Balloon angioplasty for congenital mitral stenosis.

We attempted balloon angioplasty in 9 children (ages 0.1 to 10 years) with congenital mitral stenosis. All were symptomatic with severe congestive heart failure and failure to thrive. Effective reduction in mitral gradient was initially achieved in 7 patients. For the entire group, mean valve gradient decreased from 14.8 +/- 5.0 to 8.1 +/- 6.7 mm (p = 0.0007) and mean valve area increased from 1.1 +/- 0.5 to 1.8 +/- 0.9 cm2/m2 (p = 0.003). More than mild mitral regurgitation developed in 2 patients but none required surgery for mitral regurgitation. Poor gradient relief followed dilation of valves with unbalanced chordal attachments, with restriction to the valve apparatus as in mitral arcade, and where the obstruction was not purely valvar as it is with a supramitral ring. No strokes, infection or deaths were due to the procedure. Based on these data, balloon angioplasty of congenital mitral stenosis should be considered before mitral valve replacement in younger patients and in those in whom mitral valve replacement would be problematic.

Balloon aortic valvuloplasty: results of the Valvuloplasty and Angioplasty of Congenital Anomalies Registry.

Data from 204 children and infants who underwent aortic balloon valvuloplasty between 1982 and 1986, reported to the Valvuloplasty and Angioplasty of Congenital Anomalies Registry, were reviewed. Valvuloplasty was successful in 192 of 204 children, reducing the peak systolic left ventricular ejection gradient from 77 +/- 2 to 30 +/- 1 mm Hg, p less than 0.001. The same degree of aortic stenosis gradients reduction was noted in both the 38 children under 1 year of age and in the 166 children over 1 year of age. Significant complications included death, aortic regurgitation and femoral artery thrombosis or damage. The incidence of these complications correlated with the age of the child, the ratio of valvuloplasty balloon size/anulus size, or both. The data suggest that percutaneous balloon valvuloplasty provides effective acute relief of valvar aortic stenosis in both infants and children. However, long-term follow-up data are necessary before balloon valvuloplasty can be established as a treatment of choice for congenital valvar aortic stenosis.

Ventricular trabeculations in the chick embryo heart and their contribution to ventricular and muscular septal development.

Sixty-two chick embryo hearts were studied at incremental stages of development (Hamburger-Hamilton stages 16 to 39) by scanning electron microscopy following 3% glutaraldehyde fixation and critical point drying. Early in cardiac development, the primitive ventricle becomes homogeneously trabeculated with highly organized sheets of myocytes lined by endocardial cells, with the trabeculae generally oriented in the dorsoventral direction. Coalescence of these trabecular sheets begins at stage 26, initially at the area of the bulboventricular flange, and later proceeding caudally toward the floor of the ventricle. The fusion process is finished by stage 30, resulting in a muscular ventricular septum that has now divided the primitive ventricle into right and left ventricles. Further growth of the ventricular septum is by continued fusion of the adjoining trabecular sheets. Remnants of the apposing trabecular sheets are found in the solidified muscular septum in the form of endocardial channels. We suggest that persistent patency of these channels results in muscular ventricular septal defects.

Intelligence and hypoxemia in children with congenital heart disease: fact or artifact?

Previous studies have reported lower intelligence for cyanotic than for acyanotic children with congenital heart disorders, a finding attributed to the degree of hypoxemia present. Several important variables have not been examined consistently, however, including coexisting neurologic or genetic disorders, definitive surgery, degree of sickness, age at testing sex and social class. The present study examined the relation of these variables to obtained intelligence measures for 82 consecutively admitted children, excluding children with abnormal neurologic examinations and those having received definitive surgery. Consistent with earlier reports, intelligence quotients for the acyanotic children (112.81 +/- 14.52 mean +/- SD) were significantly higher (t = 2.60; p = 0.006) than for the cyanotic group (103.50 +/- 15.81). Although sex, race and social class were not significantly different between the 28 cyanotic and the 54 acyanotic children, the cyanotic children were significantly sicker (x2 = 9.12; p = 0.005) and younger (t = 4.10; p = 0.001). However, when young and old children and the degree of sickness within cyanotic and acyanotic groups were compared, no significant differences were found. These findings demonstrate that intelligence differences between cyanotic and acyanotic children persist when the effect of neurologic abnormalities and definitive surgery is removed and remain despite the severity of sickness or child's age at testing.

Acute continuous argon-laser induced tissue effects in the isolated canine heart.

