Unusual cardiac malformations in conjoined twins: thoracopagus twins with conjoined pentalogy of Cantrell and an omphalopagus twin with atretic ventricles.

Two unrelated cases of conjoined twins were found to have cardiac malformations that apparently have not been reported previously. In one case, thoracopagus twins had an extensive thoracoabdominal wall defect that resulted in ectopia cordis of a conjoined heart along with evisceration of the shared liver and intestine along with one spleen. These malformations, accompanied by defects in the sternum, diaphragm, and supraumbilical abdominal wall, constitute a conjoined pentalogy of Cantrell. In the second case, the heart of one of omphalopagus twins consisted of a solid ventricular mass with only a minute aortic cavity but no atrioventricular communication-an ineffective heart that could develop only in a conjoined or chorioangiopagus twin. In both cases, a common atrium lay in the primitive (embryologic) position caudal to the ventricles.

Wire-snare technique with distal flow control for coil occlusion of a modified Blalock-Taussig shunt.

Coil occlusion of Blalock-Taussig shunts has been associated with a high rate of device embolization. We describe a technique consisting of transvenous snaring and exteriorization of a guidewire advanced through a modified left Blalock-Taussig shunt, allowing distal shunt flow control and successful coil occlusion of the shunt. Cathet. Cardiovasc. Intervent. 49:51-54, 2000.

Atrial septostomy as a bridge to lung transplantation in patients with severe pulmonary hypertension.

Long waiting times for lung transplantation have limited the survival of patients with advanced pulmonary hypertension. Atrial septostomy has been used in this group of patients in an attempt to prolong survival. We evaluated the results of atrial septostomy in 12 patients using the static graded balloon dilation technique. Between December 1990 and May 1998, 10 women and 2 men (ages 13 to 56 years, mean 37 years) underwent atrial septostomy. Nine patients had primary and 3 patents had secondary pulmonary hypertension. Five patients deteriorated despite long-term intravenous prostacyclin infusions. The atrial septum was crossed with a Brockenbrough needle, followed by an 0.035-J exchange wire and progressively larger catheter balloons for atrial septal dilation, until systemic oxygen saturation decreased 5% to 10%. An atrial septal defect was successfully created in each patient. The mean right atrial pressure decreased from 23 to 18 mm Hg and the mean systemic oxygen saturation decreased from 93% to 85%. The mean cardiac index increased from 1.7 to 2.1 L/min/m2 and the mean systemic oxygen transport increased from 268 to 317 ml/min/m2. Complications occurred in 3 patients: transient hypotension during transesophageal echocardiography, a femoral pseudoaneurysm, and a femoral arteriovenous fistula. After septostomy, 6 patients had clinical improvement (resolution of ascites, edema, and no further episodes of syncope); 5 of these 6 patients underwent lung transplantation a mean of 6.1 months after septostomy. Six patients did not have clinical improvement after septostomy. Atrial septostomy improves the hemodynamic status and may be useful as a bridge to lung transplantation in selected patients with pulmonary hypertension.

Percutaneous coil occlusion of ascending aorta to pulmonary artery shunts.

Two patients with pulmonary atresia and intact ventricular septum each underwent early palliative surgery with a pulmonary valvotomy and an ascending aorta to pulmonary artery shunt. Adequate right ventricular growth and relief of pulmonary stenosis rendered the shunts unnecessary. The shunts were successfully occluded percutaneously with Gianturco coils.

Balloon angioplasty of native aortic coarctation in infants 3 months of age and younger.

The use of balloon dilation to treat native aortic coarctation is controversial, particularly in infants. Between January 1991 and September 1996, 12 patients < or = 3 months of age with native coarctation of the aorta (CoA) underwent balloon angioplasty (BA). All 12 lesions were dilated successfully with a mean reduction in peak systolic gradient from 49.3 +/- 16.5 mm Hg to 6.8 +/- 4.0 mm Hg (p < 0.001) and a mean increase in minimum CoA diameter from 2.4 +/- 0.6 mm to 5.5 +/- 1.3 mm (p < 0.001). Intimal flaps or tears were detected immediately after BA in 4 (33%) of 12 patients by angiography and in 8 (89%) of 9 patients by intravascular ultrasonography. No deaths or major complications related to the BA occurred. One patient had documented asymptomatic femoral artery obstruction, and one patient with hydrops fetalis and congenital pleural effusions died with gram-negative sepsis 1 week after the procedure. Follow-up was available for 10 patients (1 was lost to follow-up) between 2 months and 4.1 years (mean 2.4 +/- 1.3 years) after BA. No patient had an aortic aneurysm. Restenosis occurred in 5 (50%) of 10 patients, requiring reintervention a mean of 2.6 +/- 2.1 months after BA. One patient underwent surgical repair. Repeat BAs were performed in the other four patients; three were successful, and one with partial gradient relief required surgical repair. Five patients have not required reintervention a mean of 2.9 +/- 1.0 years after the initial BA. Among these five patients, follow-up intravascular ultrasound performed in three patients a mean of 2.0 +/- 1.9 years after BA showed favorable endovascular remodeling. There was a tendency for early reintervention in patients < 1 month of age and coexistence of a patent ductus arteriosus at the time of BA. In conclusion, selected infants < or = 3 months of age with discrete native CoA may be treated initially with balloon dilation. Most patients who have restenosis respond successfully to repeat BA.

