Relationship between cardiac imaging data and simultaneous physiological measurements

This study aimed to quantitatively link cardiac imaging and simultaneous physiological measurements. Cardiac valve movement and valve blood flow were examined by M-mode and Doppler echocardiography simultaneously with cardiac electrical activity, thoracic impedance and peripheral pulse. The timing sequence of cardiovascular events through the cardiac cycle was reconstructed, and the relationships between valve movement/blood flow and physiological measurements were investigated. Data from one subject were studied. The timing of mitral and aortic flow was quantified as starting within 19 ms of the valves opening, and ending within 13 ms of the valves closing, except at the end of ventricular relaxation when mitral flow stopped 39 ms after valve closure. Mitral peak flow always occurred after the valve was fully open. Thoracic impedance stared to fall soon after aortic flow onset (12 ± 16 ms), while the minimum impedance occurred 107 ms (± 20 ms) before the flow stopped, with impedance taking account of both left ventricular volume and aortic blood volume. Similarly, left ventricular ejection produced a longer effect on peripheral pulse (jrom foot to the notch, 390 ± 13 ms). In conclusion, with simultaneously recorded cardiac images and physiological signals, we have analyzed the cardiovascular timing sequence through the cardiac cycle and linked echocardiograms to thoracic impedance and peripheral pulse.