Ashby B. Taylor

Lateral Tunnel Versus Extracardiac Conduit Fontan Procedure: A Concurrent Comparison

BACKGROUNDnThe aim of this study was to compare the outcomes of the lateral tunnel (LT) and extracardiac conduit (ECC) Fontan procedures at a single institution over the same time period.nnnMETHODSnFrom November 1995 through October 2002, 70 Fontan procedures were performed: 37 LT and 33 ECC. All were fenestrated; 96% were staged with a prior superior cavopulmonary connection. Compared with the ECC patients, the LT patients were younger (2.7 +/- 1.1 vs 3.9 +/- 2.5 years; p = 0.01), had a higher incidence of hypoplastic left heart syndrome (57% vs 21%; p < 0.01), and a longer aortic cross-clamp time (55 +/- 13 vs 26 +/- 15 min; p < 0.01). Weight, gender, preoperative cardiac catheterization values, and cardiopulmonary bypass time did not differ between the two groups.nnnRESULTSnOperative mortality was 2.8%, 1 patient in each group (p = 1.0). Over the first 24 hours following operation the mean Fontan pressure, transpulmonary gradient, and common atrial pressure did not differ between LT and ECC patients. The median duration of mechanical ventilation (LT 12 vs ECC 18 hours), intensive care unit stay (LT 2 vs ECC 3 days), chest tube drainage (LT 10 vs ECC 8 days), and hospital stay (LT 11 vs ECC 12 days) did not differ. The ECC patients had a higher incidence of sinus node dysfunction both in the postoperative period (27% vs LT 8%; p = 0.09), and persisting at hospital discharge (10% vs LT 0%; p = 0.02). Mean follow-up was 3.6 +/- 1.6 years in LT, and 3.0 +/- 2.2 years in ECC patients (p = 0.2). There was one late death. Actuarial survival at 5 years is 97% for LT, and 91% for ECC patients (p = 0.4); 96% of patients are in NYHA class I, and 4% in class II, with no difference between groups. Sinus node dysfunction was seen during follow-up in 15% LT vs 28% ECC patients (p = 0.2).nnnCONCLUSIONSnThe LT and ECC approaches had comparable early and mid-term outcomes, including operative morbidity and mortality, postoperative hemodynamics, resource use, and mid-term survival and functional status. ECC patients had a higher incidence of sinus node dysfunction early after operation.

Blood pressure, heart rate, pressure-rate product and electrocardiographic changes in healthy children during treadmill exercise

Heart rate, systolic and diastolic blood pressure, rate-pressure product and electrocardiographic changes were measured in 288 healthy children during treadmill exercise. A constant speed (3.5 miles/hour) protocol was used to facilitate the measurements of physiologic data during exercise. Because responses to exercise vary with size, the children were separated into four groups according to body surface area. Comparisons were also made between male and female and between black and white children. The values for heart rate and systolic pressure showed excellent reproducibility in repeated tests. These data establish for clinical use reference values for children during treadmill exercise.

Abnormal Regulation of Circulating 25-Hydroxyvitamin D in the Williams Syndrome

THE Williams syndrome is characterized by the triad supravalvular aortic stenosis, mental retardation, and an elfin facies.1 , 2 In addition, mild microcephaly, neurologic dysfunction, hallux valgus, hernias, pectus excavatum, and other congenital cardiac and vascular defects may be present. The unique facies is characterized by a medial eyebrow flare, short palpebral fissures, ocular hypotelorism, a depressed nasal bridge, periorbital fullness, strabismus, blue eyes, a stellate pattern in the iris, prominent lips, and molar hyperplasia.2 The syndrome is often associated with idiopathic hypercalcemia of infancy, which usually occurs in the first year of life.3 4 5 6 7 8 9 10 11 Patients have increased sensitivity to vitamin D.5 , 6 Balance .xa0.xa0.