Fresh isolated myocardial, elastic-arterial, and valvular tissues from seven canine hearts were irradiated by argon laser. Irradiation was transmitted through 300 and 400 micron flexible quartz fiberoptic elements. Minimal power densities for vaporization of the myocardial, arterial, and valvular tissues were 80, 90, and 110 W/cm2, respectively, with maximal vaporization distances (fiberoptic tip to tissue) of 4 mm, 1 mm, and 1 mm, respectively. Irradiation of the valves at power densities approaching perforation caused contraction of the tissue. When tissue vaporization occurred, histologic examination of irradiated tissues showed a central crater surrounded by sequential layers of char, vaporization, and coagulation necrosis. These findings were common to all cardiac tissues. Additional findings unique to myocardium were a normal-appearing myocardial layer (skip-area), circumferential halo, and tissue clefts. Elastic arteries showed concentration of necrosis around the collagen and elastic fibers. Valvular damage was the most extensive and also included contraction of adjacent valvular tissue and endocardial sloughing.

Hemitruncal sling: a newly recognized anomaly and its surgical correction.

A new type of vascular ring formed by a hemitruncal pulmonary artery is described. Early reimplantation of the hemitruncal pulmonary artery resulted in resolution of the respiratory distress, protection of the pulmonary arterial bed from obstructive vascular disease, and preparation of the pulmonary artery for future surgical correction.

Development of infundibular obstruction after percutaneous pulmonary balloon valvuloplasty.

A 14 month old boy with suprasystemic right ventricular pressure secondary to pulmonary valvular stenosis and anular size of 10 mm underwent percutaneous balloon valvuloplasty with a 12 mm balloon. Right ventricular pressure almost doubled after valvuloplasty and the electrocardiogram revealed development of severe right ventricular strain. Both findings persisted on the following day. A postvalvuloplasty right ventriculogram demonstrated a severe systolic infundibular obstruction not present before. The patient underwent surgical relief of infundibular obstruction; successful opening of the pulmonary valve by the balloon valvuloplasty was observed. It is concluded that a balloon size 20% larger than anular size can be safe in human subjects and that infundibular obstruction may appear or even worsen after balloon valvuloplasty. Such an obstruction may be related to the severity of pulmonary valvular obstruction and a hypercontractile infundibulum.

Neurologic sequelae of cardiac catheterization.

Neurologic complications are a known and at times tragic consequence of cardiac catheterization. During a four-year period, 1,362 procedures were performed at our institution on children less than 15 years of age. Eighteen children, without prior nervous system disease, developed neurologic sequelae within 24 hours of cardiac catheterization (1.3%). Three presented with seizures only, ten with neurologic deficits, and five with both focal seizures and stroke. Computerized tomography scans (16 patients) demonstrated areas of nonhemorrhagic infarction in all but one. The 18 patients were studied retrospectively for possible factors contributing to the neurologic complications. They were matched to controls by age, cardiac lesion, and catheterization technique. Data examined included catheterization duration and approach, contrast agent, precatheterization urine specific gravity, pre- and postcatheterization hematocrit, blood loss, and intracatheterization events. Catheter and catheter sheath clots were noted in both patient groups. The neurologic complication group had 7/18 intracatheterization neurologic events versus only one in the controls and the change in hematocrit was greater in the complication group (t = 2.89, p less than 0.01). Due to this study's results and to prevent possible thromboembolic events, a heparinization protocol was instituted and patients were prospectively observed for neurologic complications. No neurologic complications have occurred over three years since the institution of this protocol.

Separation of neointima from Dacron graft causing obstruction. Case following Fontan procedure for tricuspid atresia.

A nine-year-old patient with tricuspid atresia and normally related great vessels underwent a Fontan procedure, in which a porcine valved Dacron conduit was interposed between the right atrium and pulmonary trunk. After death, 6 months postoperatively, pathological examination revealed a thick layer of neointima (peel) lining the conduit. The peel was thicker in the segment of the conduit proximal to the valve, where it measured up to 4.5 mm in thickness. Proximal to the valve, the peel had separated from the wall of the graft and a hematoma had developed between the separated peel and graft. The result was reduction in the caliber of the conduit to about half the original. The patient's final illness was complicated, being associated with acute pancreatitis. Reduction in the caliber of the graft may have contributed to the death.

Embolization of multiple pulmonary artery fistulas.

Therapeutic embolization of pulmonary arteriovenous fistulas is described as an alternate method of treatment for patients with diffuse pulmonary involvement in whom resection is not feasible.

Intoxication with ajmaline in an infant.

We present a case of overdosage of ajmaline in an infant. The appearance of atactic gait and clonic tonic seizures were followed by loss of consciousness, apnea, supraventricular tachycardia, left bundle-branch block, and a prolonged Q-T interval. Cardiopulmonary resuscitation, gastric lavage, and forced diuresis were followed by complete recovery. Continuous electrocardiographic monitoring is mandatory in these cases, and the use of a cardiac pacemaker, respirator, and therapy with antiarrhythmic agents should be considered.