Familial occurrence of pulmonary atresia with intact ventricular septum.

Pulmonary atresia with intact ventricular septum (PA/IVS) is a rare disease, accounting for less than 3% of all congenital heart lesions. The cause of PA/IVS is unknown. We report the occurrence of two first cousins with PA/IVS, suggestive of autosomal dominant inheritance with incomplete penetrance. The study of such families should ultimately lead to the identification of the gene(s) that cause congenital heart disease.

Percutaneous coil occlusion of patent ductus arteriosus.

OBJECTIVE: To determine the success rate and safety of percutaneous patient ductus arteriosus (PDA) coll occlusion. DESIGN: Thirty consecutive pediatric patients with small to moderate-size PDAs (minimum diameter < or = 4 mm) underwent percutaneous coll occlusion. The results were assessed by angiography and echocardiography. The mean age was 5.1 +/- 4.2 years (range, 0.8 to 18.8 years); mean weight was 19.2 +/- 10.3 kg (range, 8.1 to 40.0 kg). The mean minimum diameter of the PDA was 1.8 +/- 0.8 mm (range, 1.0 to 4.0 mm). RESULTS: PDA occlusion was achieved with one coil in 24 patients, 2 coils in 3 patients and 3 coils in 3 patients. The mean coil/PDA diameter ratio was 2.5 +/- 0.5. Immediately after coil occlusion, 29 PDAs had no flow by anglography; one had a small residual shunt. There were no significant complications. In the first 24 hours after coil implantation, echocardiography showed complete occlusion in 28 patients, a small left-to-right shunt in the same patient that had a residual shunt by anglography, and a trace shunt in one additional patient. In the two patients with residual flow by echocardiography, follow-up ultrasonography revealed no residual shunt 1 and 3 months later. At a mean follow-up of 11.8 +/- 9.3 months (range, 0 to 36.0 months), there was no PDA flow by color Doppler echocardiography in any of the 30 patients. CONCLUSION: Coil occlusion is a safe and effective method of percutaneous closure of small to moderate-size PDAs. The largest PDA that can be closed with this technique remains to be determined.

Comparison of results of stent implantation in small (<20 kg) children versus larger children with pulmonary artery stenoses.

We compared the results of stent implantation for pulmonary artery stenoses in patients weighing <20 kg (group 1, 17 patients, 21 stents) versus those weighing > or = 20 kg (group 2, 11 patients, 13 stents). There was no significant difference in the mean percent increase in diameter or mean percent gradient reduction acutely and at short-term follow-up between group 1 and 2 patients.

Successful balloon dilation of an abdominal coarctation of the aorta in patient with presumed Takayasu's aortitis.

An 11-year-old male with a severe abdominal aortic coarctation, presumably secondary to aortitis, underwent successful percutaneous balloon dilation that resulted in near-complete relief of the obstruction. Intravascular ultrasound imaging showed a major endovascular tear immediately following dilation and satisfactorily excluded significant branch (superior mesenteric) artery compromise. Arterial remodeling was demonstrated with persistence of the gradient relief over a 12-month follow-up period.

Accessory hepatic vein to pulmonary venous atrium as a cause of cyanosis after the Fontan operation.

The presence of an accessory hepatic vein to the pulmonary venous atrium should be considered in the setting of progressive cyanosis following the Fontan procedure. An inferior vena caval angiogram with "levo-phase" should demonstrate it. Surgical intervention or transcatheter occlusion should lead to prompt resolution of cyanosis.

Atrioventricular situs concordance with atrioventricular alignment discordance: fetal and neonatal echocardiographic findings.

