LEFT VENTRICULAR SYSTOLIC TIME INTERVALS BY DOPPLER-COMPARISON WITH CAROTID PULSE METHOD

We compared left ventricular systolic time intervals (L STI's) derived from pulsed Doppler(D) and from conventional(C) carotid pulse tracing(CPT) and phonocardiography(PCG) in 24 subjects, aged 1.7 to 18.5 yrs, median=12.1 yr. Using the apical 2-chamber view, D frequency-time curves from the proximal ascending aorta were recorded simultaneously with CPT,PCG and ECG. L STI's from the D tracings were measured as follows: pre-ejection period (PEP)-beginning of QRS to onset of D systolic upstroke; ventricular ejection time(VET)-onset of D systolic upstroke to maximal end-systolic flow reversal. The difference in pulse transmission time between onset and end of systole resulted in a systematically shorter PEP and longer VET by C. C PEP was best predicted by the regression equation C PEP=1.03(D PEP)-14, and C VET by C VET=0.99(D VET)+8. The cumulative distribution of the error of the predicted values and correlation coefficients(r) using these formulae were