[Left high R wave amplitude and blood pressure levels before and after 5 minutes' rest in a mass screening program]

In order to evaluate the implication of blood pressures measured without 5 minutes' rest in mass screening programs, blood pressures were measured before and after 5 minutes' rest on 820 subjects in a rural community, aged 35 to 65 years and not receiving hypertensive treatment. Although the systolic blood pressure showed a significant drop of an average of 3 mmHg among males and 4 mmHg among females after rest, 23.3% of 820 subjects had higher systolic blood pressure reading after rest than before. The relationship between left high R (LHR) in electrocardiograms and blood pressure (BP) before and after rest was studied. The presence of LHR was significantly related to BP both before and after rest among males, but more strongly associated to BP before rest. The relationship of the difference between BP before and after rest to the prevalence of LHR was analyzed by multiple logistic method. A significantly higher prevalence of LHR with greater difference between systolic BP before and after rest was observed among males, even with age and systolic BP level after rest taken into account. These findings suggest the potential significance of blood pressure readings before 5 minutes' rest which may be a response to mental stress of having the initial blood pressure reading taken by the observer. It would seem worthy to obtain blood pressure before rest as well as after rest in detecting blood pressure abnormalities.