Delayed blood pressure recovery ratio might indicate increased arterial stiffness in hypertensive patients with reduced aerobic exercise capacity

CAVI (Cardio-Ankle Vascular Index) as an independent predictor of hypertensive response to exercise

OBJECTIVES

Hypertensive response to exercise (HRE) is related to the development of future hypertension, cardiovascular morbidity, and mortality, independent of resting blood pressure. We hypothesized that arterial stiffness as measured by cardio-ankle vascular index (CAVI) could be an independent predictor of HRE.

MATERIALS AND METHODS

Retrospective chart review of patients participated in the preventive health program at the Bangkok Heart Hospital who underwent both CAVI and treadmill stress testing on the same day between June and December 2018 were performed. Variables for the prediction of HRE were analyzed using univariate analysis, and significant variables were entered into multiple logistic regression. An ROC curve was created to test the sensitivity and specificity of CAVI as a predictor of HRE.

RESULTS

A total of 285 participants (55.1% female) were enrolled in this study. There were 58 patients (20.4%) who met the HRE definition (SBP > 210 mmHg in males, SBP > 190 mmHg in females, or DBP > 110 mmHg in both males and females), with a mean age of 46.4 12.8 years. In univariate analysis, age, systolic blood pressure at rest, diastolic blood pressure at rest, pulse pressure at rest, diabetes mellitus, hypertension, dyslipidemia, history of beta-blocker, and CAVI results were statistically significant. Multiple logistic regression revealed that CAVI and systolic blood pressure were statistically significant predictors of HRE with OR of 5.8, 95%CI: 2.9-11.7, P < 0.001 and OR 1.07, 95%CI: 1.03-1.10, P = 0.001 respectively. ROC curve analysis of the CAVI revealed an AUC of 0.827 (95%CI: 0.76-0.89, p < 0.001), and the sensitivity and specificity of cut-point CAVI > 8 were 53% and 92%, respectively.

CONCLUSION

This study demonstrated that CAVI is an independent predictor of hypertensive response to exercise. Additionally, the findings suggest that CAVI > 8 can be a valuable tool in identifying individuals at risk for hypertensive responses during exercise.

Delayed blood pressure recovery after exercise stress test is associated with autonomic dysfunction and pulse pressure in a middle-aged healthy group

BACKGROUND

Delayed heart rate (HR) and blood pressure recovery after exercise test is known as the reliable indexes of autonomic dysfunction. Here we tried to evaluate the serial changes in various indicators during exercise test and correlations with recovery of HR and blood pressure in a normotensive healthy middle-aged group.

METHODS

A total of 122 patients without hypertension or diabetes was enrolled (mean age, 55.6 ± 11.0; male, 56.6%; mean blood pressure, 124.8 ± 16.6 / 81.5 ± 9.6 mmHg). Treadmill test was performed for evaluation of chest pain. Patients with coronary artery disease, positive treadmill test result, left ventricular dysfunction or renal failure were excluded. Heart rate recovery was calculated by subtracting the HR in the first or second minute of recovery period from the HR of peak exercise (HRR1 or HRR2). Systolic blood pressure in the 4th minute of recovery stage (SBPR4) was used to show delayed blood pressure recovery.

RESULTS

Metabolic equivalents (METs) and HR in stage 2 to 4 were significantly correlated with both HRR1 and HRR2. Multiple regression analysis of HRR revealed significant correlation of METs and SBPR4. SBPR4 was significantly correlated with both HRR1 and HRR2 (HRR1, r = -0.376, p<0.001; HRR2, r = -0.244, p = 0.008) as well as SBP in the baseline to stage 3 and pulse pressure (r = 0.406, p<0.001).

CONCLUSIONS

Delayed BP recovery after peak exercise test revealed significant association with autonomic dysfunction and increased pulse pressure in normotensive middle-aged healthy group. It can be a simple and useful marker of autonomic dysfunction and arterial stiffness.

The Independent and Joint Association of Blood Pressure, Serum Total Homocysteine, and Fasting Serum Glucose Levels With Brachial-Ankle Pulse Wave Velocity in Chinese Hypertensive Adults

This study aimed to investigate the independent and joint association of blood pressure (BP), homocysteine (Hcy), and fasting blood glucose (FBG) levels with brachial-ankle pulse wave velocity (baPWV, a measure of arterial stiffness) in Chinese hypertensive adults.The analyses included 3967 participants whose BP, Hcy, FBG, and baPWV were measured along with other covariates. Systolic BP (SBP) was analyzed as 3 categories (SBP < 160 mmHg; 160 to 179 mmHg; ≥ 180 mmHg); Hcy as 3 categories (< 10 μmol/L; 10 to 14.9 μmol/L; ≥ 15.0 μmol/L) and FBG: normal (FBG < 5.6 mmol/L), impaired (5.6 mmol/L ≤ FBG < 7.0 mmol/L), and diabetes mellitus (FBG ≥ 7.0 mmol/L). We performed linear regression analyses to evaluate their associations with baPWV with adjustment for covariables.When analyzed individually, BP, Hcy, and FBG were each associated with baPWV. When BP and FBG were analyzed jointly, the highest baPWV value (mean ± SD: 2227 ± 466 cm/s) was observed in participants with FBG ≥ 7.0 mmol/L and SBP ≥ 180 mmHg (β = 432.5, P < 0.001), and the lowest baPWV value (mean ± SD: 1692 ± 289 cm/s) was seen in participants with NFG and SBP < 160 mmHg. When Hcy and FBG were analyzed jointly, the highest baPWV value (2072 ± 480 cm/s) was observed in participants with FBG ≥ 7.0 mmol/L and Hcy ≥ 15.0 μmol/L (β = 167.6, P < 0.001), while the lowest baPWV value (mean ± SD: 1773 ± 334 cm/s) was observed in participants with NFG and Hcy < 10 μmol/L.In Chinese hypertensive adults, SBP, Hcy, and FBG are individually and jointly associated with baPWV.Our findings underscore the importance of identifying individuals with multiple risk factors of baPWV including high SBP, FBG, and Hcy.

