFO), the morphology of these lesions is much neglected. A better understanding of the morphological aspects is needed for developing lesion-specific devices. We reviewed ten heart specimens and distinguished two forms of PFO: valve competent and valve incompetent. In the valve-competent form, the thin valve of the oval foramen adequately overlaps the firmer muscular rim of the foramen, leaving a crevice-like aperture sandwiched between the two structures. In contrast, the valve-incompetent form results from aneurysmal ballooning of the valve, or stretching of the muscular rim, creating an interatrial communication in a previously competent flap valve. Distinguishing between the two forms can help in designing and selecting the most appropriate device for implantation.

Percutaneous retrieval of central venous catheter fragments

Children with indwelling central venous catheters are at risk of embolisation of catheter fragments. Often their underlying condition means that they are poor candidates for surgical removal. We describe six children who underwent uncomplicated percutaneous transcatheter retrieval (and one who underwent percutaneous line tip repositioning), and suggest that this approach should be the treatment of choice.

Pulmonary vascular-bronchial interactions: acute reduction in pulmonary blood flow alters lung mechanics

BACKGROUND

Postoperative pulmonary hypertension in children after congenital heart surgery is a risk factor for death and is associated with severe acute changes in both pulmonary vascular resistance and lung mechanics.

OBJECTIVE

To examine the impact of changes in pulmonary blood flow on lung mechanics in preoperative children with congenital heart disease, in order to assess the cause-effect relation of pulmonary vascular-bronchial interactions.

DESIGN

Prospective, cross sectional study.

SETTING

Cardiac catheterisation laboratory, general anaesthesia with mechanical ventilation.

INTERVENTIONS

Variation of pulmonary blood flow (Qp) by either balloon occlusion of an atrial septal defect before interventional closure, or by complete occlusion of the pulmonary artery during balloon pulmonary valvuloplasty for pulmonary valve stenosis.

MAIN OUTCOME MEASURES

Ventilatory tidal volume (Vt), dynamic respiratory system compliance (Cdyn), respiratory system resistance (Rrs).

RESULTS

28 occlusions were examined in nine patients with atrial septal defect (median age 9.5 years) and 22 in eight patients with pulmonary stenosis (median age 1.2 years). Normalisation of Qp during balloon occlusion of atrial septal defect caused no significant change in airway pressures and Rrs, but there was a small decrease in Vt (mean (SD): 9.61 (0.85) to 9.52 (0.97) ml/kg; p < 0.05) and Cdyn (0.64 (0.11) to 0.59 (0.10) ml/cm H(2)O*kg; p < 0.01). These changes were more pronounced when there was complete cessation of Qp during balloon valvuloplasty in pulmonary stenosis, with a fall in Vt (9.71 (2.95) to 9.32 (2.84) ml/kg; p < 0.05) and Cdyn (0.72 (0.29) to 0.64 (0.26) ml/cm H(2)O*kg; p < 0.001), and there was also an increase in Rrs (25.1 (1. 7) to 28.8 (1.6) cm H(2)O/litre*s; p < 0.01). All these changes exceeded the variability of the baseline measurements more than threefold.

CONCLUSIONS

Acute changes in pulmonary blood flow are associated with simultaneous changes in lung mechanics. While these changes are small they may represent a valid model to explain the pathophysiological impact of spontaneous changes in pulmonary blood flow in clinically more critical situations in children with congenital heart disease.

Subclavian flap angioplasty: does the arch look after itself?

OBJECTIVES

We sought to assess the early and long-term results of subclavian flap angioplasty in neonates and infants, with particular attention to growth of the hypoplastic arch.

METHODS

A retrospective analysis of 185 consecutive patients who underwent subclavian flap angioplasty between 1974 and 1998 was carried out. The patients included 125 neonates and 60 infants, with a median age of 18 days. Sixty-six (36%) patients had an additional ventricular septal defect, 41 (22%) patients had aortic arch hypoplasia diagnosed preoperatively, 141 (76%) had an associated patent ductus arteriosus, and 41 (22%) had additional complex heart disease. Follow-up was with transthoracic Doppler echocardiography in all patients.

RESULTS

The early mortality was 3%. Recoarctation, defined as a Doppler gradient of 25 mm Hg or more, occurred in 11 (6%) patients at a median follow-up of 6.2 years (6.2 +/- 4.6 years). This included 4 of the 41 patients in whom arch hypoplasia was diagnosed preoperatively. There were no complications with the left arm. By multivariate analysis, risk factors for death were determined to be residual arch hypoplasia and low birth weight. The only risk factor for recoarctation was persistent arch hypoplasia after surgical treatment. However, angiographic imaging of the aorta showed that recoarctation was not due to a hypoplastic transverse arch, and it was probably at the site of ductal tissue. Survival at 5 and 10 years was 98% and 96%, respectively. Freedom from reoperation for recoarctation at 2 years was 95%, and at 5, 10, and 15 years, it was 92%.

