Seismocardiography-based detection of cardiac quiescence for cardiac computed tomography angiography

As a measure of chest wall acceleration caused by cardiac motion, the seismocardiogram (SCG) has the potential to supplement the electrocardiogram (ECG) to more accurately trigger cardiac computed tomography angiography (CTA) data acquisition during periods of cardiac quiescence. The SCG was used to identify the systolic and diastolic quiescent periods of the cardiac cycle on a beat-by-beat basis and from composite velocity signals for nine healthy subjects. The cardiac velocity transmitted to the chest wall was calculated using a Kalman filter. The average systolic and diastolic quiescent periods were centered at 30% and 76%, respectively. Inter- and intra-subject variability of the quiescent phases with respect to the ECG was observed, suggesting that the ECG may be a suboptimal modality for predicting cardiac quiescence.