The systolic time intervals, hemodynamics, and indices of myocardial contractility were measured in 158 normal Koreans with average age of 34(14~69) years by non-invasive technique, i.e. simultaneous recording of ECG, PCG, and carotid and femoral pulse tracing with paper speed 100mm/sec. by cardiograph. 1. Normal values of systolic time intervals were as follows(M+/-SD): QS1was 61.5+/-10.8, ICT 41.9+/-12.0, PEP 10.+/-14, LVET 281+/-24, and QS2 385+/-26 msec. 2. Regression equations of systolic time intervals to pulse rate were as follows: QS1; 0.04 x PR + 60.0 (r=+0.038, p>0.05), ICT; -0.2 x PR + 59.6 (r=-0.234, p<0.01), PEP; -0.2 x PR + 117 (r=-0.162, pp<0.05), LVET; -1.5 x PR + 389 (r=-0.725, pp<0.001), QS2; -1.7 x PR + 507 (r=-0.745, pp<0.001). 3. Each phase of systolic time intervals was affected by various factors: ICT and PEP by pulse rate, diastolic pressure and stroke volume, LVET by pulse rate and stroke volume, QS1by diastolic pressure, and QS2by pulse rate. Multiple linear regression analysis results in the following formulas for prediction of the systolic time intervals from the pulse rate, diastolic pressure and stroke volume: ICT; -0.299PR+0.230Pd-0.139Vs+28.1(r=0.38), PEP; -0.272PR+0.356Pd-0119Vs+104.8 (r=0.39), LVET; -1.475PR+0.167Vs+376.6 (r=0.74). 4. Systolic time intervals were not influenced by height, weight or body surface, but LVET and QS2were prolonged significantly in female group. 5. Normal values of hemodynamics calculated by Wezler's formula were as follows: stroke volume was 68.1+/-21.7ml, stroke index 50.2+/-14.9ml/m2, cardiac output 4.9+/-1.71/min., cardiac index 3.6+/-1.3 1min/m2, peripheral resistance 1696+/-507 dyne sec. cm(-5), and volume elasticity coefficient 1916+/-422 dyne cm(-5). 6. Normal values of non-invasive indices of myocardial contractility were as follows: ICT was 42+/-21 msec. PEP 10.+/-14 msec., 1/PEP2 9.87x10-5+/-2.79x10-5msec., 1/ICT28.56x10-3+/-1.65+/-10-3msec-2., Pd/ICT 1.96+/-0.92 mmHg/msec., Pd/PEP 0.723+/-0.125 mmHg/msec., PEP/LVEE 0.37+/-0.06, LVET/PEP 2.77+/-0.47, and LVET/ICT 7.45+/-3.19. 7. Each index of myocardial contractility was affected by various factors: ICT, PEP, 1/PEP2, PEP/LVET, LVET/PEP and LVET/ICT by pulse rate, diastolic pressure and stroke volume, 1/ICT2by pulse rate, and Pd/ICT and PD/PEP by pulse rate and diastolic pressure. 8. Correlation coefficients between PEP/LVET and other indices were relatively high in PEP, 1/PEP2and LVET/PEP, and relatively low in ICT, 1/ICT2Pd/ICT, Pd/PEP and LVET/ICT.
Blood Pressure ; Cardiac Output ; Elasticity ; Electrocardiography ; Female ; Heart Rate ; Hemodynamics* ; Humans ; Linear Models ; Reference Values ; Stroke ; Stroke Volume ; Systole* ; Vascular Resistance