CONCLUSIONS

Subclavian flap repair remains an effective technique for repair of aortic coarctation with excellent results and low mortality. In the majority of patients, arch hypoplasia regresses after this procedure.

L-arginine and substance P reverse the pulmonary endothelial dysfunction caused by congenital heart surgery

BACKGROUND

The increase in pulmonary vascular resistance (PVR) seen in children after cardiopulmonary bypass has been attributed to transient pulmonary endothelial dysfunction (PED). We therefore examined PED in children with congenital heart disease by assessing the L-arginine-nitric oxide (NO) pathway in terms of substrate supplementation (L-arginine [L-Arg]), stimulation of endogenous NO release (substance P [Sub-P]), and end-product provision (inhaled NO) before and after open heart surgery.

METHODS AND RESULTS

Ten patients (aged 0.62+/-0.27 years) with pulmonary hypertension undergoing cardiac catheterization who had not had surgery and 10 patients (aged 0.65+/-0.73 years) who had recently undergone cardiopulmonary bypass were examined. All were sedated and paralyzed and received positive-pressure ventilation. Blood samples and pressure measurements were taken from catheters in the pulmonary artery and the pulmonary vein or left atrium. Respiratory mass spectrometry was used to measure oxygen uptake, and cardiac output was determined by the direct Fick method. PVR was calculated during steady state at ventilation with room air, during FIO(2) of 0.65, then during additional intravenous infusion of L-Arg (15 mg. kg(-1). min(-1)) and Sub-P (1 pmol. kg(-1). min(-1)), and finally during inhalation of NO (20 ppm). In preoperative patients, the lack of an additional significant change of PVR with L-Arg, Sub-P, and inhaled NO suggests little preexisting PED. Postoperative PVR was higher, with an additional pulmonary endothelial contribution that was restorable with L-Arg and Sub-P.

CONCLUSIONS

Postoperatively, the rise in PVR suggested PED, which was restorable by L-Arg and Sub-P, with no additional effect of inhaled NO. These results may indicate important new treatment strategies for these patients.

The nature of the obstructive muscular bundles in double-chambered right ventricle

OBJECTIVE

Our goal was to establish the morphologic nature of the obstructive muscular lesions in double-chambered right ventricle.

METHODS

We based our morphologic observations on 10 normal hearts and on the surgical findings in 26 patients, aged 0.5 to 24 years, with a mean of 6.9 years (SD 5.8 years). In the normal hearts, we measured the distance from the pulmonary valve to the apex of the right ventricle and from the takeoff of the moderator band to the ventricular apex. From angiograms available in 20 patients, using the frontal view, we then measured the distance from the pulmonary valve to the apex of the right ventricle and from the midpoint of the obstructive lesion to the apex of the right ventricle. This permitted calculations of multiple ratios.

RESULTS

In the 10 normal hearts, the moderator band took origin at a mean ratio of 0.48 (SD 0.16) of the ventricular length. On the basis of the angiographic findings, we identified 2 basic forms of double-chambered right ventricle. In 9 patients, the obstructive muscular shelf was positioned low and diagonally across the apical component, with a mean ratio of 0.38 relative to the ventricular length (SD 0.02). In the other 11 patients, the obstructive shelf was high and horizontal, with a mean ratio of 0.27 (SD 0.02). The difference was statistically significant (P =.001). Surgical repair was performed successfully in all 26 patients through a right ventriculotomy.

CONCLUSIONS

Double-chambered right ventricle is the consequence of a high or low muscular division of the apical component of the right ventricle. The abnormal muscular bundle probably represents accentuated septoparietal trabeculations, rather than always being an abnormal moderator band.

The feasibility of complete anatomical correction in the setting of discordant atrioventricular connections

OBJECTIVE

To evaluate the feasibility of anatomical correction based on morphological and echocardiographic findings in patients and preserved hearts with discordant atrioventricular connections.

DESIGN

A retrospective study with clinicomorphological correlations to assess potential contraindications for anatomical correction in the setting of discordant atrioventricular connections.

SETTING

A tertiary referral centre for congenital heart disease.

MATERIAL

25 specimens and 53 patients unified by presence of discordant atrioventricular connections.

METHODS

The potential contraindications for anatomical correction were first evaluated on the basis of morphological findings in all 25 specimens with discordant atrioventricular connections collected in the department museum, including study of the major coronary arterial patterns in 20. These contraindications were then sought in a population of 53 patients examined echocardiographically between January 1992 and October 1997.

