[Physiological variations of arterial pressure and heart rate in the first 5 minutes after moving from a supine to an upright position].

The physiological variations of blood pressure and heart rate were studied in the first five minutes of orthostatism in conditions identical to those encountered in clinical medicine. An increase in heart rate and diastolic blood pressure was observed from the first minute. The value of systolic blood pressure decreased as the subject got up and then rose to the value measured when lying down. At the fourth and fifth minute the three parameters were stable at significantly higher values than observed when lying down for the heart rate and diastolic blood pressure, but at an identical level for the systolic blood pressure. This study shows the necessity of measuring the orthostatic blood pressure using a precise technique which detects postural abnormalities when measured in the minute of orthostatism and which gives an assessment of the standing blood pressure when measured at the fifth minute.