Postnatal Outcomes in Infants With a History of Fetal Supraventricular Tachycardia.

BACKGROUND: Fetal supraventricular tachycardia (SVT) is rare and proposed predictors of postnatal outcomes in fetal SVT have not been validated. Valid predictors can guide postnatal management. OBJECTIVES: The authors correlated fetal characteristics to the incidence of postnatal SVT and compared SVT outcomes in infants with and without a history of fetal SVT. METHODS: Mother-fetus dyads with fetal SVT and a structurally normal heart were described and compared with a second cohort of infants with a postnatal diagnosis of SVT. RESULTS: SVT was observed in 78 fetuses and 76 survived to delivery. Maternally administered transplacental antiarrhythmics were used in 49 mother-fetus dyads. Rhythm control was achieved in 37 of 49 (76%). Among fetuses with intermittent SVT, there was no ventricular dysfunction or hydrops. Postnatal SVT occurred in one-half of infants (37 of 76), and 94% presented within the first 2 days of life. The following fetal characteristics were associated with postnatal SVT on univariable analysis: sustained SVT (87% vs 56%), ventricular dysfunction (41% vs 15%), lack of conversion to sinus rhythm (49% vs 10%), and earlier gestational age at delivery (37.6 weeks vs 38.9 weeks; P ≤ 0.01 for each comparison). Compared with infants with a postnatal diagnosis of SVT, infants with a fetal diagnosis presented earlier (median age 0 days vs 17 days; P < 0.01) and had a lower incidence ventricular dysfunction at presentation (5% vs 42%; P < 0.01). CONCLUSIONS: One-half of infants with fetal SVT had postnatal SVT, nearly all within 2 days of life. These data and predictors of postnatal SVT may influence parental counseling and postnatal clinical decision-making.

Patient-activated anti-tachycardia pacing in adult congenital heart disease.

INTRODUCTION: In adults with congenital heart disease, intra-atrial reentrant tachycardia (IART) is a common arrhythmia that causes significant morbidity and mortality. One treatment option for IART is antitachycardia pacing. Atrial antitachycardia pacing algorithms deliver therapy for IART with ≥2:1 conduction, but most algorithms will not recognize IART with 1:1 conduction. Temporary Patient Activated Rx (TPARx) is Medtronic software that can be installed in antitachycardia pacemakers allowing patients to deliver therapies on demand for IART with 1:1 conduction. METHODS: Retrospective chart review at a single institution of all patients who had TPARx installed into their pacemaker. RESULTS: Four adults with single ventricle congenital heart disease and IART underwent Fontan conversion, arrhythmia surgery, and placement of an epicardial dual-chamber antitachycardia pacemaker. They had recurrent IART with a long cycle length and 1:1 conduction that failed to trigger antitachycardia pacing therapies. TPARx software was programmed into their pacemakers to allow recognition and treatment of IART with 1:1 conduction. Mean follow-up duration after TPARx programming was 4.9 years. Each patient received at least one successful antitachycardia pacing therapy via TPARx - range 0.4-26 treated IART episodes per year. There were no atrial or ventricular arrhythmias induced with antitachycardia pacing. Two patients were able to discontinue anticoagulation after TPARx installation. CONCLUSION: This series demonstrates the use of TPARx software as part of a long-term IART management strategy in select patients with IART who have failed more conventional therapies.

Persistence of Palpitations After Slow Pathway Modification for AVNRT in Young People.