Fetal echocardiography can reliably assess visceroatrial situs, ventricular morphology, and atrioventricular and ventriculoarterial alignments. The echocardiographic findings of this case were consistent with visceroatrial situs solitus, atrioventricular alignment discordance, and ventriculoarterial alignment concordance. This arrangement is almost always associated with ventricular inversion, or L-looped ventricles, and has therefore been widely referred to as isolated ventricular inversion. Rarely, as in this report, the arrangement may be associated with D-looped ventricles. Fetal and neonatal echocardiography may distinguish situs concordance with atrioventricular alignment discordance from isolated ventricular inversion in situs solitus by the presence, in the former, of superior-inferior ventricles, an anterior right ventricle, and a tricuspid valve that is anterior and to the right of the pulmonary valve, consistent with D-looped ventricles.

Multiple coronary thromboemboli and myocardial infarction in a newborn infant.

We report the case of a newborn infant with myocardial infarction caused by thromboembolic occlusion of the left main coronary artery. The clinical presentation was similar to that of hypoplastic left heart. This infant had no condition previously associated with perinatal myocardial infarction. Recognition and management of this rare condition, including the use of thrombolytic therapy, and the implication of deficient natural anticoagulant factors as a cause are discussed.

Epinephrine absorption following endotracheal administration: effects of hypoxia-induced low pulmonary blood flow.

To investigate the effects of hypoxia-induced decreased pulmonary blood flow on the trans-pulmonary absorption of epinephrine, we measured pulmonary blood flow and arterial plasma tritium counts per minute following endotracheal [3H]epinephrine administration in six chronically instrumented newborn lambs. The lambs were ventilated alternately with room air and with an hypoxic gas mixture sufficient to decrease pulmonary blood flow to approximately 50% of baseline values. Using this model, we found that hypoxia-induced low pulmonary blood flow did not lead to lower concentrations of epinephrine following endotracheal administration, but rather higher concentrations (P < 0.03). In all six lambs, counts per minute of tritium were higher following administration during low pulmonary blood flow. There was a negative correlation between pulmonary blood flow and arterial plasma tritium counts per minute (r = -0.64, P < 0.03). We conclude that trans-pulmonary absorption of epinephrine is not decreased during times of hypoxia-induced low pulmonary blood flow. These data lend support to the clinical practice of intratracheal epinephrine administration during neonatal resuscitation.

Effects of graded doses of epinephrine during asphxia-induced bradycardia in newborn lambs.

To study the hemodynamic effects of graded doses of epinephrine (EPI) in a newborn animal model of hemodynamically significant bradycardia, we performed the following study. Ten newborn lambs were chronically instrumented with catheters and flow transducers so that systemic, pulmonary arterial, left atrial and right atrial pressures as well as heart rate, cardiac output and left carotid artery flow could be monitored. During each of five asphyxia induced bradycardia episodes, with cardiac output depressed to approximately 30% of baseline, lambs were given either 0, 1, 10, 50, or 100 micrograms of EPI in a randomized sequence. After 30 s, the lambs were resuscitated with room air ventilation while hemodynamic parameters were monitored. During asphyxia and prior to EPI administration, all hemodynamic parameters were similar. In addition, for the first 30 s following EPI administration, hemodynamic parameters continued to deteriorate in a manner that was not influenced by the dose of EPI administered. During the resuscitation period with resumption of ventilation, systemic blood pressure and coronary perfusion pressure rose higher following 50 and 100 micrograms/kg of EPI than after the smaller doses. Heart rate was highest following the 100 micrograms/kg dose. Stroke volume and cardiac output, however, appeared to be blunted by the 100 micrograms/kg dose of EPI with no differences in carotid flow noted by dose of EPI administered. It appears that doses of EPI greater than 10 micrograms/kg, the dose currently recommended by the American Heart Association, may be beneficial as an adjunct in treatment of hemodynamically significant bradycardia. However, doses as high as 100 micrograms/kg may blunt cardiac output and stroke volume and should be used with caution.

Disposition and pharmacodynamics of methamphetamine in pregnant sheep.

To determine the placental transfer of methamphetamine, its subsequent fetal disposition, and its hemodynamic effects, we administered methamphetamine intravenously to 15 pregnant ewes 3 days after placement of maternal and fetal vascular catheters. Methamphetamine crossed the placenta within 30 seconds of its administration. Although the ewes had higher peak concentrations, the fetuses' longer elimination half-life ultimately led to higher fetal than maternal methamphetamine concentrations. The ratio of fetal tissue to plasma drug concentration 2 hours after administration was highest in the lung, followed by the placenta, kidney, intestine, liver, brain, and heart. Methamphetamine caused a 54% to 63% rise in maternal blood pressure, a 20% to 37% increase in fetal blood pressure, and a drop in fetal oxyhemoglobin saturation and arterial pH. We conclude that methamphetamine, in doses at or below what is commonly abused, has effects that could be detrimental to the health of the mother and her fetus.