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: