Cardiac arrhythmias occur at all ages. Cardiac mapping and ablation are established methods for curing arrhythmia substrates; however, complications may occur. We report a patient with transient Wenckebach heart block during radiofrequency ablation in the setting of Wolff Parkinson White syndrome despite the ablation catheter being well away from the atrioventricular node, and we speculate on the potential mechanism.

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

Symptomatic, circulatory collapse occurred in an unvaccinated child with repaired congenital heart and a backup pacemaker during an Influenza B viral infection with complete atrioventricular block and pacemaker non-capture. Ventricular arrhythmias occurred during her collapse. Atrioventricular conduction recovered within 24 hours. Influenza-associated cardiac inflammation can adversely affect patients with repaired CHD. Proactive immunisation is strongly recommended.

A 16-year-old male was admitted to the paediatric ICU with acute onset of vomiting, somnolence, and chest pain, and electrocardiogram showing 2nd degree heart block after ingesting an Aleurites moluccana (Candlenut) seed as a herbal weight loss supplement. Electrocardiogram showed progressively worsening heart block with down-sloping of the ST segments, resembling digoxin toxicity. After 2 days of ICU observation, his symptoms began to improve and eventually resolved. The side effects of herbal supplements are often unknown but by analysing cases such as these, physicians can develop a better understanding of these substances to help guide management.

Prolongation of the QT interval and development of torsades de pointes are known in patients with complete heart block and profound bradycardia. We report the case of a patient with complete heart block and torsades, with long QT seen during a period of junctional tachycardia at a rate faster than the minimum pacemaker rate.

Balloon pulmonary valvoplasty was performed in a patient with congenitally corrected transposition, aged 28 years, who had already undergone surgical closure of a ventricular septal defect and implantation of a conduit between the pulmonary arteries and the right-sided morphologically left ventricle. The patient developed stenosis of the conduit 22 years after the procedure as confirmed by cardiac catheterization and angiocardiography, which also showed stenosis of the native pulmonary valve. A balloon valvoplasty of the native valve was carried out with improvement of the gradient from the ventricle to the pulmonary arteries. The patient developed complete heart block immediately after the procedure, which reverted to first degree block in one week and to the previous cardiac rhythm within 21 days.

Between 1989 and 2000, 21 fetuses were diagnosed with complete atrioventricular block. Seven women with fetal ventricular rates of less than 60 were given oral terbutaline, and 6 of these had an initial increase in the fetal ventricular rate. Four fetuses (57%) maintained an increased average rate of 60 beats per minute and survived. Two fetuses returned to rates below 55 and died. The final fetus, with hypertrophic cardiomyopathy, was unresponsive. Terbutaline, therefore, is initially effective in raising the fetal ventricular rate, but this effect may be transient.

Patients with acute rheumatic fever sometimes present with atypical signs and symptoms. In these circumstances, the Jones criterions may not be sufficient to make a clinical diagnosis. We describe here two patients with unusual presentations, highlighting that, both in regions where the disease is endemic, or where it is seen only sporadically, physicians should be more alert and careful in making the diagnosis.

At 32 weeks, a fetus was found to be hydropic with congenitally complete heart block in an asymptomatic mother who was positive to anti-Ro antibodies. Maternal therapy with oral salbutamol was successful in prolonging gestation for a period of 3 weeks so that preterm delivery was delayed until the 35th week of gestation. Following treatment with inotropes and diuretics, a permanent transvenous pacemaker was implanted at 8 weeks of age. The child is now thriving at 20 months of age.

Therapeutic doses of lofepramine and fluvoxamine were associated with the development of first degree and second degree heart block, respectively, in an 83 year old man with a normal ECG prior to treatment and with no history of cardiovascular disease. Caution is recommended in treating patients with newer generation antidepressants, even in cases where cardiac status appears normal prior to treatment.