We introduced a simple technique to eliminate electromagnetic interference between a left ventricular assist device (LVAD) and an implantable cardioverter-defibrillator (ICD). A 43-year-old male with heart failure and a reduced ejection fraction (HFrEF) who had an ICD presented with decompensated heart failure and received an LVAD as a bridge to transplant. Remote monitoring showed persistent atrial fibrillation causing an inappropriate ICD shock leading to a decision to disable shock therapies. However, an in-office interrogation was unsuccessful due to electromagnetic interference. Patient was instructed to extend his arm above his head on the ipsilateral side of the ICD, thus increasing the distance between LVAD and ICD, eliminating the interaction to allow reprogramming of the device.
Twiddler’s syndrome is a rare complication where a pacemaker or implantable cardioverter-defibrillator (ICD) is displaced with or without patient manipulation of their device. There are reports on transvenous devices but a paucity of data on subcutaneous devices. A 50-year-old male with hypertrophic cardiomyopathy and non-sustained ventricular tachycardia underwent subcutaneous-ICD (S-ICD) implantation for primary prevention. Remote device interrogation 4 weeks after device placement reported a shock due to “ventricular fibrillation”. It also showed abnormal lead impedance. Chest X-ray showed lead was dislodged and coiled around the pulse generator. Patient underwent lead revision and device replacement without further complications.
HCM is associated with an increased risk of various cardiac arrhythmias, including atrial fibrillation (AF), nonsustained ventricular tachycardia (NSVT), and sustained ventricular tachycardia (VT). Furthermore, the presence of cardiac arrhythmias has an important effect on the prognosis of HCM patients, especially with respect to ventricular arrhythmias as a major cause of sudden cardiac death (SCD). In this issue of Journal of Cardiovascular Electrophysiology, Magnusson and Mörner describe the incidence of NSVT, AF, and bradycardia in thirty patients at relatively low risk of SCD by utilizing an implantable cardiac monitor (ICM). These data are useful in demonstrating a fairly significant arrhythmia burden in a low risk population. The ramifications of these findings are a bit unclear, however. Certainly, atrial fibrillation is important to detect in order to mitigate the increased stroke risk by instituting anticoagulation. Detection of NSVT was less useful in this low risk population, but could be potentially more actionable in intermediate risk HCM patients. Thus, although further investigation is needed, the authors have taken the first step in determining appropriate treatment strategies for arrhythmias in HCM by helping to define the scope of the problem.