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The goal of this research was to develop an automated algorithm for tracking the borders of the left ventricle (LV) in a cine-MRI gradient-echo temporal data set. The algorithm was validated on four patient populations: healthy volunteers and patients with dilated cardiomyopathy (DCM), left ventricular hypertrophy (LVH), or left ventricular aneurysm (LVA). A full tomographic set (approximately 11 slices/case) of short-axis images through systole was obtained for each patient. Initial endocardial and epicardial contours for the end-diastolic (ED) and end-systolic (ES) frames were manually traced on the computer by an experienced radiologist. The ED tracings were used as the starting point for the algorithm. The borders were tracked through each phase of the temporal data set, until the ES frame was reached (approximately 7 phases/slice). Peak gradients along equally spaced chords calculated perpendicular to a centerline determined midway between the endocardial and epicardial borders were used for border detection. This approach was tested by comparing the LV epicardial and endocardial volumes calculated at ES to those based on the manual tracings. The results of the algorithm compared favorably with both the endocardial (r2 = 0.72 - 0.98) and epicardial (r2 = 0.96 - 0.99) volumes of the tracer.

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BACKGROUND: A variety of transcatheter atrial septal defect (ASD) occluders are currently in use around the world. Although for the most part effective, all of these devices lack features that would be desirable in a "perfect" device. The Helex septal occluder is a new type of device designed to improve the results of transcatheter ASD closure. This study was designed to examine the effectiveness and safety of this occluder in an animal model. METHODS AND RESULTS: The Helex was implanted into 24 dogs with surgically created ASDs. Procedural details focusing on deployment, removal, and early closure rates were examined. Follow-up consisted of sequential transesophageal echocardiography and fluoroscopy as well as epicardial contrast echocardiography and angiography at the time of death. Specimens were examined grossly and histologically, and devices were tested for metal fatigue. All animals had successful ASD closure. Implantation was uncomplicated (mean fluoroscopy time 11.7 minutes), and removal or repositioning was always possible. Closure rate as judged by transesophageal echocardiography was 88% initially and 100% at 2-week follow-up. Devices rapidly became infiltrated with connective tissue without inflammation and were endothelialized over time. There were no instances of thromboembolism. A single wire-frame fracture occurred secondary to a prototype delivery system malfunction. CONCLUSIONS: The Helex septal occluder proved safe and effective for ASD closure. Several advantages over currently available devices were evident in this model. Controlled prospective clinical trials are needed.

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During surgical repair of a neonatal coarctation it was recognized that this was a rare, previously undescribed form of stenosis of the entire descending thoracic aorta. A few hours after the end-to-end surgical repair, the child underwent successful balloon angioplasty, involving the entire descending thoracic aorta, and in which we intentionally avoided the surgical site.

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Critical pulmonary stenosis causes cyanosis and can be potentially lethal in the neonate. Initial treatment includes general resuscitation and infusion of prostaglandin E1 to dilate the ductus. The diagnosis is usually made echocardiographically, but a right ventriculogram in the outflow tract may be necessary in some patients with only a tiny valve opening. Preformed catheters may aid in the passage of an appropriate guidewire. Valvuloplasty should be performed with a balloon approximately 1.2 times the annulus diameter. Most patients remain mildly to moderately cyanotic immediately after the procedure. With right ventricular (RV) growth and improved RV compliance, the cyanosis eventually resolves. Some patients may require prolonged prostaglandin infusion, a surgical shunt, or other mechanical means of maintaining systemic-to-pulmonary artery flow. Intermediate--to long-term results are excellent. However, only 5%-10% of patients may require surgical relief of residual valve or subvalvular stenosis. Very long-term follow-up raises concern about the significance of induced pulmonary insufficiency. Up to 30% of patients may require repeat balloon valvuloplasty.

