Emerging electromagnetic interferences between implantable cardioverter-defibrillators and left ventricular assist devices.

AIMS: To investigate the prevalence of electromagnetic interference (EMI) between left ventricular assist devices (LVADs) and implantable cardioverter-defibrillators (ICDs)/pacemakers (PMs). METHODS AND RESULTS: A retrospective single-centre study was conducted, including all patients undergoing HeartMate II (HMII) and HeartMate 3 (HM3) LVAD implantation (n = 106). Electromagnetic interference was determined by the inability to interrogate the ICD/PM. Overall, 85 (mean age 59 ± 8, 79% male) patients had an ICD/PM at the time of LVAD implantation; 46 patients with HMII and 40 patients with HM3. Among the 85 LVAD patients with an ICD's/PM's, 11 patients (13%) experienced EMI; 6 patients (15%) with an HMII and 5 patients (11%) with an HM3 (P = 0.59). Electromagnetic interference from the HMII LVADs was only present in patients with a St Jude/Abbott device; 6 of the 23 St Jude/Abbott devices. However, in the HM3 patients, EMI was mainly present in patients with Biotronik devices: 4 of the 18 with only one (1/25) patient with a Medtronic device. While initial interrogation of these devices was not successful, none of the 11 cases experienced pacing inhibition or inappropriate shocks. CONCLUSION: In summary, the prevalence of EMI between ICDs in the older and newer type of LVAD's remains rather high. While HMII patients experienced EMI with a St Jude/Abbott device (which was already known), HM3 LVAD patients experience EMI mainly with Biotronik devices. Prospective follow-up, preferably in large registries, is warranted to investigate the overall prevalence and impact of EMI in LVAD patients.

Theophylline Use to Prevent Permanent Pacing in the Contemporary Era of Heart Transplantation: The Rotterdam Experience.

Introduction: Sinus node dysfunction and atrioventricular conduction disorders occur increasingly after orthotopic heart transplantation (HTX) due to aging donors and may require permanent pacemaker (PM) implantation. Theophylline has been used in the past in selected cases as an alternative to PM implantation. Purpose: The aim of this study was to investigate the rate and success of oral theophylline administration after orthotopic heart transplantation preventing permanent PM implantation. Methods: We included all patients treated with theophylline post HTX due to bradyarrhythmia's in our center from January 1985 to January 2020. Data was obtained retrospectively through electronic patient files. Re-transplants and patients who died within 1 month post HTX were excluded from the analysis. Results: Of the total of 751 heart transplant recipients, 73 (9,7%) patients (mean age 46 ± 15.2 years; 73% male) were treated with theophylline for bradyarrhythmia's early post HTX. Of these patients, 14 (19%) patients needed a permanent PM during hospitalization and 10(14%) patients stopped using theophylline because of adequate heart rhythm. In the end, 49 (6.5% of the total) patients were discharged with a theophylline (mean maintenance doses of 354 ± 143 mg). At the outpatient clinics, additional 6 (12%) patients needed a PM within 7 months after discharge, with the rest stable sinus rhythm. Conclusion: In this retrospective data analyses oral theophylline remained a viable alternative to permanent PM implantations in patients post HTX with increased heart rates, facilitating the withdrawal of chronotropic support and avoiding the need of permanent PM implantation.