Assessment of paediatric exertional or peri-exertional syncope: does the story matter?

Exertional syncope has been suggested to correlate with a cardiac aetiology, particularly when occurring in mid-stride. The aim of the study is to evaluate the incidence of cardiac disease among children presenting with exertional syncope, determine the influence of timing within activity, and determine the utility of genetic testing and implantable event monitors in the evaluation of cardiac syncope. The patients ≤18 years old with exertional syncope who underwent exercise stress testing between 2008 and 2019 were retrospectively included. Patients were assessed to be in one of three groups: mid-exertion (mid-stride syncope), peri-exertion (syncope during activity but not moving), and post-exertion (within minutes of the activity). A total of 334 patients were included; 46 % were mid-exertion, 18 % were peri-exertion, and 36 % were post-exertion. Thirteen patients (3.8 %) were diagnosed with cardiac syncope; n = 9 (69 %) mid-exertion. Only mid-exertional syncope was significantly associated with a cardiac diagnosis (OR: 2.6). Cardiac diagnoses included inherited arrhythmia syndromes (n = 9), abnormal coronary origins (n = 2), and supraventricular tachycardia (n = 2). Only catecholaminergic polymorphic ventricular tachycardia (n = 5) was associated with mid-exertional syncope (OR: 1.4). The definitive diagnostic test was exercise testing (n = 8), echocardiogram (n = 2), genetic testing (n = 1), ambulatory monitor (n = 1), and EKG (n = 1). Mid-stride syncope was more likely to result in a cardiac diagnosis, and exercise testing is the most common definitive test as catecholaminergic polymorphic ventricular tachycardia was the primary aetiology of exertional syncope in our cohort. Implantable event monitors and genetic testing could be helpful in ruling out cardiac disease.

Transesophageal three-dimensional echocardiographic guidance for pacemaker lead extraction.

BACKGROUND: The ability of transesophageal three-dimensional echocardiography (3DE) to aid in pacemaker lead extraction has not yet been evaluated. 3DE provides real-time evaluation of intracardiac anatomy and the location of pacemaker leads in greater detail than either fluoroscopy or -two-dimensional echocardiography (2DE), aiding in the extraction of such leads, which can be potentially dangerous. We sought to investigate the feasibility and utility of 3DE to visualize intracardiac anatomy and pacemaker leads, and to assist in lead extraction procedures. METHODS: We utilized 3DE in nine encounters for eight different patients, to visualize intracardiac anatomy and leads before, during, and after extraction to evaluate the feasibility and utility to aid in the procedure and evaluate for potential sequelae. RESULTS: 3DE was able to identify pertinent intracardiac anatomy and leads in all cases. 3DE detected procedural complications or altered management in five of nine encounters (five of eight patients); this included detection of an avulsed papillary muscle, tricuspid valve leaflet damage, and cast/thrombus after lead removal, as well as adjustment of excess lead slack to avoid future valve damage, or risk stratification of lead removal. CONCLUSION: 3DE is feasible and adds utility to lead extraction cases by visualizing intracardiac anatomy and leads beyond fluoroscopy or 2DE, providing real-time information during extraction, and identifying potential complications.

Intermittent versus Persistent Wolff-Parkinson-White Syndrome in Children: Electrophysiologic Properties and Clinical Outcomes.

BACKGROUND: Intermittent Wolff-Parkinson-White (WPW) syndrome is considered to have a lower risk of sudden death. Fewer data exist regarding electrophysiologic (EP) characteristics and the natural history of intermittent WPW in children. METHODS: All patients with WPW age 1-18 years at a single institution (1996-2013) were reviewed. Patients with intermittent preexcitation were compared to those with loss of preexcitation on Holter/exercise testing and those with persistent preexcitation. High-risk accessory pathway (AP) was defined as AP effective refractory period (APERP), block cycle length, or shortest preexcited RR interval during atrial fibrillation ≤250 ms. RESULTS: A total of 295 patients were included: 226 (76.6%) persistent, 39 (13.2%) intermittent, and 30 (10.2%) loss of preexcitation Holter/exercise. There were no differences in symptoms between groups. Median interquartile range APERP was significantly longer in intermittent WPW (380 [320, 488] ms vs 320 [300, 350] ms persistent, 310 [290, 330] ms loss of preexcitation Holter/exercise; P = 0.0008). At baseline, there was no difference between groups in frequency of high-risk pathways. However, when isoproterenol values were included, high-risk pathways were more frequent among patients with loss of preexcitation on Holter/exercise (54% vs 16% persistent, 11% intermittent; P = 0.005). There was one death in a patient with loss of preexcitation on exercise testing, no EP study, and prior drug use. A second patient with persistent WPW and APERP 270 ms required resuscitation following a methadone overdose. CONCLUSION: Intermittent preexcitation in children does not connote a lower risk AP by EP criteria or reduced symptoms. The low number of pediatric WPW patients who develop preexcited atrial fibrillation or sudden death warrants larger studies to investigate these outcomes.

