[Seismocardiography--a noninvasive technique for estimating left ventricular function. Preliminary results]

Seismocardiography (SCG) is a precardiac registration of low frequency waves generated during mechanical work of the heart and transmitted to the surface of the chest. It is a methodology derived from the field of seismology combined with signal analysis to evaluate the biomechanical function of the heart. SCG can be used for monitoring changes in cardiac function during stress testing.

Usefulness of SCG exercise testing for estimating left ventricular systolic and diastolic function in patients with coronary heart disease. The study population consisted of 50 patients divided into two groups: Group A with 20 patients after myocardial infraction aged 52 +/- 10 years with left ventricular dysfunction and ejection fraction min. 20%, max. 45%, mean 38%; Group B with 30 healthy volunteers aged 34 +/- 7 years.

All patients underwent symptom-limited exercise testing (ETT) combined with SCG testing. We measured ETT duration as well as workload, heart rate and blood pressure during ETT. In addition, we measured left ventricular systolic and diastolic time intervals (PEP, LVET, PEP/LVET, IRT) at rest and during SCG exercise testing.

Group B exhibited better physical capacity; in particular the mean ETT duration was longer (9 +/- 2 vs. 7 +/- 2 min p < 0.0001), maximal workload was higher (168 +/- 28 vs. 118 +/- 33 W p < 0.0001), and heart rate during exercise was higher (162 +/- 10 vs. 129 +/- 25 p < 0.0001). In group A with lower EF PEP was prolonged (123 +/- 19 vs. 111 +/- 9 ms p < 0.05), PEP/LVET was higher (0.41 vs. 0.37) and IRT was increased (72 +/- 3 vs. 57 +/- 14) ms at rest and during exercise PEP (121 +/- 13 ms p < 0.05), PEP/LVET (0.39 vs. 0.37, IRT 51 +/- 25) vs. (38 +/- 16 ms p = 0.05).

SCG may be helpful in monitoring left ventricular systolic and diastolic function in patients with IHD.