Symptoms are the most common indication for ablation in children with atrioventricular nodal reentrant tachycardia (AVNRT). After the procedure, patients may continue to report palpitations. The objective of this study was to quantify the risk and duration of palpitations after pediatric slow pathway modification as well as demographic and technical associations. This was a retrospective review of consecutive patients at a pediatric center who underwent slow pathway modification for AVNRT from 2012 to 2018. Patients with a prior ablation attempt or congenital heart disease were excluded. Palpitations were documented in 35% of patients after ablation. Neither post-ablation echo beats nor other evidence of residual dual AV nodal physiology were associated with a higher risk of post-ablation palpitations. Of the 35 patients with post-ablation palpitations, the median time to resolution of palpitations was 48 months. Acute procedural success was achieved in all 100 cases. There were two recurrences of AVNRT during long-term follow-up and one instance of ectopic atrial tachycardia (3% SVT recurrence). Palpitations after AVNRT ablation occurred in approximately one-third of cases, despite a low recurrence of true arrhythmia. Prior to ablation, patients and families should be counseled that post-ablation palpitations are common and AVNRT recurrence is rare.

Right ventricular septal pacing via transmural approach for resynchronization in a child with postoperative heart block.

An infant with transposition of the great arteries was paced for postoperative heart block (single-site, right ventricular [RV] epicardial). She developed severe left ventricular (LV) dysfunction and septal dyskinesis. Resynchronization was performed at the age of 4 with an LV epicardial lead and an RV septal endocardial lead. The endocardial lead was affixed to the interventricular septum, then tunneled through the RV free wall and attached to an abdominal pulse generator. QRS duration decreased (176 to 122 ms) and LV ejection fraction improved (26 to 61%) and remained stable for 8 years. We present a case of successful resynchronization in congenital heart disease using a transmural RV septal lead.

Screening for prevention of sudden death in the young: what is new?

PURPOSE OF REVIEW: The optimal approach to screening young people to decrease the risk of sudden death remains unknown. It deserves the passionate attention that researchers, clinicians and families have given it. The new data from January 2018 to July 2019 are reviewed here. RECENT FINDINGS: Cardiac findings associated with a risk of sudden death were reported in 0.4% of screened athletes. Well run programs continue report varying sensitivity for screening ECGs (between 86 and 100%). One major article reported a higher incidence of sudden death in young people than has been previously published (6.8/100 000 athletes). SUMMARY: The rate of important findings in sophisticated screening programs is approximately 0.4%, suggesting that this is near the population rate of detectable disease in most athletic groups. ECGs are unquestionably capable of detecting disease that can be missed by history and physical, but the performance characteristics of ECGs continue to vary from study to study. In addition, the underlying cost and infrastructure of ECG and echocardiographic screening remains unaddressed by the recent literature. A few small studies have started to look at alternative technology approaches to ECG screening. VIDEO ABSTRACT.

Fontan Revision: Presurgical Planning Using Four-Dimensional (4D) Flow and Three-Dimensional (3D) Printing.

Pulmonary arteriovenous malformations (AVMs) can be a complication of certain postoperative Fontan patients whose hepatic venous blood return is not distributed evenly to both lungs. A ten-year-old female, who had previously undergone staged single ventricle palliation for complex congenital heart disease, underwent a Fontan revision due to significant left-sided pulmonary AVMs and increasing arterial oxygen desaturation. The combination of four-dimensional flow cardiac magnetic resonance imaging and three-dimensional printing enabled presurgical planning for a Fontan takedown and diversion of hepatic venous flow to the azygous vein that resulted in significant clinical improvement.

Elucidation of the interaction mechanism with liposomes of gH625-peptide functionalized dendrimers.

We have demonstrated that amide-based dendrimers functionalized with the membrane-interacting peptide gH625 derived from the herpes simplex virus type 1 (HSV-1) envelope glycoprotein H enter cells mainly through a non-active translocation mechanism. Herein, we investigate the interaction between the peptide-functionalized dendrimer and liposomes composed of PC/Chol using fluorescence spectroscopy, isothermal titration calorimetry, and surface plasmon resonance to get insights into the mechanism of internalization. The affinity for the membrane bilayer is very high and the interaction between the peptide-dendrimer and liposomes took place without evidence of pore formation. These results suggest that the presented peptidodendrimeric scaffold may be a promising material for efficient drug delivery.