Sang Yoon Lee

Permanent Epicardial Pacing in Pediatric Patients: 12-Year Experience at a Single Center

BACKGROUND Permanent cardiac pacing is not often done in children, and when done is usually accomplished through epicardial pacing. We reviewed a 12-year experience with the implantation of epicardial pacemakers by our clinical group. METHODS Fifty-three patients who underwent their first implantation of an epicardial pacemaker before the age of 18 years and between 1997 and 2009 were included in our study. The mean age of the patients at the time of first pacemaker implantation was 5.7±4.8 years. Indications for pacemaker implantation included postoperative or congenital atrioventricular block and sinus node dysfunction. The patients underwent 105 operations for the replacement of pacemaker pulse generators and 75 operations for the replacement of pacemaker leads. The most commonly used generator mode was the rate-responsive accelerometer-based (DDDR) mode, which was used in 40.9% of the patients. We used more non-steroid-eluting leads (70.1%) than steroid-eluting leads (29.1%). RESULTS The overall duration of follow-up in the study was 8.0±4.5 years (range, 2.1 months to approximately 17.0 years). Freedom from the need for generator replacement was 98.0%, 60.7%, and 11.1% at 1, 5, and 8 years, respectively. A tendency toward early generator exhaustion was observed among younger patients (p=0.058). The generator mode used for pacing did not significantly affect generator longevity. Freedom from the need for lead replacement was 98.3%, 83.8%, and 63.6% at 1, 5, and 10 years, respectively. The mean longevity of the leads used in the study was 10.8±0.8 years. Neither patient age at the time of lead implantation nor type of lead significantly affected lead longevity. CONCLUSIONS Lead longevity was sufficiently long and did not vary significantly according to type of lead. Generator longevity was not affected by lead type, generator mode, or patient age at the time of pacemaker implantation.

Outcome of Transcatheter Closure of Oval Shaped Atrial Septal Defect with Amplatzer Septal Occluder

Purpose For the successful completion of transcatheter closure of atrial septal defects with the Amplatzer septal occluder, shape of the defects should be considered prior to selecting the device. The purpose of this study is to evaluate the results of a transcatheter closure of oval shaped atrial septal defect. Materials and Methods From November 2009 until November 2011, cardiac computed tomography was performed on 69 patients who needed a transcatheter closure of atrial septal defect. We defined an oval shaped atrial septal defect as the ratio of the shortest diameter to the longest diameter ≤0.75 measured using computed tomography. A trans-thoracic echocardiogram was performed one day after and six months after. Results The transcatheter closure of atrial septal defect was performed successfully in 24 patients in the ovoid group and 45 patients in the circular group. There were no serious complications in both groups and the complete closure rate at 6 months later was 92.3% in the ovoid group and 93.1% in the circular group (p>0.05). The differences between the device size to the longest diameter of the defect and the ratios of the device size to the longest diameter were significantly smaller in the ovoid group (1.8±2.8 vs. 3.7±2.6 and 1.1±0.1 vs. 1.2±0.2). Conclusion Transcatheter closure of an oval shaped atrial septal defect was found to be safe with the smaller Amplatzer septal occluder device when compared with circular atrial septal defects.

Transcatheter Closure of Multiple Atrial Septal Defects With the Amplatzer Device

Percutaneous device occlusion of secundum atrial septal defect (ASD) has become an accepted alternative to surgical repair. A variety of devices have been used successfully. However, all of them have limitations. We report our experience with two devices used to close multiple ASDs.

Transcatheter closure of small ductus arteriosus with amplatzer vascular plug.

Purpose The purpose of this study was to share our experience of transcatheter closure of small patent ductus arteriosus (PDA) by using an Amplatzer vascular plug (AVP). Methods We reviewed the medical records of 20 patients who underwent transcatheter closure at Samsung Medical Center and Sejong General Hospital from January 2008 to August 2012. The size and shape of the PDAs were evaluated by performing angiograms, and the PDA size and the AVP devices size were compared. Results The mean age of the patients was 54.9±45.7 months old. The PDAs were of type C (n=5), type D (n=12), and type E (n=3). The mean pulmonary end diameter of the PDA was 1.7±0.6 mm, and the aortic end diameter was 3.6±1.4 mm. The mean length was 7.3±1.8 mm. We used 3 types of AVP devices: AVP I (n=5), AVP II (n=7), and AVP IV (n=8). The ratio of AVP size to the pulmonary end diameter was 3.37±1.64, and AVP size/aortic end ratio was 1.72±0.97. The aortic end diameter was significantly larger in those cases repaired with AVP II than in the others (P=0.002). The AVP size did not significantly correlate with the PDA size, but did correlate with smaller ratio of AVP size to aortic end diameter (1.10±0.31, P=0.032). Conclusion Transcatheter closure of small PDA with AVP devices yielded satisfactory outcome. AVP II was equally effective with smaller size of device, compared to others.

The outcome of percutaneous stent implantation in congenital heart disease: experience of a single institute

Purpose The efficacy of percutaneous stent implantation for congenital heart disease (CHD) in Korea, where stent availability is limited, has not been determined. This study evaluated the acute and midterm results of stent implantation in different CHD subgroups. Methods Stents were implanted in 75 patients with 81 lesions: (1) pulmonary artery stenosis (PAS) group, 56 lesions in 51 patients; (2) coarctation of the aorta (CoA) group, 5 lesions in 5 patients; (3) Fontan group, 13 lesions in 12 patients; (4) ductal stent group, 3 lesions in 3 patients; and (5) other CHD group, 4 lesions in 4 patients. Mean follow-up duration was 2.1 years (0.1–4 years). Medical records were reviewed retrospectively. Results The minimum lumen diameter (MLD) in PAS and CoA increased from 5.0±1.9 mm and 8.4±1.6 mm to 10.1±3.6 mm and 12.3±2.5 mm, respectively (P<0.01). In the PAS group, pressure gradient decreased from 25.7±15.6 mmHg to 10.4±10.1 mmHg, and right ventricular to aortic pressure ratio from 0.56±0.21 to 0.46±0.19. In the CoA group, the pressure gradient decreased from 50±33 mmHg to 17±8 mmHg. In the ductal stent group, the MLD of the ductus increased from 2.3 mm to 4.3 mm and arterial oxygen saturation from 40%–70% to 90%. No deaths were associated with stent implantation. Stent migration occurred in 3 patients, but repositioning was successful in all. Stent redilation was performed successfully in 26 cases after 29±12 months. Conclusion Percutaneous stent implantation was safe and effective, with acceptable short and mid-term outcomes in Korean CHD patients.