Transcatheter closure of perimembranous ventricular septal defect with immediate follow-up.

BACKGROUND: Surgical closure of membranous ventricular septal defect (VSD) is performed by open heart surgery with a small but significant morbidity and mortality. The authors reported here the first group of patients who underwent transcatheter closure of membranous VSD. METHOD: Patients who had membranous VSD with significant left to right shunt as shown by echocardiogram were selected for closure. A standard right and left heart catheterization was done under general anesthesia. A complete arteriovenous wire loop from the aorta to the left ventricle and VSD out into right ventricle was formed in order to guide the delivery sheath into the VSD from the right ventricle. The authors used the new Amplatzer Membranous VSD Occluder (AGA Medical Corp., USA) to deploy in the VSD position. RESULTS: There were 4 patients in the present study with age range of 2 to 24 years old (median: 4 years old). Their weight ranged from 10 to 45 kg (median: 12 kg). Qp:Qs ranged from 1.7-2.5 to 1. The device diameter selected was from 6 to 10 mm. All of them were placed without any residual shunt. At one month follow-up all the patients had echocardiographic examination which showed no evidence of residual shunt. CONCLUSIONS: The authors demonstrated that transcatheter closure of membranous VSD could be safely and effectively performed in small children. This device also provided an opportunity for closure of VSD in patients with pulmonary hypertension.

Radiofrequency catheter ablation of ventricular tachycardia from right ventricular outflow tract.

From January 1996 to May 2002, 61 patients with ventricular tachycardia from right ventricular outflow tract were referred to Siriraj hospital. All patients underwent clinical examination, Doppler echocardiography and electrophysiologic study. Mapping of ventricular tachycardia was performed by activation mapping and pacemapping. There were 44 females and 17 males with an average age of 41.7 +/- 9.9 years. Presenting symptoms were palpitation (95.1%), presyncope (39.3%), and syncope (26.2%). Six patients were found to have underlying cardiac disease. Radiofrequency catheter ablation was successful in 56 patients (91.8%). There were no major complications. Seven patients (12.5%) had recurrent ventricular tachycardia. Five of them were successfully reablated. The authors concluded that radiofrequency ablation is an effective treatment in patients with ventricular tachycardia from right ventricular outflow tract.

Successful implantation of transveneous biventricular permanent pacemaker for refractory congestive heart failure: the first case-report in Thailand.

Biventricular pacemaker is a pacemaker that can pace both the right and left ventricle at the same time. There have been progression in the development of biventricular pacemaker from thoracotomy system to fully transveneous system. The benefit in improving quality of life in selected medical refractory congestive heart failure patients of this device had been shown in randomized controlled trials. The authors reported successful implantation fully transveneous biventricular pacemaker in Thailand.

Transcatheter closure of atrial septal defects by amplatzerTM septal occluder instead of open heart surgery.

Although surgical repair of secundum atrial septal defect (ASD) is a safe, widely accepted procedure with negligible mortality, it is associated with morbidity, discomfort and a thoracotomy scar. As an alternative to surgery, a variety of devices for transcatheter closure of ASD have been developed. Large delivery sheath, difficult implantation technique, inability to capture, and structural failure are some of the limitations of previous devices. Objective: This study reports our clinical experience with transcatheter closure of ASD using the AmplatzerTM Septal Occluder , a new occlusion device. Methods: Patients with ASD met established two-dimensional echocardiographic criteria for transcatheter closure. ASD size was measured by transesophageal echocardiogram (TEE) and balloon occlusion catheter (stretched diameter). The AmplatzerTM ’s size was chosen to be equal to stretched dia-meter (+ 1 mm). The device was advanced transvenously into a guiding sheath and deployed under fluoroscopic and TEE guidance. Once its position was optimal, it was released. Right atrial atriogram and TEE were undertaken to demonstrate the residual shunt. Results: There were 5 patients with mean age of 9.6+8.4 years and mean weight of 24.7 + 14.9 kg. The mean ASD diameter measured by TEE was 16.1+ 2 mm and by stretched diameter was 18.5 + 3.5 mm. The mean device diameter was 19.2 + 4 mm (range 15 to 24 mm). Immediately after the deployment, a tiny residual shunt was observed at the core of the device in each case. However, at 24 hours only one patient who had a 24 mm device placed had a small (<2 mm) residual shunt. No complication was encountered during the procedure. Conclusion: The AmplatzerTM Septal Occluder is a prosthesis that can be easily deployed in patients with secundum ASD. The result of closure was excellent. This device could be used to close large ASD (particularly with diameter > 20 mm) safely in our patients.