Aortoplasty Compared with Resection for Coarctation of the Aorta in Young Children

We repaired coarctation of the aorta in a group of 18 children less than 3 years old, using either resection with end-to-end anastomosis (8 patients, Group 1) or patch graft aortoplasty (10 patients, Group 2). The two groups were similar preoperatively in age, pressure difference between proximal and distal aorta (delta PA0), and severity of aortic arch hypoplasia. Three patients, all less than 2 months old, died early postoperatively. Among the survivors, the right brachial artery systolic pressure was significantly higher in Group 1 (133.1 +/- 7.0 mm Hg) (mean +/- standard error of the mean) than in Group 2 (102.5 +/- 7.2 mm Hg) (p less than 0.05). The delta PA0 was significantly higher in Group 1 (33.0 +/- 7.5 mm Hg) than in Group 2 (5.1 +/- 2.3 mm Hg) (p less than 0.01). Three patients in Group 1 required reoperation and were treated with patch graft aortoplasty; relief of delta PO0 was complete in 2. Patch graft aortoplasty is more effective than resection in reducing proximal aortic systolic pressure and in relieving delta PA0 in infants and small children with coarctation of the aorta.

Growth of the Aorta after Prosthetic Patch Aortoplasty for Coarctation in Infants

We have shown that patch aortoplasty relieves the aortic pressure gradient substantially better than resection with end-to-end anastomosis in infants with coarctation of the aorta. Growth of the intact posterior wall of the unresected coarctation after aortoplasty, however, has not yet been demonstrated to occur. We studied 21 infants less than 2 years of age who underwent prosthetic patch repair of coarctation after 1975. Associated lesions were present in 16 patients, and 12 had a concomitant procedure. Two patients died in the hospital, and 4 died later, all of causes unrelated to the coarctation repair. Systolic blood pressure in the right arm declined from 140 +/- 41 mm Hg (mean +/- standard deviation) preoperatively to 101 +/- 19 mm Hg postoperatively in the whole group and to 95 +/- 12 in 10 patients followed for more than 3 years. The right arm-left leg systolic pressure gradient declined from 66 +/- 22 mm Hg to 5 +/- 14 in all patients and to 4 +/- 13 in the group followed more than 3 years. Hypoplastic transverse arch was seen in all but 2 patients. Its relative diameter increased in 6 of 9 patients who underwent catheterization postoperatively and increased more than 50% in 3 patients. Two patients have evidence of narrowing of the aorta at the patch, but both have normal blood pressure in the right arm. In the patient with longest follow-up, an 8-month-old infant seen 8 years after operation, angiograms show the diameter of the aorta at the coarctation to be greater than that at the transverse arch and at the descending aorta.(ABSTRACT TRUNCATED AT 250 WORDS)

Double-chambered right ventricle

Thirty (10.8%) of 279 patients undergoing correction of a ventricular septal defect (VSD) from January, 1972, to September, 1986, also had a double-chambered right ventricle (DCRV). Age at operation ranged from 1.3 to 18.8 years (mean, 6.7 +/- 4.5 years [+/- standard deviation]). Seventeen patients were male, and 13 were female. Two-dimensional echocardiography was used after 1978 in the initial evaluation of 20 patients; however, the diagnosis of DCRV was made with the use of subcostal views only since 1984 in 4 of 5 patients. Surgical correction consisted of closure of the VSD and resection of anomalous muscle bundles through a right ventriculotomy (28 patients), and right atriotomy (2 patients). All patients survived and are asymptomatic 4.2 +/- 3.4 years following operation. Six patients have undergone catheterization postoperatively and 8 patients had intraoperative pressure recordings. The mean preoperative ratio of right ventricular to left ventricular pressures was 0.67 +/- 0.22 compared with 0.34 +/- 0.15 postoperatively (p less than .001). In 2 patients, DCRV was not recognized preoperatively or at VSD closure through a right atriotomy, and reoperation was necessary after DCRV was demonstrated at postoperative catheterization. DCRV may occur in approximately 10% of patients undergoing correction of VSD. Careful evaluation of echocardiographic and catheterization data preoperatively and careful evaluation of the anatomy intraoperatively are necessary so that DCRV not be overlooked, especially because most VSDs are now closed through the right atrium. Successful correction of VSD and DCRV is associated with excellent long-term results.

