Electrocardiographic and clinical anticipation of the left ventricular systolic function, systemic vascular resistance, and myocardial hypertrophy--normal values and validation of method in patients with arterial hypertension.

In order to study the hemodynamic effects of the antihypertensive drugs in patients with essential hypertension, systolic time intervals from ECG data were extrapolated. The study was performed in 36 healthy individuals and 38 patients with essential hypertension without a drug therapy and/or in the wash out period more than three weeks and after a treatment. The stroke volume (SV) was determined as a product of the ejection time (ET), the pulse pressure (PP) and the flow coefficient (Kf). The Kf was extrapolated from Doppler-cardiographic parameters and it significantly correlated with the normal diastolic blood pressure (TA(d)) if the QT is not prolonged and the electrical systole/mechanical systole ratio (QS2/MS) not disturbed: Kf = 9.356 e-0.008 TA(d); r = -0.9. In arterial hypertension the correlation was also curvilinear: kf = 3.962 e-0.001 TA(d); r = -0.99. The arteriolar stiffness was defined as the PP/SV ratio. The cardiac output (CO) and systemic vascular resistance (SVR) were determined according to conventional formulas by known clinical and extrapolated ECG data. The cardiac contractile or muscle performance was defined as corrected changes of the ejection function for the given afterload according to the formula: I (-0.004 TA(d) + PEP/ET) -0.014 x 100; the normal 95% confidence limits for the laboratory used are -6.6% to +6%. Systolic time intervals were extrapolated from ECG data in the consecutive manner: QS2 = kQS2 x QT, ET = kET x JT, and MS = kMS x ET. The correlation of kQS2 with QT is curvilinear: kQS2 = 2.760 e-2.732 QT.(ABSTRACT TRUNCATED AT 250 WORDS)