Disease severity, arrhythmogenesis, and fibrosis are related to longer action potentials in tetralogy of Fallot.

Background: Arrhythmias may originate from surgically unaffected right ventricular (RV) regions in patients with tetralogy of Fallot (TOF). We aimed to investigate action potential (AP) remodelling and arrhythmia susceptibility in RV myocardium of patients with repaired and with unrepaired TOF, identify possible correlations with clinical phenotype and myocardial fibrosis, and compare findings with data from patients with atrial septal defect (ASD), a less severe congenital heart disease.

Methods: Intracellular AP were recorded ex vivo in RV outflow tract samples from 22 TOF and three ASD patients.

Benefit From a Humanitarian Pediatric Congenital Heart Surgery Program Over a 10-Year Period.

The charity organization (KHR) enables humanitarian congenital heart surgery for pediatric patients from low- and middle-income countries at the University Heart Center Freiburg, Germany. The aim of this study was to assess periprocedural and mid-term outcomes of these patients for evaluation of KHR sustainability. Part one of the study comprised retrospective medical chart analyses of the periprocedural course of all KHR-treated children from 2008 to 2017, and part two a prospective evaluation of their mid-term outcome, assessed by questionnaires concerning survival, medical history, mental and physical development, and socioeconomic situation.

Arrhythmic risk during pregnancy in patients with congenital heart disease.

Arrhythmias play a significant role in the morbidity and mortality of patients with adult congenital heart disease (CHD). Pregnancy-associated physiological changes in hormonal status, hemodynamics, and myocardial structure further enhance arrhythmic risk in CHD patients, leading to increased adverse maternal and foetal events and making arrhythmias one of the most common complications during pregnancy. Nearly all CHD patients are affected by asymptomatic rhythm disturbances during the ante-, peri-, or post-partum periods, and almost one tenth of patients develop sustained, symptomatic arrhythmias requiring treatment.

Quantitative collagen assessment in right ventricular myectomies from patients with tetralogy of Fallot.

Aims: Patients with tetralogy of Fallot (TOF) are often affected by right ventricular fibrosis, which has been associated with arrhythmias. This study aimed to assess fibrosis distribution in right ventricular outflow tract (RVOT) myocardium of TOF patients to evaluate the utility of single histology-section analyses, and to explore the possibility of fibrosis quantification in unlabelled tissue by second harmonic generation imaging (SHGI) as an alternative to conventional histology-based assays.

Methods And Results: We quantified fibrosis in 11 TOF RVOT samples, using a tailor-made automated image analysis method on Picrosirius red-stained sections.