In-vitro investigation of cardiac implantable electronic device malfunction during and after direct photon exposure: A three-centres experience.

PURPOSE: Radiotherapy may cause malfunction of implantable cardioverter-defibrillators (ICDs) and pacemakers (PMs). We carried-out a multicentre randomized in-vitro study on 65 ICDs and 145 PMs to evaluate malfunctions during and after direct irradiation to doses up to 10 Gy. METHODS: Three centres equipped with different linear accelerator and treatment-planning systems participated in the study. Computed Tomography (CT) acquisitions were performed to build the treatment plans. All devices were exposed to dose of 2, 5, or 10 Gy (6 MV). All devices underwent a baseline examination and 64 wireless real-time telemetry-transmissions (47 ICDs and 17 PMs) were monitored during photon exposures. All devices were interrogated after exposure and once monthly for six subsequent months. RESULTS: Fifty-four of the 64 wireless-enabled CIEDs (84.4%) recorded noise-related interferences during exposure. In detail, 40/47 ICDs (85.1%) reported interference, of which 16 ICDs (34%) reported potentially clinically relevant pacing inhibition and inappropriate detections. Following exposure, a soft reset occurred in 1/145 PM (0.7%) while 7/145 PMs (4.8%) reported battery issues. During the six-month follow-up, 1/145 PM (0.7%) reported a soft reset, while 12/145 more PMs (8.3%) and 1/64 ICD (1.5%) showed abnormal battery depletion. All reported issues occurred independently of exposure dose. Finally, irreversible effects on software and battery life occurred in only non-MRI-compatible devices. CONCLUSION: ICDs mostly featured real-time transient sensing issues, while PMs mostly experienced long-term battery or software issues that were observed immediately following radiation exposure and during follow-up. Irreversible effects on battery life and software occurred in only non-MRI-compatible devices.

Can we improve the accuracy of electrocardiographic algorithms for accessory pathway location in children?

BACKGROUND: Predicting an accessory pathway location is extremely important in pediatric patients. AIMS: We designed a study to compare previously published algorithms by Arruda, Boersma, and Chiang. METHODS: This multicenter study included patients who had undergone successful ablation of one accessory pathway. Analysis of resting 12-lead electrocardiograms was carried out. An aggregated prediction score was constructed on the basis of algorithm agreement, and a structured workflow approach was proposed. RESULTS: The total population was 120 patients (mean age, 12.7 [± 3.6] years). The algorithm by Boersma had the highest accuracy (71.7%). The inter-rater agreement among the 3 reference algorithms, according to left-sided accessory pathway (AP) identification, was good between Boersma and Chiang (κ = 0.611; 95% confidence interval [CI], 0.468-0.753) but moderate between Arruda and Chiang and between Arruda and Boersma (κ = 0.566; 95% CI, 0.419-0.713 and κ = 0.582; 95% CI, 0.438-0.727, respectively). Regarding locations at risk of atrioventricular (AV) block, agreement was fair between Arruda and Chiang and between Boersma and Chiang (κ = 0.358; 95% CI, 0.195-0.520 and κ = 0.307; 95% CI, 0.192-0.422, respectively) but moderate between Arruda and Boersma (κ = 0.45; 95% CI, 0.304-0.597). On applying a first-step diagnostic evaluation, when concordance was achieved, we were able to correctly identify left-sided or non-left-sided ablation sites in 96.4% (n = 80) of cases. When concordance was achieved, correct prediction of risk/no risk of AV block was achieved in 92.2% (n = 59) of cases. CONCLUSIONS: An aggregated prediction score based on 3 reference algorithms proved able to predict an accessory pathway location very precisely and could be used to plan safely invasive procedures.

Challenges in the remote monitoring of cardiac implantable electronic devices in 2021.

Patients with cardiac implantable electronic devices have usually been scheduled for routine in­hospital visits. In addition, they are now monitored remotely. The remote monitoring of cardiac implantable electronic devices is a valuable tool to screen and triage patients at very high risk of deterioration. The continuous expansion of remote monitoring in real­world settings brought a substantial increase of published evidence on the topic. Therefore, this review aims to summarize challenges and knowledge gaps in the field. Challenges that were identified as issues to be solved comprise warranty of data security and accessibility, integration with clinical repositories, patient selection and persistence, and resource availability. Future improvements of telemedicine will need to face these significant residual challenges.

Elective replacement of a 4-year-old leadless pacemaker: New approach for end-of-life management.

We report the first case of new technique of replacement of a Micra TPS, due to battery depletion. A 38-year-old patient was admitted due to battery depletion of a TPS, after 44 months of regular pacemaker functioning. After routine implantation of a new TPS, we use a snare loop inserted in the delivery system to capture the old TPS. We believe this approach a good option not to abandon the depleted device, to avoid possible electrical interference or space occupation in right ventricle. This new approach allows to change the strategy during procedure and does not increase significantly the procedure costs.

