Transcatheter closure of right coronary artery fistula to the right ventricle.

Coronary artery fistula (CAF) is an uncommon anomaly that is usually congenital but can be acquired. Although most patients are asymptomatic, some may present with congestive heart failure, infective endocarditis, myocardial ischemia or rupture. In the past, surgical ligation was the only option in the management of CAF, but since 1983, transcatheter closure of CAF has been increasing as an alternative to surgery. We report a 3-year-old boy, presented in Queen Alia Heart Institute, who underwent successful transcatheter closure of a large fistula communicating the distal part of the right coronary artery to the right ventricle. Our case differs from other CAFs in that the fistula was communicating the right coronary artery itself to the right ventricle.

"Bendy" stents help negotiate hairpin intracardiac curves.

Simple transposition of the great arteries (TGA) occurs in 0.2 per 1000 live births. The condition is surgically repaired in the neonatal period by the arterial switch procedure (ASO) sometimes preceded by an atrial septostomy. The ASO involves transecting the great arteries and relocating them to the appropriate ventriculo-arterial (VA) connection with attachment of the disconnected coronary arteries to the aorta. In the process, the attachment of the pulmonary artery to the right ventricle involves the Le Compte manoeuvre and to achieve this the pulmonary arteries must be fully mobilised and sometimes the main pulmonary artery may require patch augmentation as well. Nevertheless, pulmonary artery stenosis (PAS) is one of the potential problems with the ASO. However, with improved surgical techniques, this has dropped from around 15% in the 1980s to less than 3%. Apart from surgical revision when PAS occurs, there are interventional options which include angioplasty and/or stent insertion. The latter is preferred in small children and works well in around 60% but may require repeat procedures. In older patients or when angioplasty fails, stent insertion can be considered. These procedures may involve negotiating tight bends in order to reach the site of stenosis. The passage of non-premounted stents may be problematic in such situations, especially with longer stents and tighter bends as they tend to slip off balloon. We describe several techniques that may facilitate such interventions, and these were utilised in an adolescent patient who had had ASO for TGA in the neonatal period. These included manually giving the mounted stent a slight bend in order to help the balloon-stent assembly negotiate hairpin bends.

Radiofrequency catheter septal ablation for hypertrophic obstructive cardiomyopathy in childhood.

Two patients, a 5 year old boy with progressive hypertrophic obstructive cardiomyopathy and increasing symptoms despite appropriate pharmacologic therapy and an 11 year old girl with symptoms of tiredness and peak instantaneous LVOT gradient of 80 and 90 mmHg respectively were considered for radiofrequency catheter septal ablation, to relieve the left ventricular outflow tract obstruction. Via a femoral arterial approach, the His bundle was initially plotted and marked using the LocaLisa navigation system. Subsequently, using a cooled tip catheter a series of lesions was placed in the hypertrophied septum, commencing distally in the ventricle and proceeding towards the aortic valve, taking care to stay away from the His bundle. The procedure was deemed to be completed when the entire extent of the hypertrophied septum had been treated. In the boy the procedure was complicated by two episodes of ventricular fibrillation, requiring DC cardioversion, but without any neurologic sequelae. The peak to peak gradient between left ventricle and aorta was 50 mmHg and 60 mmHg respectively pre-ablation, and remained unchanged immediately after. Both patients were discharged from the hospital 48 hours later. Serial measurement of serum Troponin T and CK-MB isoenzyme confirmed significant myocardial necrosis. Follow-up echocardiography at 7 days and at 6 weeks post-ablation respectively confirmed a beneficial hemodynamic result, with reduction of left ventricular outflow obstruction and relief of symptoms. In young children, in whom alcohol induced septal ablation is not an option, radiofrequency catheter ablation offers an alternative to surgery, with the benefits of repeatability and a lower risk of procedure-related permanent AV block.

Percutaneous transhepatic dual chamber pacing in children with Fontan circulation.

Permanent pacing is often required following the Fontan operation and is usually performed epicardially as there is no direct access to the ventricle from the systemic veins. Dual chamber endocardial pacing was achieved by the transhepatic approach in two children with Fontan circulation. The patients were a 7 year old boy with left atrial isomerism, single ventricle with pulmonary stenosis, interrupted inferior vena caval vein with azygous continuation, and direct drainage of the hepatic veins to the right sided atrium, and a 6 year old girl with tricuspid atresia. This approach to endocardial pacemaker implantation is potentially of considerable value in patients who do not have direct access to the ventricle from the systemic veins.

Endocarditis caused by Haemophilus parainfluenzae identified by 16S ribosomal RNA sequencing.

Haemophilus parainfluenzae, a human commensal, is an infrequent cause of serious disease. A case of endocarditis caused by this organism in a five year old boy with complex congenital heart disease is reported. The course of this disease was very aggressive, leading to heart failure, disseminated intravascular coagulation and multiorgan failure in spite of appropriate antibiotics and surgical intervention. The difficulties in the detection and identification of H parainfluenzae using conventional culture based technology, and the potential role of molecular techniques, are highlighted.