DETERMINATION OF SYSTOLIC LEFT-VENTRICULA R TIME INTERVALS USING THE DOPPLER-TECHNIQUE - ECHOCARDIOGRAPHIC ANALYSIS OF AORTIC FLOW PATTERN

In 10 healthy volunteers (age 21-28 years; mean age 24,8 years +/-1.9 years) systolic left ventricular time intervals (STI) were determined by analysis of aortic Doppler flow pattern. This method was compared w ith conventional calculation of STI, using electrocardiogram, carotid pulse curve and phonocardiography, which were registered in synchronic ity to the Doppler examination. Both, CW- and PW Doppler echocardiogra phy constantly showed slightly lower values than the conventional meth od. This referred to basic measurements as well as to measurements aft er the application of isoprenaline and quinidine. The PW Doppler metho d underestimated the conventional method concerning the electromechani c systole (QS2) by on average 3.98 %, the left ventricular ejection pe riod (LVET) by on average 2,24 % and the preejection period (PEP) by o n average 7.3 %. Using CW-Doppler-method, QS2 was on average 5.31 % an d LVET was on average 6.67 % smaller than the values determined by con ventional method, whereas PEP was overestimated by on average 1.69 %. The study documented that positive and negative inotropic pharmacologi cal effects were measured reliably by the Doppler-echocardiographic me thod. Isoprenaline caused a significant shortening of frequency correc ted QS2 (QS2c) from -55 +/- 17 to -85 +/- 20 ms (p <0.05) using the PW -Doppler method; frequency corrected PEP (PEPc) was shortened from -40 +/- 14 to -67 +/- 14 ms (p < 0.05). The CW Doppler method also showed a statistically significant reduction of QS2c (from -64 +/- 18 to -89 +/- 25 ms; p < 0.05) and PEPc (from -37 +/- 16 to -64 +/- 12; p < 0.0 5). Likewise, the conventional method demonstrated statistically signi ficant shortening of QS2c and PEPc after application of isoprenaline. LVETc did not change in a state of positive inotropy, no matter which method was used for determination. The negative inotropic effect of qu inidine, measured by PW-Doppler, resulted in a prolongation of QS2c fr om -55 +/- 16 to -32 +/- 24 ms (p <0,05) and of LVETc from -20 +/- 11 to + 6 +/- 17 ms (p < 0.05). Using CW Doppler method, quinidine led to a lengthening of QS2c from -63 +/- 16 to -42 +/- 22 (p < 0.05) and of LVETc from -33 +/- 11 to -12 +/- 8 ms (p < 0.05). The conventional me thod also demonstrated a statistically significant increase of QS2c an d LVETc. None of the 3 methods in question showed a statistically sign ificant alteration of PEPc in the negative inotropic state. Conclusion s: Doppler-echocardiographic analysis of aortic flow pattern constitut es a new method for the measuring of systolic time intervals. Basic va lues as well as changes due to positive or negative inotropic effects are reliably determined, in comparison with conventional methods the m easurements are slightly lower.