Doppler echocardiographic evaluation of streptokinase lysis of thrombosed right-sided St. Jude Medical valves in patients with congenital heart defects

Four episodes of St. Jude Medical prosthesis leaflet thrombosis were serially evaluated by two-dimensional and Doppler echocardiography during treatment with streptokinase. Three patients aged 4, 11, and 24 years with congenital heart disease had St. Jude Medical valves in pulmonary positions (two cases) for tetralogy of Fallot and in the tricuspid position (one case). The duration of thrombosis was not known in any patient. Leaflet immobility and its resolution were demonstrated by echocardiography and were confirmed fluoroscopically. Continuous wave Doppler echocardiography showed abnormal stenotic gradients in thrombosed valves that were reduced after thrombolysis. These studies demonstrate the utility of two-dimensional and Doppler echocardiography in serial evaluation of prosthetic pulmonary and tricuspid valve thrombosis during thrombolysis.

Cardiomyopathy with arrhythmias and ectodermal dysplasia: A previously unreported association

Hidrotic ectodermal dysplasia represents a group of congenital or hereditary disorders that involve ectodermal derivatives. It is characterized by partial or complete alopecia, dystrophic nails, and dental abnormalities. Dilated cardiomyopathy has not previously been reported in association with this illness. We report the cases of three children with fatal dilated cardiomyopathy with associated cardiac arrhythmias and ectodermal dysplasia. Laboratory investigations revealed no specific cause for the cardiomyopathy. It is speculated that this association is not simply coincidental.

Stress testing for comparison of synthetic patch aortoplasty with resection and end to end anastomosis for repair of coarctation in childhood

Excellent clinical results have been achieved by both resection with end to end anastomosis and synthetic patch aortoplasty for the repair of coarctation of the aorta in older children. Increasing experience with exercise stress testing in the postoperative evaluation of patients with coarctation has allowed the discovery of less obvious differences between the two procedures. To evaluate these differences further, the stress tests of 50 postoperative patients who underwent coarctation repair were reviewed: 26 patients with end to end anastomosis and 24 with synthetic patch aortoplasty. Twenty normal control subjects were similarly exercised. Systolic blood pressure in the arm and leg was evaluated before and after the test. Heart rate, electrocardiogram and arm blood pressure were monitored during the test. The mean arm systolic blood pressure was higher at all points of measurement in the patients who underwent repair by end to end anastomosis than in the group who underwent patch aortoplasty. These systolic pressure differences reached statistical significance only for standing arm blood pressure before exercise (p less than 0.05) and for supine arm systolic blood pressure immediately after exercise (p less than 0.01). There was no difference in arm-leg pressure gradient between the two study groups before exercise; however, after exercise the group with end to end anastomosis had significantly higher arm-leg pressure gradients (p less than 0.001). Significant differences between the two types of repair not apparent at rest were found immediately after exercise. The long-term prognostic importance of an exercise-induced arm-leg blood pressure gradient remains to be determined. However, exercise stress testing is sensitive in demonstrating these differences.

Real-time, automated, interactive cardiac electrophysiology testing

We describe a new automated interactive system that performs all of the functions required for complete evaluation of the intracardiac conduction system, for inducing, terminating and analyzing tnchydys‐rhythmias, and for locating and characterizing accessory atrioventricuJar (AV) connections and ectopic foci. In the first year of operation, the system was used to conduct 220 electrophysiology studies. These ranged from simple postoperative evaluation of the conduction system to complete tachycardia studies during pharmacological manipulation of the patient. Patient age at time of catheterization ranged from 6 days to 70 years, with median age of 8 years and 7 months. Advantages accruing from automated electrophysiology testing with this system included great precision and accuracy of timing measurements, flexibility in designing and implementing pacing protocols, and rapid management of induced or spontaneous dysrhythmias. Significant savings of time and labor were achieved by computer generation of reports and graphs as opposed to manual data extraction and plotting. The single most significant advantage is the ability of the system to provide information on a real‐time basis, permitting the electrophysiol‐ogist to analyze, modify, extend or curtail the procedure.