Modeling an Activation of Heart Ventricular Segments

Radovan Smisek1, Pavel Jurak2, Josef Halamek3, Filip Plesinger2, Ivo Viscor2, Magdalena Matejkova4, Pavel Leinveber5
1Brno University of Technology, 2Institute of Scientific Instruments of the CAS, 3Institute of Scientific Instruments, CAS, CZ, 4International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic, 5International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic


Background: Knowing activation times of specific myocardium segments can help to identify conduction disturbances which may, consequently, result in more targeted treatment of patients. Here, we present a 2D activation model evaluating activation of specific myocardium segments: 3 in the right ventricle, 3 in the left ventricle, 3 in the septum and 2 in the apex. Methods: Precordial six-lead ECG signal was measured with a 5kHz sampling frequency. A total of 10 left bundle branch block (LBBB) and 5 right bundle branch block (RBBB) recordings were analyzed. The analysis includes following steps: 1) QRS complexes detection, 2) QRS complexes morphology clustering, 3) averaging of 100-1000 Hz envelograms (9x step 100 Hz) of dominant QRS complexes, 4) a genetic algorithm (GA) produces artificial averaged envelograms from (initially random) timing of myocardium segments. The task for GA is to produce envelograms the most similar to measured; then final timing should reflect real activation of examined myocardium segments. Results: Presented activation model determined activation of left ventricular segments before right ventricular segments in all RBBB patients (mean 61.4 ± 13.7 ms) and activation of right ventricular segments before the left ventricle segments in all LBBB patients (mean 87.8 ± 15.8 ms). Computed activation of segments also created sequences related to input pathology. Conclusion: We introduced a new method determining activation times of myocardium segments; this is achieved noninvasively using only high-frequency ECG signal from precordial leads.