Axillary versus infraclavicular placement for endocardial heart rhythm devices in patients with pediatric and congenital heart disease.

Our objective was to evaluate the implant and mid-term outcomes of transvenous pacemaker or internal cardioverter-defibrillator placement by alternative axillary approaches compared to the infraclavicular approach in a pediatric and congenital heart disease population. We conducted a retrospective review of all patients with new endocardial heart rhythm devices placed at 4 pediatric arrhythmia centers. A total of 317 patients were included, 63 had undergone a 2-incision axillary approach, 51 a retropectoral axillary approach, and 203 an infraclavicular approach. Congenital heart disease was present in 62% of the patients. The patients with the 2-incision axillary approach were younger and smaller. The patients with the retropectoral axillary approach were less likely to have undergone previous cardiac surgery and were more likely to have had an internal cardioverter-defibrillator placed. The duration of follow-up was 2.4 ± 1.9 years for the 2-incision axillary, 2.6 ± 2.6 years for retropectoral axillary, and 3.5 ± 1.4 years for the infraclavicular technique (p = 0.01). No differences were seen in implant characteristics, lead longevity, implant complications, lead fractures or dislodgements, inappropriate internal cardioverter-defibrillator discharges, or device infections among the 3 groups. In conclusion, our data support that the outcomes of axillary approaches are comparable to the infraclavicular approach for endocardial heart rhythm device placement and that axillary approaches should be considered a viable option in patients with pediatric and congenital heart disease.

Cryothermal catheter ablation of atrioventricular nodal reentrant tachycardia in a pediatric patient after atrioventricular canal repair.

Anatomic displacement of the atrioventricular node and associated conduction tissue in atrioventricular septal defects has been previously described. In spite of the increasing use of cryothermal catheter ablation in the pediatric population, there remains very little literature regarding its use in congenital heart disease. We describe successful cryothermal modification of the slow atrioventricular nodal pathway in a 12-year-old patient with a previously repaired partial atrioventricular septal defect and inducible atrioventricular nodal reentrant tachycardia. The use of a steerable catheter to locate the displaced His signal combined with the use of cryothermal energy allowed for the safe and effective treatment of this patient's tachycardia.

Toward improved cosmetic results: a novel technique for the placement of a pacemaker or internal cardioverter/defibrillator generators in the axilla of young patients.

Surgical scars secondary to the placement of pacemakers or internal cardioverter/defibrillators in the infraclavicular area can be unsightly. This report describes a novel cosmetic approach for the placement of pacemakers or internal cardioverter/defibrillators. The approach involves a small infraclavicular incision for placement of the leads and then a larger incision hidden high up in the axilla. The theoretical advantages of this approach are improved cosmetic outcome, ease of subsequent surgeries for device generator changes, and potentially improved defibrillation thresholds.

Investigation of cardiac function in children with suspected obstructive sleep apnea.

OBJECTIVE: To assess the prevalence of cardiac failure in a group of children with suspected obstructive sleep apnea (OSA) and to assess the need for preoperative electrocardiograms (ECGs) and chest radiographs (CXRs) in children with OSA. DESIGN: Case record review of 271 children having (adeno)tonsillectomy for symptoms of OSA. METHOD: Preoperative ECGs and CXRs were assessed for signs of right atrial or ventricular hypertrophy or failure. Case records were assessed for evidence of cardiac failure during anaesthesia. RESULTS: One child with congenital heart disease had signs of cardiac failure preoperatively. No other cases of atrial or ventricular hypertrophy or failure were found. CONCLUSIONS: Cardiac failure appears to be uncommon in children with symptoms of OSA. Preoperative ECG and CXR are essential in only selected cases.