Investigation To Changes Of Cardivascular System Of Hypertensive Patients In Exercise Stress Testing

Objective:To investigate blood pressure and heart rate change characteristics of hypertensive patients in exercise stress testing.Methods:60patients of grade1or grade2essential hypertension without complications (H group, N=60)and24normal persons (N group, N=24) were investigated. Patients in H group were subdivided into two groups, exercise group (HE) and sedentary group (Hse); According to the control conditions of blood pressure, patients in H group were subdived into nomal pressure group (HN), poor control of SBP (HS), and poor control of DBP (HD). All participants were asked to finish a questionnaire and a symptom-limited exercise stress testing on a horizontal cycle ergometer. Blood pressure and heart rate were monitored in the whole testing process.Results:1, For H group, SBP increased significantly for each load exercise after30watt (P<0.01). DBP showed little changes. After exercise testing, SBP decreased quickly and respectively at the time of2nd minute,4th minute and6th minute (P<0.01). SBP of6th minute had recoverd to rest level. DBP even recovered to lower level than rest(DBPrest) after6minutes recovery.2, Both exercising SBP and DBP of patients in H group were higher than those of persons in N group (P<001). After exercise testing, SBP at6th minute and DBP at the time of2nd minute,4th minute, and6th minute were still higher than those of N group (P<0.05).3, SBP of patients in HSe group at0watt exercise and DBP at rest,0watt,60watt,120watt exercise were all higher than those of HE group (P<0.05).4, For HS group, SBP at rest, Owatt,30watt,60watt, and120watt exercise was significantly higher than those of HN and HD group (P<0.01), but DBP was only higher than that of HN group (P<0.05). For HD group, SBP at rest,0watt exercise and DBP at rest, Owatt,30watt, and60watt were obviously higher than those of HN group (P<0.05or P<0.01). During recovery time after exercise testing, SBP of HS group at2nd minute,4th minute, and6th minute were higher than those of HN and HD group (P<0.01). DBP of HS group was still higher than that of HN group at6th minute (P<0.01). For HD group, DBP at6th minute was also higher than that of HN group (P<0.01).5, Heart Rate (HR) increased significantly for each load stage from15watt to105watt (P<0.05) in H group, but it showed no significant difference between105watt and120watt (P>0.05). After exercise testing, HR gradually decreased at1st minute,2nd minute, and3rd minute (P<0.05).6, HR at90watt,105watt, and120watt exercise, heart rate reserve and HRR3in H group were significantly lower than those of N group (P<0.0).7, HR of HS group and HD group at75watt and120watt exercise was significantly lower than that of HN group (P<0.05).Conclusions:1, SBP of hypertensive patients is sensitive to exercise intensity with several ascending break points appearing in the Intensity-SBP curve. DBP of hypertensive patients only increases obviously in high-intensity exercise. Both SBP and DBP recovers slowly after exercise. Poor control of blood pressure leads to more obvious changes mentioned above.2, HR of hypertensive patients is also sensitive to exercise intensity, it increases obviouly at low intensity. However, HR stops increasing at high intensity, which suggests a lower heart rate reserve for hypertensive patients. During recovery time after exercise, HR recovers slowly;3, Good exercise habits help to reduce over-response of blood pressure in hypertensive patients while exercise, improve recovery of DBP and HR’s response to exercise.