Focal atrial tachycardia originating from the donor superior vena cava after bicaval orthotopic heart transplantation.

An 11-year-old boy, who underwent bicaval orthotopic heart transplantation for idiopathic dilated cardiomyopathy, had a focal atrial tachycardia originating from the donor superior vena cava. The pathogenesis of this tachycardia may be related to transplant rejection or transplant vasculopathy. Radiofrequency catheter ablation can eliminate this unique tachycardia and result in hemodynamic improvement.

Application of head-up tilt table testing in children.

BACKGROUND/PURPOSE: We investigated the application of head-up tilt table testing (HUT) and management of neurocardiogenic syncope (NCS) in children, as pediatric studies are limited. METHODS: Seventy-nine patients (ages 6-18 years) underwent HUT for evaluation of syncope. Patient triggers and premonitory symptoms allowed the clinical diagnosis of NCS or non-NCS. Results were divided into four hemodynamic types (1, 2A, 2B, and 3) according to patient response to HUT. RESULTS: NCS occurred in 65 patients and non-NCS in 14 patients. Isoproterenol infusion significantly increased the sensitivity of the test (from 28% to 45%) and was associated with a slight decrease in the specificity (from 93% to 86%). Subjects in the type 1 group accounted for the majority of responses to the test (69%). There were no complications associated with the test. At follow-up (16.6 ± 9.3 months), the overall recurrence rate was 30.8% but NCS was less severe in most patients. The recurrence rate was similar for patients with a positive or negative HUT and for both pharmacologically and non-pharmacologically treated patients. CONCLUSION: HUT can be safely performed with a high specificity in children, with the sensitivity of HUT improved by isoproterenol. Therefore, a positive response to treatment is reassuring to the physician and family. NCS is generally a self-limited condition despite a high recurrence rate.

The most common site of success and its predictors in radiofrequency catheter ablation of the slow atrioventricular nodal pathway in children.

BACKGROUND: Locating ablation targets on the slow pathway in children as one would in adults may not accommodate the dimensional changes of Koch's triangle that occur with heart growth. We investigated the most common site of success and the effect of a variety of variables on the outcome of slow pathway ablation in children. METHODS: A total of 116 patients (ages 4-16 years) with structurally normal hearts underwent radiofrequency ablation of either the antegrade or the retrograde slow pathway. Ablation sites were divided into eight regions (A1, A2, M1, M2, P1, P2, CS1, and CS2) at the septal tricuspid annulus. RESULTS: Ablation was successful in 112 (97%) children. The most common successful ablation sites were at the P1 region. The less the patient weighed, the more posteriorly the successful site was located (P = 0.023, OR 0.970, 95% CI 0.946-0.996), and the more likely the slow pathway was eliminated rather than modified: median weight was 46.7 kg (range, 14.5-94.3 kg) in the eliminated group and 56.5 kg (range, 20-82.6 kg) in the modified group (P = 0.021, OR 1.039, 95% CI 1.006-1.073). CONCLUSIONS: The most common site of success for slow pathway ablation in children is at the P1 region of the tricuspid annulus. The successful sites in lighter children are more posteriorly located. Weight is also a predictor of whether the slow pathway is eliminated or only modified.

Amplatzer septal occluder-induced transient complete atrioventricular block.

Percutaneous transcatheter atrial septal defect (ASD) closure is a widely used technique that has replaced open-heart surgical closure in many centers. The most common implant is the Amplatzer septal occluder which seems to be a highly effective and safe device. However, there are reports of complications associated with its implantation. We report a 9-year-old boy who presented with complete atrioventricular block after undergoing percutaneous closure of a large secundum ASD with an Amplatzer septal occluder. We treated the patient with oral prednisolone. The patients atrioventricular conduction improved to second-degree Mobitz type 1 block on post-procedure day 24 and first-degree block on day 35. We conclude that patients with Amplatzer septal occluder-induced complete atrioventricular block generally have a good outcome, although it may take several weeks for improvement.

