The influence of heart rate, age, blood pressure, obesity, and work on systolic and diastolic time intervals.

Systolic and diastolic time intervals were measured in 655 men who did not have coronary or hypertensive heart disease. The correlation between systolic and diastolic intervals (STI) and the heart rate, age, height, weight, weight/height index, blood pressure and work heaviness were calculated using multiple stepwise regression analysis. There was a significant correlation between heart rate and the majority of STI. Also there was a significant influence of systolic and diastolic blood pressure and age on the ejection variables (QS2, LVET, S1S2). The PEP and ICT were influenced by heart rate, and systolic and diastolic blood pressure. The PEP/LVET ratio was dependent on diastolic and systolic blood pressure. The height of the A wave of apex cardiogram was significantly dependent on diastolic and systolic blood pressure, obesity, heart rate, and age. The IRT was dependent on heart rate, obesity, and height. When interpreting systolic time intervals one must use systolic time interval indices which are calculated by using the effect of heart rate on them, but in some cases the effect of other factors must be taken into account because blood pressure, age, and obesity also have a significant physiological effect on the STI values.