Discussion

This survey shows that there continues to be a wide variation in cardiovascular implantable electronic device in person evaluation, remote monitoring, and cardiovascular implantable electronic device-related ancillary testing practices in the paediatric population. A variety of factors might be influential including patient age, patient/family preferences, patient symptoms, reimbursement schedules, cardiovascular implantable electronic device management resources, geographic location, cost of Wi-Fi and internet services, underlying CHD, and complex clinic scheduling. Since 2015, a major difference in paediatric cardiovascular implantable electronic device monitoring practice is the reduction in utilisation of TTM for monitoring pacemakers (down to 23% from 67%) and increase in wireless remote monitoring (up to 94% from 87%). ^{Reference Boyer, Silka and Bar-Cohen6}

While it may be impossible to counter some heterogeneity in clinical practice, a paediatric-specific cardiovascular implantable electronic device follow-up paradigm that provides recommendations for minimal frequency of in-person evaluation, remote monitoring, and ancillary testing in uncomplicated patients is necessary. Standardized guidelines may maximise the opportunity for early detection and intervention of cardiovascular implantable electronic device system problems, prolong cardiovascular implantable electronic device battery longevity, enable early detection of haemodynamic and adverse events, initiate appropriate follow-up with corrective action/safety alerts, and minimises unnecessary device in-person evaluation and excessive testing. ^{Reference Wilkoff, Auricchio and Brugada1,Reference Slotwiner, Varma and Akar2,Reference Dechert, Serwer, Bradley, Dick and LaPage7–Reference Akar, Bao and Jones9} In particular, there are two phases after device implantation that are crucial and should be addressed in an expert consensus statement as immediate post implant “acute” phase and nearing elective replacement indicator phase. Many complications, such as lead dislocation and perforation, wound infection, and loose set-screws, can be seen within the first 7–10 days after implantation, if not recognised prior to discharge from the hospital. In this survey, <50% of respondents performed an in-person evaluation within 2 weeks of cardiovascular implantable electronic device implantation. When a cardiovascular implantable electronic device approaches elective replacement indicator, intensified surveillance frequency may be helpful. ^{Reference Wilkoff, Auricchio and Brugada1,Reference Slotwiner, Varma and Akar2} Conversely, during the “maintenance” phase of the device, less frequent follow-up may be sufficient, thereby reducing patient travel, time, and economic burdens as well as surplus workload on the clinical providers. A 2015 Paediatric and Congenital Electrophysiology Society survey of cardiovascular implantable electronic device monitoring showed that remote monitoring utilisation did not reduce the frequency of in-person evaluation. ^{Reference Boyer, Silka and Bar-Cohen6} The recent remote monitoring experience during the ongoing COVID19 pandemic has highlighted its utility in reducing in-person evaluation. ^{Reference Bricker, Garson and Traweek10} However, despite the ease with which patients are able to send remote interrogations, the amount of data produced from these reports is extensive and time for staff to prepare, interpret reports, and follow-up with patients is substantial. While assessment of variability in programming various cardiovascular implantable electronic device alert settings triggering automatic remote transmissions was beyond the scope of this survey, this was also an area where a streamlined and standardised approach may benefit the patient and providers. ^{Reference Wilkoff, Auricchio and Brugada1,Reference Slotwiner, Varma and Akar2,Reference Boyer, Silka and Bar-Cohen6,Reference Dechert, Serwer, Bradley, Dick and LaPage7}

Another area of inconsistency highlighted by this survey and not previously addressed is cardiovascular implantable electronic device-related ancillary testing. Standardised ancillary testing in paediatric patients may be of benefit as many children will require a lifetime of cardiovascular implantable electronic device therapy that may include a range of hardware implanted during periods of physical growth and vigorous activity. Chest X-rays can be helpful in detecting lead-related problems such as coronary compression, myocardial strangulation, dislodgement, and fracture. ^{Reference Berul, Villafane and Atkins4,Reference Mah, Prakash and Porras5} Echocardiography is useful in monitoring ventricular function in patients with high percentage of ventricular pacing and identifying endocardial lead-related complications. ^{Reference Dasgupta, Madani and Figueroa3} Exercise testing can provide data for programming upper rates, arrhythmia detection parameters, as well as detecting QRS morphology and T wave changes. In patients with single chamber that utilise electrogram morphology template matches during sinus rhythm to discriminate between supraventricular and ventricular arrhythmias, exercise testing may be useful to avoid inappropriate implantable cardioverter defibrillator shocks in patients who develop rate related QRS changes such as bundle branch block. Exercise testing may be particularly useful in patients with subcutaneous implantable cardioverter defibrillators to select a more appropriate sensing vector as well as for troubleshooting T wave oversensing at higher heart rates. Furthermore, important physiologic data can be obtained to guide decision making for pacemaker programming and upgrades. ^{Reference Bricker, Garson and Traweek10,Reference Gonzalez Corcia, Remy, Marchandise and Moniotte11} Periodic ambulatory Holter monitoring may be useful to identify subclinical device malfunction and arrhythmias. ^{Reference Chudzik, Klimczak and Wranicz12}

This survey should serve as a catalyst for proposing a framework for paediatric-specific guidelines for cardiovascular implantable electronic device follow-up and ancillary monitoring. The time frames for cardiovascular implantable electronic device monitoring published in expert consensus recommendations do not vary significantly from current paediatric practice, but given the higher incidence of device-related complications in paediatric patients, revisions to recommendation are needed. ^{Reference Dechert, Serwer, Bradley, Dick and LaPage13} For example, in-person follow-up after cardiovascular implantable electronic device implantation should occur as early as possible, and at least within 4 weeks (instead of the recommended 12 weeks) as early detection of surgical wound, lead, and device implant complications have better outcomes when addressed in the acute post implant period. ^{Reference Berul, Villafane and Atkins4} The proposed framework should also include guidance for performing ancillary testing such as imaging, ambulatory rhythm monitoring, and exercise stress testing for cardiovascular implantable electronic device optimisation. ^{Reference Dasgupta, Madani and Figueroa3,Reference Bricker, Garson and Traweek10,Reference Chudzik, Klimczak and Wranicz12} This is an area that is currently not addressed in any published cardiovascular implantable electronic device clinical guidelines. Standardisation of cardiovascular implantable electronic device surveillance is likely to become even more important as technology advances into the realm of remote device programming. ^{Reference Alexander and Baranchuk14} In addition, standardisation will provide benchmarks for adequate reimbursement and enable payers to recognise the human and technological resources necessary for cardiovascular implantable electronic device surveillance including ancillary testing to optimise care and safety of this vulnerable patient population.