An isolated left common carotid artery from the main pulmonary artery: possible malseptation of the truncoaortic sac

An isolated left common carotid artery (LCA) is an extremely rare condition with only four reported cases. In each case, the isolated carotid artery connects to the right or left pulmonary artery via the ductus arteriosus and the embryologic basis for the abnormalities is believed to reflect an error in the development of the branchial arches. We present a case of an isolated LCA connecting to the main pulmonary artery in association with a right aortic arch and an anomalous origin of the left subclavian artery from the descending aorta. The left ligamentus arteriosus was identified separately. This may represent a disturbance in the septation of the truncoaortic sac secondary to abnormal migration of neural crest cells rather than a pure developmental anomaly of the branchial arches.

Balloon angioplasty of native coarctation of the aorta in infants and neonates: is it worth the hassle?

Balloon angioplasty (BA) for native coarctation of the aorta (CA) in infants and neonates remains controversial with a high incidence of restenosis. The purpose of this study is to analyze our acute and midterm results for BA of native CA in infants and neonates and try to identify factors that may be predictive of outcome. Between September 1991 and June 1999, 17 patients with CA underwent BA at a median age of 3 months (range 2 weeks--9 months) and median weight of 4.8 kg (range 2.8--7 kg). Fourteen patients had discrete CA and 3 had tubular hypoplasia. All patients were hemodynamically stable prior to BA and no patients had critical coarctation requiring prostaglandin E(1) infusion to maintain ductus arteriosus patency. Seven patients had other associated cardiac defects. All patients had significant initial improvement. The mean peak systolic gradient across the CA improved from 43 +/- 15 mmHg to 10 +/- 8 mmHg (p < 0.001), and the mean minimum diameter of the aortic lumen increased from 2.4 +/- 0.9 mm to 5.2 +/- 1.0 mm (p < 0.001). There was no mortality or major complication. At median follow-up interval of 2.7 years (0.15-7.75 years), 10 (59%) of 17 patients are clinically well and have an upper to lower limb systolic blood pressure difference of <20 mmHg. Seven (41%) of 17 patients developed significant restenosis (5 of these patients underwent repeat BA, which was successful in 3 patients). Four (24%) patients underwent surgical repair at a median age of 4.5 months (3--6.9 months) and a median time interval of 4 months (2--6.5 months) from the initial BA. All 3 patients with tubular hypoplasia type of CA underwent surgical repair. No patients developed aortic aneurysm following initial or repeat BA. All patients who underwent surgical repair were 1 month or less in age at the time of their initial BA. We conclude that BA of native CA in infants and neonates can be performed safely with low mortality and morbidity. It appears to offer the best results in patients who are older than 1 month with discrete CA and a well-developed aortic arch. Further restenosis of the discrete CA can be managed successfully by repeat BA.

Phenotypical features of long Q-T syndrome in transgenic mice expressing human Na-K-ATPase alpha(3)-isoform in hearts

To understand why the adult human heart expresses three isoforms of the sodium pump, we generated transgenic mice (TGM) with 2.3- to 5. 5-fold overexpression of the human alpha(3)-isoform of Na-K-ATPase in the heart. Hearts from the TGM had increased maximal Na-K-ATPase activity and ouabain affinity compared with control hearts, even though the density of Na-K-ATPase pump sites (of all isoforms) was similar to that of control mice. In perfused hearts, contractility both at baseline and in the presence of ouabain tended to be greater in TGM than in controls. Surface electrocardiograms in anesthetized TGM had a steeper dependence of Q-T on sinus cycle length, and Q-T intervals measured during atrial pacing were significantly longer in TGM. Q-T dispersion during sinus rhythm also tended to be longer in TGM. Thus TGM overexpressing human alpha(3)-isoform have several of the phenotypical features of human long Q-T syndrome, despite the absence of previously described mutations in Na(+) or K(+) channels.

