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Biomedical subjects

L A Latson

Publications and source records attributed to L A Latson.

At least 37 records · Page 2Linked to original sources
PubMed1995

Improvement in noninvasive electrophysiologic findings in children after transcatheter atrial septal defect closure.

To evaluate whether transcatheter closure of secundum atrial septal defects (ASD) affected noninvasive electrophysiologic variables in children, we reviewed the pre-procedural and 1-year postprocedural electrocardiograms and Holter recordings of 18 consecutive children referred for ASD closure. Patients included in the study were a mean of 5.0 years old (SD 1.1) and weighed a mean of 17.9 kg (SD 4.1). ASDs had a mean diameter of 14.0 mm (SD 2.4) and average shunt ratio (pulmonary-to-systemic flow) of 2.1:1. One year after occluder device placement, 9 children (50%) had detectable residual shunts by transthoracic echocardiograms, but only 2 (11%) had shunts that were felt to be possibly significant. One or more fractured occluder legs were noted by chest roentgenogram in 15 patients (83%). Electrocardiograms at follow-up demonstrated improvement in right ventricular dilation in 4 of 7 patients, right atrial enlargement in 3 of 4 patients, and 1 degree atrioventricular block in 2 of 3 patients. Holter recordings showed a decreased incidence of accelerated atrial rhythm in 3 of 7 patients, prolonged junctional escape rhythm in 2 of 2 patients, and premature atrial contractions in 2 of 2 patients. No finding correlated with patient age, defect or occluder diameter, occluder leg fracture(s), or residual defects. These improvements in electrophysiologic abnormalities compare favorably with changes seen 1 year after surgical closure. In conclusion, placement of a transcatheter ASD device in children diminishes noninvasive electrophysiologic abnormalities at 1-year follow-up. By relieving hemodynamic stress caused by an ASD in childhood, a transcatheter device may prevent arrhythmia disturbance later in life.

Cardiac Catheterization↗
PubMed1995

Transcatheter embolization coil closure of patent ductus arteriosus--modified delivery for enhanced control during coil positioning.

The use of Gianturco coils (Cook, Inc., Bloomington, IN) has been recently described as a method of occluding restrictive patent ductus arteriosus (PDA). Precise control of the coil during positioning or withdrawal is difficult. We designed an inexpensive and readily available system to control the coil during delivery and repositioning. A 5 French Mallincrodt vertebral catheter was heat tapered to allow slight, but definite resistance of a 0.035" guide wire when it was passed through the catheter. The delivery system has been used to successfully coil occlude restrictive PDAs in seven patients. The system has added no additional costs to the procedure and has provided improved control of the coil position prior to release of the coil.

Cardiac Catheterization↗
PubMed1995

Surgical repair of severe bilateral branch pulmonary artery stenosis.

Management options for severe, bilateral branch pulmonary artery stenosis include percutaneous balloon dilation and direct surgical correction. Results with both balloon angioplasty and operation have been somewhat unpredictable. We report a case of staged surgical correction involving bilateral branch pulmonary artery reconstruction.

Anastomosis, Surgical↗
PubMed1994

Endocarditis risk of the USCI PDA umbrella for transcatheter closure of patent ductus arteriosus.

BACKGROUND: The USCI PDA Umbrella is a device to close patent ductus arteriosus (PDA) by a transcatheter technique. Human clinical trials have shown excellent efficacy in reducing or eliminating the PDA shunt, but concerns remain about the risk of infection with this device. The purpose of this study was to evaluate the risk of infection using an animal model. METHODS AND RESULTS: Susceptibility to developing endocarditis was tested by injecting a single intravenous dose of group L streptococcus. Ten piglets with a closed ductus served as controls. Two of these developed valvular vegetations. PDA was produced in 19 animals by balloon dilation of the ductus. Seven of 7 animals with PDA at the time of bacterial injection developed endarteritis of the ductus and valvular vegetations. A PDA Umbrella was placed in the remaining 12 animals, and bacteria were injected 2 weeks after device implantation. Infection was evident in the PDA Umbrella only in the single animal in which the Umbrella had embolized and been left in the left pulmonary artery. Three of the remaining 11 piglets had a significant residual leak, and all developed infection in the ductus and an additional valve. Similar to the control group, none of the animals with complete (n = 8) or nearly complete (n = 2) closure of the ductus by the PDA Umbrella had infection in or around the ductus, and only 1 had a valvular vegetation. CONCLUSIONS: In this animal model, presence of a significant PDA shunt (with or without a PDA Umbrella present) results in significantly increased susceptibility to endarteritis and endocarditis. The PDA Umbrella device does not appear to be susceptible to direct infection as early as 2 weeks after implantation if it is properly located in the ductus arteriosus. Animals with no shunt or a trivial shunt are no more susceptible to developing endocarditis 2 weeks after PDA Umbrella implantation than are controls.

Animals↗
PubMed1994

Coronary intravascular ultrasound in 2 children after cardiac transplantation.