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BACKGROUND: In patients with atrioventricular and arterioventricular discordance congenitally corrected transposition, the morphologically right ventricle may progressively deteriorate while functioning in the systemic circuit. The double switch operation has been proposed to limit this functional deterioration. METHODS: From October 1993 to August 1998, the records of 27 patients with congenitally corrected transposition were reviewed. Age at operation ranged from 3 months to 55 years. Associated defects included ventricular septal defects in 18, pulmonary atresia in 7, and pulmonary stenosis in 11 patients. Twenty-two patients had double switch operations (10 arterial switch plus Senning procedures and 12 Rastelli plus Senning procedures). Five patients were not candidates for the double switch. Before the double switch, 6 patients required pulmonary artery banding and 10 had functioning systemic to pulmonary artery or cavopulmonary shunts. RESULTS: There was no early or late mortality. Two patients required pacemaker implantation, both later regained normal sinus rhythm. Tricuspid valve function improved in all patients except one. Moderate left ventricular dysfunction developed 5 months postoperatively in 1 patient. CONCLUSIONS: The double switch operation can be performed in selected patients with minimal early morbidity and mortality. Longer follow-up is necessary to determine whether this complex approach is indeed warranted.

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A 6-year-old malnourished child had persisting hemolysis after attempted valve repair and two surgeries for mitral valve replacement due to partial dehiscence of the valve ring. A modified catheter delivery system was utilized to deploy a total of six Gianturco coils. The hemolysis resolved and the patient was doing well 17 months later. The technique may be helpful in other patients with perivalvular mitral leaks. Cathet. Cardiovasc. Intervent. 49:64-67, 2000.

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A new type of delivery catheter, designed with a 0.033-inch distal tip that grips a 0.038-inch Gianturco coil, was used to occlude 61 abnormal vascular connections in 44 patients with a complete closure rate of 87%. Withdrawal (n = 6) or repositioning (n = 2) of an inappropriately positioned coil was necessary in 8 of 44 patients, and was successfully achieved in all by the delivery catheter without need for additional equipment.

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OBJECTIVE: The objective of this study was to compare the cost (measured as resource utilization by the institution) and clinical effectiveness of transcatheter coil occlusion and surgical patent ductus arteriosus (PDA) closure. Similar comparisons have been made previously with other devices no longer in use in the United States. No such comparison has been made for coil occlusion, which has been performed increasingly since 1992. METHODS: All patients who underwent either coil or surgical closure of uncomplicated PDA at our institution between August 1993 and June 1996 were retrospectively identified. Patients were included in the study if they were eligible for either closure technique. Thus, they had a restrictive PDA (not associated with pulmonary hypertension) and no overt evidence of congestive heart failure. Patients were excluded if they had other significant cardiac or noncardiac problems. Total procedural and recovery costs (including labor, material, equipment, and overhead) incurred by the provider were determined using a cost accounting system called Transition Systems, Inc. To define further how costs differed for the two techniques, total costs were subdivided into the categories of professional, technical, inpatient hospital stay, postprocedure testing, and supplies and other miscellaneous costs. PDA closure rates and associated complications also were compared. Follow-up information was sought from outpatient visits to our institution or by contacting the referring physicians. RESULTS: A total of 39 patients were identified, 3 of whom were excluded because of coexisting medical problems. The study group consisted of 36 patients; 24 underwent PDA coil occlusion and 12 surgical closure. Mean age and weight were 8.8 years and 28.5 kg for the coil patients, and 7.3 years and 32.8 kg for the surgical patients. Median procedural duration was 150 minutes for the coil group and 165 minutes for the surgical group. The total cost to the institution of coil occlusion was significantly lower than that of surgical closure ($5273 vs $8509). The largest difference lay in the cost of hospital stay ($398 vs $2566) and in the professional costs ($1506 vs $2782). Technical costs were similar ($2156 for coil, $2151 for surgery), although use of the catheterization laboratory per unit of time was more expensive than use of the operating room ($800 vs $400 per hour). Additional technical costs of the surgical procedure related to general anesthesia and postoperative care made up the difference. No patient in either group had a residual PDA murmur at hospital discharge or thereafter. Follow-up echocardiography was performed in all coil occlusion patients, and tiny residual leaks were detected in 17%. Only 42% of the surgical patients had postoperative echocardiography; none had residual leaks. There were no deaths or major complications in either group. CONCLUSIONS: Transcatheter coil occlusion is as effective and less costly than surgical closure if silent residual leaks are not considered clinically significant. This information may be used increasingly in patient care decisions in the current era of managed medical care.