Early ECG abnormalities associated with transcatheter closure of atrial septal defects using the Amplatzer septal occluder

Conduction abnormalities and arrhythmias may occur in patients following secundum atrial septal defect (ASD) closure using the Amplatzer septal occluder (ASO). Therefore, the aim of this study was to prospectively perform ambulatory ECG monitoring to assess the electrocardiographic effects of transcatheter closure (TCC) of ASD using the ASO device. From 5/97 to 3/99, 41 patients with secundum ASD, underwent TCC using the ASO device at a median age of 9.2[emsp4 ]y. (0.5-87[emsp4 ]y.) and median weight of 34[emsp4 ]kg (5. 6-88[emsp4 ]kg.). Ambulatory Holter monitoring was performed pre- and immediately post TCC. Holter analysis included heart rate (HR), ECG intervals, supraventricular ectopy (SVE), ventricular ectopy (VE), and AV block. No change in baseline rhythm was noted in 37 patients (90%). Changes in AV conduction occurred in 3 patients (7%), including intermittent second degree AV block type II, and complete AV dissociation post closure. SVE was noted in 26 patients (63%) post closure, ranging from 5-2207 supraventricular premature beats (SVPB), including 9 patients (23%) with non-sustained supraventricular tachycardia (SVT), 3 of whom had short runs of SVT prior to closure. A significant increase in post-closure number of SVPB per hour (p=0.047) was noted. No significant difference was noted in PR interval, ventricular premature beats per hour, or QRS duration.

CONCLUSIONS

Based on ambulatory ECG analysis, TCC of ASD with the ASO device is associated with an acute increase in SVE and a small risk of AV conduction abnormalities, including complete heart block. Long term follow-up studies will be necessary to determine late arrhythmia prevalence and relative frequency compared with standard surgical ASD repair.

Long-term outcome of transcatheter coil closure of small to large patent ductus arteriosus

Coil closure of patent ductus arteriosus (PDA) has become an accepted alternative to surgical closure in most pediatric cardiac centers. However, little is known about the mid-to long-term outcome of this procedure. Therefore, we evaluated the immediate, short-, and long-term outcome of transcatheter coil closure (TCC) of PDA using single or multiple Gianturco coils or the Gianturco-Grifka Vascular Occlusive Device (GGVOD). One hundred forty-nine patients underwent an attempt at TCC of their PDAs at a median age of 2.4 years (2 weeks to 55 years) and median weight of 13.5 kg (2.3-87 kg). There were 33 patients < 1 year of age. The median PDA minimal diameter was 2 mm (0.4-7 mm) with 26 patients whose PDA minimal diameter was > 4 mm. A 4 Fr catheter was used for coil deployment in 136 patients, a 3 Fr in 4, and an 8 Fr in 4 patients who received the GGVOD. A single coil was used in 77 patients and multiple coils (2-6) were used in 66 patients. One hundred forty-six patients had successful closure (142 had immediate complete closure and 4 had residual shunt), 3 patients failed the initial attempt (2 underwent surgical ligation and 1 had a successful second attempt a year later). Of the four patients with residual shunt, three underwent a second procedure with implantation of 1-3 coils resulting in complete closure in all and one patient had spontaneous resolution of the residual shunt. Complications were encountered in nine patients: six had coil migration with successful retrieval in four; two had left pulmonary artery stenosis (2.4 kg and 6.3 kg infants), and one patient had loss of femoral arterial pulse. The median fluoroscopy time was 16 min (2-152 min). One hundred forty-two patients had the procedure as an outpatient, five patients stayed greater than 24 hr, and two of these patients were in hospital for 1 month for noncardiac reasons. At a median follow-up interval of 3.0 years (1 month to 5.1 years), there were no episodes of delayed coil migration, delayed recanalization, thromboembolic episodes, or bacterial endocarditis. Lung perfusion scans performed at a median follow-up interval of 1.6 years in 31 patients who received multiple coils revealed 45% +/- 5% blood flow to the left lung. Long-term follow-up of coil closure of PDA indicates that the technique is safe and effective for most patients with PDA up to a diameter of 7 mm.

Bilateral dislocation of the shoulders due to nocturnal hypoglycaemia

A young insulin-dependent diabetic awoke with apparently spontaneous bilateral anterior dislocation of his shoulders. The most likely explanation was nocturnal hypoglycaemia. Similar case reports describing this complication have not been discovered.