Current standard electrocardiography is a useful and easily applicable method that has been in clinical use for more than hundred years. However, it is hampered by low spatial resolution. Thus, precise electro-anatomical mapping of arrhythmias still has to be conducted by invasive catheterization. The main long-term objective of this project is to answer the question whether invasive mapping of arrhythmic substrates (current standard) can be replaced by a non-invasive alternative, namely analyses using signals obtained from ME sensors combined with electric measurements.
We will thus investigate if a multi-channel combined ECG/MCG (electrocardiogram/magnetocardiogram) approach allows for reliable non-invasive localization of the origin of cardiac arrhythmias. This is becoming even more important, as recently stereotactic body radiation therapy was successfully applied for ablation of ventricular tachycardia, promising a completely non-invasive way to cure arrhythmias in the future.
To perform the required measurements with a multitude of magnetic (both ME sensors originating from this CRC [B10-3, B10-6] and already established systems) as well as electric sensors, individual real-time signalto-noise ratio estimations of all involved sensors will be investigated that permit optimal sensor placement, sensor signal combination, and parameter extraction. An appropriate automatic signal quality analysis should guarantee a minimum recording time for patients. To answer these research questions, forward modelling and a solution of the inverse problem is necessary. Here the results of the former CRC project B3 will be used and further extended. To evaluate the accuracy and clinical utility of this approach, we plan to compare it with results from electrophysiological studies (current standard) in 3 different groups of patients: (1) premature ventricular contractions, (2) idiopathic ventricular tachycardia, (3) ischemic ventricular tachycardia. For each patient, magnetic resonance imaging (MRI) and computed tomography (CT) for anatomy and electric and magnetic measurements will be performed.
Involved Researchers: Gerhard Schmidt, Norbert Frey, Erik Engelhardt