Post-exercise hypotension and heart rate variability response after water- and land-ergometry exercise in hypertensive patients

Abstract

Background: systemic arterial hypertension is the most prevalent cardiovascular disease; physical activity for hypertensive patients is related to several beneficial cardiovascular adaptations. This paper evaluated the effect of water- and land-ergometry exercise sessions on post-exercise hypotension (PEH) of healthy normotensive subjects versus treated or untreated hypertensive patients.

Methods: Forty-five older women composed three experimental groups: normotensive (N, n = 10), treated hypertensive (TH, n = 15) and untreated hypertensive (UH, n = 20). The physical exercise acute session protocol was performed at 75% of maximum oxygen consumption (VO2max) for 45 minutes; systolic (SBP), diastolic (DBP) and mean (MBP) blood pressure were evaluated at rest, peak and at 15, 30, 45, 60, 75 and 90 minutes after exercise cessation. Additionally, the heart rate variability (HRV) was analyzed by R-R intervals in the frequency domain for the assessment of cardiac autonomic function.

Results: In both exercise modalities, equivalent increases in SBP were observed from rest to peak exercise for all groups, and during recovery, significant PEH was noted. At 90 minutes after the exercise session, the prevalence of hypotension was significantly higher in water- than in the land-based protocol. Moreover, more pronounced reductions in SBP and DBP were observed in the UH patients compared to TH and N subjects. Finally, exercise in the water was more effective in restoring HRV during recovery, with greater effects in the untreated hypertensive group.

Conclusion: Our data demonstrated that water-ergometry exercise was able to induce expressive PEH and improve cardiac autonomic modulation in older normotensive, hypertensive treated or hypertensive untreated subjects when compared to conventional land-ergometry.

Fig 1. Effects of a single exercise session on the blood pressure.

Systolic (SBP) and diastolic blood pressures (DBP) were evaluated at rest, at exercise peak and after 15, 30, 45, 60 and 90 minutes after land- or water-ergometry in groups Normotensive, Treated hypertensive and Untreated hypertensive. Values are presented in mean ± SEM. *p<0.05 vs rest; ^†p<0.05 vs. land-based protocol.

Fig 2. Absolute and percent of changes in the mean blood pressure after 90 minutes of the exercise session.

A) Absolute of changes in the mean blood pressure (MBP) after exercise session land- or water-based in all groups. B) Percent of changes in the MBP. Values are presented in mean ± SEM. ^‡p<0.05 vs N and TH. ^†p<0.05 vs land-based protocol. (Two-way ANOVA paired by protocol, followed by Bonferroni’s post-hoc test).

Fig 3. Heart rate variability changes at rest and after 90 minutes of recovery from land- and water-based exercise session.

In A-B: the low frequency (LF) component, C-D: the high frequency (HF) component and, E-F: their ratio (LF/HF). N: normotensive individuals; TH: treated hypertensive patients; UH: untreated hypertensive patients. Values are mean ± SEM. *p<0.05 vs. rest (Two-way ANOVA paired by groups, followed by Bonferroni’s post-hoc test). ^‡p<0.05 vs N and TH. ^†p<0.05 vs land-based protocol. (Two-way ANOVA paired by protocol, followed by Bonferroni’s post-hoc test).