Subcutaneous implantable cardioverter-defibrillator: Initial experience.

BACKGROUND: Implantable cardioverter-defibrillators (ICDs) are important tools in the prevention of sudden death, but implantation requires transvenous access, which is associated with complications. Subcutaneous implantable cardioverter-defibrillators (S-ICDs) may prevent some of these complications. AIM: To evaluate the therapeutics and complications associated with S-ICD systems. METHODS: S-ICD implantation was planned in 23 patients, for whom the indications were vascular access problems, increased risk of infection or young patients with long predicted follow-up. The population consisted of four patients with ischemic heart disease, three of them on hemodialysis (two with subclavian vein thrombosis), five with left ventricular noncompaction, four with Brugada syndrome, three with arrhythmogenic right ventricular cardiomyopathy, one with transposition of the great vessels, two with dilated cardiomyopathy and four with hypertrophic cardiomyopathy. RESULTS: S-ICDs were implanted in 21 patients, two having failed to fulfil the initial screening criteria. Mean implantation time was 77 minutes, with no complications. Defibrillation tests were performed, and in one patient the generator had to be repositioned to obtain an acceptable threshold. In a mean follow-up of 14 months, 10 patients had S-ICD shocks, which were appropriate in half of them; one developed infection, one needed early replacement due to loss of telemetry and one patient died of noncardiac cause. CONCLUSIONS: S-ICD implantation can be performed by cardiologists with a high success rate. Initial experience appears favorable, but further studies are needed with longer follow-up times to assess the safety and efficacy of this strategy compared to conventional devices.

Percutaneous epicardial ablation in ventricular arrhythmias.

INTRODUCTION: Reentrant circuits of ventricular tachycardia may involve not only the endocardium but also the epicardium. Epicardial ablation can be useful in these situations. OBJECTIVE: The aim of this study was to assess efficacy, safety and complications in a series of consecutive patients who underwent ablation of ventricular tachycardia with epicardial mapping. METHODS: The study included all patients undergoing ventricular tachycardia ablation with epicardial mapping from 2004 to 2012. Of a total of 95 ablations, an epicardial approach was attempted in nine patients, eight male, mean age 58±12 years. Endocardial mapping was performed in all patients previously or simultaneously. The etiology of the arrhythmia was non-ischemic in eight patients and ischemic in one. We compared the number of events in the six months prior to the epicardial procedure and six months after. RESULTS: Percutaneous epicardial access was achieved in eight patients. In one case it was not possible due to the presence of adhesions. In none of the patients was the procedure repeated and there were no major complications during hospitalization. In a mean follow-up of 3.5±1.2 years, one patient suffered stroke; there were no other medium-to-long-term complications and the number of ventricular tachycardia episodes was reduced in all patients after ablation. CONCLUSIONS: Epicardial radiofrequency ablation of ventricular tachycardia was effective in reducing morbidity in eight patients, with a low risk of complications in the short and medium-to-long term.

[Left ventricular assist device in a five-year-old child: a bridge to recovery in a case of viral myocarditis]. / Assistência ventricular esquerda numa criança de 5 anos - ponte para recuperação num caso de miocardite viral.

INTRODUCTION: Viral myocarditis can lead to heart failure that is refractory to medication. In these cases, a ventricular assist device is a good therapeutic option that can be used as a bridge to transplantation or recovery. We describe the first case in Portugal of recovery with ventricular assistance after severe myocarditis. CASE REPORT: A five-year-old boy with no previous cardiac disease presented with severe viral myocarditis, refractory to medical treatment, with positive serology for parvovirus B19 and Ebstein-Barr virus. A Berlin Heart Excor(®) was implanted 15 days after diagnosis. A biopsy at the time of implantation showed subendocardial fibrosis. After 40 days of assistance ventricular function recovered and the device was explanted. The patient was discharged from hospital 15 days later. DISCUSSION: Survival of children with ventricular assistance has improved significantly because of earlier implantation and coagulation monitoring. The presence of subendocardial fibrosis in the context of myocarditis is not a mandatory indication for transplantation.

Percutaneous closure of perimembranous ventricular septal defects: initial experience in Portugal.

INTRODUCTION: Closure of ventricular septal defects (VSDs) with significant shunt is indicated due to the risks associated with increased pulmonary flow leading to left chamber dilatation, the possibility of cardiac dysfunction and arrhythmias, and the risk of bacterial endocarditis. Percutaneous VSD closure is an effective and safe alternative to surgery in selected patients. However, perimembranous VSD (PMVSD) constitutes a special case since the technique for percutaneous closure is more complex and hence warrants individual evaluation. OBJECTIVES: To assess the efficacy and safety of percutaneous closure of PMVSD based on the initial experience of our center, the first to use this technique in Portugal. METHODS: Five patients, aged between 5 and 23 years, with PMVSD of a suitable size for percutaneous closure, were selected since they showed evidence of a significant left-to-right shunt together with left chamber dilatation. The procedure was performed under general anesthesia, guided by fluoroscopy and transesophageal echocardiography (TEE). A femoro-femoral arteriovenous loop was established and an Amplatzer occluder implanted, the characteristics and dimensions of which were chosen according to the angiographic and TEE findings. Besides therapeutic efficacy and complications during the procedure and follow-up, left ventricular dimensions and function and degree of mitral, aortic and tricuspid regurgitation were also assessed pre- and post-procedure, during a follow-up of 5 to 23 months. RESULTS: All patients had a Qp:Qs ratio of > 2:1. In one case, the procedure was abandoned as the VSD diameter was over 17 mm, and the patient was referred for surgical closure. In the other four patients, two membranous (8 and 16 mm) and two muscular (6 and 12 mm) VSD occluders were used. On final angiographic assessment, no residual shunt was observed in any patient. One patient presented a transient junctional rhythm during the procedure. During follow-up, there was no prolongation of the PQ interval or de novo aortic regurgitation in any patient. Catheterization time ranged between 90 and 176 minutes and fluoroscopy time between 10 and 17 minutes. CONCLUSIONS: 1) Percutaneous closure of PMVSD is an effective and safe method of treatment in selected patients. 2) It is a complex procedure, but is likely to be refined and extended to a larger number of patients in suitably qualified centers.

Aortopulmonary window--a review of nine cases.

INTRODUCTION: Aortopulmonary window (APW) is a rare anomaly, accounting for 0.1% of congenital heart defects. It consists of a communication between the ascending aorta and the pulmonary artery in the presence of normal separate aortic and pulmonary valves. Early treatment is usually required in order to prevent the development of irreversible pulmonary hypertension. OBJECTIVE: To assess the results of treatment in all patients diagnosed at our institution between January 1994 and November 2007, based on a retrospective longitudinal study. RESULTS: Nine patients treated for APW were identified. Their ages at diagnosis ranged from two days to 23 years; eight were infants aged 2 +/- 2.9 months. In this group clinical presentation was congestive heart failure in all cases. Five patients had associated lesions (interrupted aortic arch: 2; coarctation of the aorta: 2; VSD: 1; ASD: 3). In seven cases the diagnosis was made on the basis of echocardiography only. In the other two it was by cardiac catheterization, one patient with coarctation of the aorta and the other an adult patient with a smaller lesion who was initially misdiagnosed as having ductus arteriosus. All patients had corrective surgery, via a transaortic approach, with implantation of an autologous pericardial patch. All patients are alive and only one case has a small residual shunt at the correction site. CONCLUSION: A diagnosis of APW should always be kept in mind in the differential diagnosis of a child with congestive heart failure. Associated congenital heart anomalies should be excluded. Surgical repair appears to provide good short- and long-term results.