While published guidelines are useful in the care of patients with long-QT syndrome, it can be difficult to decide how to apply the guidelines to individual patients, particularly those with intermediate risk. We explored the diversity of opinion among 24 clinicians with expertise in long-QT syndrome. Experts from various regions and institutions were presented with 4 challenging clinical scenarios and asked to provide commentary emphasizing why they would make their treatment recommendations. All 24 authors were asked to vote on case-specific questions so as to demonstrate the degree of consensus or divergence of opinion. Of 24 authors, 23 voted and 1 abstained. Details of voting results with commentary are presented. There was consensus on several key points, particularly on the importance of the diagnostic evaluation and of β-blocker use. There was diversity of opinion about the appropriate use of other therapeutic measures in intermediate-risk individuals. Significant gaps in knowledge were identified.
Introduction: Intermittent pre-excitation (I-PX) in patients with Wolff Parkinson White syndrome (WPW) is thought to indicate low risk of a life-threatening event (LTE), which is reflected by recen...
Implantable loop recorders are commonly used to sense arrhythmias. The purpose of this study is to assess the P- and R-wave amplitudes at implantation (I) and follow-up (F) following insertion of the Reveal LINQ™ Insertable Cardiac Monitor (Medtronic, Minneapolis, MN) in an institutional review board-approved, multicenter study performed on pediatric patients younger than 18 years old. Collected data included demographics, presence of congenital heart disease (CHD), P- and R-wave-sensed amplitude at I and F, and the method of implant (i.e. mapping or standard.) P waves were manually measured and R-wave sensing was recorded by the device. A total of 87 patients had a Reveal LINQ™ (Medtronic, Minneapolis, MN) device implanted; the mean patient age was 11.8 years (0.5 years to 18 years) with 48% of patients being female and 19% of patients having CHD; mapping was used in 43% of patients. The Reveal LINQ™ (Medtronic, Minneapolis, MN) experienced no change in average sensed R-wave amplitude at either I or F (1.28 mV vs 1.26 mV, p = NS). There was no difference in sensed R-wave amplitude noted with or without mapping used at I (1.29 mV vs 1.26 mV, p = NS) or F (1.48 mV vs 1.18 mV, p = NS). Additionally, no difference could be found in R-wave sensing of patients with CHD or without CHD at I (1.26 mV vs 1.4 mV, p = NS) or F (1.32 mV vs 1.32 mV, p = NS). R-wave sensing trended towards being inversely proportional to patient body surface area (BSA) (p = NS). P waves were detected on 48% of tracings in all patients at I and/or F, irrespective of whether the Reveal LINQ™ (Medtronic, Minneapolis, MN) device was placed with mapping. The R wave was (0.37-3.5 mV) at I and (0.3-3 mV) (p = NS) at F when P waves were detected. From these results, it can be said that the Reveal LINQ™ Insertable Cardiac Monitor (Medtronic, Minneapolis, MN) has an excellent ability to sense R-wave amplitude in pediatric patients. No significant difference in the sensing ability of the device could be identified with respect to the presence of CHD, use of mapping or BSA. P waves tended to be identified when there was a higher baseline R-wave amplitude.
Key Teaching Points•Children and young adults with NKX2-5 mutations can present with a varied spectrum of electrical phenotypes in addition to their structural phenotype.•Bradyarrhythmias such as atrioventricular block and tachyarrhythmias such as atrial fibrillation and ventricular tachycardia can all coexist in patients with NKX2-5 mutations and may manifest as early as teenage years. It is pertinent to have a high index of suspicion for such arrhythmias and maintain longitudinal follow-up for patients with known NKX2-5 mutation.•Given the risk of sudden death in this population, early intervention with pacemaker implantation and/or implantable cardioverter-defibrillator placement should be considered. •Children and young adults with NKX2-5 mutations can present with a varied spectrum of electrical phenotypes in addition to their structural phenotype.•Bradyarrhythmias such as atrioventricular block and tachyarrhythmias such as atrial fibrillation and ventricular tachycardia can all coexist in patients with NKX2-5 mutations and may manifest as early as teenage years. It is pertinent to have a high index of suspicion for such arrhythmias and maintain longitudinal follow-up for patients with known NKX2-5 mutation.•Given the risk of sudden death in this population, early intervention with pacemaker implantation and/or implantable cardioverter-defibrillator placement should be considered.
