Relationship Between Heart Rate Threshold, Lactate Turn Point and Myocardial Function

Watanabe²

2008

Abstract. Privious studies have used an exercise stress testing blood pressure (BP) monitor to detect the double product break point (DPBP). However, not all clinical sites of physical therapy are equipped with an exercise stress testing BP monitor. Digital automatic blood pressure monitors (portable sphygmomanometer), which come in more compact, portable models, are becoming more common at general clinical sites. The purpose of this study was to investigate whether a portable sphygmomanometer can be used to derive the DPBP in healthy adults. Exercise stress tests were conducted on 11 healthy adults (8 male, 3 female), using a portable sphygmomanometer and ergometer. To investigate the double product (DP) reproducibility in derivation of DPBP by the portable sphygmomanometer, we repeated the exercise trials within one week. Moreover, using an exercise testing BP monitor, the exercise stress protocol was conducted again within 3 weeks under the same conditions. The results show that DP at DPBP calculated from measurements with a portable sphygmomanometer in the first and second exercise trials with the portable sphygmomanometer were 17084.9 ± 1109.4 and 17131.1 ± 979.2 mmHg × bpm, with an intraclass correlation coefficient of 0.84. The DP at DPBP calculated using measurements from an exercise stress testing BP monitor was 17533.9 ± 1459.2 mmHg × bpm, and the correlation coefficient with the DP value of the second trials with the portable sphygmomanometer was r = 0.80. The results of this study suggest that a comparatively accurate DPBP can be derived using a portable sphygmomanometer.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Double-Product-Break-Point Derived from Measurents with a Digital Automatic Sphygmomanometer

Watanabe²

2008

“…The anaerobic threshold (AT) determined by expired gas analysis and the lactate threshold (LT) obtained by lactate measurement are useful not only for the measurement of physical fitness in athletes but also as indices of health in middle-aged and older individuals, and of optimal exercise intensity in patients with diabetes mellitus, ischemic heart disease, or stroke [1][2][3] . However, their evaluation require an expensive expired gas analyzer and frequent blood sampling; thus, they are difficult to implement in clinical physical therapy settings.…”

Section: Introductionmentioning

confidence: 99%

Effect of Incremental Load of Circulatory Response on Double Product Break Point Detection

Watanabe²

2007

Abstract. The purpose of this study was to examine the effect of circulatory response changes on DPBP evaliation. Seventeen healthy males and females who did not perform exercises daily participated in this study. All subjects performed a graded ergometric test that is generally performed on a cycle ergometer. The SBP and HR were measured at 1-min intervals. In healthy subjects who don't exercise daily, the relationship between HR and SBP, was described by a third order regression curve during exercise in males, and a continuously increasing linear equation in females. The relationship between work rate and DP was described by a third order regression curve during exercise in males, while there was no increase in suppression for females, for whom the relationship could be described by a linear equation. At DPBP, HR was 64.4 ± 4% for males and 60.4 ± 5% for females of maximum heart rate. It is possible to detect with DPBP, the increasing pattern of SBP or HR that was expressed as linear or third regression curve against the work load. It was suggested that DP can be compensated even when the increase of SBP (or HR) was low, because DP is the integral number of SBP and HR.

“…Most of these studies reported arrhythmias, and there have been numerous studies reporting oxygen uptake kinetics and heart rate threshold in relation to exercise tolerance, gender and age [3][4][5][6][7][8][9] . However, we have found no previous reports of DPBP in relation to gender and age.…”

Section: Introductionmentioning

confidence: 99%

“…Cardiac rehabilitation programs are based on electrocardiography, cardiac ultrasonography, angiography, and evaluation of exercise tolerance to measure the anaerobic threshold using oxygen uptake kinetics [1][2][3][4][5][6][7][8][9][10][11][12][13] . Tanaka et al 8) developed the DPBP method, a simple method for measuring the anaerobic threshold (AT) and lactate threshold (LT).…”

Section: Introductionmentioning

confidence: 99%

Gender Differences in Circulatory Response Measured by the Double Product Break-Point Method

Watanabe

2007

Abstract. The purposes of this study were to evaluate the gender difference in exercise tolerance. We analyzed the relationship between the double product (DP) at the double product break-point (DPBP) and the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MAP), pulse pressure (PP), heart rate (HR) at DPBP. The subjects were 18 healthy men and 15 healthy women. Exercise tests were performed on a cycle ergometer. The DP at DPBP increased more in women than in men (p<0.05). There were no significant differences in DBP, MAP, PP or HR at DPBP between the groups. At DPBP of men, DP was significantly correlated with SBP, MAP, PP and HR (p<0.05). In women, the only significant correlation was between HR and DP at DPBP (p<0.05). This suggests that the configuration factors of exercise tolerance differ between men and women, although men have a blood pressure dominant response at DPBP, women have a heart rate dominant response.