Postexercise Hypotension after Heart Transplant

Abstract

Heart transplant recipients (HTx) have a high prevalence of hypertension. Although exercise training promotes blood pressure (BP) reduction in HTx, the effects of a single exercise bout are unknown. Thus, we analyzed the acute effects of heated water-based exercise (HEx) versus land-based exercise (LEx) on ambulatory BP (ABP) in HTx. Eighteen (six females) clinically stable HTx (time since surgery = 5.0 ± 0.7 yr) age 45.7 ± 2.7 yr underwent 30 min of HEx (walking inside the pool), LEx (walking on a treadmill), and nonexercise control (CON) intervention in random order (2-5 d between interventions). HEx and LEx intensity was set at 11-13 in the 6-20 RPE scale. Twenty-four-hour (24-h) ABP monitoring was performed after each intervention. No significant differences between interventions were found in 24-h and nighttime BP. However, daytime diastolic BP was significantly lower after HEx than CON (-4 ± 1.6 mm Hg, P = 0.03), and daytime diastolic BP tended to be lower after LEx than CON (-2.3 ± 1.1 mm Hg, P = 0.052). Hourly analysis showed that systolic and diastolic BP values were lower after HEx (average reductions of 6.6 to 12.3 mm Hg, P < 0.01) and LEx (average reductions of 5 to 8.3 mm Hg, P < 0.05) than after CON in several hours. No significant differences between HEx and LEx were found in any ABP data. HEx and LEx promoted similar reductions in ABP of heart transplant recipients, which suggests that they may be a tool to counteract hypertension in this high-risk population.