VACTERL Association Complicated with Right-sided Congenital Diaphragmatic Hernia.

We describe a neonate with VACTERL association and right-sided congenital diaphragmatic hernia (CDH). Such coexistence is rare. The lack of symptoms during the early neonatal period, the absence of bowel loops herniated into the right thoracic cavity, and an unfinished surgery led to clinical and radiological diagnostic difficulties. Respiratory distress occurred when the patient was 2 months old. Chest radiology plain film revealed typical findings of right-sided CDH. The diagnosis was confirmed after surgical exploration.

Cardiovascular changes in mucopolysaccharidoses in Taiwan.

From 1991 to 2002, we managed 72 patients with mucopolysaccharidoses. We retrospectively reviewed the records of 37 for whom detailed physical findings and cardiovascular evaluation were available. Twenty patients had serial electrocardiographic (ECG) examinations, and none had arrhythmias. All 20 patients had low R wave voltage in V6. One type VI patient had ischaemic changes secondary to severe cardiomyopathy at the terminal stage of her disease. Among the 37 patients in whom echocardiography was performed, cardiovascular abnormalities progressed with age, although most had mild clinical signs and symptoms. The most common changes were abnormalities of the mitral and aortic valves hypertrophy of the interventricular septum, especially in types I, II, and VI. During the follow-up period of up to 5 years, 3 type II patients and I type VI patient expired. In at least 3 of these patients, death was related to cardiopulmonary failure. As MPS patients are surviving longer, complete cardiac evaluation at regular intervals is mandatory and should be part of their routine assessment.

Cardiac catheterization in low birth weight infants.

BACKGROUND AND PURPOSE: The increased survival of low birth weight infants means that more of these infants may be candidates for cardiac catheterization. There is a lack of data from Taiwan on the results of cardiac catheterization in these infants. This study investigated the outcome of cardiac catheterization in infants weighing less than 2500 g in a single hospital over an 11-year period. METHODS: The records of 41 infants (17 males and 24 females) weighing less than 2500 g at the time of cardiac catheterization from August 1993 to July 2004 were reviewed. Morbidity and mortality were compared between diagnostic and intervention groups. RESULTS: Interventional procedures were performed in 14 and diagnostic catheterizations in 27 infants. These interventional procedures included 5 balloon valvuloplasties for pulmonary stenosis and 1 for aortic stenosis, 1 balloon angioplasty for critical coarctation, 1 aortic valvuloplasty, 1 dilatation for coarctation plus aortic valvuloplasty, 1 temporary pacemaker implantation, and 5 balloon atrioseptostomies. The median age at catheterization was 5 days and the median weight was 2.35 kg. All diagnostic and interventional procedures were successfully performed without mortality. Complications included 2 cases each of arrhythmia, bleeding, apnea, and thromboembolism in the diagnostic group and, in the intervention group, 2 cases each of supraventricular tachycardia and bleeding, and 1 case of linear dissection of a coarctation. CONCLUSIONS: None of the 41 catheterized low birth weight infants died. Furthermore, the complication rate in the intervention group was no higher than in the diagnostic group. We conclude that cardiac catheterization, even with an interventional procedure, can be performed safely in low birth weight infants.

Horseshoe lung with pseudo-ring-sling complex.

We report on a 1-month-old boy who presented with a "horseshoe" lung, complete "O" rings of the trachea, and an unusual course of the left pulmonary artery mimicking a left pulmonary artery sling. Computed tomography, cardiac catheterization, and bronchoscopy were performed to confirm the rare coexistence of these anomalies. To our knowledge, such a combination of anomalies has not been reported in the English-language literature.

Acquired aortic regurgitation after coil occlusion of patent ductus arteriosus.