Blood pressure monitoring during exercise: comparison of pulse transit time and volume clamp methods

During physical exercise, pulse transit time (PTT), expressed as the interval between ventricular electrical activity and peripheral pulse wave, may provide a surrogate estimate for blood pressure by the use of specific calibration procedures. The objective of this study was to determine systolic blood pressure (SBP) values derived from the PTT method and from an established method of non-invasive continuous blood pressure measurement based on the volume clamp technique, and to compare their agreement with sphygmomanometry during exercise tests. In 18 subjects, electrocardiogram (ECG) and finger-photoplethysmography were continuously recorded during maximal cycle exercise tests. Intermittent and continuous blood pressure measurements were simultaneously taken using automated sphygmomanometry and a Portapres Model-2 device, respectively. PTT was calculated for each ECG R-wave and the corresponding steepest upstroke slope in the photoplethysmogram, and was transformed to a continuous blood pressure estimate using multipoint nonlinear regression calibration based on the individual subject's sphygmomanometer readings. Bland-Altman limits of agreement between PTT-derived SBP estimates and sphygmomanometer values were -24.7 to 24.1 mmHg, and between Portapres and sphygmomanometer SBP values were -42.0 to 70.1 mmHg. For beat-to-beat SBP estimation during exercise, PTT measurement combined with multipoint nonlinear regression calibration based on intermittent sphygmomanometry may be an alternative to volume clamp devices.

Cardiopulmonary Exercise Test in Patients with Hypertension: Focused on Hypertensive Response to Exercise

The cardiopulmonary exercise test (CPET) provides integrative exercise responses including the cardiovascular, pulmonary and skeletal muscle systems. It can be used for the identification of myocardial ischemia, evaluation of exercise capacity and tolerance, and the assessment of chronotropic competence or arrhythmias with the addition of ventilatory and gas exchange measurement information. Among them, hypertensive response to exercise (HRE) is known to be related with higher risk of future heart failure and cardiovascular events in patients with hypertension. Proposed underlying mechanisms of HRE can be found in ventricular-vascular uncoupling including decreased aortic distensibility, increased left ventricular mass, endothelial dysfunction, and diastolic dysfunction. The CPET might be useful in the identification of masked hypertension and the assessment of antihypertensive treatment efficacy in patients with hypertension.

Blood pressure morning surge, exercise blood pressure response and autonomic nervous system

OBJECTIVE

We investigated blood pressure (BP) response to exercise with respect to BP morning surge (MS), and the association between MS, exercise treadmill test (ETT) and heart rate variability (HRV) indices.

DESIGN

Eighty-four healthy subjects without hypertension were enrolled. Ambulatory BP monitoring and 24-hour Holter recordings were obtained for sleep-trough MS and HRV indices: low-frequency (LF) component, high-frequency (HF) component and LF/HF ratio. ETT was performed, and BPs were obtained at rest, end of each stage, and recovery. Third-minute heart rate recovery (HRR) and BP recovery ratio (BPRR) were calculated.

RESULTS

When analysed in quartiles of MS, systolic BP at low workloads was higher in the highest than in the lowest quartile, although maximum BPs at maximum exercise were not significantly different. BPRR was highest in the highest quartile in contrast to HRR, which was lowest in the highest quartile. LF/HF was highest during both at daytime and night-time in the highest quartile. BPRR and LF/HF were positively, and HRR was inversely associated with MS.

CONCLUSIONS

Subjects with a high MS have higher BP at low workloads, at which most daily activities are performed, and impairment in some indices, which indirectly reflect the autonomic nervous system.

Recovery after aerobic exercise is manipulated by tempo change in a rhythmic sound pattern, as indicated by autonomic reaction on heart functioning

Physical prowess is associated with rapid recovery from exhaustion. Here we examined whether recovery from aerobic exercise could be manipulated with a rhythmic sound pattern that either decreased or increased in tempo. Six men and six women exercised repeatedly for six minutes on a cycle ergometer at 60 percent of their individual maximal oxygen consumption, and then relaxed for six minutes while listening to one of two sound pattern conditions, which seemed to infinitely either decrease or increase in tempo, during which heart and breathing activity was measured. Participants exhibited more high-frequent heart rate variability when listening to decreasing tempo than when listening to increasing tempo, accompanied by a non-significant trend towards lower heart rate. The results show that neuropsychological entrainment to a sound pattern may directly affect the autonomic nervous system, which in turn may facilitate physiological recovery after exercise. Applications using rhythmic entrainment to aid physical recovery are discussed.