Correlation Between the SPhENo-Cardiograph™, a Seismocardiograph Device, and GE Vivid Q, an Echocardiograph, for Known Systemic Timing Intervals (STI)

The study Sponsor, Heart Force Medical Inc. (HFM), has developed a patented medical device called the SPhENo-CardiographTM. The SPhENo-Cardiograph™ provides a non-invasive assessment of the electro-mechanical function of the heart. The electrocardiograph (ECG) represents the waveform of the electrical stimulus to the cardiac muscle. The mechanical actions of the electrical potentials delivered in the ECG are revealed as the seismocardiograph (SCG). The SCG represents the changes in acceleration of the heart during the cardiac cycle. The SCG waveform reflects the ultra-low frequency vibrations of cardiac contraction. These low frequency vibrations are transmitted through the sternum. Using the point of initiation of ventricular contraction on the ECG, the Q wave, with fiduciary points on the synchronous seismocardiograph, it is possible to determine timing events of the cardiac cycle. The timing events of the cardiac cycle during systole are referred to as Systolic Timing Intervals (STI) and comprise the Pre-Ejection Period (PEP) and the Left Ventricular Ejection Time (LVET). The PEP is the time from the Q wave to the Aortic valve opening. The Left Ventricular Eject Time (LVET) is the time between the Aortic Valve opening and closing. The ratio of PEP/LVET in individuals with established heart disease is > 0.42. It is based on the formula described by Dr Arnold Weissler and first published in Circulation in 1968 (Weissler et al,1968). Weissler et al showed that the PEP/LVET ratio >0.42 are indicative of a lengthening of the PEP with some marginal shortening of the LVET. This is indicative of pathology associated with the coronary circulation (Ahmed et al, 1972;). This ratio can then be used as part of a non-invasive quantitative assessment of cardiac performance (Lewis et al 1977).

Using the SPhENo-CardiographTM, HFM has developed an algorithm to assess heart health that otherwise requires a number of technologies; stethoscope, ECG and Carotid pulse tracing to identify the dicrotic notch or Aortic Valve closure.