Effect of age on systolic intervals (STI).

Weissler's corrected STI was to be used in the assessment of cardiac performance taking into account only the heart rate and sex. But there are many other determinants of STI, among them an important one is the age. In the present paper, in 422 normal adults (280 men and 142 women) divided according the age into three groups (20-29, 30-39, 40-60 years), we found significant differences concerning STIc with age, especially over 40 years old.

Absence of increased cardiac voltage and the importance of Q vectors for the diagnosis of left ventricular hypertrophy in early stages of hypertension in patients over 40 years of age.

The quantitative VCG criteria (VCGer) for left ventricular hypertrophy (LVH) and their diagnostic power were determined in 165 hypertensive men and 86 women over 40 years of age without congestive cardiac failure in comparison with 91 normal men and 108 normal women. The patients were grouped according to the presence or absence of LVH determined by X-ray (men: 96 without and 69 with LVH, women: 41 without and 45 with LVH). The proper statistical methods were used taking into account whether their distributions were symmetrical or asymmetrical.

New mathematical statistical methods for detecting correct echocardiographic (ECG) and vectorcardiographic (VCG) diagnosis criteria by computerization. I. The determination of the upper (Lu) and low (Ll) limits for VCG amplitudes. The multivariate analysis.

The mathematical statistical methods for the determination of the upper (Lu) and low (Ll) limits of the 95 percentile range of symmetrical and asymmetrical frequency distribution curves for electrocardiographic (ECG) or vectorcardiographic (VCG) amplitudes, ECG and VCG diagnostic criteria, and the multivariate analysis as well as the bases of their computerization-program have been presented, in order to find out the ECG and VCG diagnostic criteria. The formulae for the determination of sensitivity, specificity and performance score of the ECG and VCG diagnostic criteria, in both the above mentioned methods are presented.

Effect of age on the heart electrical phenomena, left ventricular wall thickness and blood pressure in men.

The effect of age on the maximal spatial QRS vector (MSQRSV) in the Frank lead system was correlated with th posterior left ventricular wall thickness (PLVWT), the interventricular septum thickness (IVST) determined by echocardiography, and with blood pressure in 300 normal men, distributed by age groups (20-29, 30-39, 40-60). With advancing age, a significant decrease of MSQRSV accompanied by a significant increase of PLVWT was observed while the increase of IVST and of blood pressures with age were found non significant. It was concluded that: 1.