RESULTS

At least one lesion was discovered that might have contraindicated anatomical correction in 14 of the specimens and in 16 of the patients. The most common lesions that might militate against the anatomical approach were severe Ebstein's malformation or straddling and overriding of the tricuspid valve, each when combined with hypoplasia of the morphologically right ventricle. Other potential contraindications were atrioventricular septal defect with common atrioventricular junction, and obstruction of the left ventricular outlet combined with a restrictive ventricular septal defect, although these may be overcome with increasing experience and expertise.

CONCLUSIONS

According to the morphological and echocardiographic findings, at least 10 hearts and 37 patients would have produced no anatomical problems for the type of surgical correction in which the morphologically left ventricle is restored its rightful role as the systemic pumping chamber.

Cross sectional echocardiographic assessment of the extent of the atrial septum relative to the atrioventricular junction in atrioventricular septal defect

OBJECTIVE

To study patients with atrioventricular septal defect to determine the pathognomonic morphological features of the lesion and the relation between the septal structures and the atrioventricular junction. Setting : Tertiary level paediatric cardiology centre.

METHODS

Cross sectional echocardiograms from 60 patients were reviewed using qualitative and quantitative analysis. The unifying feature was the presence of a common atrioventricular junction. The overall dimensions of the septal defect were determined and related to the plane of the common junction; the extent of both the atrial and the ventricular septal components was then measured according to the site of closure of the bridging leaflets.

RESULTS

In 48 cases, the common junction was guarded by a common valvar orifice, but in 12 cases there were separate right and left valvar orifices. Irrespective of the valvar morphology, no significant difference was found between the groups in terms of the dimensions of the atrial and ventricular septal components. In all patients, the hole permitting shunting at atrial level extended below the plane of the atrioventricular junction, with a variable position of the leading edge of the atrial septum itself.

CONCLUSIONS

The atrioventricular junction is a common structure irrespective of valvar morphology. In spite of the presence of unequivocal shunting at atrial level, the atrial septum is usually a well formed structure, even extending in some below the level of the common atrioventricular junction.

Increasing workload and changing referral patterns in paediatric cardiology outreach clinics: implications for consultant staffing

OBJECTIVE

To assess the workload of, and referral patterns to, paediatric cardiology outreach clinics to provide data for future planning.

DESIGN

Descriptive study of outpatient attendance during 1991 and 1996.

SETTING

Five district general hospitals with unchanged local demographics and referral patterns during the study period.

METHODS

Postal, telephone, and on site survey of clinic records and case notes.

RESULTS

The number of outpatients increased by 61%, with a consequent increase in the number of clinics held and patients seen in each clinic. The number of patients aged between 10 and 15 years doubled.

CONCLUSION

These data confirm the impression that demands for paediatric cardiology services are increasing. The increased need for attendance at outreach clinics has inevitable consequences for the clinical, teaching, and research activities of specialists in tertiary centres. An increase in the number of paediatric cardiologists, or development of local expertise (general paediatricians with an interest in cardiology), will be required. Furthermore, the increasingly large cohort of older teenagers and young adults with congenital heart disease underscores the need for the development of specialist facilities.

Traumatic damage to the mitral valve during percutaneous balloon valvotomy for critical aortic stenosis

Percutaneous balloon valvuloplasty is now a widely accepted alternative to surgical valvotomy for patients with congenital aortic valve stenosis. Mitral valve anomalies are well known to coexist and influence the prognosis from all palliative procedures. Two cases of mitral valve injury occurring during balloon aortic valvuloplasty are reported, one an 11 month old boy, the other a 2 day old baby boy. Both cases were characterised by an unusually posterior position of the guidewire, over which the balloon was deployed. The wire, and hence the balloon, may have been placed through the tension apparatus of the mitral valve with subsequent damage to its free edge on inflation. This is at least conceptually more likely to occur if the orifice of the valve is posterior, if there is a small left ventricular cavity, or if the mitral valve itself is abnormal-features present in both cases. Possible strategies for decreasing the incidence of such damage are considered.

Anatomical criteria for the diagnosis of sinus venosus defects

BACKGROUND

The diagnosis of sinus venosus defects remains a matter of debate. It is crucial to provide solid anatomical criteria, by identifying the very nature of the atrial septum relative to sinus venosus defects, to diagnose and differentiate them from other interatrial communications.

OBJECTIVE

This study was designed to reestablish the anatomical criteria for the diagnosis of sinus venosus defects.

