Body surface mapping of the mechanical cardiac activity

Introduction: Studies of the movement of the chest wall show their potential in the diagnosis of heart diseases. Few studies have focused on mapping these movements especially in the lower inaudible frequency band. Aims: This study evaluates Body Surface Mapping (BSM) as a method for describing mechanical cardiac activity. Methods: The chest wall's velocity was measured with a Laser Doppler Vibrometer (LDV) on six healthy subjects. The measuring procedure was repeated for 30 points positioned in a grid at the subjects chest. An electrocardiogram (ECG) and respiration was measured to support the signal processing. The heart movement were described using amplitude maps, constructed from the integrated LDV signal components of 1-20 Hz. Results: The impact of the cardiac motion on the displacement of the chest wall was shown as a typical pattern of the changes of the amplitude maps as a function of time. Conclusion: The results had a high reproducibility and were in concordance with existing evidence, thus indicating BSM to be a valid method for characterization of the mechanical cardiac activity.