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Per-catheter devices for atrial septal defect (ASD) closure have been evolving since 1974. The four major devices available for use on a limited basis in early 1997 are reviewed. These include (in alphabetical order) the Angel Wing device, the ASDOS device, the Buttoned device, and the CardioSeal device (successor to the Clamshell). Sufficient data have been collected to indicate that transcatheter ASD closure is a viable alternative to surgery in selected patients. The advantages of the concept of per-catheter closure over surgical closure should lead to the continued development of devices and techniques for per-catheter treatment of ASD and other septal defects in the years to come.

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OBJECTIVES: In this study we report our preliminary results and intermediate-term follow-up (up to 3.5 years) of stent implantation for coarctation of the aorta (COA). BACKGROUND: Balloon angioplasty has gained acceptance as a modality of treatment for COA. Some patients do not respond optimally to balloon angioplasty alone. Balloon-expandable stents have been used in pulmonary arteries and large systemic arteries such as the femoroiliac vessels, with a significant improvement in vessel patency and a reduction in the pressure gradient compared with balloon angioplasty alone. METHODS: Nine patients (>10 years old) with COA in whom balloon dilation alone was thought to be ineffective underwent stent implantation. Seven patients had a previous operation or balloon dilation, or both, to relieve their coarctation but had a significant residual/recurrent gradient. RESULTS: At the time of stent implantation, the systolic and mean gradients decreased from a mean (+/-SEM) of 37 +/- 7 and 14 +/- 3 mm Hg to 4 +/- 1 and 2 +/- 0.6 mm Hg, respectively (p < or = 0.002). The coarctation diameter increased from a mean of 9 +/- 1 to 15 +/- 1 mm (p < 0.002). The patients have been followed for up to 42 months (mean 18, median 13) with no complications; the stents remain in position with no fracture. One patient underwent further successful dilation 3 years after stent implantation because of an exercise-induced gradient. No other intervention has been required. The systolic gradient at latest follow-up is 7 +/- 2 mm Hg. Only two (a 44-year old with diabetes and a 50-year old with long-standing hypertension) of five patients previously requiring antihypertensive treatment still remain on medications for blood pressure control. CONCLUSIONS: The use of stents in COA is a feasible alternative to surgical repair or balloon angioplasty in selected patients with an effective gradient reduction. Intermediate-term follow-up shows excellent gradient relief, with no complications in this group of patients.

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An infant with hypoplastic left heart syndrome presented for surgical repair at 9 months of age, the ductus having remained open in the presence of a restrictive atrial septal defect. In addition, an anomalous left coronary artery originating from the right pulmonary artery was found. After preliminary blade/balloon atrial septostomy, a successful modified Norwood procedure with concomitant reimplantation of the anomalous coronary artery was performed.

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The desire for less invasive treatments and for reduction of the cost of hospitalizations has spurred the development of interventional catheterization. The range of corrections that can be performed through the use of catheters is much more limited than what can be accomplished with surgery, but in patients with certain conditions, interventional catheterization techniques offer results similar to those of surgery at considerably less pain and expense. We expect the range of defects that can be treated nonoperatively to continue to increase in the years to come.

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Balloon atrial septostomy remains an important interventional procedure in the pediatric age group. The incidence of potential complications using the conventional balloon ranges from 0-11%. The purpose of this study was to evaluate a new low-profile end-hole septostomy balloon catheter with dual lumen, inserted via a 5F or 6F sheath. Seventeen neonates and infants with various forms of congenital heart disease requiring palliation underwent septostomy using the new catheter at a median age of 19 days (with a range of 1-593 days), and a median weight of 3.4 kg (a range of 2.5-8.4 kg). The aortic saturation increased from 72 +/- 20% to 87 +/- 7%, p < .001; and the gradient across the atrial septum decreased (a-wave gradient from 11.2 +/- 10.3 to 2.1 +/- 3.6 mm Hg; v-wave from 10.4 +/- 7.7 to 1.2 +/- 1.2 mm Hg; and mean gradient from 8.5 +/- 6.9 to 0.9 +/- 1.3 mm Hg, p < .002). The diameter of the defect increased from 2.7 +/- 1.7 mm to 8 +/- 2.3 mm, p < .001. There were no complications. We conclude that this new low-profile septostomy catheter is safe and effective in creating a large defect size between the atria. Because of the smaller inflation size of the balloon and smaller introducer sheath compared with the conventional catheter, this new septostomy catheter should be especially useful in small neonates.