Some patients with patent ductus arteriosus (PDA) may develop new aortic regurgitation (AR) after coil occlusion. This study evaluated the risk factors for the development of AR after coil occlusion of PDA. A total of 23 patients with PDA were managed with coil embolization over a three-and-a-half-year period. Three patients with pre-embolization AR were excluded. A post-occlusion transthoracic echocardiogram was performed within 24 hours after the procedure. Ten patients developed AR and 10 did not. Gender, age, weight, body surface area (BSA), pulmonary artery pressure, and pulmonary vascular resistance did not differ significantly between the 2 groups. Both larger PDA size (either corrected for weight or BSA, p = 0.008 and 0.002, respectively) and a higher ratio of pulmonary to systemic flow (Qp/Qs) [p = 0.013] were significant risk factors for the development of AR after coil occlusion. Re-evaluation of the patients at 3 and 6 months after the procedure revealed 7 patients still had a regurgitant jet. The results of this study suggest that the larger the PDA and larger the shunt, the greater the likelihood of developing AR after coil occlusion.

Congenital right intermediate bronchial stenosis with carina trifurcation: successful management with slide tracheobronchial plasty.

Congenital bronchial stenosis is rarely described and is difficult to manage. Here we report two cases of right intermediate bronchial stenosis (stenotic orifice with complete cartilage rings). Both cases were associated with ventricular septal defects, and a "trifurcation" pattern was found in both carinas. Both patients underwent surgical repair of the ventricular septal defects but could not be separated from ventilator support despite successful cardiac operations. Slide tracheobronchial plasty was applied to the right intermediate bronchus and lower trachea. After correction of the bronchial stenosis, both patients could be extubated and live without supplementary ventilation support.

Post-traumatic left ventricular aneurysm with massive hemopericardium in a child presenting 3 years after a fall.

A 7-year-old boy developed a left ventricular aneurysm with massive hemopericardium 3 years ago due to a fall from a fourth-floor window. He had mild neurological sequelae including cranial nerve III palsy and abnormal electroencephalography findings at that time. He had no chest pain until recently when he presented with chest tightness and abdominal pain for 2 days prior to admission. Chest X-ray showed marked cardiomegaly. Echocardiography revealed massive pericardial effusion and a large left ventricular aneurysm. The massive hemopericardium was surgically drained, and the aneurysm was resected under cardiopulmonary bypass. He was discharged uneventfully 1 week after operation. Because symptoms and signs can vary in patients with ventricular aneurysm, we strongly suggest a close clinical follow-up, preferably with chest X-ray or echocardiography, for patients experiencing a blunt chest trauma.

Concomitant slide tracheoplasty and cardiac operation for congenital tracheal stenosis associated with VACTERL.

The association of congenital tracheal stenosis and tracheoesophageal (TE) fistula is rare. Here, we report 2 patients with tracheobronchial stenosis (complete cartilage ring) involving the lower trachea and right bronchus. Both patients had associated VACTERL (vertebral anomalies, anal atresia, cardiovascular anomalies, TE, renal, and limb defects) congenital cardiac defects and tracheal diverticula after repair of the TE fistula in type C esophageal atresia. The stenotic segment began at the orifice of the TE fistula, which became diverticula after the TE fistula was repaired. Concomitant repair of congenital cardiac defects and a slide tracheoplasty with elimination of the diverticula were performed successfully.

Restrictive cardiomyopathy in a child.

Restrictive cardiomyopathy in young children is rare and carries a poor prognosis. We report an 18-month-old girl with poor feeding and abdominal distension. Except for hepatomegaly, no other gastrointestinal abnormalities were found. She had normal-sized ventricles but biatrial enlargement. Echocardiography demonstrated normal systolic but impaired diastolic function. Cardiac catheterization revealed a characteristic dip-and-plateau configuration of the right ventricular pressure tracing. The diagnosis turned out to be typical restrictive cardiomyopathy. The patient was maintained on aspirin while awaiting cardiac transplant.

Occlusion of an aberrant artery to an intralobar pulmonary sequestration using an Amplatzer Vascular Plug.

Pulmonary sequestration is a rare anomaly and is conventionally treated with surgical excision. This report describes the successful occlusion of a large aberrant artery to an intralobar pulmonary sequestration using an Amplatzer Vascular Plug.