METHODS

Five specimens with sinus venosus defects from the cardiopathological museum were examined. Study of the abnormal hearts was supplemented by examining the extent and structure of the atrial septum in 10 normal hearts. The echocardiograms and surgical notes were reviewed from 18 patients seen between July 1991 and August 1996 at the Royal Brompton Hospital in London diagnosed preoperatively to have a sinus venosus defect.

RESULTS

The nature of the oval fossa and its muscular borders were identified in the normal hearts. In all three autopsied specimens of the superior variety of sinus venosus defect, the mouth of the superior caval vein was overriding the intact muscular anterosuperior border of the oval fossa. Two specimens thought initially to have the inferior variety of sinus venosus defect were re-classified as having defects within the oval fossa as it was the deficient oval fossa itself, rather than its intact muscular border, that was overridden by the mouth of the inferior caval vein. Sixteen patients had been diagnosed echocardiographically as exhibiting the superior variant of the defect. Retrospective review showed overriding of the superior caval vein across the upper rim of the oval fossa in 12 patients. These findings were confirmed by surgery in 11 patients with the 12th awaiting operation. Overriding of the fossa by the caval vein was not found in the other four patients. Surgery in all of these showed the defect to be within the oval fossa. In two patients diagnosed echocardiographically as having inferior defects, the surgical findings confirmed a biatrial connection of the inferior caval vein in one patient, the findings in the second were equivocal.

CONCLUSIONS

The key anatomical criterion for the diagnosis of sinus venosus defects is overriding of the mouth of the superior or inferior caval vein across the intact muscular border of the oval fossa. The interatrial communication is then formed within the mouth of the overriding vein, and is outside the confines of the oval fossa.

Transcatheter umbrella closure of aorto-pulmonary window

Aorto-pulmonary window (aorto-pulmonary septal defect) is an uncommon congenital cardiac malformation which is repaired using cardiopulmonary bypass. A case is described of an infant with a small aorto-pulmonary window which was closed by transcatheter insertion of a double umbrella device. Complete occlusion of the defect was achieved without complications. Transcatheter umbrella closure of a small aorto-pulmonary window is feasible in infancy and the technique is likely to be applicable in a few cases.

Perforation of the right aortic valve cusp: complication of ventricular septal defect closure with a modified Rashkind umbrella

An 18-month-old boy with a perimembranous ventricular septal defect (VSD) had undergone transcatheter closure of the defect with a modified 17 mm Rashkind umbrella device at age 4 months (weight 3.8 kg). The clinical signs of a VSD persisted, and he developed aortic incompetence, first detected 5 months after the procedure, which progressed from mild to moderate. A three-dimensional echocardiographic study demonstrated that one of the four arms holding the umbrella was protruding into the aortic valve and had perforated the right aortic valve cusp. This diagnosis was confirmed at subsequent surgery. Surgical repair of the perforated right aortic valve leaflet was necessary. The umbrella was adherent to the tricuspid valve and could not be removed. Instead it was left in situ, but three of the stainless steel arms were cut off. When umbrella closure of a perimembranous VSD is undertaken, the close proximity of part of the distal umbrella to the aortic valve can lead to aortic regurgitation.

Open-access paediatric echocardiography: changing role and referral patterns to a consultant-led service in a tertiary referral centre

OBJECTIVES

To evaluate the changing role of an open-access consultant-led paediatric echocardiography service for the detection and assessment of cardiac disease in children.

DESIGN

A retrospective analysis comparing two patient groups undergoing echocardiography over two corresponding six month periods in 1989 and 1994.

SETTING

A tertiary referral centre.

MAIN OUTCOME MEASURES

Patient demographics, indication for echocardiogram, source of referral and findings on scan in new referrals, subsequent follow up arrangements.

RESULTS

The total workload increased by 51% over 5 years but in 1994 fewer neonates were scanned. Patients were referred by hospital paediatricians, community paediatricians, and general practitioners and the number of "new referrals" as a percentage of the total number of patients scanned remained constant. The number of children referred with asymptomatic murmurs who had "normal" echocardiograms increased. Fewer patients were referred directly for surgery in 1994, but the number of children referred for interventional catheterisation rose.

CONCLUSIONS

Open-access echocardiography has an expanding role in the tertiary referral centre despite increasing availability of echocardiography facilities in local hospitals and increased demand in local outreach clinics with paediatricians. Asymptomatic murmurs continue to be the single most common reason for referral of "new patients" and many scans are used to confirm the clinical suspicion of a "normal" heart. The appropriateness of using echocardiography as a screening procedure must be questioned where it would be more logical to refer only the children who present diagnostic difficulty. None the less these data confirm the impression of increasing demands on the paediatric cardiologist, and thus may be useful in planning consultant services within the specialty.