Chiu Is

Electrophysiological properties of dual atrioventricular nodes in patients with right atrial isomerism.

There are reports that in right atrial isomerism the conduction system has paired sinus nodes and paired atrioventricular nodes. Electrophysiological studies were performed in two patients with right atrial isomerism. One patient had a delta wave on the surface electrocardiogram without tachycardia attacks. The other, who did not have manifest pre-excitation, had recurrent narrow QRS tachycardia. Electrophysiological studies suggested the presence of dual atrioventricular nodes. Only unidirectional atrioventricular or ventriculoatrial conduction was demonstrated for these dual atrioventricular nodes even after infusion of isoprenaline. It is suggested that unidirectional conduction may be a common property of the dual atrioventricular nodes in right atrial isomerism and that the absence of retrograde ventriculoatrial conduction protects the patients against tachycardia.

CT AND MRI FINDINGS IN A CHILD WITH CONSTRICTIVE PERICARDITIS

Abstract. Constrictive pericarditis is rare in children. We report computed tomography (CT) and magnetic resonance imaging (MRI) findings in a 3-year-old girl. She had a swollen abdomen that increased in two months. CT and MRI showed a thickened pericardium (5.2 mm) without calcification. Both atria were enlarged and ventricles were relatively small. The engorged inferior vena cava had 2.8× the diameter of the descending aorta at the same level. Symptoms were dramatically improved after pericardiectomy. The histopathological features confirmed chronic pericarditis.

Evolving strategies and improving outcomes of Norwood stage one reconstruction: a decade experience of a single institution in Taiwan.

AIM The aim of this study was to define the improvement in short-term outcome and risk factors of Norwood stage one reconstruction for hypoplastic left heart syndrome (HLHS) in Taiwan, after implementing new perioperative management strategies. METHODS Data were retrieved from a retrospective chart review of patients with HLHS treated between July 1997 and July 2007. Since we implemented new perioperative strategies in 2004, we divided our patients into two groups, early era (1997-2003) and late era (2004-2007), and compared the outcome. RESULTS We enrolled 48 patients. In the early era group (n=28), the diagnosis was confirmed by cardiac catheterization and controlled ventilation was used to manipulate the balance between systemic and pulmonary blood flow. The survival rate was only 17.9% (5/28). Surgery was performed at 15.2+/-10.7 days, which was significantly later than in the late era group (4.6+/-4.0 days, n=20). A lower preoperative shock and more prenatal diagnoses were recorded for the late era group. RV-PA conduit was used in 17 patients in the late era group of which 12 (70.6%) survived to be discharged from hospital. The risk factor was significant TR (tricuspid regurgitation). CONCLUSIONS With our contemporary perioperative management and change in surgical strategy, survival after first-stage palliation has improved. We believe that our HLHS experience is valuable for low volume centers and also for Asian cohorts.

Computed tomographic virtual cardioscopy in a case of left atrial myxoma

Computed tomographic virtual cardioscopy was used to provide clear and precise visualisation of a myxoma with a stalk arising from the interatrial septum. This technique permits the safe, reliable, and non-invasive diagnosis of intracardiac lesions. This case is presented to assist the cardiovascular surgeon in preoperative planning or in developing a simulation of robotic cardiac surgery.

Echocardiographic features of left juxtaposed atrial appendages associated with dextro-transposition of the great arteries.

We found that echocardiography in cases of left juxtaposed atrial appendage (JAA) consistently featured a malpositioned right atrial appendage, abnormal spatial orientation of the atrial septum, and posterior deviation of the septum secundum toward the left atrium. The qualitative displacement of the septum secundum together with the posterior and leftward displacement of the right atrial appendage (with respect to the great arteries) prompted us to pose questions concerning the morphogenesis of left JAA and the implications for surgery. The importance of precatheterization and preoperative recognition of left JAA in dextrotransposition of the great arteries by echocardiography cannot be overemphasized when planning a balloon atrial septostomy or a biventricular repair.

Demonstration of tracheal stenosis by computed tomography of different modalities and their comparisons : report of one child with congenital stridor and wheezing

Most vascular rings are not associated with intrinsic tracheal anomalies or stenosis other than extrinsic tracheal compression, with the exception of the pulmonary artery sling (l-3). However, we describe an infant presenting with stridor, wheezing and recurrent pneumonia, which is refractory to medical treatment. Preoperative recognition and documentation of intrinsic tracheal stenosis, as well as extrinsic tracheal compression of a vascular ring, which is composed of an aberrant left subclavian artery originating from a right aortic arch, by direct coronal, spiral, and ultrafast or electron beam compute tomography (CT) with three-dimensional reconstruction images, can be therapeutically rewarding in this patient. Respiratory symptoms of wheezing and stridor were alleviated by one-stage cardiothoracic surgery, including division of the aberrant artery and tracheoplasty with pericardial patch (4).