gms | German Medical Science

Objective: Implanted neuromodulation devices are known to interact with ECG-recordings. This has been reported as for DBS, SCS, as well as baroreceptor cell stimulation patients. In cardiac emergencies, interpretation of heart rate, rhythm, or even ST-segment can be completely impeded preventing emergency treatment of myocardial infarction or cardiac arrhythmia. Therefore, effects of varied ECG derivation, reprogramming neurostimulator devices and different implantation sites of neurostimulators have been evaluated to optimize emergency ECG recordings for neuromodulation patients.

Methods: 40 patients, who have undergone implantation of a neuromodulation device due to Parkinson Disease (PD), tremor, dystonia (DBS, each n=20, n=6, n=7), failed back surgery syndrome (SCS, n= 2) or refractory hypertension (BRS, n= 5), underwent systematic ECG recordings comparing three different electrocardiographs. The impact of ECG derivation (4 lead, 12 lead, Nehb or defibrillation patches), implantation site (subclavicular, n= 35 vs. paraumbilical, n= 5) or stimulation mode (monopolar n= 29, bipolar n= 8, both n=3) on analysability of heart rate, rhythm, QRS-complex, regularity and ST-segment have been evaluated.

Results: Analysis of the ECG recordings revealed an increased electrical noise during neuromodulation (disturbed n=37(92.5%), undisturbed n= 3(7.5%), which is especial noticeable when a subclavicular device position was chosen. Bipolar stimulation mode showed a significantly increased ECG quality. Significant differences in ECG quality were found comparing different electrocardiographs, varying from about 40% to 70%. Comparing the ECG derivations, defibrillation patches got the most plausible ECG registration, resulting in an increase of ECG quality of about 10 %. Analysing ECG items, ST-segment and rhythms were more sensitive against interfering fields than heat rate or regularity.

Conclusion: This study highlights the necessity for (neuro-)surgeons to plan an optimized positioning of neuromodulation devices. Programming the neuromodulation devices, in order to ameliorate the underlying disease, must however also consider the impact on ECG recordings and to inform patient and relatives. For emergency physicians and paramedics, knowledge about the increasing number and indications for neuromodulation devices and handling the resulting ECG artefacts has to be improved, giving them a strategy pathway, so that they can acquire largely undisturbed ECG recording as a basis for needed cardiac therapy or intervention.

Figure 1 [Fig. 1], Figure 2 [Fig. 2]