Coronary intravascular ultrasound imaging has been found to be the most sensitive method for detecting postcardiac transplantation coronary vasculopathy. Techniques for this type of imaging have been well established for adult patients, but coronary intravascular ultrasound imaging in young children has not been previously reported. We describe the cases of 2 children, ages 8.5 years and 9 months, respectively, who had confusing clinical pictures after cardiac transplantation. Currently available imaging equipment and techniques were used in these children to visualize the coronary arteries. The results of ultrasound imaging were considered helpful in determining future treatment for these 2 pediatric patients.

Cardiac Catheterization↗
PubMed1992

Fenestrated Fontan with delayed catheter closure. Effects of volume loading and baffle fenestration on cardiac index and oxygen delivery.

BACKGROUND. The fenestrated Fontan operation has been applied to high-risk patients with univentricular hearts, resulting in improved survival. The purpose of this study was to determine the hemodynamic factors responsible for these improved results. METHODS AND RESULTS. We performed the fenestrated Fontan operation in 17 high-risk patients with univentricular hearts (median age, 3 years; age range, 1.2-25 years). High-risk characteristics were depressed ventricular function and/or hypertrophy (n = 12), atrioventricular valve insufficiency (n = 5), pulmonary artery distortion (n = 6), elevated pulmonary vascular resistance (> 2 units/m2) (n = 4), previously failed Fontan operation (n = 2), or associated Wolff-Parkinson-White syndrome (n = 1). Intraoperative hemodynamic measurements (n = 8) included cardiac index (by aortic flow probe), peripheral arterial O2 saturations, and left and right atrial pressures during inflow occlusion, followed by volume loading with open versus closed fenestration. Mean baffle fenestration was 3.5 mm (range, 2.7-5.0 mm). Multiple regression analysis (cardiac index versus atrial pressure) revealed cardiac index was greater with open than with closed fenestration (p < 0.001) during volume loading. Oxygen delivery (cardiac index multiplied by oxygen content) was also greater with open than with closed fenestration (p < 0.001). Survival was 100% with a mean follow-up of 10.4 months; pleural drainage was high in two patients. Subsequent transcatheter fenestration closure resulted in increased O2 saturation (87 +/- 1% to 96 +/- 0.3%, p < 0.05). CONCLUSIONS. The fenestrated Fontan operation improves survival in high-risk patients by increasing cardiac index and maintaining oxygen delivery, despite mild arterial O2 desaturation. Subsequent transcatheter fenestration closure can be performed after hemodynamic assessment.

Cardiac Catheterization↗
PubMed1991

Associated occurrence of persistent truncus arteriosus and asplenia.

An infant with persistent truncus arteriosus associated with splenic agenesis and the asplenia syndrome is reported, including clinical, echocardiographic and autopsy findings. To the authors' knowledge this association has not been previously reported.

Abnormalities, Multiple↗
PubMed1990

Balloon dilation of miscellaneous lesions: results of Valvuloplasty and Angioplasty of Congenital Anomalies Registry.

Data on 111 lesions, in addition to pulmonary valve, aortic valve, branch pulmonary stenosis, native coarctation and recoarctation, were submitted to the Valvuloplasty and Angioplasty of Congenital Anomalies Registry. Because there was a very heterogenous group of lesions both in types of lesions and techniques of dilation, only minimal data can be offered concerning the efficacy of the dilation of any or all of these lesions. The registry data do, however, demonstrate the safety of these dilations compared to alternative surgical therapy.

Catheterization↗
PubMed1990

Omphalocele associated with coronary sinus atrial septal defect: report of two cases.

Two children with omphalocele were found to have coronary sinus atrial septal defect as part of their congenital heart disease complex. This unusual atrial communication may elude preoperative detection unless specifically sought. Its occurrence in conjunction with omphalocele may represent more than a chance association.

Abnormalities, Multiple↗
PubMed1990

Late potentials and inducible ventricular tachycardia in surgically repaired congenital heart disease.

We compared signal-averaged electrocardiography with invasive electrophysiological study in patients after surgical repair of congenital heart disease to determine if potentially useful correlations exist between the two methods for assessment of risk for ventricular tachycardia. Thirty-one patients (age, 1-49 years; mean, 10.6 years) with congenital heart disease repaired with right ventriculotomy or postrepair right bundle branch block (77% postoperative tetralogy of Fallot) who had electrophysiological study were studied with signal-averaged electrocardiography. Patients were classified by electrophysiological study results as having no inducible ventricular tachycardia, nonsustained ventricular tachycardia, or sustained ventricular tachycardia. Signal-averaged electrocardiograms were examined for the duration of low-amplitude (less than or equal to 40 microV) QRS signal, duration of total QRS, and root-mean-square voltage of the terminal 40 msec of the QRS. Low-amplitude terminal root-mean-square voltage of 100 microV or less had 91% sensitivity and 70% specificity for ventricular tachycardia inducible by electrophysiological study. Similar sensitivity but less specificity were seen using the criterion of 20 msec or more total low-amplitude QRS signal (initial plus terminal) or using total QRS duration of 128 msec or more. There was a weaker association between terminal low-amplitude QRS signal of 15 msec or more and inducible ventricular tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Pacing, Artificial↗