Remote monitoring of subcutaneous implantable cardioverter defibrillators.

BACKGROUND: Remote monitoring (RM) of implantable cardioverter defibrillators (ICD) has been shown to improve patient safety and reduce in-office visits. The subcutaneous ICD (S-ICD) is an effective alternative to transvenous ICD and has recently been endowed with the RM function. However, the RM communicator for S-ICD requires patient interaction to activate data transmission. We assessed patient compliance and acceptance. METHODS: Patients with S-ICD received the communicator and were followed up for 15 months. Weekly remote transmissions were programmed. Compliance with checks was measured as the number of checks performed by the patient divided by the number of automatic notifications by the communicator. A questionnaire on acceptance of the system was administered to patients. RESULTS: A total of 106 patients were analyzed. The proportion of weekly checks properly executed by the patients was 94% during the first 3 months and 93% from months 12 to 15. Of the checks performed, 93% were on the same day as the automatic notification. On a patient basis, compliance with weekly checks was > 85% (less than one check missed per month) in 88% of patients during the first 3 months and in 82% from months 12 to 15 (p = 0.615). No variables emerged as predictors of lower (≤ 85%) long-term compliance with weekly checks. During follow-up, 49 alerts were transmitted and the mean delay between the detected event and the patient transmission was 2 ± 2 days. The majority of patients found the system easy to use and felt confident about being remotely monitored. CONCLUSIONS: The level of patient compliance with remote checks is high with current technology for RM of S-ICD. The vast majority of data transmissions are consistently performed on a weekly basis on the day scheduled.

Transvenous pacing in pediatric patients with bipolar lumenless lead: Ten-year clinical experience.

INTRODUCTION: A number of challenges can affect long-term performance of endocardial implanted systems in pediatric patients. Select Secure™ lead offers potential advantages for this population. This analysis aims to evaluate long-term performance of this lead in children, with and without congenital heart disease. METHODS: A retrospective analysis of all patients younger than 16years, implanted with at least one Select Secure™ lead at our institution, was performed. Clinical patient characteristics, electrical lead parameters, implant related complications, occurrence of surgical revisions and other complications were analyzed. RESULTS: From 2006 to 2016, 40 pediatric patients (26 males; age: 10.3±4.6years) underwent a cardiac device implantation with at least one Select Secure™ lead. Axillary vein access was chosen in 77.5% of the procedures. The intra-atrial loop of the leads was successfully created and the generator was placed in a sub-pectoral pocket in all patients. A total of 57 Select Secure™ leads were implanted: 23 in the right atrium and 34 in the right ventricle. PM/ICDs implantation was uneventful in all 40 patients. One lead, dislodged the day after implantation, was successfully extracted and replaced in the same day. Adequate pacing parameters were achieved during a follow-up of 6±2.9years (range 0.9-10.8years). CONCLUSIONS: In a pediatric population, the Select Secure™ lead used in the axillary vein, the creation of an intra-atrial loop and the placement of the generator in a sub-pectoral pocket ensured a safe implantation of pacemaker or ICD and an effective stimulation at medium-term follow-up.

External closed-circuit cooling system for management of patients after device implantation: A feasibility study.

BACKGROUND: In the first 24h after pacemaker or implantable cardioverter/defibrillator (ICD) implantation or replacement, the occurrence of hematoma and pain in the surgically treated region is not infrequent and may result in re-intervention and/or more severe complications, such as infections. Currently, the post-implant phase management is very empiric. The aim of this study was to test the clinical applicability and usefulness of an external close-circuit cooling system for the management of the early post-implant period in patients with high risk of hematoma due to anticoagulant and/or antiplatelet therapy. METHODS: We studied 135 patients (78M; 71±11years) with high risk of hematoma occurrence after pace-maker (63 patients) or ICD (72 patients) implantation or replacement. Immediately after the intervention, a closed-circuit cooling system (CAREPACE™ system, Zamar, Italy) was externally applied on the pre-pectoral region to each patient and maintained for 24h. The system has a compressive pad and a refrigerating circuit in which non-toxic glycolic fluid is pumped. The fluid temperature was set and kept at 5°C for the whole period. RESULTS: The compressive and cooling effect of the system was well tolerated by all the patients at the temperature set. Four patients complained of noise due to machine operation, but in none the treatment was interrupted. The average length of hospital stay was 2.8±0.4days. No clinically significant hematoma was observed at discharge and after one month follow-up visit. CONCLUSIONS: This new system can be used for the management of the early phase after device implantation or replacement and appears clinically useful and well tolerated. Further studies on a larger scale are needed to test the potential reduction of post-intervention complications and the cost-effectiveness of this device.