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OBJECTIVES: This study sought to compare the immediate results and risk factors for suboptimal outcomes of percutaneous balloon angioplasty for native versus recurrent aortic obstruction. BACKGROUND: Some cardiology centers have been reluctant to adopt balloon angioplasty for treatment of native aortic coarctation, while advocating balloon angioplasty over an operation for treatment of postsurgical or recurrent aortic obstruction. METHODS: Acute results were analyzed from 970 procedures (422 native and 548 recurrent lesions) performed between 1982 and 1995 in 907 patients from 25 centers. An acute suboptimal outcome was defined as one or more of the following: residual systolic pressure gradient > or = 20 mm Hg, residual proximal to distal systolic pressure ration > or = 1.33 or a major complication (death, aortic transmural tear, stroke). RESULTS: Bal loon angioplasty significantly (p = 0.0001) increased lesion diameter fo r both native (mean [+/= SD] 128 +/= 94%) and recurrent aortic obstruction (97 +/= 87%), with a significantly greater increase in the native group (p = 0.0001). A reduction in systolic pressure gradients was significant in both groups (p = 0.0001), but slightly higher (p = 0.01) for native (-74 +/- 24%) versus recurrent obstruction (-70 +/- 31%). Death associated with angioplasty was reported in 0.7% of patients with native and in 0.7% of patients with recurrent lesions (p = 1.00). An acute suboptimal outcome was noted with angioplasty in 19% of native and in 25% of recurrent lesions (p = 0.04). Significant independent risk factors included higher preangioplasty systolic gradient (odds ratio [OR] 1.39/10-mm Hg increment; 95% confidence interval [CI] 1.28 to 1.50, p = 0.0001), earlier study date (OR 0.92/1-year increment, 95% CI 1.02 to 1.26, p = 0.02) and recurrent obstruction (OR 1.39 vs. native lesions, 95% CI 1.00 to 1.94, p = 0.05). CONCLUSIONS: Acute results and complications of balloon angioplasty of native coarctation appear to be equivalent or slightly superior to those of recurrent aortic obstructions.

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Of 31 patients who underwent transcatheter atrial septal defect occlusion with the Bard Clamshell Septal Umbrella, only 1 had a clinically significant residual atrial septal defect at a mean follow-up of 41 months. All patients were asymptomatic despite the occurrence of device arm fractures in 84% of these patients.

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Moderate to severe aortic stenosis in children requires an initial procedure to improve the stenosis and often additional procedures for recurrent stenosis or aortic insufficiency before adulthood. The purpose of this study was to evaluate children who underwent balloon valvuloplasty and were followed with a specific management plan. Twenty-two children with aortic stenosis underwent balloon valvuloplasty and were followed on a regular basis. Repeat valvuloplasty was performed if indicated. The initial gradient was reduced from 63 +/- 9 mmHg to 28 +/- 8 mmHg (P < 0.001). There were no deaths and only one major complication, which had no sequelae. Average follow-up was 61 +/- 23 months. Three patients required valve replacement 39-76 months after valvuloplasty for progressive insufficiency. Seven patients underwent successful repeat valvuloplasty. The overall probability of survival without surgical intervention was 75% at 100 months. Balloon valvuloplasty is an effective intermediate palliation for aortic stenosis and is an acceptable alternative to surgical valvotomy. Repeat valvuloplasty is successful without additional risk. In a subgroup of patients, aortic insufficiency is progressive and will require surgical intervention.

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