Mitral annular disjunction and mitral valve prolapse extrapolating adult data to an adolescent cohort?

PURPOSE OF REVIEW: The aim of this study is to provide an update on mitral valve prolapse (MVP) and mitral annular disjunction (MAD) and who may be at risk for ventricular arrhythmias and sudden cardiac death. RECENT FINDINGS: MVP is generally considered a benign condition. However, a small subset of patients may be at risk for life-threatening ventricular arrhythmias. Among the risk factors identified in adults include patients with bileaflet mitral valves, myxomatous changes, myocardial fibrosis, and the presence of MAD. Advances in multimodal imaging have allowed for improved identification of fibrosis, anatomical valve derangements, and the amount of MAD. Recent guidelines have suggested that patients with MVP with or without MAD may be at risk for life-threatening arrhythmias if they have had prior ventricular arrhythmias, ventricular dysfunction, or unexplained syncope. Yet, extrapolation of adult data to a pediatric cohort with similar MVP and MAD at this juncture is challenging. There is, however, early evidence that some pediatric patients with significant myocardial fibrosis or abnormal tissue Doppler may be at risk for ventricular tachycardia. SUMMARY: Mitral valve prolapse and mitral annular disjunction at times coexist and at other times can be seen as isolated entities. While the incidence of arrhythmic MVP is quite rare, there is increasing evidence that certain select adults with MVP may be at risk for ventricular tachycardia and sudden cardiac death. Future multicenter studies are needed to better understand the natural history of arrhythmic mitral valve disease and how early disease manifestation in children may impact findings now being reported in young adults.

Intracardiac tumor causing left-ventricular outflow-tract obstruction in a newborn.

The following report describes the case of newborn girl with an asymptomatic systolic murmur, which on imaging revealed a nearly obstructive mass in the left-ventricular outflow tract. The mass was resected and found to be consistent with a rhabdomyoma. Here, we describe the pathologic and clinical characteristics of this tumor.

Minimally invasive percutaneous pericardial ICD placement in an infant piglet model: Head-to-head comparison with an open surgical thoracotomy approach.

BACKGROUND: Epicardial implantable cardioverter-defibrillator (ICD) placement in infants, children, and patients with complex cardiac anatomy requires an open surgical thoracotomy and is associated with increased pain, longer length of stay, and higher cost. OBJECTIVE: The purpose of this study was to compare an open surgical epicardial placement approach with percutaneous pericardial placement of an ICD lead system in an infant piglet model. METHODS: Animals underwent either epicardial placement by direct suture fixation through a left thoracotomy or minimally invasive pericardial placement with thoracoscopic visualization. Initial lead testing and defibrillation threshold testing (DFT) were performed. After the 2-week survival period, repeat lead testing and DFT were performed before euthanasia. RESULTS: Minimally invasive placement was performed in 8 piglets and open surgical placement in 7 piglets without procedural morbidity or mortality. The mean initial DFT value was 10.5 J (range 3-28 J) in the minimally invasive group and 10.0 J (range 5-35 J) in the open surgical group (P = .90). After the survival period, the mean DFT value was 12.0 J (range 3-20 J) in the minimally invasive group and 12.3 J (range 3-35 J) in the open surgical group (P = .95). All lead and shock impedances, R-wave amplitudes, and ventricular pacing thresholds remained stable throughout the survival period. CONCLUSION: Compared with open surgical epicardial ICD lead placement, minimally invasive pericardial placement demonstrates an equivalent ability to effectively defibrillate the heart and has demonstrated similar lead stability. With continued technical development and operator experience, the minimally invasive method may provide a viable alternative to epicardial ICD lead placement in infants, children, and adults at risk of sudden cardiac death.

Minimally invasive resynchronization pacemaker: a pediatric animal model.

PURPOSE: We developed a minimally invasive epicardial pacemaker implantation method for infants and congenital heart disease patients for whom a transvenous approach is contraindicated. The piglet is an ideal model for technical development. DESCRIPTION: In 5 piglets we introduced a needle through subxiphoid approach under thoracoscopic guidance, inserting a wire into the pericardial space. Pacing leads were affixed to the left ventricular free wall and left atrial appendage. After verifying functionality with atrial and ventricular pacing and sensing, animals were euthanized. Pacemaker monitoring occurred daily for 4 days in the fifth animal. EVALUATION: Through minimally invasive pericardial access, we directly visualized and fixated pacing leads to the left ventricle and left atrial appendage, successfully pacing atrium and ventricle. Epicardial structures were visualized. One piglet had contralateral pneumothorax, which resolved with needle decompression. No other adverse events occurred. CONCLUSIONS: Minimally invasive epicardial pacemaker implantation in an infant model is feasible and effective. This innovation may be of value for pacing and resynchronization in infants and congenital heart disease patients. Survival studies with permanent generator implantation are under way.